1 Introduction

Currently, there has been a surge in interest in the study of natural polysaccharides, particularly pectin, due to their variety of biological features and potential pharmacological uses [1, 2]. It is believed that these studies will benefit from the advancement of relatively simple as well as more complex in vitro analyses for influence on immunity, along with purification and characterization techniques. Pectic polysaccharides hold great promise for the medical, food, and pharmaceutical industries due to their medicinal qualities and very low toxicity.

The Food and Agriculture Organization has issued guidelines stating that industrial pectins must contain at least 65% polygalacturonic acid in order to meet the E440 specification, which serves as a food additive. The most common raw materials used for pectin extraction are apple pomace, jackfruit, or other citrus peels, which are left over following the juice-making process. The materials described have high pectic content but have varied chemical properties that make them ideal for particular purposes [3]. Sugar beet pulp, citrus peel, and apple pomace are the three main residue from which commercial pectin is produced. For acidic beverages, citrus pectin has mostly been explored as a gel-forming, thickening, or stabilizing component. Despite being ineffective gel-forming agents, sugar beet pectin extracts have potential applications as emulsifiers [4]. Pectin is taken from Greek word [5]. Sources of pectin determine its properties such as size, content, branching pattern and others. Therapeutical potential of pectin is influenced by its structure. There are different procedures like chemical, enzymatic, or thermal are being used for modification in the structure of pectin. These modifications boost the therapeutical effects. Pectin can also be utilized for drug delivery to the gastrointestinal system in the form of film, matrix tablets, and gel beads.

Moreover, the chemical characteristics of pectin, such as the amounts of galacturonic acid, methoxyl, and acetylation, influence how it is used [3]. A vast number of neutral saccharides, such as arabinose, galactose, and others, make up the core of pectin, which is a polysaccharide. These neutral saccharides consist of D-galacturonic acid-1,4-linked and L-rhamnose-1,2-linked units. According to Noreen [1, 6], pectins feature a linear anionic backbone with "hairy parts" and "smooth regions" that have nonionic side chains. Homogalacturonan (HG), rhamnogalacturonan I (RG-I), and substituted galacturonans such as rhamnogalacturonan II are included in the structural classification of pectin (RG-II). The article includes descriptions of all the major types of pectins [1]. The structure of pectin is shown in Fig. 1.

Fig. 1
figure 1

Schematic structure of pectin (adopted from [8])

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Due to its widespread availability, pectin is now a crucial component in the research and development of health products and natural medicines. In-depth research has been conducted on pectin extracted from different plants as well as modified pectin. On the one hand, this study examined the biological applications of pectin, including its antidiabetic, antibacterial, antiviral, antioxidant, anticancer, immunomodulatory, and anti-inflammatory effects, as well as its usage as a vehicle for drug delivery [7].

On the other hand, to increase the use of pectin in pharmacology and medicine, research has concentrated on the biological activities of pectin in relation to its chemical composition. The core objective of the present study is to provide a comprehensive update on the various therapeutic effects of pectin specifically focusing on diabetes prevention, management and associated molecular mechanisms that may contribute to its anti-diabetic properties.

1.1 Sources and extraction of pectin

The use of commercial fruit and vegetable sources for pectin extraction does not depend solely on the presence of a significant amount of pectin [9]. The pectin concentration in plant cell walls gradually decreases from the primary cell wall to the plasma membrane, with the middle lamella having the highest concentration. Citrus fruits, apples, and the byproducts produced after their processing, such as citrus peel and apple pomace, are the main sources of profitable pectin extraction [10]; as an alternative, carrot, banana, watermelon, mango, sugar beet, pomegranate, pumpkin, berries (blueberry, strawberry, raspberry), and grapes are alternate sources of pectin. Table 1 provides an illustration of the primary components and sources of pectin. The nontoxic nature and numerous uses of pectin across a variety of industries have led to a sharp rise in demand, necessitating the search for additional pectin sources. Therefore, a thorough understanding of pectins will be helpful for comprehending the uses for which we can presently only make assumptions [11].

Table 1 Sources of pectin and its quantity and composition
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The process of extracting pectin can be a challenging and time-consuming task because of the high moisture content present in the raw materials, such as fruit peels or pomace, which can breakdown easily. This breakdown is primarily caused by fungal enzymes, including pectic enzymes that include de-esterifying (pectin methylesterase) and depolymerizing (pectin lyase, polygalacturonase, and pectate lyase) enzymes [12]. Compared to citrus peels, apple pomace requires more work to extract pectin because it is more likely to become spoiled by pectolytic enzymes unless it is immediately dried to remove moisture before being stored for the procedure [13].

For successful extraction of apple juice in some apple varieties, the apple pulp must undergo enzymatic treatment, making the apple pomace unsuitable for the extraction of pectin. The extraction factors, including particle size, pH, temperature, extraction duration, and type of extraction solvent, have considerable impacts on the production of pectin [14] and on the drying methods used [15]. Due to the greater accessibility of protopectin in smaller substrate particles compared to larger ones, the raw material particle size affects the pectin yield [16, 17].

Aqueous extraction is frequently used to separate pectin from raw materials; the most popular techniques include direct boiling, microwave heating [18], ultrasonic heating [19, 20], autoclave cooking [21], and electromagnetic induction [22]. Each of the methods used to extract pectin results in some level of degradation in terms of pectin quality. The yield of pectin can differ depending on factors such as the source material, pH, extraction time, and temperature [23]. Mineral acids such as citric, hydrochloric, or sulfuric acid, phosphoric acid, and nitric acid are used to extract pectin from an acidic aqueous medium [24].

Acid extraction and alcoholic precipitation are typically utilized on an industrial scale to extract pectin for commercial purposes. Because protopectin hydrolysis occurs at relatively high temperatures, pectin is extracted using acid [25, 26]. The main benefits of utilizing strong acids for pectin extraction are a high pectin yield and a shorter extraction time; nevertheless, this method has significant environmental drawbacks, including the disposal of acidic effluent and expensive energy and chemical costs. To produce pectin from finely ground lyophilized apple peels, environmentally friendly food-grade organic acids, such as malic, tartaric, and citric acids, were utilized as substitutes for HCl. This method, which operates at 85 °C, was deemed more acceptable from an environmental standpoint, as per [27]. The process of extracting pectin using citric acid resulted in a higher molecular weight and apparent viscosity than those of pectin extracted using other organic acids. The pectin extracted with organic acids was found to undergo a high level of methyl esterification. Citric acid was the most effective and efficient in terms of yield (13.75%), environmental impact, and cost compared to other organic acids, such as tartaric, malic, and phosphoric acids, as well as mineral acids, such as hydrochloric, sulfuric and nitric acids, when used to extract pectin from apple pomace [16].

1.2 Types of pectin

Pectin is a biologically important heteropolysaccharide found in plants. Furthermore, there are two main categories of methoxylas: high methoxylpectin and low methoxyl pectin [28].

1.2.1 High methoxylpectin

The most prevalent kind of pectin is high methoxyl (HM) pectin [29]. It is typically described as "rapid-set" or "slow-set." The key distinction between the two types, both of which are made from citrus fruit peel extraction, is how long and at what temperature they set. Slow-set pectin requires a longer time and a lower temperature to set, whereas rapid-set pectin requires a higher temperature [30]. If a recipe requires suspension, then it is recommended that rapid-set pectin be used to make jams and preserves with excellent suspended fruit morsels. On the other hand, slow-set pectin is more suitable for recipes that do not require any suspension, such as smooth jelly. HM pectin requires specific levels of sugar and acid to solidify properly, which is why it is ideal for preserving fruit, jams, and jellies.

1.2.2 Low methoxyl pectin

Citrus peels are another source of low methoxyl pectin (LM). Since it uses calcium rather than sugar to solidify, it is frequently used to make jams and jellies that are low in calories. Additionally, it works well for dairy-based recipes without added sugar. As calcium is added, LM pectin becomes increasingly hard until it reaches a saturation point. At that point, the process turns around and gets softer [31].

1.3 Nutritional facts

The majority of plants, including citrus fruits, contain pectin, which is most abundant in the skins, cores, and seeds of these sources. We can absorb it directly once it has been extracted from its sources, or we can simply obtain it by eating fibrous plants [45]. It is conveniently available from neighborhood health food stores as dry mix pectin.

According to [46], one packet of a dry, unsweetened pectin mixture weighing approximately 50 g contains approximately 163 cal, which are found in 46.8 g of carbohydrates (including fibres), 0.1 g of proteins, and 0.1 g of fat. Minerals, including copper, iron, and zinc, are also present in pectin in good quantities.

The vitamin content is negligible in both the liquid and powdered forms, and all of the calories are derived from fibre-rich carbs [47].

Nonetheless, some items, referred to as pectin dry mixes, have extra sugar and calories. Jams and jellies can also be made using these mixtures.

1.4 Industrial uses of pectin

Pectin is usually utilized as a thickening agent in home cooking and food processing. It is frequently added to both commercially produced and homemade jams, jellies, and preserves. Additionally, it can be employed as a stabilizer in drinkable yogurt and flavoured milk [25]. Pectin is offered as a colorless liquid or a white, light-brown, or brown powder for use in domestic kitchens. Pectin is usually sold in capsule form and is used as an additional source of soluble fibre. Soluble fibre has the potential to lower blood pressure, maintain a healthy weight, reduce cholesterol and triglyceride levels, and improve blood sugar levels [48]. Finally, this fibre is an essential component of the time-release coatings that are applied to several pharmaceuticals.

2 Biological activities

Due to its abundant availability in nature, its application in various industries, including the pharmaceutical sector, is increasing [49]. Pectin has various biological activities that are beneficial for human health. One of the most important properties of pectin is its ability to form gels and thicken solutions, which makes it useful in food processing and as a natural thickening agent. As a result of their exceptional physical, chemical, and biological characteristics, various types of biopolymers have been developed for biomedical applications [25, 50]. In general, pectin is a versatile and beneficial compound with an extensive range of biological activities. In this section, the primary pharmacological characteristics of pectin are described. These attributes support its potential to combat cancer, diabetes, inflammation, and oxidative stress, as well as its antibacterial, antiviral, and cholesterol-lowering properties. Additionally, pectin has the ability to enhance the immune system.

2.1 Anticancer potential of pectin

Despite a wide range of scientific investigations being intensified to combat this disease, the incidence of cancer is increasing as a result of metastasis and tumor cell treatment tolerance [51]. Research has shown that pectin can inhibit the growth and proliferation of various types of cancer cells [25].

Pectin has a high affinity for binding to the protein galectin-3, which plays a role in the progression of colorectal cancer. By binding to galectin-3, pectin can inhibit cancer cell proliferation and induce apoptosis. Pectin can inhibit the expression of certain enzymes that promote breast cancer cell invasion and metastasis. Pectin has also been shown to induce apoptosis in breast cancer cells by activating the intrinsic apoptosis pathway [52]. Studies have shown that pectin may have potential in the prevention and treatment of prostate cancer. Pectin can inhibit the expression of certain enzymes that promote prostate cancer cell invasion and metastasis. Pectin has also been shown to induce apoptosis in prostate cancer cells through the intrinsic apoptosis pathway [53].

Pectin can also inhibit the expression of certain enzymes that promote lung cancer cell invasion and metastasis. Pectin has also been shown to induce apoptosis in lung cancer cells through the intrinsic apoptosis pathway [52].

Studies on liver cancer have shown that low-molecular-weight citrus pectin can inhibit the expression of certain enzymes that promote liver cancer cell proliferation and invasion. It can also induce apoptosis in liver cancer cells by activating the caspase cascade [54].

2.2 Pectin in the regulation of blood cholesterol levels

High-viscosity pectin can have a greater impact on reducing blood cholesterol levels by disrupting the production of micelles, impeding the diffusion of bile acid, obstructing the absorption of micelles containing cholesterol, and lowering the rate of bile acid diffusion [55, 56]. The ability of citrus peels to decrease cholesterol is likely a result of their pectin content [31]. In persons with normal or elevated lipid levels, consuming at least 6 g of pectin per day can lower the level of cholesterol, resulting in a reduction in coronary heart disease risk [55, 57]. Pectin is also known to lower cholesterol levels, regulate the level of sugar in blood, and promote gut health by acting as a prebiotic; moreover, the plasma triglyceride level does not change. The hepatic cholesterol homeostasis of guinea pigs was shown to be impacted by pectin from prickly pears. Research has indicated that pectin obtained from prickly pears can influence hepatic cholesterol homeostasis in guinea pigs [55, 56, 58]. The kind of pectin used to create a thick substance in the digestive system has been shown to have a significant impact on its exact molecular makeup, which has a significant impact on reducing cholesterol and blood sugar levels [59].

2.3 Antibacterial activity

Pectin has been shown to have antibacterial activity against a range of pathogenic bacteria. The antibacterial activity of pectin is thought to be due to its ability to bind to bacterial cell walls, disrupting their structure and preventing their growth and replication [60]. Escherichia coli, Salmonella enteritidis, and Staphylococcus aureus are prominent causes of foodborne diseases and infections. Research has shown that pectin can suppress the growth of these and other types of bacteria [61]. Furthermore, the antibacterial activity of pectin has been found to be enhanced in combination with other compounds, such as chitosan and essential oils, suggesting its potential as a natural alternative to conventional antibacterial agents [62]. The antibacterial activity of pectin is a promising area of research with potential applications in food preservation and medical settings.

2.4 Antiviral activity

The antiviral activity of pectin is believed to be due to its ability to interfere with the viral replication process, as well as its ability to enhance the immune system's response to viral infections [63]. Pectin has demonstrated antiviral activity through its ability to inhibit the entry of viruses into host cells. Pectin has been shown to interfere with the binding of some viruses to host cells, which can prevent the virus from infecting the cell and replicating [64]. This can help to reduce the severity of the infection and prevent the spread of the virus to other cells. In addition to its direct antiviral effects, pectin has also been shown to have immunomodulatory effects, which can enhance the immune system's response to viral infections. Pectin has been found to stimulate the production of cytokines and other immune system mediators, which can help to fight viral infections. Some studies have also suggested that pectin may have antiviral activity against certain human viruses, such as human papillomavirus and hepatitis B virus [65, 66]. However, more research is needed to fully understand the mechanisms by which pectin may exert its antiviral effects and to determine its effectiveness against different viral infections.

2.5 Pectin in drug delivery

Along with its other unique properties, pectin has also been explored for use in drug delivery due to its ability to form gels in the presence of calcium ions [67]. This property can be exploited to develop controlled-release drug delivery systems. In these systems, pectin is often combined with other polymers to form a hydrogel. The drug is then incorporated into the hydrogel, and the gel is injected or implanted into the body. As the hydrogel absorbs water, it swells and releases the drug in a controlled manner. Drug delivery systems are the most promising biological tools for accessing pectin and structurally modified pectin [68, 69].

Pectin-based drug delivery systems have been investigated for a variety of applications, including cancer therapy, wound healing, and diabetes treatment [70]. One study revealed that pectin-based hydrogels could be used to deliver a chemotherapy drug to brain tumor cells, increasing the effectiveness of the treatment while minimizing side effects [71]. Another study revealed that pectin-based wound dressings could improve wound healing by releasing growth factors in a controlled manner. The unique properties of pectin make it a promising material for drug delivery applications, and ongoing research is exploring new ways to use this natural polysaccharide in medical applications.

2.6 Other activities

Apart from the aforementioned activities, pectin is known to exhibit a range of other biological activities. For instance, pectin has demonstrated potent antifungal properties and may serve as a natural alternative to synthetic antifungal agents in the treatment of fungal infections. The mechanisms underlying this antifungal effect of pectin are thought to involve the inhibition of fungal cell wall synthesis, as well as disruption of cell membrane integrity, leading to cellular leakage and ultimately cell death [58]. Pectin has also been investigated for its potential as an anti-protozoal agent, with some evidence suggesting that it may have efficacy against the protozoan parasites that cause malaria. The antiprotozoal mechanisms of pectin are thought to involve disruption of the parasite's cell membrane, as well as interference with various stages of the parasite's life cycle [72]. Additionally, pectin has been shown to act as a prebiotic, promoting the growth of beneficial gut bacteria, which may be attributed to its resistance to digestion in the upper gastrointestinal tract, allowing it to reach the colon intact, where it can serve as a substrate for bacterial fermentation. The prebiotic mechanisms of pectin involve the modulation of the gut microbiota, which can have far-reaching implications for overall health and wellbeing [73]. These diverse biological activities of pectin highlight its potential for use in various applications, including the development of functional foods, nutraceuticals, and novel drug delivery systems. Various activities are shown in Fig. 2.

Fig. 2
figure 2

Therapeutical effects of Pectin

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3 Diabetes

Diabetes is a chronic condition that lasts a long time and has an impact on how the body uses food for energy [74]. The majority of the food we eat is converted by our body into glucose (monosaccharide), which is released into the bloodstream after we eat. The pancreas releases insulin when blood glucose levels rise. For blood glucose to reach the body's cells, where it may be used as energy, this hormone functions as a key.

When a person has diabetes, their pancreas either produces insufficient insulin or the body does not properly utilize it. When there is inadequate insulin or the cells develop resistance to it, too much glucose stays in the bloodstream. This condition can cause serious health issues such as renal failure, eyesight loss, nerve damage, heart disease and other related complications [75].

There are three major types of diabetes mellitus (DM), types 1 and 2, and gestational diabetes.

Type 1 diabetes is believed to occur due to an autoimmune response in which the body mistakenly attacks itself. This attack disrupts the production of insulin in the body. Approximately 5 to 10% of individuals with diabetes have type 1 diabetes [76].

Symptoms of type 1 diabetes tend to appear suddenly and are commonly observed in children, teenagers, and young adults. Managing this condition requires daily insulin administration, without which survival is not possible. At present, there is no known cure for type 1 diabetes.

Type 2 diabetes is characterized by the body's inability to use insulin efficiently, leading to difficulties in maintaining normal blood sugar levels. Type 2 diabetes constitutes 90–95% of all diabetes cases [77]. Type 2 diabetes usually develops over a prolonged period, and adults are commonly diagnosed with it. However, it is becoming increasingly prevalent in children, teenagers, and young adults. Since the condition may not present any symptoms, individuals at risk are advised to undergo a blood sugar test. Healthy lifestyle changes such as weight loss, a nutritious diet, and regular exercise may help prevent or delay the onset of type 2 diabetes.

Women who have not previously experienced diabetes can develop gestational diabetes during pregnancy, which may increase the susceptibility of their unborn child to health complications [78]. Although gestational diabetes typically resolves after giving birth, it increases the likelihood of developing type 2 diabetes in the future. Moreover, if your child is obese during their childhood or teenage years, they are at a greater risk of developing type 2 diabetes.

3.1 Diabetes as a global burden

DM is a primary metabolic disorder that affects 382 million individuals worldwide. Almost 90% of those with diabetes have type 2 DM, the most prevalent DM [79, 80] and causes chronically high blood glucose levels by reducing insulin secretion or activity. Type 2 disease arises later in life, especially at one age, and is caused by pancreatic diseases as opposed to type 1 disease, which often begins in childhood and is mediated by the immune system [81].

DM is a significant contributor to cardiac mortality, blindness, renal failure, depression, and suicide [82]. With the progression of this disease, diabetic foot amputations are becoming more frequent. The chronic consequences of diabetes include cerebrovascular disease, foot disorders and other ailments [83].

Type 2 diabetes mellitus is more prevalent, as 90% of diabetes patients around the globe [84]. India, China and Pakistan ranks top in the world for diabetes incidences [84,85,86].

There is also reason to believe that many cases are undiagnosed, which would significantly increase the prevalence of untreated illnesses as well as the risk of consequences in Pakistan and around 26.7% adults are diabetic [87].

According to the World Health Organization, diabetes was responsible for more than 1.5 million deaths in 2019, making it the leading cause of death [88]. In Pakistan, the total weighted prevalence of generalized obesity was 57.9% (42% in men and 58% in women), while central obesity was calculated to be 73.1% (37.3% in men and 62.7% in women) using the WHO Asia–Pacific cut-offs [89]. Prediabetics are those who are always at risk of developing diabetes, and as of 2018, approximately 10.91% of adults in the country were in this category [86]. The potential increase in instances is made more worrisome by the increasing urbanization of people from rural regions and their adaptation to sedentary urban lifestyles [90].

A component of the effort is the Continuing Medical Education Program for healthcare professionals and the assurance of the supply of necessary medications [91]. A national diabetes care programme that centres on registration, treatment, and referral guidelines may also be implemented [92].

3.2 Diet for diabetic patients

For people with either type of diabetes, monitoring their diet is essential. Doctors recommend a healthy and balanced diet, as well as efforts to maintain a healthy weight. Consulting with a nutritionist or a diabetes educator can help individuals with diabetes create a healthy meal plan. This plan entails avoiding sugary treats and processed foods, increasing the intake of dietary fibre, and limiting portions of high-fat and high-carbohydrate foods (particularly those containing saturated fats).

Insulin users should avoid going too long between meals to avoid hypoglycemia. The amount of carbohydrates directly influences blood glucose levels, while the amount of protein and fat in the diet determines how many calories a person consumes [93]. The American Diabetes Association offers a variety of recipes and other useful dietary advice. To reduce the risk of heart disease, even when people eat a healthy diet, cholesterol-lowering medications are frequently needed.

Individuals with type 1 diabetes and some with type 2 diabetes can utilize carbohydrate counting or the carbohydrate exchange method to adjust their insulin dosage based on the amount of carbohydrates in their meal. This involves "counting" the number of carbs in a meal and calculating the insulin dose to be taken before eating. To fine-tune this approach, people with diabetes need to work closely with an experienced dietician who specializes in diabetes care [94]. The carbohydrate-to-insulin ratio (the quantity of insulin administered for each gram of carbohydrate in the meal) differs for each person [95]. Despite the lack of substantial evidence, a few specialists have recommended the utilization of the glycemic index to differentiate between carbohydrates that are metabolized quickly and those that are metabolized slowly. The glycemic index quantifies the effect of a carbohydrate-containing meal on blood glucose levels.

4 Pectin and diabetes

All forms of diabetes are characterized by high blood sugar levels (hyperglycemia), a limited or absent response to insulin, insulin resistance that is specific to certain pathways, and the development of diabetes-related complications in the retina, renal glomerulus, and peripheral nerves [96].

Treatment and management of these complications should be accompanied by the intake of proper biomolecules, such as pectin, which has been proven to be a promising antidiabetic agent [97], such as those related to glucose metabolism, improved insulin sensitivity, slowed glucose absorption, reduced lipid levels, improved gut health and other related complications. Further research is needed to fully understand the mechanisms by which pectin may help to treat diabetes, but the evidence thus far suggests that it may be a useful therapeutic agent for individuals with diabetes.

Pectin may also have a beneficial effect on lipid metabolism, which is a major contributor to the development of diabetes and cardiovascular disease. Pectin has been shown to lower total cholesterol levels and reduce the risk of cardiovascular disease [98]. This is likely due to its ability to bind to bile acids in the gut, which promotes their excretion and reduces their reabsorption.

Another mechanism by which pectin may have antidiabetic effects is through its effects on the gut microbiota [99]. The gut microbiota plays a crucial role in glucose metabolism, and imbalances in the gut microbiome have been linked to the development of metabolic disorders such as diabetes. Pectin has been shown to promote the growth of beneficial bacteria in the gut, which can improve gut health and glucose metabolism.

Synthetic antidiabetic medications have the potential to produce significant side effects despite being often used to treat diabetes. There is much interest in the use of natural substances in the fight against diabetes.Citrus pectin has been researched in diabetic rats and found to be effective in treating type 2 DM caused by a low dosage of streptozotocin and a high-fat diet. Citrus pectin has also been shown to enhance diabetic rat hyperlipidaemia, hepatic glycogen levels, and glucose tolerance [62].

The antidiabetic mechanisms of pectin include hypoglycaemic activity, insulin sensitivity enhancement, appetite suppression, starch metabolism, oxidative stress reduction, diabetic wound healing and synergistic activity against diabetes.

4.1 Pectin as a hypoglycemic agent

Diabetes is particularly associated with several complications. Hyperglycemia can damage vessels that carry blood towards the retina, leading to diabetic retinopathy, which can cause loss of vision or even blindness if left untreated [100]. Elevated levels of blood sugar can harm nerves and result in diabetic neuropathy, which may cause tingling, numbness, or discomfort in the hands and feet [101]. High blood sugar levels can also harm the kidneys, resulting in diabetic nephropathy [102]. Untreated diabetic nephropathy caused by hyperglycemia can result in kidney damage and even kidney failure. Moreover, hyperglycemia can increase the risk of cardiovascular disease by harming blood vessels, which can lead to a greater likelihood of heart attack and stroke [103]. High blood sugar levels can harm nerves and decrease blood flow to the feet, increasing the chances of developing foot ulcers in people with diabetes. These ulcers can become infected and, in severe cases, may require amputation [104].

Hypoglycemia is a condition in which the level of glucose in the blood decreases, which is considered less severe than the complications associated with high blood sugar levels. Hyperglycemia, on the other hand, can cause tissue damage through five primary mechanisms:

4.1.1 Elevated flow of glucose and other sugars through the polyol pathway

In diabetes, high blood glucose levels can overwhelm the normal metabolic pathways for glucose utilization, leading to increased flow of glucose through the polyol pathway. This can result in the accumulation of sugar alcohols such as sorbitol and fructose, which can cause osmotic stress, cell damage, and other adverse effects [105]. The accumulation of sorbitol due to increased glucose flux through the polyol pathway can cause osmotic stress, oxidative damage, and other changes that contribute to the development of diabetic cataracts in the lens of the eye. Additionally, in nerves, this process can lead to the accumulation of sorbitol and fructose, resulting in osmotic stress, oxidative damage, and other changes that contribute to diabetic neuropathy [106]. Pectin may prevent sorbitol accumulation and cataract development by reducing glucose absorption, thus lowering postprandial blood glucose levels [107]. It can also act as a prebiotic, promoting the growth of beneficial gut bacteria and improving glucose tolerance and insulin sensitivity. Additionally, pectin has antioxidant properties that protect against oxidative damage in the eye lens [108]. Pectin has potential as a dietary intervention to reduce the risk of diabetic cataracts and other complications.

4.1.2 Augmented intracellular advanced glycation end products (AGEs)

An increase in the intracellular formation of advanced glycation end products (AGEs) can result in various negative consequences. For instance, AGEs may activate receptors on immune cells and trigger an inflammatory response, which could lead to the release of proinflammatory cytokines and contribute to chronic inflammation [109]. In the case of increased intracellular AGE formation, reactive oxygen species (ROS) are generated, which can cause cellular damage and contribute to the development of oxidative stress. AGEs can also accumulate in tissues and contribute to the development of tissue damage, particularly in organs such as the kidneys, eyes, and blood vessels. Protein functions can be modified and altered by these products. For example, AGE-modified proteins can have reduced enzymatic activity, altered binding properties, and increased susceptibility to degradation [106]. In diabetes, high levels of glucose in the blood can increase the formation of AGEs by accelerating glycation. This can lead to the accumulation of AGEs in tissues and contribute to the development of diabetic complications such as nephropathy, retinopathy, and neuropathy [110]. Pectin can prevent diabetic complications by slowing carbohydrate digestion, promoting beneficial gut bacteria, and reducing oxidative stress. These mechanisms decrease postprandial blood glucose levels and improve glucose tolerance, reducing the formation of AGEs [111].

4.1.3 Augmented production of the receptor for advanced glycation end products (RAGE) and its stimulating agents

RAGE is a type of receptor on the cell membrane that binds to AGEs, S100 proteins, and HMGB1 ligands. An increase in the expression of RAGE and its activating ligands can lead to various harmful effects [112].

The binding of AGEs, S100 proteins, and HMGB1 to RAGE can trigger an inflammatory response by activating immune cells and releasing proinflammatory cytokines. This can contribute to the development of chronic inflammation, a hallmark of many chronic diseases [113]. RAGE activation can generate ROS that can cause cellular damage, contribute to the development of oxidative stress and can alter cellular function by modifying intracellular signalling pathways and gene expression patterns. Binding of RAGE ligands to RAGE can also contribute to tissue damage, particularly in organs such as the kidneys, eyes, and blood vessels.

In diabetes, high levels of glucose in the blood can increase the expression of RAGE and its activating ligands, particularly AGEs. This can contribute to the development of diabetic complications, such as nephropathy, retinopathy, and neuropathy [114]. Pectin can prevent such diabetic complications caused by increased RAGE expression and activating ligands by reducing postprandial blood glucose levels, acting as a prebiotic to improve glucose tolerance and insulin sensitivity and providing antioxidant protection against oxidative stress. These mechanisms suggest that pectin could be a valuable dietary intervention for reducing the risk of diabetic complications associated with RAGE expression and its ligands [115].

4.1.4 Stimulation of different types of protein kinase C (PKC) isoforms

The PKC family of enzymes plays important roles in cell pathways that control a variety of biological processes, including cellular proliferation, differentiation, and death. TNF-alpha, IL-6, and IL-1 beta are examples of proinflammatory cytokines that can be produced when PKC isoforms are activated, and these cytokines can contribute to the development of chronic inflammation [116]. When activated, PKC isoforms can generate reactive oxygen species, which damage cells via oxidative stress. These factors also contribute to the production of proinflammatory cytokines. In diabetes, PKC isoforms, mainly PKC-, can be activated by hyperglycemia, which can cause the development of diabetic conditions such as diabetic retinopathy, neuropathy, and nephropathy [117]. Increased growth factor, cytokine, and extracellular matrix protein expression may result from PKC activation, which may promote aberrant cell proliferation and aid in the development of fibrosis and tissue damage [118]. Pectin can prevent PKC activation-induced damage by inhibiting growth factor and cytokine expression, as well as the expression of extracellular matrix proteins. By doing so, pectin can reduce the risk of aberrant cell proliferation, fibrosis, and tissue damage. Additionally, the antioxidant properties of pectin may help to protect against oxidative stress-induced PKC activation [119].

4.1.5 Overactivity of the hexosamine pathway

If the hexosamine pathway becomes excessively active, it can cause an increase in the buildup of UDP-GlcNAc. This can hinder insulin signalling and promote the onset of insulin resistance [120]. Overactivity of the hexosamine pathway can trigger the generation of proinflammatory cytokines, such as TNF-α, IL-6, and IL-1β, which may lead to the emergence of chronic inflammation [116] and the production of ROS that can cause cellular damage and contribute to the development of oxidative stress.

In diabetes, high levels of glucose in the blood can accelerate hexosamine pathway activity, causing an increased flux of glucose and contributing to the development of diabetic complications such as nephropathy, retinopathy, and neuropathy. The overactivity of the pathway can lead to the production of extracellular matrix proteins such as collagen and fibronectin, which promote abnormal cell proliferation and cause fibrosis and tissue damage [121]. Pectin has the potential to prevent diabetic complications by reducing the absorption of glucose in the intestine, thereby decreasing the flux of glucose through the hexosamine pathway. This can reduce the overactivity of the pathway and the subsequent production of ECM proteins, which may help to prevent fibrosis and tissue damage [122].

All of these mechanisms are linked to hyperglycemic complications, which is why it is necessary to maintain blood glucose levels by using various types of biological compounds, such as pectin, which has been shown to have potential hypoglycemic effects, making it a promising dietary supplement for people with diabetes [123].

4.2 The role of pectin in enhancing insulin sensitivity

In addition to its hypoglycemic effects, pectin has been shown to enhance insulin sensitivity [124], which can help prevent and manage type 2 diabetes. Insulin sensitivity is the ability of cells to respond to insulin and take up glucose from the blood. When cells become insulin resistant, they are less able to respond to insulin, which can lead to high blood glucose levels.

The mechanism by which pectin enhances insulin sensitivity involves several steps:

  • Pectin is a soluble fibre that is not digested by enzymes in the small intestine.

  • As pectin passes through the digestive tract, it binds to bile acids, which are produced by the liver to aid in the digestion of fats.

  • The pectin-bile acid complex is then transported to the large intestine, where it is broken down by gut bacteria.

  • Bacteria ferment the pectin-bile acid complex, producing short-chain fatty acids (SCFAs) as a byproduct [125].

  • SCFAs are absorbed into the bloodstream and transported to the liver, where they inhibit the production of glucose by the liver.

  • By reducing the amount of glucose produced by the liver, SCFAs can help regulate blood glucose levels and improve insulin sensitivity.

  • SCFAs also activate signalling pathways in adipose tissue and skeletal muscle [126, 127] that promote glucose uptake and utilization, further improving insulin sensitivity.

Overall, the mechanism by which pectin enhances insulin sensitivity involves the binding of pectin to bile acids in the digestive tract, the fermentation of pectin by gut bacteria to produce SCFAs, and the inhibition of glucose production by the liver and the activation of glucose uptake and utilization by peripheral tissues, leading to improved insulin sensitivity. In addition, those of normal weight experienced enhanced glucose and insulin responses from soybean pectin [80]. Pectin and modified pectin may lower blood sugar levels and ameliorate insulin resistance. According to earlier research, methoxylated apple pectin has been proposed as a potential functional element for reducing insulin resistance [128]. One of the main mechanisms by which pectin may help to reduce glucose levels is through its effects on insulin sensitivity. Pectin has been shown to improve insulin sensitivity, which can lead to better glucose uptake and utilization by cells [43]. This improved insulin sensitivity can also help to reduce the risk of developing type 2 diabetes. Pectin has also been shown to affect glucose absorption. Pectin slows the rate of glucose absorption from the gut into the bloodstream, which helps to regulate blood sugar levels [129]. This is especially important in individuals with diabetes, as rapid spikes in blood sugar levels can lead to further complications. Various mechanisms associated with oxidative stress regulated hyperglycemia, insulin resistance in diabetes mellitus is presented in Fig. 3.

Fig. 3
figure 3

Proposed mechanisms of oxidative stress related consequences such as hyperglycemia, insulin resistance associated signalling pathways in the progress of diabetes mellitus and its complications. Oxidative stress is a significant contributing factor in the development of diabetes and connected health problems. AD: Antioxidant defense; AGEs: Advanced glycation end-products; CVD: Cardiovascular diseases; FA: Fatty acids; GS: Glycogen synthesis; HB: Hexosamine biosynthesis; HL: Hyperlipidemia; IS: Insulin secretion; LA: Lipid accumulation; MAPK: Mitogen-activated protein kinases; NeuP: Neuropathy; NP: Nephropathy; O-GlcNAcylation: O-linked-acetylglucosamine; OP: Oxidant production; PKC: Protein kinase C; PPARγ: Peroxisome proliferator activated receptor-γ; RP: Retinopathy; β-CA: β-Cell apoptosis. Red upward arrow indicates increase/induced, downward arrow indicates decrease, indicates downregulation/suppression by pectin

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4.3 Pectin in starch utilization and regulation

Pectin plays a significant role in the utilization and regulation of starch [130]. Starch is the primary carbohydrate source for most plants, and it is also an important dietary component for humans and animals. The mechanism by which pectin is involved in the utilization and regulation of starch is complex and involves several different pathways.

The primary way to utilize starch is through its ability to interact with amylase. Amylase is the enzyme responsible for breaking down starch into glucose, which can be used as an energy source by plants or animals. Pectin has been shown to bind to amylase [131], which can slow its activity and reduce the rate of starch digestion. This can have important implications for plant growth and development, as well as for human health, as it can help to regulate blood sugar levels and prevent spikes in insulin.

Pectin is also involved in the regulation of starch synthesis in plants [132]. Starch synthesis is a complex process that involves several different enzymes, including sucrose synthase, starch synthase, and branching enzymes. Pectin has been shown to interact with these enzymes and modulate their activity, which can affect the rate of starch synthesis. This can have important implications for plant growth and development, as well as for the quality and quantity of starch produced.

In addition to its direct effects on amylase and starch synthesis enzymes, pectin is also involved in the regulation of starch metabolism [133] through its effects on the gut microbiota. The gut microbiota plays an important role in the digestion and metabolism of dietary carbohydrates, including starch. Pectin is a prebiotic fibre, meaning that it can promote the growth and activity of beneficial bacteria in the gut. These bacteria can produce enzymes such as alpha-glucosidase and alpha-amylase [134], which can help to break down starch into smaller, more easily digestible molecules.

Finally, pectin is also involved in the regulation of starch metabolism through its effects on insulin sensitivity. Insulin is a hormone that is essential for the uptake and utilization of glucose by cells. Pectin has been shown to improve insulin sensitivity in several ways. First, pectin can reduce the absorption of glucose from the gut [73], which can help to prevent spikes in blood sugar levels. Second, pectin can improve the activity of insulin receptors on cells, which can enhance the uptake of glucose. Third, pectin can reduce inflammation in the body [135], which can impair insulin signalling and lead to insulin resistance.

In summary, pectin plays a significant role in the utilization and regulation of starch. Its ability to interact with amylase and starch synthesis enzymes, modulate the gut microbiota, and improve insulin sensitivity can have important implications for plant growth and development, as well as for human health.

4.4 Anti-inflammatory and immunomodulatory activity

The body's natural response to an infection, injury, or tissue damage is inflammation. However, persistent inflammation can accelerate the onset and progression of a number of chronic illnesses, including diabetes. Pectin has significant anti-inflammatory effects on diabetes [136]. The anti-inflammatory effect of pectin is primarily attributed to its ability to modulate immune function and reduce the production of proinflammatory cytokines. TNF-alpha, interleukin-6, and IL-1 are examples of proinflammatory cytokines that are important mediators of inflammation and have been linked to the development of diabetes [137, 138]. Pectin can inhibit the production and release of these cytokines, thus reducing inflammation. Li, T and his coworkers investigated “the effects of pectin on inflammation in high-fat diet-induced diabetic mice [139]. The results showed that pectin administration reduced the expression of proinflammatory cytokines such as TNF-α and IL-6 in adipose tissue. Another study investigated the effects of pectin on inflammation in diabetic patients. Pectin supplementation reduced the levels of proinflammatory cytokines [140], such as TNF-α and IL-6, in the serum. Pectin supplementation also improved glycemic control and lipid profile parameters. In addition to its direct anti-inflammatory effects, pectin may also exert its anti-inflammatory effects by modulating the gut microbiota [73]. The gut microbiota plays a critical role in regulating immune function and inflammation in the body. Pectin is a prebiotic fibre, meaning that it can promote the growth and activity of beneficial bacteria in the gut. These bacteria can produce short-chain fatty acids, which can reduce inflammation in the body. As a result, pectin possesses significant anti-inflammatory properties with respect to diabetes. Its ability to modulate immune function, reduce the production of proinflammatory cytokines, and modulate the gut microbiota can help to reduce inflammation and prevent diabetes complications. Further research is needed to fully understand the extent and clinical significance of the anti-inflammatory effects of pectin and its potential as a therapeutic agent for diabetes. Additionally, pectin has been shown to have anti-inflammatory and antioxidant properties, which may help prevent chronic diseases such as cancer, heart disease, and diabetes [141, 142].

4.5 Pectin in the reduction of oxidative stress

Oxidative stress refers to a condition in which there is an imbalance between the body's ability to eliminate or combat ROS and the rate at which they are produced. This is typically observed in a variety of serious illnesses, including diabetes. Proteins, lipids, and DNA are among the biological constituents that damage ROS [143] and lead to the development of diabetes complications such as retinopathy, nephropathy and neuropathy [144, 145], as mentioned earlier. Antioxidants are compounds that can neutralize ROS and prevent oxidative damage. Pectin has been shown to possess significant antioxidant potential with respect to diabetes. During metabolism, pectin is broken down into SCFAs by the gut microbiota. These SCFAs can act as signalling molecules and regulate various metabolic pathways in the body. The nuclear factor erythroid 2-related factor 2 (Nrf2) signalling pathway is activated by SCFAs. Superoxide dismutase, catalase, and glutathione peroxidase are examples of antioxidant and detoxifying enzymes that are regulated by the transcription factor Nrf2 [146]. Activation of the Nrf2 pathway increases the expression of these antioxidant enzymes, which in turn scavenges ROS and reduces oxidative stress.

Pectin also has the ability to modulate the composition and activity of the gut microbiota, which can further enhance the production of SCFAs and reduce oxidative stress [147]. Additionally, pectin has been shown to improve glucose metabolism by inhibiting the activity of alpha-amylase and alpha-glucosidase enzymes that breakdown complex carbohydrates into simple sugars, which can lead to hyperglycemia.

The antioxidant potential of pectin is also attributed to its ability to scavenge free radicals and chelate metal ions [148]. Free radicals are highly reactive molecules that can damage cellular structures, while metal ions can catalyze the formation of free radicals. Pectin can act as a free radical scavenger and reduce oxidative damage by donating electrons to neutralize free radicals. Additionally, pectin can chelate metal ions, which can prevent them from participating in oxidative reactions.

Studies have investigated the potential of pectin as an antioxidant in the context of diabetes. For example, Sibiya and coworkers investigated the effects of pectin on oxidative stress and inflammation in streptozotocin-induced diabetic rats [149]. The findings revealed that pectin decreased oxidative stress indicators such as malondialdehyde and boosted the activity of antioxidant enzymes such as catalase and superoxide dismutase. Moreover, pectin decreased inflammatory biomarkers, including interleukin-6 and tumor necrosis factor-alpha.

Another study examined how pectin affects diabetes patients' oxidative stress [150]. According to the findings, the addition of pectin to the diet decreased the levels of oxidative stress indicators such as 8-hydroxy-2'-deoxyguanosine and increased the activities of antioxidant enzymes such as glutathione peroxidase and catalase. Moreover, glycemic control and lipid profile markers were enhanced by pectin supplementation.

In addition to its direct antioxidant effects, pectin may also exert its antioxidant potential by modulating the gut microbiota [151]. The gut microbiota plays a critical role in regulating oxidative stress and inflammation in the body. Pectin is a prebiotic fibre, meaning that it can promote the growth and activity of beneficial bacteria in the gut. These bacteria can produce short-chain fatty acids, which can reduce oxidative stress and inflammation in the body.

Pectin has been proven to be a dependable antioxidant that can effectively eliminate free radicals and pose fewer health risks than synthetic compounds. Rhamnogalacturonan I, a pectin, showed significant antioxidant activity by scavenging DPPH- and ABTS- + radicals. According to one study, pectin with lengthy HG-1 (homogalacturonan) segments alternating with RG-I segments, arabinogalactan type I, and arabinanas side chains (as illustrated in Fig. 1) offers efficient defense against the oxidative effects of intestinal stress [62]. When the viscosity is not excessive, the -OH groups of the polysaccharides in pectin can exhibit good antioxidant activity [61]. DPPH scavenging activity and ferric reducing ability of plasma [152]. According to the IC50 values, the nanoscale Fe3O4 with pectin nanoparticles displayed strong antioxidant activity. The antioxidant characteristics of newer nanoparticles seem to have a protective impact against human liver cancer [153].

4.6 Pectin in diabetic wound healing

Diabetic wound healing is a complex process that is often impaired in people with diabetes due to factors such as poor circulation, neuropathy, and impaired immune function. Pectin has potential benefits for diabetic wound healing [154]. The mechanism by which pectin promotes wound healing in diabetes involves several different pathways.

Pectin can promote diabetic wound healing by modulating inflammation [155]. Inflammation is a critical component of the wound healing process, as it helps to clear damaged tissue and promote the growth of new tissue. However, chronic inflammation can impair wound healing by prolonging the inflammatory phase and leading to tissue damage. Pectin has been shown to reduce chronic inflammation in several ways. First, pectin can reduce the expression of proinflammatory cytokines [156], which are molecules that promote inflammation. Second, pectin can promote the expression of anti-inflammatory cytokines, which can help to resolve inflammation. Finally, pectin can reduce the infiltration of immune cells [157] into the wound site, which can help to prevent further tissue damage.

Another way that pectin promotes diabetic wound healing is by promoting angiogenesis [158, 159]. Angiogenesis is the process by which new blood vessels form, and it is essential for delivering oxygen and nutrients to the wound site. Pectin has been shown to promote angiogenesis by upregulating the expression of vascular endothelial growth factor (VEGF), a molecule that promotes blood vessel growth. This can help to improve blood flow to the wound site and accelerate the healing process.

Pectin also promotes diabetic wound healing by promoting the production of extracellular matrix (ECM) proteins. ECM proteins are the building blocks of tissue, and they play an essential role in wound healing by providing structural support and promoting cell adhesion and migration [160]. Pectin can increase the expression of ECM proteins such as collagen and fibronectin, which can help to improve the strength and stability of new tissue.

Pectin can also promote diabetic wound healing by modulating the gut microbiota. The gut microbiota has been shown to play an important role in wound healing because it can influence immune function and inflammation [161]. Pectin is a prebiotic fibre, meaning that it can promote the growth and activity of beneficial bacteria in the gut. These bacteria can produce metabolites such as short-chain fatty acids (SCFAs), which have been shown to improve wound healing by reducing inflammation and promoting tissue regeneration.

4.7 Pectin in appetite suppression

Pectin has been shown to have several health benefits for people with diabetes, including its potential to act as an appetite suppressor. It is a type of soluble fibre that absorbs water in the digestive tract, forming a gel-like substance that can increase feelings of fullness and reduce hunger [162]. This can help to prevent overeating and promote weight loss, which can be particularly beneficial for people with diabetes who are overweight or obese.

Studies have shown that consuming pectin or pectin-rich foods can lead to reduced caloric intake and increased feelings of satiety in both healthy individuals and those with type 2 diabetes [163]. In one study [164], people with type 2 diabetes who consumed pectin in a beverage before a meal had lower blood glucose levels and reported feeling fuller for longer periods of time compared to those who consumed a placebo beverage.

The appetite-suppressing effects of pectin are thought to be due to its ability to slow the emptying of the stomach and delay the absorption of nutrients, including glucose. This can help to regulate blood glucose levels and reduce insulin resistance over time, which are important factors in managing diabetes.

Overall, pectin may act as an appetite suppressor in people with diabetes by increasing feelings of fullness and reducing hunger, which can help to prevent overeating and promote weight loss [165]. Incorporating pectin-rich foods such as citrus fruits, apples, and berries into the diet may be a simple and effective way to achieve these benefits. However, it is important to talk to a healthcare provider before making significant changes to the diet, especially if you have diabetes and are taking medications to manage your blood sugar levels.

4.8 Pectin as a synergistic agent

In addition to its other beneficial effects on the management of diabetes, pectin has other beneficial effects, as discussed earlier. These effects include slowing glucose absorption, increasing insulin sensitivity, and reducing inflammation and oxidative stress. However, the activity of pectin against diabetes can be further enhanced when it is combined with other natural compounds [166] that also have antidiabetic effects, leading to a synergistic effect. There are several compounds that may interact with pectin to exert synergistic effects on the management of diabetes, some of which are mentioned below.

Procyanidins are a type of flavonoid that are found in many fruits and vegetables and have been shown to have antidiabetic effects along with antioxidant, anti-inflammatory, and cardioprotective effects [167]. When combined with pectin, procyanidins may enhance the ability of pectin to slow the absorption of glucose and improve insulin sensitivity, potentially reducing the risk of developing type 2 diabetes.

The extent to which pectin can enhance the capability of procyanidins after interaction can depend on various factors, such as the type and source of pectin and procyanidins, the dosage and mode of administration, and the specific health benefits being studied. Pectin enhanced the antioxidant activity of proanthocyanidins in cocoa by up to 2.6-fold, while another study revealed that pectin-coated cranberry procyanidins had greater bioavailability and stronger antimicrobial activity against E. coli than noncoated procyanidins.

Resveratrol is a natural compound found in grapes, red wine, and other fruits and has been shown to have antidiabetic effects, including improving insulin sensitivity and reducing oxidative stress. The combination of pectin and resveratrol had a synergistic effect on reducing blood glucose levels in diabetic rats [168].

Chromium is an essential mineral that plays a role in glucose metabolism and insulin signalling. Studies have shown that chromium supplements may help to improve glucose control in people with type 2 diabetes [169]. When combined with pectin, chromium may enhance the insulin-sensitizing effects of pectin, potentially further improving glucose control.

Cinnamonis spice has been shown to have antidiabetic effects, possibly due to its ability to improve insulin sensitivity and reduce inflammation [170]. When combined with pectin, cinnamon may enhance the insulin-sensitizing and anti-inflammatory effects of pectin, potentially improving glucose control in people with diabetes.

Omega-3 fatty acids are forms of polyunsaturated fat present in fatty fish and other seafood. Research has revealed that taking omega-3 supplements could help patients with type 2 diabetes better control their blood sugar [171]. The anti-inflammatory properties of pectin may be enhanced by omega-3 fatty acids when mixed with pectin, potentially lowering the risk of chronic inflammation.

Therefore, procyanidins, resveratrol, chromium, cinnamon, and omega-3 fatty acids combined with pectin may have synergistic effects on the management of diabetes, possibly improving glucose control and reducing the chance of developing problems related to the illness [172]. To fully comprehend the mechanics of these interactions and to establish the best dosages and methods of administration for multiple health advantages, more research is still needed.

4.9 Pectin as an inducer of antidiabetic drugs

Pectin can enhance the activity of antidiabetic drugs such as insulin and metformin and inhibit the activity of alpha-amylase, an enzyme involved in carbohydrate digestion [173].

One way pectin enhances the activity of insulin is by slowing the digestion and absorption of carbohydrates in the gastrointestinal tract. This leads to a more gradual and sustained release of glucose into the bloodstream, reducing the demand for insulin and potentially improving insulin sensitivity [174]. Pectin has also been shown to enhance the uptake of metformin in the intestine. Metformin is an antidiabetic drug that reduces glucose production in the liver and improves glucose uptake in the muscles [166]. By enhancing the uptake of metformin, pectin may increase its bioavailability and improve its effectiveness in managing blood glucose levels.

In addition, pectin has been shown to inhibit the activity of alpha-amylase, an enzyme that breaks down carbohydrates in the digestive system. This inhibition leads to slower carbohydrate digestion and absorption, reducing the postprandial blood glucose response. By reducing the postprandial blood glucose response, pectin may also reduce the demand for insulin and improve insulin sensitivity [175].

Generally, the ability of pectin to enhance the activity of antidiabetic drugs and inhibit carbohydrate digestion makes it a promising natural compound for the management of diabetes. However, more research is needed to fully understand the mechanisms of action and potential benefits of pectin in diabetes management. Various mechanisms associated with antidiabetic effects are provided in Table 2.

Table 2 Antidiabetic associated mechanisms of pectin from different sources
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5 Conclusion

In summary, pectin has been found to have therapeutic effects on the management of diabetes and related complications, as well as other potential health benefits. Its ability to improve glycemic control; reduce insulin resistance, starch utilization and regulation, and appetite suppression; lower cholesterol levels; and promote the rapid healing of diabetic wounds make it a valuable dietary supplement for individuals with diabetes. Moreover, the antioxidant, anti-inflammatory and immune-modulatory properties of pectin may help prevent the development of diabetic complications such as cardiovascular disease, diabetic nephropathy and neuropathy. Pectin can also reduce blood glucose levels by exhibiting synergistic effects on other diabetes-preventing components and by promoting the effects of antidiabetic drugs. Although further studies are needed to confirm its long-term effects and optimal dosage, pectin shows promise as a natural, safe, and effective therapeutic functional food formulation for the management of diabetes and related complications.