Species differences in the antidiarrheal and antispasmodic activities of Lepidium sativum and insight into underlying mechanisms

Bronchodilator Secondary Metabolites from Rhazya stricta Decne Aerial Parts

The plant kingdom comprises medicinally useful plants that have provided many new drugs used to treat various diseases. In our search for bronchodilator secondary metabolites from plants growing in Saudi Arabia, the total extract of Rhazya stricta showed activity against carbamylcholine- (CCh) induced bronchoconstriction in guinea pig tracheal muscles used as an ex vivo model. The fractions obtained from liquid–liquid extraction process were tested for bronchodilator effects. The most active ethyl acetate fraction (RS-E) and aqueous fraction (RS-H) were subjected to biologically guided phytochemical study using different stationary phases and chromatographic techniques to isolate the pure secondary metabolites. Five known compounds were isolated from the active fractions. Three alkaloids namely; (-)-quebrachamine (1), (+)-eburenine (2), (+)-stemmadenine (3) as well as the two iridoid glycosides loganic acid (4) and loganine (5) were identified by various spectroscopic methods. Among the isolated compounds 1 and 5 were the only active as bronchodilators in the plant. It is worth to mention that iridoid glycosides are isolated for the first time from R. stricta.

Evidence for Health-Promoting Properties of Lepidium sativum L.: An Updated Comprehensive Review

Lepidium sativum L. is a common herb distributed worldwide, used as a food ingredient and therapeutic agent in traditional medicine for treating health-related disorders. L. sativum and its extracts have been described to possess numerous biological activities including antimicrobial, antidiabetic, antioxidant, antidiarrheal, anticancer, and numerous health-promoting effects in in vivo and in vitro studies. The purpose of this review is to summarize the findings describing important biological functions and therapeutic effects of L. sativum in various cell lines and animal models. In this review, the English-language articles were gathered from electronic databases including Web of Science, PubMed and Google Scholar with no time limit applied to any database. The search terms used in this review include, "Lepidium sativum L." and/or "chemical composition", "health benefits", "antimicrobial", "antioxidant", "anticancer", "diuretic", "nephro-protection", "antidiarrheal", "antidiabetic", "anti-asthmatic", "neuroprotection", "metabolic", "bone fracture", and "reproductive performance". Additional and eligible studies were collected from reference lists of appropriate articles. The information presented will be helpful to attract more interest toward medicinal plants by defining and developing novel clinical applications and new drug formulations in the future. Pre-clinical studies showed that L. sativum possesses potent health-promoting effects involving various molecular mechanisms. Taken all together, data suggested that identified herbal plants such as L. sativum, can be exploited as nutritional and therapeutic agents to combat various ailments. Despite much research in this field, further comprehensive in vitro/in vivo studies and clinical trials are needed to identify the mechanisms underlying the biological and therapeutic activities of L. sativum.

Dual Inhibition of Phosphodiesterase and Ca++ Channels Explains the Medicinal Use of Balanites aegyptiaca (L.) in Hyperactive Gut Disorders

The present study attempted to evaluate and rationalize the medicinal use of the methanolic extract of the fruits of Balanites aegyptiaca (B. aegyptiaca) in the treatment of hyperactive gut disorders. The in vivo, castor oil-induced diarrhea model in mice was followed to test its antidiarrheal effect. To test the antispasmodic effect and to explore its pharmacodynamic details, isolated small intestines (ileum) obtained from rats were selected to provide physiological conditions for the ex vivo assays. In the in vivo assays, the orally administered extract of B. aegyptiaca protected mice from diarrheal drops with resultant percent inhibitions of 40% and 80% at the respective doses of 200 mg/kg and 400 mg/kg, while the highest protection (100%) was observed with a positive control drug, loperamide, at 10 mg/kg. In the ileum, B. aegyptiaca produced an antispasmodic effect in a concentration-dependent manner by inhibiting the carbachol (CCh; 1 µM) and high K⁺ (80 mM)-evoked spasms with resultant EC₅₀ values of 1.44 mg/mL (1.08–1.78) and 1.27 mg/mL (0.98–1.66), respectively. Papaverine, a known phosphodiesterase enzyme (PDE) inhibitor and blocker of Ca⁺⁺ channels (CCB), also inhibited both CCh and high K⁺ induced contractions at comparable EC₅₀ values of 8.72 µM (7.92–9.24) and 8.14 µM (7.62–8.84), respectively. Contrary to the extract and papaverine, verapamil showed distinctly higher potency in regard to inhibiting high K⁺, compared to CCh-evoked spasms that had EC₅₀ values of 0.16 µM (0.13–0.261) and 2.54 µM (2.28–2.92), respectively. The inhibitory effects of B. aegyptiaca on PDE were further confirmed when the pre-incubated extract shifted the isoprenaline-mediated relaxation curves (CRCs) towards the left, similar to papaverine, whereas the CCB-like effect was confirmed when the pre-incubated tissues with B. aegyptiaca caused deflection in the Ca⁺⁺ CRCs towards the right, constructed in Ca⁺⁺ free medium with suppression of the maximum response. Thus, this study provides detailed, mechanistic support for the medicinal use of B. aegyptiaca in the treatment of hyperactive gut disorders.

GC-MS Analysis and In Vivo and Ex Vivo Antidiarrheal and Antispasmodic Effects of the Methanolic Extract of Acacia nilotica

This present study evaluated and rationalized the medicinal use of the fruit part of Acacia nilotica methanolic extract. The phytochemicals were detected using gas chromatography−mass spectrometry (GC−MS) while the in vivo antidiarrheal test was done using Swiss albino mice. To determine the details of the mechanism(s) involved in the antispasmodic effect, isolated rat ileum was chosen using different ex vivo assays by maintaining a physiological environment. GC−MS results showed that A. nilotica contained pyrogallol as the major polyphenol present (64.04%) in addition to polysaccharides, polyphenol, amino acid, steroids, fatty acid esters, and triterpenoids. In the antidiarrheal experiment, A. nilotica inhibited diarrheal episodes in mice significantly (p < 0.05) by 40% protection of mice at 200 mg/kg, while 80% protection was observed at 400 mg/kg by the orally administered extract. The highest antidiarrheal effect was observed with loperamide (p < 0.01), used as a control drug. In the ex vivo experiments, A. nilotica inhibited completely in increasing concentrations (0.3 to 10 mg/mL) the carbachol (CCh; 1 µM) and high K+ (80 mM)-evoked spasms in ileum tissues at equal potencies (p > 0.05), similar to papaverine, a dual inhibitor of the phosphodiesterase enzyme (PDE) and Ca++ channels. The dual inhibitory-like effects of A. nilotica on PDE and Ca++ were further validated when A. nilotica extract (1 and 3 mg/mL)-pre-incubated ileum tissues potentiated and shifted isoprenaline relaxation curves towards lower doses (leftward), similar to papaverine, thus confirming the PDE inhibitory-like mechanism whereas its CCB-like effect of the extract was confirmed at 3 and 5 mg/mL by non-specific inhibition of CaCl2-mediated concentration response curves towards the right with suppression of the maximum peaks, similar to verapamil, used as standard CCB. Thus, this study characterized the chemical composition and provides mechanistic support for medicinal use of A. nilotica in diarrheal and hyperactive gut motility disorders.

In Silico, Ex Vivo and In Vivo Studies of Roflumilast as a Potential Antidiarrheal and Antispasmodic agent: Inhibition of the PDE-4 Enzyme and Voltage-gated Ca++ ion Channels

The aim of the present study was to evaluate the possible gut inhibitory role of the phosphodiesterase (PDE) inhibitor roflumilast. Increasing doses of roflumilast were tested against castor oil-induced diarrhea in mice, whereas the pharmacodynamics of the same effect was determined in isolated rabbit jejunum tissues. For in silico analysis, the identified PDE protein was docked with roflumilast and papaverine using the Autodock vina program from the PyRx virtual screening tool. Roflumilast protected against diarrhea significantly at 0.5 and 1.5 mg/kg doses, with 40% and 80% protection. Ex vivo findings from jejunum tissues show that roflumilast possesses an antispasmodic effect by inhibiting spontaneous contractions in a concentration-dependent manner. Roflumilast reversed carbachol (CCh, 1 µM)-mediated and potassium (K+, 80 mM)-mediated contractile responses with comparable efficacies but different potencies. The observed potency against K+ was significantly higher in comparison to CCh, similar to verapamil. Experiments were extended to further confirm the inhibitory effect on Ca++ channels. Interestingly, roflumilast deflected Ca++ concentration–response curves (CRCs) to the right with suppression of the maximum peak at both tested doses (0.001-0.003 mg/mL), similar to verapamil. The PDE-inhibitory effect was authenticated when pre-incubation of jejunum tissues with roflumilast (0.03-0.1 mg/mL) produced a leftward deflection of isoprenaline-mediated inhibitory CRCs and increased the tissue level of cAMP, similar to papaverine. This idea was further strengthened by molecular docking studies, where roflumilast exhibited a better binding affinity (-9.4 kcal/mol) with the PDE protein than the standard papaverine (-8.3 kcal/mol). In conclusion, inhibition of Ca++ channels and the PDE-4 enzyme explains the pharmacodynamics of the gut inhibitory effect of roflumilast.

Therapeutic potential of the methanolic extract of Lepidium sativum seeds on mice infected with Trypanosoma evansi

The present study aimed to investigate the therapeutic potential of the methanolic extract of Lepidium sativum seeds in mice experimentally infected with Trypanosoma evansi. A total of thirty-two male Swiss albino mice were randomly divided into four groups: the first group was the normal control, while the second, third and fourth groups were infected intraperitoneally with 1 × 10⁴ trypanosomes. The third and fourth groups were treated with 100 μl of Lepidium sativum seed extract (LSSE) at a dose of 200 mg/kg body weight intraperitoneally (infected + LSSEI) and orally (infected + LSSEO) respectively, once a day, for a period of four days.

Parasitaemia was found to be significantly raised in the untreated infected group, reaching 2 × 10⁷ at day 4 post-infection, but was significantly reduced by 65.5% and 88% in the mice treated orally and intraperitoneally with LSSE, respectively. The erythrocyte count, HCT, haemoglobin content, leucocyte count and the percentage of lymphocytes was significantly reduced in the untreated infected group, while the treatment with LSSE returned these parameters to their pre-infection values. In addition, our study proved that LSSE provided protection against liver tissue damage and decreased the levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT). The present study also established that intraperitoneal injection of LSSE is more effective than oral administration in the treatment of trypanosome infection in mice. In conclusion, the infection caused haematological, biochemical and histological changes that were ameliorated following treatment with LSSE.

Medicinal Plants Used for Treatment of Diarrhoeal Related Diseases in Ethiopia

This paper presents a review of relevant antidiarrhoeal medicinal plants based on the fundamental knowledge accumulated by indigenous people of Ethiopia. The review includes an inventory carried out on the phytochemical and pharmacological analysis of plant species used in the treatments of diarrhoeal diseases. This study is based on a review of the literature published in scientific journals, books, theses, proceedings, and reports. A total of 132 medicinal plants used by local people of Ethiopia are reported in the reviewed literature. Herbs (43.6%) were the primary source of medicinal plants, followed by trees (27%). Some findings include the predominance of leaf material used (78%), as well as the frequent use of crushing of the plant parts (38%) as a mode of preparation. This study demonstrates the importance of traditional medicines in the treatment of basic human ailments such as diarrhoeal diseases in Ethiopia. Baseline information gaps were observed in different regions of Ethiopia. Thus, documentation of the knowledge held by other regions of Ethiopia that have so far received less attention and urban ethnobotany is recommended for future ethnobotanical studies. In addition, phytochemical studies are recommended mainly on frequently utilized medicinal plants for treatment of diarrhoeal diseases which can serve as a basis for future investigation of modern drug development. Although societies in Ethiopia have long used medicinal plants for diarrhoeal diseases treatment, it is also a good practice to perform toxicological tests.

Antidiarrheal activity of 80 % methanol extract of the aerial part of Ajuga remota Benth (Lamiaceae) in mice

Background

In the Ethiopian traditional medicine, the aerial part of Ajuga remota Benth is used in the treatment of diarrhea. There are different mechanisms by which Ajuga remota may have antidiarrheal effect. Some of the possible mechanisms are through its anthelmintic and antibacterial activity. The present study aimed to evaluate whether the antidiarrheal effect of the plant also include antimotility and antisecretory effect using 80 % methanol extract of A. remota (MEAR).

Methods

The MEAR was administered at doses of 200, 400, 600 and 800 mg/kg to four groups of mice (six animals per group) orally in castor oil diarrhea model. The effect of the extract on enteropooling and gastrointestinal transit model was also evaluated using the same grouping and dosing. Two other groups, one as control and the other as standard (loperamide 5 mg/kg) were used for comparison with the treatment groups.

Results

The extract at the doses of 400, 600, and 800 mg/kg produced a dose-dependent and significant inhibition both on the frequency and onset of diarrhea. The percentage purging frequency was 53.4, 66.7, 79.6, and 66.7 % (p < 0.001) at three doses of MEAR (400, 600, and 800 mg/kg) and with loperamide (5 mg/kg), respectively. The percentage inhibition in intestinal fluid accumulation was 42.5, 62.1, and 74.2 % (p < 0.001) at the doses of 400, 600 and 800 mg/kg of MEAR, respectively. The MEAR also inhibited the intestinal transit of charcoal meal in a dose dependent manner both in the normal and castor oil induced intestinal transit.

Conclusion

This study has shown that the 80 % methanol extract of A. remota contains pharmacologically active substances with significant antimotility and antisecretory effect contributing for its antidiarrheal activity.

Dual effectiveness of Flaxseed in constipation and diarrhea: Possible mechanism

ETHNOPHARMACOLOGICAL RELEVANCE

This study was planned to assess pharmacological basis for the medicinal use of Flaxseed in constipation and diarrhea.

MATERIALS AND METHODS

The oil and mucilage of Flaxseeds were studied for their laxative, and antidiarrheal activities in mice. The mechanisms of laxative and antidiarrheal activities were further studied using the isolated tissue preparations (rabbit jejunum and guinea-pig ileum) immersed in Tyrode׳s solution maintained at 37°C and aerated with carbogen gas. Isotonic responses were measured on spontaneously contracting isolated jejunum and guinea-pig ileum preparations.

RESULTS

Oral administration of Flaxseed oil (30 and 70mg/kg, orally) and mucilage (1 and 2.5g/kg, orally) caused dose-dependent increase in wet feces in mice. The spasmogenic effect of Flaxseed oil was partially blocked by pyrilamine (p<0.05) and atropine (p<0.01) in isolated rabbit jejunum whereas atropine completely blocked the effect of Flaxseed mucilage on isolated guinea-pig ileum. When studied for its antidiarrheal effect, Flaxseed oil reduced the castor oil-induced diarrheal score by 49.35% and 84.41% and intestinal secretions by 19% and 33.62% at the oral doses of 100 and 300mg/kg respectively. In isolated rabbit jejunum preparations, Flaxseed oil produced a dose-dependent inhibition of both spontaneous and low K(+) (25mM) -induced contractions in rabbit jejunum. The inhibitory effect against low K(+) was most sensitive to tetra-ethylammonium chloride, a non-specific K(+) channel blocker, followed by glibenclamide, a partial ATP-dependent K(+) channels blocker and 4-Aminopyridine, a voltage gated K(+)-channel blocker.

CONCLUSIONS

Our results indicate that Flaxseed oil and mucilage exhibit laxative activity, mediated primarily through cholinergic pathway with weak histaminergic effect component evident in Flaxseed oil, which also showed antidiarrheal activity, mediated possibly through K(+) channels activation. Thus this study rationalizes the medicinal use of Flaxseed in both the constipation and diarrhea with sound mechanistic basis.

Effects of fenugreek, garden cress, and black seed on theophylline pharmacokinetics in beagle dogs

CONTEXT

Herb-drug interactions are a serious problem especially for drugs with a narrow therapeutic index, taking into consideration that herbal medicines are commonly used in various parts of the world.

OBJECTIVE

The present study investigates the effect of fenugreek, garden cress, and black seed on the pharmacokinetics of theophylline in beagle dogs.

MATERIALS AND METHODS

Beagle dogs received theophylline (200 mg) orally and blood samples were withdrawn at different time intervals (0.33, 0.66, 1.0, 1.5, 2, 3, 4, 6, 8, 12, 24, and 30 h). After a suitable washout period, each herb was given orally at doses of 25, 7.5, and 2.5 g, twice daily for 7 d. On the eighth day, theophylline was re-administrated orally and blood samples were collected. Plasma concentrations of theophylline were determined using HPLC and pharmacokinetic parameters were calculated using a non-compartmental analysis.

RESULTS

Treatment with fenugreek (25 g, orally) lead to a decrease in Cmax and AUC0-t of theophylline of about 28% (p < 0.05) and 22% (p < 0.05), respectively, with no significant changes in T1/2λ compared with the baseline values. Garden cress caused a decrease in Cmax to a lesser extent and delayed Tmax of theophylline (2.10 ± 0.24 h versus 3.40 ± 0.74 h), while AUC0-∞ increased by 37.44%. No significant effect was observed for the black seed treatment on theophylline disposition as measured by Cmax, Tmax, AUC0-∞, and CL/F.

DISCUSSION AND CONCLUSION

The concurrent use of fenugreek or garden cress alters theophylline pharmacokinetic behavior in an animal model. This could represent a modulation in cytochrome P450 activity, which is responsible for theophylline metabolism in beagle dogs. Further confirmation of these results in humans will warrant changes in theophylline dosing before the co-administration of such herbs.

Antispasmodic and antidiarrhoeal activity of the fruit of Rosa moschata (J)

Background

The fruit of Rosa moschata has traditionally been used for the treatment of abdominal spasm and diarrhoea. Therefore, the aim of this study was to investigate mechanism(s) responsible for its medicinal use in gut spasm and diarrhea.

Methods

Hydro-methanolic extract of Rosa moschata (Rm.Cr) was studied in isolated rabbit’s jejunal preparations for possible antispasmodic activity. Based upon in vitro relaxant activity in isolated gut preparations, in vivo antidiarrheal activity was carried out in mice to confirm its antidiarrheal effect. Acute toxicity study was performed to determine safe dose range before in vivo experiments.

Results

In isolated rabbits’ jejunal preparations, Rm.Cr inhibited the spontaneous and high K⁺-induced contractions with respective EC₅₀ values of 0.66 (0.44-0.97; n = 5) and 2.28 mg/mL (1.43-3.62; n = 5), like that of verapamil. This suggests the presence of calcium channel blocking (CCB) activity as a possible mode of action. The Ca⁺⁺ channel blocking activity was further confirmed when pre-treatment of isolated jejunums with Rm.Cr (1-5 mg/mL) caused a rightward shift in the Ca⁺⁺ concentration-response curves (CRCs), similar to verapamil. Rm.Cr was safe up to 2000 mg/kg for in vivo acute toxicity. Rm.Cr provided 55% and 80% protection from diarrhoea in respective doses of 100 mg/kg and 1000 mg/kg. These data indicates that the crude extract of Rosa moschata possesses Ca⁺⁺ antagonist-like constituent(s), which explains its inhibitory effect on gut motility; a mechanism that underlies its antidiarrheal and antispasmodic activities.

Conclusion

The study shows that the crude extract of fruits of Rosa moschata possesses antispasmodic effects mediated possibly through voltage gated Ca++ channel blockade, which provides sound pharmacological base to its medicinal use in gut spasms and diarrhoea, though additional mechanism(s) cannot be ruled out.

Pharmacological basis for the medicinal use of Carissa carandas in constipation and diarrhea

ETHNOPHARMACOLOGICAL RELEVANCE

Carissa carandas Linn. commonly known as "Karaunda" (Apocynaceae) is a popular medicinal herb widely distributed in different parts of Pakistan. In addition to other medicinal uses, Carissa carandas is popular in indigenous system of medicine for its medicinal use in gut motility disorders like, constipation and diarrhea.

OBJECTIVE

This study was planned to provide pharmacological basis to the medicinal use of Carissa carandas in constipation and diarrhea.

MATERIALS AND METHODS

The crude extract of the leaves of Carissa carandas (Cc.Cr) was prepared in methanol and its fractionation was carried out with ethylacetate, petroleum ether and n-butanol. In-vivo studies were conducted on mice, while isolated rabbit jejunum and guinea-pig ileum preparations were used for the in-vitro experiments. The spasmogenic and spasmolytic responses of gut tissues were recorded using isotonic transducers coupled with PowerLab data acquisition system.

RESULTS

The HPLC fingerprints of Cc.Cr, its petroleum (Cc.Pef), ethylacetate (Cc.Eaf) and n-butanol (Cc.Baf) fractions showed the presence of oleanolic acid, ursolic acid, stigmasterol and β-sitosterol. Oral administration of Cc.Cr to mice increased fecal output at lower doses (30 and 50 mg/kg), while it showed protection against castor oil-induced diarrhea at higher doses (300 and 600 mg/kg). In isolated guinea-pig ileum and rabbit jejunum, Cc.Cr and Cc.Baf exhibited stimulatory effect at 0.003-3 mg/ml, which was partially sensitive to atropine or pyrillamine or partially/fully sensitive to atropine+pyrillamine, followed by relaxation at higher tested concentrations, being more potent in rabbit tissues. The ethylacetate fraction (0.1-5 mg/ml) exhibited fully atropine-sensitive contractions in both guinea-pig and rabbit tissues, being more potent in guinea-pig while more efficacious in rabbit tissues. However, the petroleum fraction (0.003-1.0 mg/ml) showed only spasmolytic activity in spontaneously contracting rabbit tissues, similar to nifedipine. In guinea-tissue, Cc.Pef did not cause any stimulant effect. When studied against high K(+) (80 mM)-induced contraction, the crude extract and its fractions caused a dose-dependent inhibition, with the following order of potency: Cc.Pef>Cc.Eaf>Cc.Cr≥Cc.Baf, similar to nifedipine indicating Ca(++) channel antagonist like activity, which was further confirmed when the plant extract displaced Ca(++) curves to the right with suppression of maximum effect similar to that of nifedipine.

CONCLUSION

This study demonstrates that the crude extract of Carissa carandas possesses a gut-stimulatory effect mediated primarily through the activation of muscarinic and histaminergic receptors while its spasmolytic effect was mediated possibly through Ca(++) antagonist pathway. Thus, this study provides a clear evidence for the dual effectiveness of Carissa carandas in constipation and diarrhea, thus validating its medicinal use.

Effects of Nigella sativa and Lepidium sativum on cyclosporine pharmacokinetics

The present study was conducted to investigate the effects of Nigella sativa and Lepidium sativum on the pharmacokinetics of cyclosporine in rabbits. Two groups of animals were treated separately with Nigella sativa (200 mg/kg p.o.) or Lepidium sativum (150 mg/kg p.o.) for eight consecutive days. On the 8th day, cyclosporine (30 mg/kg p.o.) was administered to each group one hour after herbal treatment. Blood samples were withdrawn at different time intervals (0.0, 0.5, 1.0, 1.5, 2.0, 3.0, 4.0, 6.0, 8.0, 12, and 24 hrs) from marginal ear vein. Cyclosporine was analyzed using UPLC/MS method. The coadministration of Nigella sativa significantly decreased the C_max and AUC_0−∞ of cyclosporine; the change was observed by 35.5% and 55.9%, respectively (P ≤ 0.05). Lepidium sativum did not produce any significant change in C_max of cyclosporine, although its absorption was significantly delayed compared with control group. A remarkable change was observed in T_max and AUC_0−t of Lepidium sativum treated group. Our findings suggest that concurrent consumption of Nigella sativa and Lepidium sativum could alter the pharmacokinetics of cyclosporine at various levels.