Species differences in the gut stimulatory effects of radish seeds

Efficacy of Sida pilosa Retz aqueous extract against Schistosoma mansoni - induced granulomatous inflammation in the liver and the intestine of mice: histomorphometry and gastrointestinal motility evaluation

BACKGROUND

The macerate of Sida pilosa aerial parts is used empirically for the treatment of intestinal helminthiasis. Previous studies have shown that Sida pilosa aqueous extract (SpAE) has schistosomicidal, antioxidant, anti-inflammatory and anti-fibrotic activities in Schistosoma mansoni infection. This study was designed to evaluate the effect of SpAE on the granulomatous inflammation induced by S. mansoni in the liver and the intestine of mice by histomorphometry; as well as on the gastrointestinal motility.

METHODS

To study the effect of SpAE on the liver and intestine histomorphometry and on the gastrointestinal motility, SpAE was administered at 200 mg/kg per os to S. mansoni-infected mice for 4 weeks. Praziquantel was used as reference drug. Prior to carrying out sacrifice, a batch of mice was subjected to gastrointestinal transit evaluation with 3% charcoal meal. After sacrifying another batch of mice, we performed histological and morphometric analyses of the liver and the ileum. We measured the following: total proteins, transaminases, malondialdehyde, nitrites, superoxide dismutase, catalase and reduced glutathione. The effect of SpAE (4, 8, 16 and 32 mg/mL) on the ileum contractile activity was evaluated either in the absence or in the presence of pharmacological blockers.

RESULTS

SpAE induced a significant reduction of hepatosplenomegaly and intestine enlargement. The number of granulomas was reduced by 52.82% in the liver and 52.79% in the intestine, whereas the volume of hepatic granulomas decreased by 48.76% after SpAE treatment. SpAE also reduced (p < 0.001) the ileal muscular layer thickness. The levels of total proteins, transaminases, malondialdehyde, nitrites, superoxide dismutase, catalase and reduced glutathione were restored after treatment of infected mice with SpAE. A normalization of the gastrointestinal transit was also recorded after SpAE treatment. The effect of SpAE on intestinal motility was mediated via intracellular and extracellular calcium mobilization.

CONCLUSION

Our findings provide evidence that SpAE improves granulomatous inflammation induced by S. mansoni both in the liver and in the intestine, as well as it re-establishes normal gastrointestinal transit. SpAE may be used for the development of alternative medicine against S. mansoni infection.

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.

Bidirectional effects of methanol extract of Wei-Chang-An pill on gastrointestinal transit and the spasmolytic activity on isolated rat jejunum

ETHNOPHARMACOLOGICAL RELEVANCE

Wei-Chang-An pill (WCA pill), a traditional Chinese medicine, has been used for treating various gastrointestinal diseases for several decades. Despite the popular medicinal use of WCA pill, less data was available to its activity and mechanism in gastrointestinal disorders. To examine the effects of the methanol extract of WCA pill (ME) on gastrointestinal tract so as to assess some of the possible mechanisms involved in the clinical treatment.

MATERIALS AND METHODS

ME was studied on gastrointestinal transit in vivo including gastric emptying and small intestinal motility in normal and neostigmine-induced mice, as well as on the isolated tissue preparations of rat jejunum in vitro.

RESULTS

In vivo, the gastric emptying decreased and intestinal transit increased after administration of ME in normal mice. However, administration of ME accelerated the intestinal transit ranging from 0.01 to 0.8 mg/mL and reduced it at the concentration of 1.6 and 3.2 mg/mL, while the gastric emptying was inhibited throughout the concentrations in neostigmine-induced mice. in vitro, ME caused inhibitory effect on the spontaneous contraction of rat-isolated jejunum in dose-dependent manner ranging from 0.01 to 6 mg/mL and also relaxed the acetylcholine chloride (Ach, 10(-6) M)-induced and K+ (60 mM)-induced contractions. ME shifted the Ca2+ concentration-response curves to right, similar to that caused by verapamil (0.025 mM).

CONCLUSIONS

These results indicated that ME might play a bidirectional role in gastrointestinal transit modulation and the effects on isolated tissue are probably mediated through calcium influx and muscarinic receptors, which provides pharmacological basis for the clinical use of WCA pill in gastrointestinal tract disorders.

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.

A review of the phytochemistry and pharmacological activities of raphani semen

The dried ripe seed of Raphanus sativus L., commonly known as radish seed (or Raphani Semen), is used as traditional Chinese medicine (TCM) to treat constipation, chronic tracheitis, and hypertension. The major active compounds in Raphani Semen are alkaloids, glucosinolates, brassinosteroids, and flavonoids. Fatty acids are its main nutritional contents. Raphani Semen has been demonstrated to have beneficial effects on hypertension, obesity, diabetes mellitus, constipation, and cough. So far, there is no report about the adverse/toxic effects of this herb on humans. However, Raphani Semen processed by roasting was reported to exhibit some adverse effects on mice. Additionally, erucic acid, the main fatty acid in Raphani Semen, was shown to enhance the toxicity of doxorubicin. Thus, Raphani Semen has a potential risk of causing toxicity and drug interaction. In summary, Raphani Semen is a valuable TCM herb with multiple pharmacological effects. More studies on Raphani Semen could help better understand its pharmacological mechanisms so as to provide clear scientific evidence to explain its traditional uses, to identify its therapeutic potential on other diseases, and to understand its possible harmful effects.

Prokinetic and laxative effects of the crude methanolic extract of Viola betonicifolia whole plant in rodents

Background

The present study was aimed to provide ethnopharmacological basis for the medicinal use of Viola betonicifolia whole plant in indigestion and constipation.

Methods

Mice were used in in-vivo prokinetic and laxative studies while in-vitro experiments were conducted on isolated tissues of rabbit and guinea-pig gut preparations suspended in a tissue bath to measure isotonic contractions.

Results

The crude methanolic extract of Viola betonicifolia (VBME) showed partially atropine-sensitive prokinetic (50 and 100 mg/kg) and laxative (30 and 100 mg/kg) activities in mice. When tested in isolated rabbit jejunum and guinea-pig ileum, VBME caused dose-dependent contractions at 0.01-0.3 mg/mL and 0.03-5 mg/mL, respectively. The spasmogenic effect was partially sensitive to atropine, while the presence of pyrilamine, SB203186 or hexamethonium had no effect in both gut preparations. VBME partially inhibited acetylcholinesterase enzyme (19%) in the in-vitro assay. The spasmodic effect of VBME was more efficacious in guinea-pig ileum than rabbit jejunum preparation. The phytochemical analysis of the crude methanolic extract for total alkaloids and saponins revealed that the VBME is a rich source of alkaloids and saponins.

Conclusions

This study showed the prokinetic and laxative effects of Viola betonicifolia in mice, partially mediated through cholinergic action. The in-vitro spasmodic effect of the plant extract was also partially sensitive to atropine indicating more than one mechanisms in the gut stimulant effect. This study provides a rationale for the medicinal use of Viola betonicifolia in indigestion and constipation.

Mechanisms underlying the antidiarrheal, antispasmodic and bronchodilator activities of Fumaria parviflora and involvement of tissue and species specificity

ETHNOPHARMACOLOGICAL RELEVANCE

In the Greco-Arab (Unani) traditional medicine, Fumaria parviflora Linn. is widely used in hypreractive gut and respiratory disorders including diarrhea, abdominal cramps, indigestion and asthma but scientific studies to provide rational for these medicinal uses are sparse. This study was therefore undertaken to provide ethnopharmacological basis for its medicinal use in diarrhea, abdominal cramps and asthma.

MATERIALS AND METHODS

The in vivo studies were conducted in mice and rats while isolated gut and tracheal preparations of rat, guinea-pig and rabbit were suspended in respective tissue baths to measure the isotonic and isometric responses, using Power Lab electronic recorder.

RESULTS

The aqueous-methanol extract of Fumaria parviflora (Fp.Cr) protected against diarrhea caused by castor oil in rats and mice, similar to loperamide and dicyclomine, and bronchospasm caused by carbachol (CCh) in rats, similar to aminophylline. In the in vitro studies, Fp.Cr relaxed CCh and isotonic high K(+) physiological salts solutions-induced contractions in jejunum, ileum and tracheal preparations of rat, guinea-pig and rabbit. Fp.Cr was predominately more potent against CCh than isotonic high K(+) solutions-induced contractions, similar to dicyclomine, suggesting the presence of anticholinergic and calcium channel blocking (CCB) activities, which were confirmed when Fp.Cr shifted the CCh and Ca(2+) concentration-response curves, constructed in rat ileum and trachea, towards right. Among intestinal preparations from various species, both anticholinergic and CCB effects of Fp.Cr were exhibited at lower concentrations in rat than the other species. In tracheal preparations, Fp.Cr was the most potent in its CCB effect in rabbit. Within species, CCB effect of Fp.Cr was produced at lower concentrations in rat jejunum than ileum and trachea, whereas, anticholinergic effect was produced at higher concentration in rat trachea than intestine.

CONCLUSION

This study, showing the presence of antidiarrheal, antispasmodic and bronchodilator activities in Fumaria parviflora possibly mediated through dual blockade of muscarinic receptors and Ca(2+) channels, provides sound basis for its medicinal uses in diarrhea, abdominal cramps and may be used as bronchodilator in asthma. Species and tissue-dependency of these effects underscores the importance of utilizing multiple tissues and species to get more meaningful results.

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

The aim of this study was to see if the crude extract of Lepidium sativum (Ls.Cr) exhibits species specificity in its antidiarrheal and antispasmodic activities along with insight into the underlying mechanisms using the in-vivo and in-vitro experiments. Ls.Cr inhibited castor oil-induced diarrhea in mice at doses (300 and 1000 mg/kg) three times higher dose than for rats. In isolated rat ileum and jejunum, Ls.Cr completely inhibited carbachol (CCh), low K⁺ (25 mM) and high K⁺ (80 mM)-induced contractions, while in guinea-pig tissues, Ls.Cr caused complete inhibition of only CCh-induced contraction. In rabbit tissues, Ls.Cr completely inhibited CCh and low K⁺-induced contractions sensitive to K⁺ channel antagonists. Pretreatment of guinea-pig and rat tissues with Ls.Cr caused a rightward shift in CCh-induced contractions in a pattern similar to dicyclomine, while in rabbit and rat tissues, Ls.Cr shifted isoprenaline curves to the left similar to papaverine. These data indicate that the antidiarrheal and antispasmodic activities of L. sativum are species dependent, mediating its antispasmodic effect through combinations of multiple pathways including activation of K⁺ channels, and inhibition of muscarinic receptors, Ca⁺⁺ channels and PDE enzyme. Rat tissues showed the highest potency. Based on the results, we recommend using multiple species to know the real pharmacological profile of medicinal products.

Identification of antiplatelet and acetylcholinesterase inhibitory constituents in betel nut

OBJECTIVE

To investigate the possible mechanism and the compound(s) responsible for the antiplatelet and acetylcholinesterase (AChE) inhibitory effects of Areca catechu crude extract (Ac.Cr).

METHODS

Aqueous-methanol (70%) was used for extraction of plant material (betel nut). Antiplatelet activity was measured in human platelet-rich plasma by using a Lumi-aggregometer while anti-AChE activity was measured spectrophotometrically in vitro. In an attempt to find the responsible compound(s) in betel nut for antiplatelet and anti-AChE activities, different commercially available betel nut compounds were tested.

RESULTS

Ac.Cr inhibited platelet aggregation induced by arachidonic acid (AA), adenosine diphosphate (ADP), platelet-activating factor (PAF), epinephrine and Ca(2+)-ionophore. Ac.Cr was the most potent in inhibiting ADP- and Ca(2+)-ionophore-induced aggregation. In the AChE assay, Ac.Cr showed significant AChE inhibitory activity with almost complete inhibition of the enzyme. Out of the tested compounds, none of the compounds in betel nut showed any antiplatelet effect except for catechin that was the most potent against epinephrine-induced aggregation. Catechin was significantly less potent than Ac.Cr, indicating a presence of additional compound(s) with antiplatelet activity. For the AChE inhibitory effect, only tannic acid, gallic acid, diosgenin and isoguvacine were found to be active, whereby tannic acid was more potent than Ac.Cr.

CONCLUSION

This study shows the possible antiplatelet and AChE inhibitory potential of betel nut while further studies are needed to confirm and identify more compounds in betel nut for these actions.

Species and tissue-specificity of prokinetic, laxative and spasmodic effects of Fumaria parviflora

Background

Fumaria parviflora Linn. (Fumariaceae), is a small branched annual herb found in many parts of the world including Saudi Arabia and Pakistan. This study was designed to provide pharmacological basis for the medicinal use of Fumaria parviflora in gut motility disorders.

Methods

The in-vivo prokinetic and laxative assays were conducted in mice. Isolated intestinal preparations (ileum and jejunum) from different animal species (mouse, guinea-pig and rabbit) were separately suspended in tissue baths containing Tyrode's solution bubbled with carbogen and maintained at 37°C. The spasmogenic responses were recorded using isotonic transducers coupled with PowerLab data acquisition system.

Results

The aqueous-methanol extract of Fumaria parviflora (Fp.Cr), which tested positive for the presence of alkaloids, saponins, tannins and anthraquinones showed partially atropine-sensitive prokinetic and laxative activities in the in-vivo in mice at 30 and 100 mg/kg. In the in-vitro studies, Fp.Cr (0.01-1 mg/ml) caused a concentration-dependent atropine-sensitive stimulatory effect both in mouse tissues (jejunum and ileum), and rabbit jejunum but had no effect in rabbit ileum. In guinea-pig tissues (ileum and jejunum), the crude extract showed a concentration-dependent stimulatory effect with higher efficacy in ileum and the effect was partially blocked by atropine, indicating the involvement of more than one types of gut-stimulant components (atropine-sensitive and insensitive). This could be a plausible reason for the greater efficacy of Fp.Cr in gut preparations of guinea-pig than in rabbit or mouse.

Conclusions

This study shows the prokinetic, laxative and spasmodic effects of the plant extract partially mediated through cholinergic pathways with species and tissue-selectivity, and provides a sound rationale for the medicinal use of Fumaria parviflora in gut motility disorders such as, indigestion and constipation. This study also suggests using different species to know better picture of pharmacological profile of the test material.

Gastrointestial and respiratory activities of Acacia leucophloea

ETHNOPHARMACOLOGICAL RELEVANCE

The barks of Acacia leucophloea (Fabaceae) are used in Pakistan traditional medicine as an astringent, a bitter, a thermogenic, a styptic, a preventive of infections, an anthelmintic, a vulnery, a demulcent, an expectorant, an antipyretic, an antidote for snake bites and in the treatment of bronchitis, cough, vomiting, wounds, ulcers, diarrhea, dysentery, internal and external hemorrhages, dental caries, stomatitis, and intermittent fevers and skin diseases.

MATERIALS AND METHODS

A study was carried out for the possible elucidation of mechanisms justifying the traditional medicinal uses of A. leucophloea (Fabaceae) in gastrointestinal and respiratory diseases. In vitro experiments were carried out over isolated rabbit jejunum and guinea-pig ileum in order to determine spasmolytic and bronchorelaxant activities, while in vivo studies were conducted in mice for antidiarrheal properties.

RESULTS

A methanol crude extract of barks of the plant caused a concentration-dependent relaxation (0.1-3 mg/ml) of isolated rabbit jejunum preparations in a pattern similar to that of nifedipine and dicyclomine, suggesting a Ca(2+) channel-blocking mechanism in addition to an anticholinergic effect. In guinea-pig ileum the extract caused a parallel shift in the Ach-curves without suppression of maximum contractile response, followed by a non-parallel shift with the suppression of maximum contractile response at higher concentration similar to that caused by dicyclomine. Moreover, in rabbit trachea, it also caused the relaxation of carbachol (1 μM) and high K(+)-induced contractions at a dose ranging between 0.1578 and 0.734 mg/ml and 0.46-0.94 mg/ml, respectively. These findings indicate that the extract possesses spasmolytic and bronchodilator activities, mediated possibly through blockade of Ca(2+) channels, thus justifying its medicinal use in diarrhea and asthma. Acacia leucophloea methanol extract exhibited dose-dependent (100-500 mg/ml) protective effect against castor oil induced diarrhea.

CONCLUSIONS

The data obtained contribute to the validation of the traditional use of Acacia leucophloea bark in treating gastrointestinal and respiratory disorders, providing an hypothesis on the possible mechanisms of action.

Studies on anti-inflammatory and analgesic activities of betel nut in rodents

ETHNOPHARMACOLOGICAL RELEVANCE

Areca catechu, commonly known as betel nut, is very famous for its medicinal use in multiple disorders. It is also popular as a remedy against inflammatory disorders in the Unani (Greco-Arab) system of medicine.

OBJECTIVE OF THE STUDY

This study was aimed at investigating the anti-inflammatory and analgesic activities of the crude extract of Areca catechu and its respective fractions.

MATERIALS AND METHODS

Paw edema, formalin-induced nociception and acetic acid-induced writhing assays were carried out in vivo. Free radical scavenging activity of the plant extract was performed in vitro.

RESULTS

Preliminary experiments using a single dose (100 mg/kg) of Areca catechu and its respective fractions demonstrated an anti-inflammatory effect on carrageenan-induced edema in mice and rats, the aqueous fraction being distinctly more effective. When studied on prostaglandin E₂ (PGE₂), arachidonic acid, histamine, or serotonin (5HT)-induced edema in rats, Areca catechu and its aqueous fraction markedly repressed only the PGE₂ and arachidonic acid-induced inflammation. When studied for analgesic activity, the crude extract and its aqueous fraction produced a dose-dependent (10-100 mg/kg) inhibitory effect on formalin-induced nociception in mice and acetic acid-induced writhing in rats, similar to aspirin. In DPPH assay, Areca catechu and its aqueous fraction exhibited free radical scavenging activity with respective IC(50) values of 5.34 μg/ml (4.93-5.78, CI; 95%, n=5) and 7.28 μg/ml (6.04-7.95, n=4), like that of rutin with IC(50) value of 4.75 μg/ml (3.89-5.42, n=4).

CONCLUSION

These results indicate the anti-inflammatory and analgesic effects of Areca catechu and provide a rationale for its medicinal use in inflammatory disorders.

Pharmacological basis for the medicinal use of psyllium husk (Ispaghula) in constipation and diarrhea

BACKGROUND

The objective of this study was to determine the pharmacological basis of the medicinal use of psyllium husk (Ispaghula) in gastrointestinal motility disorders.

METHODS

In-vivo studies were conducted on mice, and isolated rabbit jejunum and guinea-pig ileum were used in in-vitro experiments.

RESULTS

The crude extract of Ispaghula (Po.Cr) had a laxative effect in mice at 100 and 300 mg/kg, which was partially sensitive to atropine or SB203186 (5-HT(4) antagonist). At higher doses (500 and 1,000 mg/kg), Po.Cr had antisecretory and antidiarrheal activity. In guinea-pig ileum, Po.Cr (1-10 mg/ml) had a stimulatory effect, which was partially sensitive to atropine or SB203186. In rabbit jejunum, Po.Cr had a partially atropine-sensitive stimulatory effect followed by relaxation at 10 mg/ml. The relaxation was inhibited by the presence of L-NAME, a nitric oxide (NO) synthase inhibitor, or methylene blue, a guanylyl cyclase inhibitor. Similarly, the relaxant effect of Po.Cr on K(+) (80 mM)-induced contractions, was attenuated in the presence of L-NAME or methylene blue. Activity-directed fractionation of Po.Cr revealed that the gut stimulatory and inhibitory constituents were widely distributed in the aqueous and organic fractions.

CONCLUSION

This study demonstrates that Ispaghula has a gut-stimulatory effect, mediated partially by muscarinic and 5-HT(4) receptor activation, which may complement the laxative effect of its fiber content, and a gut-inhibitory activity possibly mediated by blockade of Ca(2+) channels and activation of NO-cyclic guanosine monophosphate pathways. This may explain its medicinal use in diarrhea. It is, perhaps, also intended by nature to offset an excessive stimulant effect.

Prokinetic and laxative activities of Lepidium sativum seed extract with species and tissue selective gut stimulatory actions

AIM OF THE STUDY

To provide ethnopharmacological basis for the medicinal use of Lepidium sativum seeds in indigestion and constipation.

MATERIALS AND METHODS

The in vivo studies were conducted in mice, while isolated tissues of mouse, guinea-pig and rabbit were suspended in tissue bath to measure isotonic contractions.

RESULTS

The aqueous-methanolic extract of Lepidium sativum seeds (Ls.Cr) at 30 and 100mg/kg showed atropine-sensitive prokinetic and laxative activities in mice, which were partially sensitive to atropine. In isolated gut preparations of mouse and guinea-pig, Ls.Cr (0.1-1mg/mL) caused a concentration-dependent stimulatory effects both in jejunum and ileum, which was blocked in the presence of atropine. In rabbit jejunum, the stimulant effect of Ls.Cr remained unchanged in the presence of atropine, pyrilamine or SB203186, while in rabbit ileum, the stimulatory effect was partially blocked by atropine. The Ls.Cr was more efficacious in gut preparations of rabbit than in guinea-pig or mouse. The phytochemical analysis of the plant extract detected alkaloids, saponins and anthraquinones as plant constituents.

CONCLUSION

This study showed the prokinetic and laxative effects of Lepidium sativum in mice, which were partially mediated through a cholinergic pathway. The in vitro spasmodic effect of the plant extract mediated through a similar mechanism with species and tissue-selectivity, provides a rationale for the medicinal use of the seeds of Lepidium sativum in indigestion and constipation, and suggests studying the plant extracts on more than one species to get the wider picture.

Effects of casoxin 4 on morphine inhibition of small animal intestinal contractility and gut transit in the mouse

Background and aims:

Chronic opioid analgesia has the debilitating side-effect of constipation in human patients. The major aims of this study were to: 1) characterize the opioid-specific antagonism of morphine-induced inhibition of electrically driven contraction of the small intestine of mice, rats, and guinea pigs; and 2) test if the oral delivery of small milk-derived opioid antagonist peptides could block morphine-induced inhibition of intestinal transit in mice.

Methods:

Mouse, rat, and guinea pig intact ileal sections were electrically stimulated to contract and inhibited with morphine in vitro. Morphine inhibition was then blocked by opioid subtype antagonists in the mouse and guinea pig. Using a polymeric dye, Poly R-478, the opioid antagonists casoxin 4 and lactoferroxin A were tested orally for blocking activity of morphine inhibition of gut transit in vivo by single or double gavage techniques.

Results:

The guinea pig tissue was more sensitive to morphine inhibition compared with the mouse or the rat (IC₅₀ [half maximal inhibitory concentration] values as nmol/L ± SEM were 34 ± 3, 230 ± 13, and 310 ± 14 respectively) (P < 0.01). The inhibitory influence of opioid agonists (IC₅₀) in electrically driven ileal mouse preparations were DADLE ([D-Ala², D-Leu⁵]-enkephalin) ≥ met-enkephalin ≥ dynorphin A ≥ DAMGO ([D-Ala², N-Me-Phe⁴, Glyol⁵]-enkephalin) > morphine > morphiceptin as nmol/L 13.9, 17.3, 19.5, 23.3, 230, and 403 respectively. The mouse demonstrated predominantly κ- and δ-opioid receptor activity with a smaller μ-opioid receptor component. Both mouse and guinea pig tissue were sensitive to casoxin 4 antagonism of morphine inhibition of contraction. In contrast to naloxone, relatively high oral doses of the μ-opioid receptor antagonists, casoxin 4 and lactoferroxin A, applied before and after morphine injection were unable to antagonize morphine inhibition of gut transit.

Conclusions:

Casoxin 4 reverses morphine-induced inhibition of contraction in mice and guinea pigs in vitro but fails to influence morphine inhibition of mouse small intestinal transit by the oral route.

Pharmacological basis for the medicinal use of black pepper and piperine in gastrointestinal disorders

Dried fruits of Piper nigrum (black pepper) are commonly used in gastrointestinal disorders. The aim of this study was to rationalize the medicinal use of pepper and its principal alkaloid, piperine, in constipation and diarrhea using in vitro and in vivo assays. When tested in isolated guinea pig ileum, the crude extract of pepper (Pn.Cr) (1–10 mg/mL) and piperine (3–300 μM) caused a concentration-dependent and atropine-sensitive stimulant effect. In rabbit jejunum, Pn.Cr (0.01–3.0 mg/mL) and piperine (30–1,000 μM) relaxed spontaneous contractions, similar to loperamide and nifedipine. The relaxant effect of Pn.Cr and piperine was partially inhibited in the presence of naloxone (1 μM) similar to that of loperamide, suggesting the naloxone-sensitive effect in addition to the Ca(2+) channel blocking (CCB)-like activity, which was evident by its relaxant effect on K+ (80 mM)-induced contractions. The CCB activity was confirmed when pretreatment of the tissue with Pn.Cr (0.03–0.3 mg/mL) or piperine (10–100 μM) caused a rightward shift in the concentration–response curves of Ca(2+), similar to loperamide and nifedipine. In mice, Pn.Cr and piperine exhibited a partially atropine-sensitive laxative effect at lower doses, whereas at higher doses it caused antisecretory and antidiarrheal activities that were partially inhibited in mice pretreated with naloxone (1.5 mg/kg), similar to loperamide. This study illustrates the presence of spasmodic (cholinergic) and antispasmodic (opioid agonist and Ca(2+) antagonist) effects, thus providing the possible explanation for the medicinal use of pepper and piperine in gastrointestinal motility disorders.

Antispasmodic and vasodilator activities of Morinda citrifolia root extract are mediated through blockade of voltage dependent calcium channels

Background

Morinda citrifolia (Noni) is an edible plant with wide range of medicinal uses. It occurs exclusively in tropical climate zone from India through Southeast Asia and Australia to Eastern Polynesia and Hawaii. The objective of this study was to explore the possible mode(s) of action for its antispasmodic, vasodilator and cardio-suppressant effects to rationalize its medicinal use in gut and cardiovascular disorders.

Methods

Isolated tissue preparations such as, rabbit jejunum, rat and rabbit aorta and guinea pig atria were used to test the antispasmodic and cardiovascular relaxant effects and the possible mode of action(s) of the 70% aqueous-ethanolic extract of Morinda citrifolia roots (Mc.Cr).

Results

The Mc.Cr produced a concentration-dependent relaxation of spontaneous and high K⁺ induced contractions in isolated rabbit jejunum preparations. It also caused right ward shift in the concentration response curves of Ca⁺⁺, similar to that of verapamil. In guinea-pig right atria, Mc.Cr caused inhibition of both atrial force and rate of spontaneous contractions. In rabbit thoracic aortic preparations, Mc.Cr also suppressed contractions induced by phenylephrine (1.0 μM) in normal- Ca⁺⁺ and Ca⁺⁺-free Kerb's solutions and by high K⁺, similar to that of verapamil. In rat thoracic aortic preparations, Mc.Cr also relaxed the phenylephrine (1.0 μM)-induced contractions. The vasodilatory responses were not altered in the presence of L-NAME (0.1 mM) or atropine (1.0 μM) and removal of endothelium.

Conclusions

These results suggest that the spasmolytic and vasodilator effects of Mc.Cr root extract are mediated possibly through blockade of voltage-dependent calcium channels and release of intracellular calcium, which may explain the medicinal use of Morinda citrifolia in diarrhea and hypertension. However, more detailed studies are required to assess the safety and efficacy of this plant.

Antispasmodic and bronchodilator activities of Artemisia vulgaris are mediated through dual blockade of muscarinic receptors and calcium influx

AIM OF THE STUDY

The present study describes antispasmodic, antidiarrheal, bronchodilatory and tracheo-relaxant activities of Artemisia vulgaris to rationalize some of its traditional uses.

MATERIALS AND METHODS

Crude extract of Artemisia vulgaris (Av.Cr) was studied in the isolated tissue preparations of rabbit jejunum and guinea-pig trachea, as well as in the in vivo castor oil-induced diarrhea and bronchodilatory techniques.

RESULTS

Av.Cr which tested positive for alkaloids, coumarins, flavonoids, saponins, sterols, tannins and terpenes caused concentration-dependent (0.03-10mg/mL) relaxation of jejunum spontaneous contractions. Av.Cr inhibited the carbachol (CCh, 1 microM) and K(+) (80 mM)-induced contractions in a pattern, similar to that of dicyclomine. Av.Cr shifted the Ca(2+) concentration-response curves to right, like that caused by verapamil and dicyclomine. Av.Cr produced rightward parallel shift in CCh-curves, followed by non-parallel shift at higher concentration with the suppression of the maximum response, similar to that caused by dicyclomine. It exhibited protective effect against castor oil-induced diarrhea and CCh-mediated bronchoconstriction in rodents. In trachea, Av.Cr relaxed the CCh (1 microM) and K(+) (80 mM)-induced contractions and shifted the CCh-curves to right.

CONCLUSION

These results indicate that Artemisia vulgaris exhibits combination of anticholinergic and Ca(2+) antagonist mechanisms, which provides pharmacological basis for its folkloric use in the hyperactive gut and airways disorders, such as abdominal colic, diarrhea and asthma.

Moringa oleifera: a food plant with multiple medicinal uses

Moringa oleifera Lam (Moringaceae) is a highly valued plant, distributed in many countries of the tropics and subtropics. It has an impressive range of medicinal uses with high nutritional value. Different parts of this plant contain a profile of important minerals, and are a good source of protein, vitamins, beta-carotene, amino acids and various phenolics. The Moringa plant provides a rich and rare combination of zeatin, quercetin, beta-sitosterol, caffeoylquinic acid and kaempferol. In addition to its compelling water purifying powers and high nutritional value, M. oleifera is very important for its medicinal value. Various parts of this plant such as the leaves, roots, seed, bark, fruit, flowers and immature pods act as cardiac and circulatory stimulants, possess antitumor, antipyretic, antiepileptic, antiinflammatory, antiulcer, antispasmodic, diuretic, antihypertensive, cholesterol lowering, antioxidant, antidiabetic, hepatoprotective, antibacterial and antifungal activities, and are being employed for the treatment of different ailments in the indigenous system of medicine, particularly in South Asia. This review focuses on the detailed phytochemical composition, medicinal uses, along with pharmacological properties of different parts of this multipurpose tree.