Background

Traditional herbal medicine is an important part of all nations’ history, therefore, an establishment of the original uses and local names of plants has significant potential societal benefits. Unfortunately, recently with the fast growth in the technical aspects of the world, loss of customs and various ethnic cultures, some of this information may disappear [1,2,3]. Since the beginning of history, human beings have used plants as medicine, and Ancient Arabic Medicine was influenced by medicinal practices in India, Persia, Mesopotamia, Spain, Rome and Greece [4].

Palestine had high ecosystem diversity due to its geographical location between Africa, Asia, and Europe and due to different climatic, zoogeographic, and phytogeographic zones, this creates great biological diversity [5, 6]. In the West Bank regions of Palestine, traditional medicine is widely used especially in rural areas; this may be due to the political conflicts in this country and the cost of conventional drugs [7,8,9]. Hundreds of shrubs, trees, and herbal species used as antipyretics, analgesics, diuretics, laxatives, antimicrobial, antidiarrheal, emetics and cardio-tonics in the West Bank area of Palestine [10]. These plants are available and cheap because they grow wildly in nature or cultivated [11, 12].

The rich variety of approaches employed by herbalists and traditional healers to treat disorders and diseases of the urinary tract is indicative of the depth and breadth of indigenous medicine practiced among these traditional healers and herbalists in the twentieth century [12].

The Kidney is the organ that has numerous physiological functions. Its role is to maintain the homeostatic balance of body fluids and electrolytes. Kidneys are vital regulators of glucose metabolism, blood pressure, and erythropoiesis. Patients with kidney diseases have significant morbidity and mortality [13, 14].

There are many urologic diseases and disorders. According to the American Urological Association Foundation, the most commonly identified urological diseases include hyperplasia, benign prostate hyperplasia (BPH), urinary tract infections, urethral and kidney stones, enuresis (urinary incontinence) and renal failure [15].

According to the Palestinian Central Bureau of Statistics and Ministry of Health annual report in 2014, the visits to the outpatient urological clinics of governmental hospitals in Palestine were 49,275 visits per year. Moreover, about 4% of death causes in Palestine were due to renal failure and other kidney diseases. In the USA, about 26 million American adults have kidney disease, and it is considered the 9th leading cause of death in the United States. Kidney diseases kill more people than breast or prostate cancer yearly [16,17,18].

For these reasons, this study aimed to collect data from herbalists and traditional healers about the folk herbal remedies, which have been utilized for treatment of urological diseases in the West Bank regions of Palestine and to verify their pharmacological and toxicological effects through literature review.

Methods

Study areas

West Bank is an important territory of Palestine. The climate in the West Bank is mostly Mediterranean, slightly colder in mountains and hills compared with the shorelines in the western lands. In the east, it includes the desert and the shoreline of the Dead Sea, both with dry and hot climate. The shores of the Dead Sea are about 430 m below sea level, and it is considered the Earth’s lowest elevation on the land. Accordingly, all these factors explain the enormous diversity of the West Bank flora. This diversity is directly reflected in the distribution and diversification of agricultural patterns, from the rain-fed farming in the mountains (Jerusalem, Ramallah, Hebron, Nablus, Bethlehem, Salfeit) to an irrigated agriculture as in Jenin, Tobas, Toulkarem, Qalqilya and Jericho lands [19, 20].

Selection of informants

An ethnopharmacological survey (questionnaire-based cross-sectional descriptive study) was used. Areas visited included all regions of the West Bank/Palestine, including Nablus, Jenin, Tubas, Toulkarem, Salfeit, Qalqilya, Ramallah, Jericho, Jerusalem, Bethlehem and Hebron (Fig. 1) between March and April 2016. The Institutional Review Board (IRB) at An-Najah National University approved the study protocol and the informed consent forms (IRB number was 134/February/2016). The study was conducted in accordance with the requirements of the declarations of Helsinki (World Medical Association 2008), the current Good Clinical Practice (GCP) Guidelines (EME 1997) and the International Conference on Harmonization (ICH1996) Guidelines, and a written informed consent was obtained from the participants.

Fig. 1
figure 1

The study area map showing all the surveyed regions in the West Bank/Palestine

Full size image

The objectives of the study were explained to the participants, they were not offered any incentives, and they were able to withdraw from this study at any time.

A total of 150 traditional healers and herbalists were interviewed in this study. 144 participants accepted to answer the questionnaire (102 males and 42 females), where 26 of them were from Hebron (16 males and 10 females), 18 from Jenin (12 males and 6 females), 17 from Jericho (14 males and 3 females), 16 Nablus and Qalqilya (12 males and 4 females from Nablus) (10 males and 6 females from Qalqilya), 14 from Toulkarem (12 males and 2 females), 11 from Ramallah (9 males and 2 females), 9 from Jerusalem (7 males and 2 females), 6 from Tubas and Jerusalem (4 males and 2 females from Tubas) and (3 males and 3 females from Jerusalem), and 5 from Salfeit (3 males and 2 females), from 11 regions of the West Bank Area of Palestine. They were from different ages (22–91 years) and were selected with the help of local people. The selected healers were well known in the community due to their long practice of providing services related to traditional health care. All the participants (i.e., 144) were asked to provide information on the plant(s) that they use for treating the urinary tract diseases, parts of the plants used such as leaves, roots, flowers, stems and seeds, methods of preparation (e.g decoction, juice, infusion, powder), and methods of administration (either orally or topically). In addition to their opinion about the advantages of herbal remedies.

The study was a face to face questionnaire. This method has proven to be a very practical and useful option of data collection. The survey was anonymous, pretested by a pilot study for reliability, validity and clarity of the questionnaire. Meanwhile, the duration of the interviews ranged from 20 to 60 min, with one visit per interviewee in each case. Interviews were conducted in Arabic, the local language of the informants and the plant names were given in Arabic and later translated into English and Latin using reference books as well as about 50% of these Arabic names were linked to an actual right scientific name [21,22,23].

Plant identification

The collected plant samples from these informants were stored in the pharmacognosy laboratory at the Pharmacy Department, An-Najah National University in appropriate glassware and individual herbarium wooden frames. They were identified later by a team of teaching assistants and technicians under the supervision of the pharmacognosist (Dr. Nidal Jaradat), all fifty-seven plants’ species that were mentioned by informants, were identified by using photographs from reference books and dried herbarium specimens [24, 25].

Data analysis

The frequency of citation (FC) for all plants species in this study were calculated by using the following formula:

FC = (Number of times a particular species was mentioned by herbalists and traditional healers/a total number of occasions that all species were mentioned) × 100 [24].

To evaluate the relative importance of plants in indigenous healthcare systems, the use value (UV) is used as a micro-statistical tool, which reflects people interaction with specific plants as the best treatments for urinary tract diseases. It is a quantitative method that can be used to prove the relative importance of species known locally. It can be calculated according to the following equation:

$$ \mathrm{UV}=\frac{\sum U}{n} $$

Where UV is the use value of a species; U is the number of citations per species; n is the number of informants [25].

Factor of informant’s consensus (Fic) was calculated according to the following equation:

$$ {F}_{ic}=\frac{Nur- Nt}{Nur-1} $$

Where Nur is the number of use citations in urinary tract disease category, and Nt is the number of taxa used for the treatment of these diseases.

This factor is employed to indicate how homogenous the information is. Fic value is close to 0 if plants are chosen randomly, or if informants do not exchange information about their use. High values of Fic (close to 1) occur when there is a clear selection criterion in the community and if information is frequently exchanged between informants [26].

The Choice Value (CV) method is a valuable assessment tool to measure related plant species for treatment of urinary tract diseases [27].

The CV is calculated as in the following equation:

$$ CV\kern0.5em species=\frac{Pcs}{Sc}\times 100 $$

Pcs: percent of informants that cited certain plant species for the treatment of urinary tract disease.

Sc: is the total number of species mentioned for treatment of disease by all informants. Choice values are ranked from 0 to 100 with 100 indicating complete preference and fewer alternatives.

The significance of medicinal plant families was assessed using the Family Use Values (FUV), which was calculated according to the following equation:

$$ FUV=\frac{UVs}{(ns)} $$

where, UVs = use values of the taxa, and ns = total number of species within each family which were used for the treatment of urological diseases in the West Bank area of Palestine [28].

Review study

A literature review was conducted by a systematic search of the scientific literature, which was published before January 2017, by using Medline, Pubmed, Scopus and Google Scholar electronic searching machines. It cited most of the plants which had FC higher than 50% and their applications in the treatment of urological disease. The investigators practiced the following Keywords: folk uses for urinary tract, ethnopharmacological uses urinary tract, traditional methods of urinary tract, evidence-based uses, toxicities and side effects for individual plant names.

Results

Socio-demographic factors

As shown in Table 1, most of the respondents who worked in this field were males. Most of them had high educational levels. In fact, 30.56% of the interviewed were secondary school graduates. The majority of respondents were from areas of the West Bank that mostly depended on agriculture or grazing as a mean of income (Hebron, Jenin, and Jericho).

Table 1 Sociodemographic factors related to the respondents
Full size table

Regarding training and knowledge acquisition; (i) 77% of the respondents acquired their skills through observing their family members, (ii) 21% gained their skills through coursework and apprenticeship, (iii) and about 2% claimed they had a divine gift for the healing of certain diseases, which means that most of them had this knowledge through their families’ historical healing knowledge skill.

Data collection of ethnopharmacological plants.

The fruits were the most commonly used parts of plants for the treatment of urinary tract diseases followed by seeds and roots. The modes and methods of preparation varied considerably from one healer to another; however, all of these methods were administered orally as described by the interviewees and shown in Table 2.

Table 2 The medicinal plants used for the treatment of some urinary tract diseases, the plant parts used, use values, choice value, frequency of citation, modes and methods of preparation
Full size table

In the case of kidney stones, the highest use values were for Paronychia Argentina, Plantago ovata, Punica granatum, Taraxacum syriacum, Morus alba and Foeniculum vulgare, respectively. In the case of urinary tract infections, the highest use values were for Capsella bursa-pastoris, Ammi visnaga, and Ammi majus, respectively. Besides, the maximum use value in case of renal failure was for Portulaca oleracea while the highest use values in the case of enuresis were for Curcuma longa and Crocus sativus, respectively. In the case of prostatic enlargement, the highest use values were for Juglans regia, Quercus infectoria, Sambucus ebulus and Zea mays, respectively. Furthermore, the frequencies of citation for these plants species were more than 50%.

The factor of informant’s consensus (Fic) was calculated for medicinal plants used for the treatment of various urinary tract diseases (i.e., 0.99 for Benign Prostate Hyperplasia (BPH) and enuresis and 0.98 in a case of kidney stones disease, urinary tract infection and renal failure). The calculated Fic value obtained for the reported diseases indicated the degree of shared knowledge among informants for the treatment of these urinary tract diseases by certain medicinal plants as shown in Table 3.

Table 3 Factor of informant’s consensus (Fic) for the studied urinary tract diseases
Full size table

Ethnopharmacological information obtained from the study area on medicinal plants used in the treatment of various urinary tract diseases revealed that 57 plant species belonging to 30 families. All of the Latin scientific names have been checked with www.theplantlist.org on March 10, 2016.

As presented in Table 4, the family use value was the highest for Apiaceae family, which was 26.67, where the most common plant parts used were fruits, seeds, and roots, respectively as shown in Fig. 2.

Table 4 Medicinal plant families used for treatment of urinary tract diseases and the family use value (30 families)
Full size table
Fig. 2
figure 2

The frequency of the used parts of medicinal plants in the treatment of some urinary tract diseases

Full size image

Pharmaceutical preparations

The methods of preparation were decoctions, infusions, juice, oil, and powder. Decoctions and infusions were the most frequently used methods of preparation as presented in Fig. 3.

Fig. 3
figure 3

The frequency of preparation methods of medicinal plants for treatment of some urinary tract diseases

Full size image

The most common urinary tract disease treated with herbal remedies was kidney stones followed by urinary tract infections, renal failure, Benign Prostate Hyperplasia (BPH) and enuresis as reported in Fig. 4.

Fig. 4
figure 4

The frequency of urinary tract diseases mentioned by herbalists and traditional healers in the West Bank area of Palestine

Full size image

Literature review

For all the listed above plants, a literature review was investigated, where it represented their ethnopharmacological use against urinary tract diseases regionally, internationally and globally. Also, in-vitro as well as in-vivo studies and their toxic or adverse reactions were reviewed for plants which had FC value more than 50%, using electronic databases and the results were summarized in Table 5.

Table 5 Summary of published ethnopharmacology, in vivo, in vitro studies, side effects and toxicity of the most frequently recommended plants for treatment of urinary tract diseases
Full size table

Discussion

In the West Bank area of Palestine, the folk medicine has been trusted and highly appreciated, and many patients go to herbalists or traditional herbal healers to get benefit from this field. In fact, herbal medicine is considered the most used complementary and alternative medicine and this part of complementary and alternative medicines are widely used among patients suffering from urinary tract diseases throughout the world. Most practitioners are males, and this was confirmed in this study; some of them have university degrees.

All over the world, the prevalence of kidney diseases varies significantly from country to country. Epidemiological data on the occurrence of kidney stone was about 12% of global population with a recurrence rate of 70–80% in males and 47–60% in females [29].

According to the use value results, the highest use values for medicinal plants, which were utilized for the treatment of kidney stones, were for Paronychia argentea, Plantago ovata, Punica granatum, Taraxacum syriacum, Morus alba, and Foeniculum vulgare. The highest use values for medicinal plants used for treatment of urinary tract infections were for Capsella bursa-pastoris, Ammi visnaga, and Ammi majus, while the highest use value for plants used for treatment of renal failure was for Portulaca oleracea as well as the highest use values for medicinal plants used for treatment of enuresis were for Curcuma longa and Crocus sativus. Furthermore the maximum use values for plants used for treatment of benign prostate hyperplasia were for Juglans regia, Quercus infectoria, Sambucus ebulus and Zea mays.

Table 5 showed that Paronychia argentea, Punica granatum, Morus alba, and Foeniculum vulgare were used in the folk medicine in many countries for the treatment of kidney stones. The evidence-based effects for this disease were documented for Paronychia argentea, Plantago ovata, Punica granatum, Morus alba, and Foeniculum vulgare, whereas Taraxacum syriacum lacked any evidence-based use for treatment of kidney stone. Moreover, specific attention must be considered during consumption of Paronychia argentea extract, which has a low hemolytic effect.

Regarding the most cited plants which were used for the treatment of urinary tract infections, all of them applied in the folk medicine in many countries and their antibacterial effect approved scientifically, but all of them may have harmful effects due to their adverse reactions and toxicological effect. Mean while the most cited plant for treatment of renal failure was Portulaca oleracea which is used in India and Sri Lanka for the treatment of this disease also, but unfortunately, this plant contains oxalic acid and nitrate. Therefore, high consumption of this plant is harmful to patients suffering from renal failure. Moreover, the most cited plants for treatment of enuresis were Curcuma longa and Crocus sativus which was not mentioned before in any folk or evidence-based medicines for the treatment of this disease and their toxicological effects were not reported.

The most cited plants which were used for the treatment of benign prostate hyperplasia (prostatic enlargement) were; Juglans regia, Sambucus ebulus and Zea mays. These plants had evidence-based studies to be useful for the treatment of this disease, but it is important to keep in mind that Juglans regia, Quercus infectoria and, Sambucus ebulus are harmful as mentioned in the literature review and cannot be used for treatment of any disease.

Over all, there are quite a few phytopharmaceuticals which can be used effectively for the treatment of the urinary tract diseases in the pharmaceutical markets. For that further phytochemical and pharmacological screenings is required to investigate new drugs from the mentioned plants in this study, especially those which have high use values and can be used safely.

Conclusion

The traditional herbal medicine has gradually become more popular, and the need for promoting awareness is perceived. This study showed that traditional herbal medicine is playing a significant role for treatment of urological diseases in the West Bank of Palestine. Based on that, all the plants in this study with high use value should have further phytochemical and pharmacological screenings to test for safety and efficacy. Despite the fact that many of the herbals are currently used by local and international herbalists and traditional healers, serious attention must be given toward many of these products, since they have serious adverse effects and toxicities. Curcuma longa and Crocus sativus were the most cited plants for treatment of enuresis. These plants could be of interest for additional research since they have not been mentioned before in any folk or evidence-based medicines for the treatment of this disease and their toxicological effects were not reported. Also, it is important to keep in mind that Juglans regia, Quercus infectoria and, Sambucus ebulus are harmful and cannot be used for the treatment of any disease.