Background

From the ancient period, natural remedies have been popular with people due to their excellent medicinal properties which can treat complicated diseases without showing any side effects at minimum expense. The medicinal plants contain different types of naturally occurred chemical compounds that contribute to their medicinal properties. With the advancement of scientific research, the researchers have been successful to detect various phytochemical compounds in medicinal plants which are proved to exhibit different types of physiological activities and are used for prophylactic purposes [1].

Thrombosis is a lethal disease that causes vascular blockage and while recovering it causes fatal consequences, such as cerebral or myocardial infarction and even death [2]. Tissue plasminogen activator (t-PA), alteplase, anistreplase, urokinase, and streptokinase (SK), and recombinant t-PA therapies are currently used for the treatment of thrombosis [3]. The post-therapeutic adverse effects of these medicines are extremely significant which may cause further deterioration of a patient’s health conditions [4]. These include intracranial hemorrhage [5], spontaneous pulmonary hemorrhage [6], angioedema [7], slow reperfusion rate, and frequent early re-occlusions which have decreased the use of thrombolytic drugs in many cases [8]. Cancer is another fatal disease that can cause abnormal cell growth, uncontrolled cell proliferation, differentiation, and ultimate death of the cells. The modern conventional treatment suggests chemotherapy, radiotherapy, or surgery fight against it which exhibited several adverse effects [9]. Natural cytotoxic agents may damage the cancerous cell and contribute to the treatment of cancer. Pain or algesia is generally an unpleasant sensation associated with tissue damage which is initially protective but responsible for many discomforts leading to adverse effects [10]. Analgesics are drugs used to treat or reduce the pain that act on the peripheral or central nervous system to selectively relieve pain without significantly altering consciousness [11]. The classical analgesic drugs are notably opiates and non-steroidal anti-inflammatory drugs (NSAIDs) [12]. Fever or pyrexia is an elevated body temperature above the normal level characterized by an increase in the thermoregulatory set-point, which results from the interaction of the central nervous and immune system. Fever is the body’s natural defense mechanism against infectious agents that can damage the tissue [13]. NSAIDs also possess antipyretic activity. But NSAIDs exhibited severe adverse effects like ulceration, gastrointestinal bleeding, respiratory distress, drowsiness, nausea and along with these side effects opiates also exhibited constipation, physical dependence, addictive potential etc. [14].

Herbal medicines as the major remedy in the traditional system of medicine have been used in medical practices since antiquity [15]. In ancient literature, about 500 medicinal plants are mentioned and about 800 plants are used in the traditional system of medicine [16]. With the introduction of conventional medicines, scientists started to doubt the safety of traditional medicine because of a lack of proper scientific data. In the nineteenth century, human began to isolate the active principles of medicinal plants and was successful to invent quinine from Cinchona bark [17]. Such discoveries convinced scientists to rely on this alternative form of medicine and proceed to further investigations. Moreover, it has started to become popular with common people because of more effectiveness, fewer health hazard risks, and cheaper rates than conventional medicine. Thus the impact of phytochemistry led to the discovery of many of the effective conventional medicinal agents which were derived from plant sources and introduced anticancer drugs like vincristine, vinblastine, and paclitaxel [18], narcotic analgesics like morphine [19], and anti-malarial drugs like quinine and artemisinin [20]. Therefore, the current study focuses on the phytochemical and pharmacological investigations of an ethnomedicinal plant Macropanax dispermus.

Macropanax dispermus is a tree from the family of Araliaceae, and it is grown in evergreen forested areas. It was traditionally used for the treatment of digestion, postpartum bathing, eliminate waste matter, improve blood flow, cough, menopausal fever, and malarial fever by ethnic people of Thailand, Myanmar [21, 22]. Previous studies reported that its crude methanol extracts showed a good amount of vitamin E, carotene, xanthophylls, tannins, phenolics, and the highest amount of vitamin C by using the β-carotene bleaching method [23].

So, the current research was conducted to investigate the phytochemical contents, thrombolytic, cytotoxic, analgesic, and antipyretic activity of the crude methanol extracts of the leaves and stem barks of M. dispermus and the solvent fractions of the crude methanol extracts of its leaves.

Methods

Chemicals

Methanol, n-hexane, carbon tetrachloride, chloroform, ethyl acetate, and other chemicals used for the extraction, solvent–solvent partitioning of plant materials, in vitro, and in vivo pharmacological tests were laboratory grade (Merck, Germany).

Collection and identification of the plant

The matured plant leaves and stem barks were collected in August 2018 with the help of a famous local traditional healer. Then it was identified by a renowned taxonomist under the herbarium no-sr20385.

Preparation of crude extracts

Plant materials (leaves and stem barks) were washed, chopped into small pieces, and semi-shed sun-dried for seven days. After drying, the plant materials were powdered with a mechanical grinder. Powder portions of the leaves (1.36 kg) and stem barks (493 g) of M. dispermus were soaked in 7.29 L and 2.60 L of methanol, respectively. After 13 days of occasional shaking, the solution was filtered and the filtrate was concentrated by evaporation method under reduced pressure at the temperature below 50 °C by using a rotary evaporator (Stuart, UK). The weight of the crude methanol extracts of M. dispermus leaves and stem barks was 28.50 gm. and 7.66 gm., respectively. The percentage (%) yield of the extract was calculated using the following equation [14]:

$$\% {\text{ Yield of extract}} = \frac{{\text{Weight of extrcated material}}}{{\text{Weight of crude powder}}}$$

The percentage of yield of crude methanol extracts of M. dispermus leaves and stem barks was 2.09% and 1.55%, respectively.

Solvent–solvent partitioning

Crude methanol extracts of M. dispermus leaves were undergone solvent–solvent partitioning according to the protocol designed by Kupchan and Tsou and modified version of Wagenen et al. by using the solvents of n-hexane, carbon tetrachloride, chloroform, and ethyl acetate consecutively [24, 25].

Qualitative phytochemical screening

The preliminary phytochemical screening was done for evaluating the qualitative detection of terpenoids, flavonoids, saponins, phenol and tannins, phlobatannins, steroids, anthraquinones, alkaloids, glycosides, cardiac glycosides, resins, carbohydrates, proteins, fat and oil, and coumarin by using standard procedure [26,27,28]. The color intensity or the precipitate formation was used as analytical responses to these qualitative tests.

Experimental animals

Male Swiss Albino mice weighing approximately 20–30 g were used for experimental purposes. They were placed in standard propylene cages and familiarized under the controlled conditions (room temperature of 25 ± 2 °C, relative humidity of 60%-70% for 14 days) and operated with a 12 h light/dark cycle with food pellets. The mice were provided with a nutritionally adequate diet and drinking water ad libitum throughout the study. Diethyl ether anesthesia was employed on mice to euthanize. All the mice were sacrificed at the end of each experiment by using diethyl ether anesthesia. All segments of this report adhere to the ARRIVE Guidelines for reporting animal research. All experiments have been examined and approved by the ethical committee under approval no-cc98056.

Acute toxicity study

An acute toxicity study was conducted following the previously described method [29]. Each group comprises five Swiss albino mice and they fasted overnight before extract administration. Each group of animals was administered oral doses of 1000, 2000, 3000, and 4000 mg/kg of body weight of each of the extracts. After the administration of plant extract, they were restrained from food for further 3–4 h. Each animal was observed for the first 30 min, then for the first 24 h, and thereafter for 3 days. The mice were observed for any changes in the skin, fur, eyes, mucous membrane, respiration rate, circulatory rate, the central and autonomic nervous system at least once a day. The effective dose would be one-tenth of the median lethal dose (LD50).

Experimental design for in vivo testing

During the evaluation of analgesic activity, 16 groups of mice were used for each investigation and five mice were selected for each group. Group (I) was treated as control (1% tween-80 10 ml/kg), Group (II) was for standard (Diclofenac sodium 50 mg/kg used in acetic acid writhing study, and morphine sulfate 10 mg/kg served as the standard in both tail immersion and formalin-induced paw licking method) and others group were used for the administration of crude methanol extract of M. dispermus stem bark and leaves and its different extracted fractions at the dose of 200 and 400 mg/kg. For brewer’s yeast-induced antipyretic study, sixteen groups of mice were selected, numbered, five mice were assigned to each group. Group (I) was treated as control (1% tween-80 10 ml/kg), Group (II) was for standard Paracetamol (150 mg/kg) and other groups were used for the administration of crude methanol extract of M. dispermus stem bark and leaves and its different extracted fractions at the dose of 200 and 400 mg/kg. After each experimental period, all the treated mice were sacrificed using diethyl ether anesthesia.

In vitro studies of Macropanax dispermus extracts

Evaluation of thrombolytic activity

Blood specimen

Venous blood samples were drawn from 30 male and female healthy volunteers (age 18–26 years) who have no recent history of oral contraceptive and anticoagulant therapy. Ten blood samples were used for each concentration of each plant extracts. After that, 6 ml of venous blood were drawn from each volunteer. Blood was collected and preserved by an expert senior medical technologist. A consent form was filed up for each volunteer for future reference.

Study design

Experiments for clot lysis were carried out as reported earlier [30]. About 500 μl of blood was taken into each pre-weighed Eppendorf tube and allowed to incubate at 37 °C for 45 min. After clot formation, fluid was completely released from each Eppendorf tubes and the clot weight was determined by subtracting the weight of the clot containing tube from the weight of the tube alone following the equation below:

$${\text{Weight of Clot}} = {\text{ Weight of Clot Filled Eppendorf}} - {\text{Weight of Empty Eppendorf}}$$

As standard, 100 μl of Streptokinase (SK) and, as a negative non-thrombolytic control, 100 μl of distilled water (DW) along with 100 μl of each sample of different concentrations (10 mg/ml, 8 mg/ml, 6 mg/ml, 3 mg/ml, 1.5 mg/ml) were separately added to the Eppendorf tubes. Then the Eppendorf tubes were incubated at 37 °C for 90 min. After incubation, the released fluid was discarded and tubes were again weighed to observe the difference in weight after clot disruption. Finally, the percentage (%) of clot lysis was determined as follows:

$${\text{\% Clot Lysis}} = \, \frac{{{\text{Weight of Clot Before Lysis}} - {\text{Weight of Clot Lysis }}}}{{\text{Weight of Clot Before Lysis}}} \times 100$$

Evaluation of cytotoxic activity

Preparation of seawater

Exactly 38 gm sea salt (without iodine) was dissolved in 1 L of distilled water and filtered off to get a clear solution. The pH of the seawater was maintained between 8.0–8.5 by applying 1 N NaOH solution [31].

Hatching of brine shrimp

Artemia salina leach (brine shrimp eggs) was collected from pet shops in Chittagong, used as the test organism. Seawater was taken in the small tank and shrimp eggs were added to the seawater in the tank. After 2 days (48 h) of hatching, the eggs would be matured as nauplii. The oxygen was supplied constantly through the oxygen pump during hatching time. The hatched shrimps were attracted to the light (phototaxis) and so nauplii free from eggshell was collected from the illuminated part of the tank. The nauplii were taken from the fish tank by a pipette.

Study design

Five milliliters of each of the plant extract solutions of different concentrations (1000, 500, 250, 125, 62.5 µg/ml) was added to 5 ml of seawater containing 10 nauplii. After 24 h, the Petri dishes were inspected using a magnifying glass against a black background and the number of survived nauplii in each was counted. The mortality endpoint of this bioassay was determined as the absence of controlled forward motion during 30 s of observation. From these data, the percentage (%) of the mortality of the brine shrimp nauplii was calculated for each concentration from the following equation [32]:

$${\text{\% Mortality}} = \frac{{N{\text{d}}}}{N} \times 100$$

Here Nd = Number of dead nauplii, N = Number of nauplii taken.

Determination of median lethal concentration (LC50)

The LC50 value represented the concentration of the extract that produced death in half of the brine shrimp nauplii after a certain exposure time and was determined by the linear regression method from plotting % of mortality against the correspondent concentration of the extracts. An approximate linear correlation was observed when concentration versus the percentage of mortality was plotted on the graph paper and the concentration–response data were transformed into a straight line utilizing a trend line fit linear regression analysis (Microsoft Excel 2007). The LC50 values were derived from the best-fit line obtained.

In vivo studies of Macropanax dispermus extracts

Evaluation of analgesic activity

Acetic acid-induced writhing method

This method was an analgesic behavioral observation assessment method that demonstrated a noxious stimulation in mice. This study was carried out using the method of Koster as modified by Dambisya and Lee [33, 34]. Fifteen minutes after administration of standard and 30 min after administration of the extract, 0.7% glacial acetic acid (10 ml/kg) was injected intraperitoneally (IP) to all the mice to induce pain characterized by abdominal constrictions or writhes. 5 min later, each mouse of all groups was observed to count the number of writhes for 20 min carefully and recorded. After each observation period, all the treated mice were euthanized using diethyl ether anesthesia. The percentage inhibition against abdominal writhing was used to assess the degree of analgesia and was calculated using the formula:

$${\text{\% of Pain Inhibition}} = \frac{{N_{\text{c}} - N_{\text{t}}}}{{N_{\text{c}}}}$$

Here Nc = number of writhings in the control group, and Nt = number of writhings in the treatment group.

Tail immersion method

This was a thermal method that was performed to evaluate the central analgesic property of the investigated extracts. The method described by Di Stasi et al. [35] was used for this experiment. Before 30 min of treatment about 2–3 cm of the tail of each of the mice was dipped into a water bath containing warm water maintained at a temperature of 50 ± 1 °C and the time taken for the mice to withdraw its tail from the warm water was recorded. The animals, which showed a flicking response within 3–5 s, were selected for the study. A cut-off period of 15 s was determined to avoid damage to the tail. After baseline, the treated mice were tested at 30, 60, 90, and 120 min after drug administration [36]. While measurements were being made, animals were briefly immobilized by wrapping them gently. After each observation period, all the treated mice were euthanized using diethyl ether anesthesia. The percentage of the Maximal Possible Effect (% MPE) was calculated using the following equation [37]:

$${\text{\% of MPE}} = \, \frac{{{\text{Post-drug Latency}} - {\text{Pre-drug Latency}}}}{{{\text{Cut off time}} - {\text{Pre-drug Latency}}}} \times 100$$

The percentage of time elongation was calculated from the following equation [38]:

$${\text{\% of Elongation of Latency}} = \, \frac{{{\text{Latency of Treatment}} - {\text{ Latency of Control}}}}{{\text{Latency of Treatment}}} \times 100$$
Formalin-induced paw licking method

This was a persistent-pain model that was used to assess both central and peripheral analgesic effects of the investigated extracts. This analgesic assay was done using a previously described method [39]. After sixty minutes of administration of control, standard, and investigated extracts, 20 µl of 1% formalin solution was injected through the subplantar route into the right hind paw of each mouse. The time (in seconds) spent licking or biting the injected paw indicated pain and was recorded. After subplantar injection of formalin, the responses of the mice were noticed for the first 5 min (early or neurogenic phase) and 15–30 min (late or inflammatory phase). After each observation period, all the treated mice were euthanized using diethyl ether anesthesia. The percentage (%) of pain inhibition was calculated using the following formula:

$${\text{\% Inhibition of Pain}} = \, \frac{{{\text{Reaction Time (Control)}} - {\text{Reaction Time (Treatment)}}}}{{\text{Reaction Time (Control)}}} \times 100$$

Evaluation of antipyretic activity

The antipyretic effect was assessed by using the brewer’s yeast-induced pyrexia method described by Adams et al. [40]. Before experimentation, the rectal temperature of mice was recorded by a digital thermometer. Hyperthermia was induced in mice by subcutaneous injection of 15% aqueous suspension of brewer’s yeast (10 ml/kg) in the back below the nape of the mice and the injected site was massaged to spread. Pre-drug temperatures were taken 24 h after the yeast injection to determine the pyretic response of yeast. Animals with 1 °F or more elevation in body temperature were used. The temperatures were recorded at 1, 2, 3, and 4 h intervals after the drug treatment. After each observation period, all the treated mice were euthanized using diethyl ether anesthesia. The percentage (%) reduction of rectal temperature could be calculated by the following formula [41]:

$${\text{\% Reduction of rectal temperature}} = \frac{B - C}{{B - A}} \times 100$$

Here A = Normal body temperature, B = Rectal temperature at 24 h after yeast administration, and C = Rectal temperature after drug administration at a different time interval.

Statistical analysis

All the data were expressed as mean ± SEM (Standard error of Mean). The results were analyzed statistically by one-way ANOVA followed by post hoc Dunnett's test using statistical software “Statistical Package for Social Science” (SPSS, Version 16.0, IBM Corporation, NY). Results below *p < 0.05, **p < 0.01, and ***p < 0.001 were considered statistically significant compared to control.

Results

Qualitative phytochemical screening

The current study was carried out to screen the presence or absence of preliminary phytochemicals in the investigated extracts which showed the presence of different types of phytochemicals in the extracts which are demonstrated in Table 1.

Table 1 Preliminary screening of phytochemicals of the investigated extracts of M. dispermus leaves and stem barks
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Acute toxicity study

No mice showed any abnormal changes such as reduced motor activity, restlessness, convulsions, coma, diarrhea, and lacrimation at the experimental doses of each of the investigational extracts. No mice were dead at the experimental doses. So, the LD50 was investigated to be greater than 4000 mg/kg.

In vitro studies of Macropanax dispermus extracts

Evaluation of thrombolytic activity

The thrombolytic activity of the investigated extracts was determined as a part of the exploration of cardio-protective drugs from plant reserves. The results conferred in Table 2 showed that among multiple extracts, MDMS, MDML, MDHL, and MDCL produced significant (p < 0.001) clot lysis (%) in a concentration-dependent manner. Among them, MDMS and its MDHL fraction showed 42.21% and 37.05% clot lysis at the dose of 10 mg/ml respectively, compared to others.

Table 2 Thrombolytic activity of the investigated extracts of M. dispermus leaves and stem barks
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Evaluation of cytotoxic activity

The level of toxicity against brine shrimp was classified as toxic having an LC50 value less than 1000 µg/ml and non-cytotoxic having an LC50 value greater than 1000 µg/ml [42]. The brief results displayed in Table 3 indicate that the MDCL, MDEL, MDAL, and MDMS produced high cytotoxicity with the lowest LC50 values whereas MDML and its MDHL, MDTL fractions were observed to be non-cytotoxic. Among these extracts, MDCL fraction and crude MDMS showed cytotoxicity with the lowest LC50 values of 23.15 and 37.11 µg/ml, respectively, compared to others. However, positive control vincristine sulfate was observed to be a highly cytotoxic substance.

Table 3 Cytotoxic activity of the multiple extracts of M. dispermus leaves and stem barks
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In vivo studies of Macropanax dispermus extracts

Evaluation of analgesic activity

Acetic acid-induced writhing method

In this method, the investigated extracts at the doses of 200 and 400 mg/kg body weight showed a decrease in the number of writhing in rodents as compared to control. Among them, MDML and its MDCL, MDEL, MDTL fractions, and MDMS produced a significant (p < 0.001) decrease in the number of writhing (i.e., % inhibition of writhing) which demonstrated their higher effectiveness as peripheral analgesic agents as revealed in Table 4. Furthermore, MDML and its MDEL fraction comparatively showed the highest percentage of inhibition of writhing observed with both doses, 200 and 400 mg/kg relative to others.

Table 4 Analgesic effect of the investigated extracts of M. dispermus leaves and stem barks on acetic acid-induced writhing test
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Tail immersion method

The extracts at doses of 200 and 400 mg/kg body weight showed a different level of increase in pain reaction time (PRT), percentage of maximal possible effect (%MPE), and percentage elongation of latency as compared to control in a dose-dependent manner. The 200 and 400 mg/kg doses of MDML, MDEL, MDAL, and MDMS showed significant (p < 0.001) analgesic activity. The same extracts exhibited a significant increase in PRT, higher %MPE, and percentage elongation of latency until 120 min. The %MPE of these extracts remained elevated throughout the observation period. In contrast, the standard morphine sulfate (10 mg/kg) increased the level significantly. MDML, MDEL, and MDMS demonstrated higher analgesic effects in both the acetic acid-induced writhing method and tail immersion method which indicated these extracts might show analgesic effect both peripherally and centrally. Among those, crude MDML and MDMS exhibited the highest effect in both methods. The results of PRT and %MPE are shown in Table 5, and the percentages of elongation of latency are presented in Table 6.

Table 5 Analgesic effect of the investigated extracts of M. dispermus leaves and stem barks on tail immersion test
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Table 6 Analgesic activity of the investigated extracts of M. dispermus leaves and stem barks on tail immersion test
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Formalin-induced paw licking method

In this method, the experimental extracts (200 and 400 mg/kg body weight) showed a greater percentage (%) of pain inhibition in the late phase than that of the early phase of investigation as compared to control in mice significantly (p < 0.001). They exhibited their potential to give the analgesic effect peripherally more than centrally. Crude extracts MDML and MDMS showed significant peripheral and central analgesic effects which are observed with both doses (200 and 400 mg/kg). However, MDTL, MDCL, MDEL fractions of MDML extract produced significant (p < 0.001) analgesia peripherally. These results were tabulated in Table 7.

Table 7 Analgesic effect of the investigated extracts of M. dispermus leaves and stem barks on formalin-induced paw licking test
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Evaluation of antipyretic activity

In brewer’s yeast-induced pyrexia method, MDML and its related MDHL and MDEL fractions significantly reduced the rectal temperature (p < 0.001) after the 1 h of extract administration at the doses of 200 and 400 mg/kg body weight. All other investigated extracts (200 and 400 mg/kg) reduced the rectal temperature of Swiss albino mice as compared to control significantly (p < 0.001) on total (4 h) experimental period as displayed in Table 8. The MDTL, MDEL, MDHL fractions of MDML showed an increased reduction of rectal temperature. The percent decrease in rectal temperature produced by these extracts conferred in Table 9.

Table 8 Antipyretic effect of the investigated extracts of M. dispermus leaves and stem barks on brewer’s yeast-induced pyrexia test
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Table 9 Percent decrease in rectal temperature of all test samples of M. dispermus leaves and stem barks on brewer’s yeast-induced pyrexia test
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Discussion

The preliminary phytochemical analysis showed that crude methanol extract of leaves, its solvent fractions, and crude methanol extracts of stem barks of M. dispermus contain a mixture of phytochemical compounds that had potential biological and therapeutic activities [43, 44]. Therefore this species was expected to have many medicinal uses. The present research on this plant showed that the crude MDML and MDMS along with some fractions possess considerable thrombolytic, cytotoxic, analgesic, and antipyretic properties.

Several types of research have been conducted to find antithrombotic agents from different types of medicinal plants. From the current study, it was evident that the clot dissolution did not occur after the addition of distilled water to the clot. In contrast, standard streptokinase lysed almost all the clots. During the investigation, it was observed that MDHL and MDMS were observed to have a significant thrombolytic effect. Among those, MDHL showed a significant thrombolytic effect with no potential cytotoxic effect. The clot lysis effect of these investigated extracts increased with the increase in their concentration. Since the thrombolytic effect of those extracts was comparable to that of Streptokinase, they possibly acted through the formation of a complex with plasminogen which could convert additional plasminogen to plasmin. Plasmin lysed clots by breaking down the fibrinogen and fibrin contained in a clot [45]. Although the role of alkaloids, saponins, tannins, terpenoids, and flavonoids as thrombolytic agents is still unknown, their presence in those extracts might contribute to thrombolysis through platelet aggregation [46, 47].

In the cytotoxicity evaluation study of plant extracts by brine shrimp lethality assay, LC50 values lower than 1000 μg/ml were considered cytotoxic [42]. From the current observation, it was found that vincristine sulfate, a known anticancer agent had the lowest LC50 value of 0.14 µg/ml which proved its highly potent cytotoxic activity. In this study, MDML extract and its MDHL and MDTL fractions were evident as a highly non-cytotoxic agent. But MDCL, MDEL, MDAL fractions of crude MDML, and MDMS were evident to possess cytotoxic activity. Hence they could be further investigated for their potential as anticancer agents. Preliminary phytochemical screening revealed the presence of flavonoids, glycosides, saponin, alkaloids, and steroids in the investigated extracts which might contribute to their cytotoxic activities [48, 49]. Flavonoids exert their cytotoxic activity by increasing the production of cellular ROS levels [50]. Saponins initiate apoptosis of cancer cells [51]. Previous studies suggested that alkaloids can inhibit the proliferation of many cancer cells [52].

The acetic acid-induced writhing method was used to evaluate the peripheral analgesic activity of the investigated extracts which used the reaction of animals to painful chemical stimuli [53, 54]. In this method, dilute acetic acid produced a writhing reflex in animals by activating the chemosensitive nociceptors [55]. It produced a localized inflammatory response due to the release of free Arachidonic acid from tissue phospholipid via COX and produced prostaglandins in the peritoneal fluid. It causes swelling and the release of endogenous substances that stimulate pain nerve endings [56]. The crude MDML, and its MDTL, MDCL, and MDEL fractions at the dose of 200 and 400 mg/kg showed a significant and higher percentage (%) of inhibition of abdominal writhing in mice as compared to control whereas the standard Diclofenac sodium, an NSAID at 50 mg/kg showed the highest activity. The significant (P < 0.001) dose-dependent analgesic effect of the investigated extracts was hypothesized to be mediated through peripheral pain mechanism and suppression of prostaglandin pathway as they had a comparable analgesic effect like NSAID [57].

The central analgesic activity evaluation model of tail immersion used thermal stimuli in this regard [54, 58]. In this model, sensory nerves sensitized the nociceptors, increased the pain thresholds [59], and the involvement of prostaglandins was decreased [60]. In the current study, the increase in %MPE, PRT, or latency period indicated the level of analgesia of drug or extract. MDML, MDEL, MDAL, and MDMS at 200 and 400 mg/kg showed a significant increase in PRT, higher percentage (%) of MPE, and elongation until 120 min as compared to control in a dose-dependent manner whereas the reference standard morphine sulfate (10 mg/kg) also increased those indices significantly. Since their effect was comparable to narcotic drug morphine sulfate, those extracts possibly showed an opiates-like mechanism of action indicating the spinal and supraspinal pathways of analgesia [59].

The analgesic model of formalin-induced paw licking test usually involved two distinct phases: an early transient phase, which occurred in the first 5 min that reflected direct stimulation of nociceptors, and a late tonic phase, evident 15 to 30 min after injection that might be associated with the release of inflammatory mediators [61, 62]. In this method, MDML and MDMS showed significant inhibition of induced pain during both early and late phases of the study as compared to control. MDTL and MDEL fractions also showed highly significant effectiveness in pain inhibition during the late phase that demonstrated its dominance as a peripheral analgesic. Several reports had shown the analgesic properties of flavonoids, tannins, and other polyphenolic compounds in different experimental animal models [63]. The presence of those phytochemicals in the extracts could be attributed to their effectiveness as analgesic agents.

In the brewer’s yeast-induced pyrexia model, the proteins present in yeast were responsible for fever induction through an inflammatory reaction [64]. In this experiment, n-hexane, carbon tetrachloride and ethyl acetate fractions of crude methanol extracts of M. dispermus leaves at the dose of 200 and 400 mg/kg exhibited an increasing percentage (%) of reduction of hyperthermia in a significant (P < 0.001) dose-dependent manner which persists up to 4 h. This effect was comparable to the standard drug paracetamol. Hence, there might be a possible mechanism of antipyretic action by inhibiting the synthesis of prostaglandins like paracetamol [65]. MDTL and MDEL exhibited both peripheral analgesic effect and antipyretic effect possibly showed action through inhibition of the synthesis of prostaglandins. So, they might act as cyclooxygenase inhibitors [66]. Furthermore, several multi-processes or mediators such as bacterial endotoxin (lipopolysaccharide), endogenous pyrogen, and interleukin-1α were emphasizing the pathogenesis of fever. Inhibition of any of these mediators might bring about antipyresis [67]. The antipyretic activity could be triggered by the presence of flavonoids, saponins, glycosides, tannins in the investigated extracts [68].

Conclusions

The current research found that the different extracts of M. dispermus leaves and stem barks revealed the presence of a mixture of phytochemicals and exhibited potent thrombolytic, anticancer, analgesic, and antipyretic effects. It may have concluded an important contribution in the herbal medicine researches and further advanced researches must be conducted on this medicinal plant to discover its more precise physiologic effect.