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 (0.03–10 mg/mL) relaxation of jejunum spontaneous contractions. Av.Cr inhibited the carbachol (CCh, 1 μM) and K⁺ (80 mM)-induced contractions in a pattern, similar to that of dicyclomine. Av.Cr shifted the Ca²⁺ 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 μM) 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 Ca²⁺ antagonist mechanisms, which provides pharmacological basis for its folkloric use in the hyperactive gut and airways disorders, such as abdominal colic, diarrhea and asthma.     

The antidiarrheal and spasmolytic activities of Phyllanthus emblica are mediated through dual blockade of muscarinic receptors and Ca2+ channels

Aim of the study

This study was aimed at providing the possible mechanisms for the medicinal use of Phyllanthus emblica in diarrhea.

Materials and methods

The in vivo studies were conducted in mice, while isolated rabbit jejunum and guinea-pig ileum were used for the in vitro experiments.

Results

The crude extract of Phyllanthus emblica (Pe.Cr), which tested positive for alkaloids, tannins, terpenes, flavonoids, sterols and coumarins, caused inhibition of castor oil-induced diarrhea and intestinal fluid accumulation in mice at 500-700 mg/kg. In isolated rabbit jejunum, Pe.Cr relaxed carbachol (CCh) and K⁺ (80 mM)-induced contractions, in a pattern similar to that of dicyclomine. The preincubation of guinea pig-ileum with Pe.Cr (0.3 mg/mL), caused a rightward parallel shift in the concentration-response curves (CRCs) of acetylcholine without suppression of the maximum response. While at the next higher concentration (1 mg/mL), it produced a non-parallel rightward shift with suppression of the maximum response, similar to that of dicyclomine, suggesting anticholinergic and Ca²⁺ channel blocking (CCB)-like antispasmodic effect. The CCB-like activity was further confirmed when pretreatment of the tissue with Pe.Cr, shifted the CRCs of Ca²⁺ to the right with suppression of the maximum response, similar to nifedipine or dicyclomine. The activity-directed fractions of Pe.Cr showed a combination of Ca²⁺ antagonist and anticholinergic like components in all fractions but with varying potency.

Conclusion

These results indicate that the Phyllanthus emblica fruit extract possesses antidiarrheal and spasmolytic activities, mediated possibly through dual blockade of muscarinic receptors and Ca²⁺ channels, thus explaining its medicinal use in diarrhea.     

Gut modulatory, blood pressure lowering, diuretic and sedative activities of cardamom

ETHNOPHARMACOLOGICAL RELEVANCE: Cardamom (Elettaria cardamomum) is traditionally used in various gastrointestinal, cardiovascular and neuronal disorders. AIM OF THE STUDY: To rationalize cardamom use in constipation, colic, diarrhea, hypertension and as diuretic. MATERIALS AND METHODS: Cardamom crude extract (Ec.Cr) was studied using in vitro and in vivo techniques. RESULTS: Ec.Cr caused atropine-sensitive stimulatory effect in isolated guinea-pig ileum at 3-10mg/ml. In rabbit jejunum preparations, Ec.Cr relaxed spontaneous and K+ (80 mM)-induced contractions as well as shifted Ca++ curves to right, like verapamil. Ec.Cr (3-100mg/kg) induced fall in the arterial blood pressure (BP) of anaesthetized rats, partially blocked in atropinized animals. In endothelium-intact rat aorta, Ec.Cr relaxed phenylephrine (1 microM)-induced contractions, partially antagonized by atropine and also inhibited K+ (80 mM) contractions. In guinea-pig atria, Ec.Cr exhibited a cardio-depressant effect. Ec.Cr (1-10mg/kg) produced diuresis in rats, accompanied by a saluretic effect. It enhanced pentobarbital-induced sleeping time in mice. Bio-assay directed fractionation revealed the separation of spasmogenic and spasmolytic components in the aqueous and organic fractions respectively. CONCLUSION: These results indicate that cardamom exhibits gut excitatory and inhibitory effects mediated through cholinergic and Ca++ antagonist mechanisms respectively and lowers BP via combination of both pathways. The diuretic and sedative effects may offer added value in its use in hypertension and epilepsy.     

Pharmacological Basis for Medicinal Use of Lens culinaris in Gastrointestinal and Respiratory Disorders

Crude extract of Lens culinaris (Lc.Cr), which tested positive for presence of anthraquinones, flavonoids, saponins, sterol, tannins, and terpenes exhibited protective effect against castor oil‐induced diarrhea in mice at 100–1000 mg/kg. In rabbit jejunum preparations, Lc.Cr caused relaxation of spontaneous contractions at 0.03–5.0 mg/mL. Lc.Cr inhibited carbachol (CCh, 1 μM) and K⁺ (80 mM)‐induced contractions in a pattern similar to dicyclomine, but different from verapamil and atropine. Lc.Cr shifted the Ca⁺⁺ concentration‐response curves to the right, like dicyclomine and verapamil. Pretreatment of tissues with Lc.Cr (0.03–0.1 mg/mL) caused leftward shift of isoprenaline‐induced inhibitory CRCs, similar to papaverine. In guinea‐pig ileum, Lc.Cr produced rightward parallel shift of CCh curves, followed by non‐parallel shift at higher concentration with suppression of maximum response, similar to dicyclomine, but different from verapamil and atropine. Lc.Cr (3.0–30 mg/kg) caused suppression of carbachol (CCh, 100 µg/kg)‐induced increase in inspiratory pressure of anesthetized rats. In guinea‐pig trachea, Lc.Cr relaxed CCh and high K⁺‐induced contractions, shifted CCh curves to right and potentiated isoprenaline response. These results suggest that L. culinaris possesses antidiarrheal, antispasmodic, and bronchodilator activities mediated possibly through a combination of Ca⁺⁺ antagonist, anticholinergic, and phosphodiesterase inhibitory effects, and this study provides sound mechanistic background to its medicinal use in disorders of gut and airways hyperactivity, like diarrhea and asthma. Copyright © 2014 John Wiley & Sons, Ltd.     

Coriander fruit exhibits gut modulatory,blood pressure lowering and diuretic activities

Aim of the study

Coriander (Coriandrum sativum) is traditionally used for various gastrointestinal and cardiovascular disorders and this study was designed to rationalize its use in dyspepsia, abdominal colic, diarrhea, hypertension and as diuretic.

Materials and methods

Coriander crude extract (Cs.Cr) was evaluated through in vitro and in vivo techniques.

Results

Cs.Cr caused atropine sensitive stimulatory effect in isolated guinea-pig ileum (0.1–10 mg/ml). In rabbit jejunum preparations, Cs.Cr evoked a similar contractile response but in the presence of atropine, it exhibited relaxation against both spontaneous and high K⁺ (80 mM)-induced contractions as well as shifted the Ca²⁺ concentration–response curves to right, similar to that caused by verapamil. Cs.Cr (1–30 mg/ml) caused fall in arterial blood pressure of anesthetized animals, partially blocked by atropine. Cs.Cr produced vasodilatation against phenylephrine and K⁺ (80 mM)-induced contractions in rabbit aorta and cardio-depressant effect in guinea-pig atria. Cs.Cr produced diuresis in rats at 1–10 mg/kg. Bio-assay-directed fractionation revealed the separation of spasmogenic and spasmolytic components in the aqueous and organic fractions respectively.

Conclusions

These results indicate that coriander fruit exhibits gut stimulatory, inhibitory and hypotensive effects mediating possibly through cholinergic, Ca²⁺ antagonist and the combination of these mechanisms respectively. Diuretic activity adds value to its use in hypertension.     

Pharmacological basis for the use of Borago officinalis in gastrointestinal, respiratory and cardiovascular disorders

AIM OF THE STUDY: In this study, we investigated the crude extract of Borago officinalis leaves (Bo.Cr) for its antispasmodic, bronchodilator, vasodilator and cardio-depressant activities to rationalize some of the traditional uses. MATERIALS AND METHODS: Bo.Cr was studied using different isolated tissue preparations including rabbit jejunum, trachea, aorta, and guinea-pig atria. RESULTS: Bo.Cr which was tested positive for flavonoids, coumarins, sterols and tannins produced a concentration-dependent relaxation of spontaneous and K+ (80mM)-induced contractions in isolated rabbit jejunum preparations, suggestive of Ca++ antagonist effect, which was confirmed when pretreatment of the tissue with Bo.Cr produced a rightward shift in the Ca++ concentration-response curves like that caused by verapamil. In rabbit tracheal preparations, Bo.Cr relaxed the carbachol (1microM) and K+-induced contractions. Verapamil also produced non-specific inhibitory effect. In rabbit aorta preparations, Bo.Cr exhibited vasodilator effect against phenylephrine and K+-induced contractions similar to verapamil. When tested in guinea-pig atria, Bo.Cr caused inhibition of both atrial force and rate of contractions. CONCLUSIONS: These results suggest that the spasmolytic effects of Bo.Cr are mediated possibly through Ca++ antagonist mechanism, which might explain the traditional use of Borago officinalis in hyperactive gastrointestinal, respiratory and cardiovascular disorders.     

Cholinomimetic and calcium channel blocking activities of Carthamus oxycantha

The crude extract of Carthamus oxycantha (Co.Cr) and its fractions were studied in vitro for their possible spasmogenic and spasmolytic activities. Co.Cr (0.03-10 mg/mL) caused an atropine sensitive spasmogenic effect in guinea-pig ileum. In spontaneously contracting rabbit jejunum preparations, Co.Cr caused a dose-dependent (0.03-3.0 mg/mL) spasmogenic effect, followed by relaxation at the next higher doses of 5.0-10.0 mg/mL. In the presence of atropine, the spasmogenic effect was blocked and the relaxant effect was observed at lower doses (0.1-5.0 mg/mL), shifting the inhibitory dose-response curves to the left. Co.Cr also inhibited K(+) (80 mm)-induced contractions in atropinized preparations at similar doses, suggesting calcium channel blockade (CCB) activity. The CCB effect was further confirmed when pretreatment of the tissue with Co.Cr produced a dose-dependent shift in the Ca(++) dose-response curves to the right, similar to that caused by verapamil. Activity-directed fractionation revealed that the spasmolytic effect was concentrated in organic fractions in the following order of potency: hexane > ethylacetate > chloroform, while the aqueous fraction exhibited spasmogenic and weak spasmolytic effects. These results indicate that Carthamus oxycantha contains a combination of spasmogenic (cholinergic) and spasmolytic (calcium antagonist) constituents.     

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.     

Gut and airways relaxant effects of Carum roxburghianum

Ethnopharmacological relevance

Carum roxburghianum is traditionally used in hyperactive gastrointestinal and respiratory disorders. The present study was carried out to investigate the possible gut and airways relaxant potential of Carum roxburghianum to rationalize its folk uses.

Materials and methods

Crude extract of Carum roxburghianum (Cr.Cr) was studied in in vivo and in vitro techniques.

Results

Cr.Cr exhibited protective effect against castor oil-induced diarrhea in mice at 100–1000 mg/kg. In rabbit jejunum preparations, Cr.Cr (0.03–3.0 mg/mL) caused relaxation of spontaneous and K⁺ (80 mM)-induced contractions at similar concentrations, like papaverine. Pretreatment of tissues with Cr.Cr (0.1–1.0 mg/mL) shifted Ca⁺⁺ concentration–response curves (CRCs) to right, like verapamil. Cr.Cr (0.03 and 0.1 mg/mL) caused leftward shift of isoprenaline-induced inhibitory CRCs, similar to papaverine. In isolated guinea-pig ileum, Cr.Cr (0.01 and 0.03 mg/mL) produced rightward parallel shift of acetylcholine-curves, like atropine. Cr.Cr (1.0–30 mg/kg) caused suppression of carbachol (CCh, 100 μg/kg)-induced increase in inspiratory pressure of anaesthetized rats. In guinea-pig trachea, Cr.Cr (0.03–1.0 mg/mL) relaxed CCh and high K⁺-induced contractions, shifted isoprenaline-induced inhibitory CRCs to left at 0.1 and 0.3 mg/mL and CCh-curves parallel to right (0.01 and 0.03 mg/mL). Cr.Cr did not cause any mortality of mice up to 10 g/kg dose.

Conclusion

These results indicate that Carum roxburghianum possess combination of antidiarrheal, antispasmodic and bronchodilatory effects, which provides pharmacological basis to its traditional use in the disorders of gut and airways hyperactivity, like diarrhea, colic and asthma.     

The presence of cholinomimetic and calcium channel antagonist constituents in Piper betle Linn

The crude aqueous extract of Piper betle leaves (Pb.Cr) was studied for the possible presence of cholinomimetic and calcium channel antagonist constituents. Pb.Cr at doses of 1-10 mg/mL caused a moderate spasmogenic effect in isolated guinea-pig ileum and this activity was concentrated in the aqueous fraction, which was found to be about 5 times more potent. Pretreatment of the tissue with atropine (1 microM) but not hexamethonium (100 microM) completely abolished the contractile effect of the aqueous fraction indicating a cholinergic (muscarinic) mechanism. In isolated rabbit jejunum preparations Pb.Cr did not produce a significant increase in the spontaneous contractions, but instead produced a dose-dependent (0.03-3.0 mg/mL) inhibition of spontaneous activity. Activity-directed fractionation revealed that the spasmolytic action was concentrated in the ethyl acetate fraction. When tested against K(+)-induced contractions, both Pb.Cr and its ethyl acetate fraction (Pb.EtAc) caused a dose-dependent inhibition, suggesting calcium channel blockade (CCB). The potent CCB effect of the crude extract and its ethyl acetate fraction was confirmed when pretreatment of the tissue with Pb.Cr or Pb.EtAc shifted the Ca(++) dose-response curves to the right in a dose-dependent manner. These data indicate that the plant contains cholinomimetic and possible calcium channel antagonist constituents, which are concentrated in the aqueous and ethyl acetate fractions respectively. It is suggested that some of the traditional uses of this plant may be explained on the basis of these activities.     

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 Ca²⁺ 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 Ca²⁺ 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.     

Ethnopharmacological studies on antispasmodic and antiplatelet activities of Ficus carica

ETHNOPHARMACOLOGICAL RELEVANCE: The ripe dried fruit of Ficus carica Linn. (Moraceae) commonly known as "Fig" has medicinal value in traditional system of medicine for its use in gastrointestinal and inflammatory disorders. AIM OF THE STUDY: To rationalize the medicinal use of Fig (Ficus carica) in gastrointestinal and inflammatory disorders. MATERIALS AND METHODS: The aqueous-ethanolic extract of Ficus carica (Fc.Cr) was studied for antispasmodic effect on the isolated rabbit jejunum preparations and for antiplatelet effect using ex vivo model of human platelets. RESULTS: Fc.Cr tested positive for alkaloids, flavonoids, coumarins, saponins, sterols and terpenes. When tested in isolated rabbit jejunum, Fc.Cr (0.1-3.0mg/mL) produced relaxation of spontaneous and low K(+) (25mM)-induced contractions with negligible effect on high K(+) (80mM) similar to that caused by cromakalim. Pretreatment of the tissue with glibenclamide caused rightward shift in the curves of low K(+)-induced contractions. Similarly, cromakalim inhibited the contractions induced by low K(+), but not of high K(+), while verapamil equally inhibited the contractions of K(+) at both concentrations. Fc.Cr (0.6 and 0.12mg/mL) inhibited the adenosine 5'-diphosphate and adrenaline-induced human platelet aggregation. CONCLUSION: This study showed the presence of spasmolytic activity in the ripe dried fruit of Ficus carica possibly mediated through the activation of K(+)(ATP) channels along with antiplatelet activity which provides sound pharmacological basis for its medicinal use in the gut motility and inflammatory disorders.     

Studies on antidiarrheal and antispasmodic activities of Lepidium sativum crude extract in rats

This study was aimed to provide the pharmacological basis for the medicinal use of Lepidium sativum in diarrhea using in vivo and in vitro assays. The seed extract of Lepidium sativum (Ls.Cr) at 100 and 300 mg/kg inhibited castor oil‐induced diarrhea in rats. In isolated rat ileum, Ls.Cr (0.01–5 mg/mL) reversed carbachol (CCh, 1 µ m ) and K⁺ (80 m m )‐induced contractions with higher potency against CCh, similar to dicyclomine. Preincubation of rat ileum with a lower concentration of Ls.Cr (0.03 mg/mL) caused a rightward parallel shift in the concentration–response curves (CRCs) of CCh without suppression of the maximum response, while at the next higher concentration (0.1 mg/mL), it produced a non‐parallel rightward shift with suppression of the maximum response, similar to that of dicyclomine. Ls.Cr shifted the CRCs of Ca⁺⁺ to the right with suppression of the maximum response, similar to verapamil. These data suggest that Lepidium sativum seed extract possesses antidiarrheal and spasmolytic activities mediated possibly through dual blockade of muscarinic receptors and Ca⁺⁺ channels, though additional mechanism(s) cannot be ruled out and this study explains its medicinal use in diarrhea and abdominal cramps. Copyright © 2011 John Wiley & Sons, Ltd.     

The Prokinetic,Laxative, and Antidiarrheal Effects of Morus nigra: Possible Muscarinic,Ca2+ Channel Blocking,and Antimuscarinic Mechanisms

Morus nigra Linn. (black mulberry) is used in gastrointestinal ailments. This study demonstrates gut modulatory properties of M. nigra. The prokinetic, laxative, and antidiarrheal activities of M. nigra were assessed in mice, while isolated rabbit jejunum and guinea‐pig ileum were used to explore insight into mechanism(s). At 30 and 70 mg/kg, the crude extract of M. nigra (Mn.Cr) exhibited atropine‐sensitive prokinetic and laxative effects, similar to carbachol (CCh). While at higher doses (100, 300, and 500 mg/kg), Mn.Cr offered protection against castor oil‐induced diarrhea. In rabbit jejunum, Mn.Cr and its chloroform fraction inhibited CCh‐induced contractions more potently compared with high K⁺ (80 mm ). Conversely, petroleum fraction was more potent against high‐K⁺‐induced contractions. At 0.01 mg/mL, Mn.Cr caused a parallel shift in acetylcholine concentration–response curves (CRCs) followed by a non‐parallel shift at 0.03 mg/mL, similar to dicyclomine. At further tested concentrations, Mn.Cr (0.1 and 0.3 mg/mL) and petroleum fraction suppressed Ca²⁺ CRCs, similar to verapamil. In guinea‐pig ileum, Mn.Cr, its aqueous and ethyl acetate fractions exhibited atropine‐sensitive gut stimulant activity along with additional uncharacterized excitatory response in the aqueous fraction only. These results suggest that black mulberry possesses prokinetic, laxative, and antidiarrheal effects, putatively mediated through cholinomimetic, antimuscarinic, and Ca²⁺ antagonist mechanisms, respectively. Copyright © 2016 John Wiley & Sons, Ltd.     

Pharmacological Evaluation of Gut Modulatory and Bronchodilator Activities of Achyranthes aspera Linn.

Achyranthes aspera L. is traditionally used to relieve constipation, diarrhea, and asthma. Its crude extract (Aa.Cr) was evaluated through in vivo and ex vivo experiments to rationalize these medicinal uses of A. aspera and to provide their scientific basis. Aa.Cr, at 3 and 10 mg/kg, increased fecal output, similar to castor oil, whereas at 30, 100, 300, and 700 mg/kg, it protected against castor oil‐induced diarrhea in mice when administered orally. Aa.Cr caused spasmogenic effect on rabbit jejunum and guinea pig ileum preparations, which was partially inhibited by atropine while completely blocked by cyproheptadine preincubation. Aa.Cr also relaxed high K⁺ (80 mM)‐induced contraction in rabbit jejunum. Aa.Cr inhibited CCh (100 μg/kg)‐induced bronchospasm in rats, similar to aminophylline. Like dicyclomine, Aa.Cr relaxed high K⁺ and CCh (1 μM)‐induced contractions in guinea pig trachea and caused rightwards parallel shift of CCh concentration–response curves at the lower concentrations followed by non‐parallel shift at the higher concentrations. On activity‐directed fractionation, spasmogenic and spasmolytic activities of Aa.Cr were concentrated in aqueous and organic fraction, respectively. This study suggests the presence of dose‐specific laxative and antidiarrheal effects in A. aspera, possibly mediated through cyproheptadine‐sensitive receptors and dual cholinergic and calcium channel blockade, respectively. The latter combination is also a suggested mechanism underlying its bronchodilator effect. Copyright © 2017 John Wiley & Sons, Ltd.     

Presence of cholinergic and calcium channel blocking activities explains the traditional use of Hibiscus rosasinensis in constipation and diarrhoea

The aqueous-ethanolic extract of the aerial parts of Hibiscus rosasinensis Linn. (Malvaceae) was studied for the possible presence of spasmogenic and spasmolytic constituents to rationalize its traditional use in gastrointestinal disorders. The crude extract (Hr.Cr) caused a concentration-dependent (1-10mg/mL) spasmogenic effect in isolated guinea-pig ileum, which was blocked in the presence of atropine (0.1 microM). In spontaneously contracting rabbit jejunum, the plant extract exhibited a weak stimulatory effect at lower doses (0.03-0.30 mg/mL) followed by an inhibitory effect at higher doses (1.0-3.0mg/mL). Pretreatment of the tissues with atropine blocked the stimulatory effect resulting in the potentiation of the spasmolytic effect. Hr.Cr (0.03-1.0mg/mL) also showed an inhibitory effect on K(+) (80 mM)-induced contractions. The calcium channel blocking activity was confirmed when Hr.Cr shifted the Ca(2+) concentration-response curves to the right, similar to verapamil. Activity-directed fractionation revealed that the spasmolytic component(s) was separated in the ethyl acetate, while the spasmogenic in the petroleum ether fraction. The aqueous fraction exhibited a combination of weak spasmogenic and spasmolytic effects. These data indicate that the crude extract contains spasmogenic and spasmolytic constituents mediating their effect through cholinergic receptors activation and blockade of Ca(2+) influx, respectively, which may explain its traditional use in constipation and diarrhoea.     

Studies on spasmogenic and spasmolytic activities of Calendula officinalis flowers

The aqueous-ethanol extract of Calendula officinalis flowers (Co.Cr) was studied for its possible spasmolytic and spasmogenic effects in isolated gut preparations. In rabbit jejunum, Co.Cr caused a dose-dependent (0.03-3.0 mg/mL) relaxation of spontaneous and K+-induced contractions, suggestive of calcium channel blockade (CCB). In a few preparations, a mild non-reproducible spasmogenic effect was observed at lower doses, followed by relaxation. The CCB effect was confirmed when pretreatment of the jejunum preparations with Co.Cr produced a dose-dependent rightward shift in the Ca(++) dose-response curves, similar to that of verapamil. Activity-directed fractionation revealed that the spasmolytic activity of the plant was concentrated in its organic fractions. The aqueous fraction exhibited a marked atropine sensitive spasmogenic effect but was found to be devoid of any spasmolytic effect. These data indicate that the crude extract of Calendula officinalis flowers contains both spasmolytic and spasmogenic constituents, exhibiting these effects through calcium channel blocking and cholinergic activities and this study provides a scientific base for its traditional use in abdominal cramps and constipation.     

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. Copyright © 2012 John Wiley & Sons, Ltd.     

Antispasmodic and anti-diarrhoeal effect of Satureja hortensis L. essential oil

Satureja hortensis L. (Lamiaceae) is an annual herb that is used in the traditional medicine of Iran for treating stomach and intestinal disorders. The antispasmodic activity of S. hortensis essential oil (SHEO) was assessed on contractions of isolated ileum, induced by KCl and acetylcholine, and compared with the effect of atropine and dicyclomine. SHEO inhibited the response to 80 mM KCl in a concentration-dependent manner (pD(2)=1.55+/-0.09 microg/ml; this is negative log concentration of SHEO causing 50% of maximum inhibition) and attenuating the maximum inducible response of acetylcholine concentration-response curve. Effect of SHEO on KCl was similar to that of dicyclomine. Dicyclomine (3.46 and 34.6 ng/ml) also reduced the response to acetylcholine on rat isolated ileum without altering the maximum response and shifted the acetylcholine concentration-response curve to the right by 16-fold at 34.6 ng/ml (100 nM) bath concentration, while atropine only inhibited the response to acetylcholine. This study shows that SHEO is a relaxant of rat isolated ileum. In addition to antispasmodic activity in vitro, essential oil of this plant at a dose of 0.1 ml/100 g inhibited castor oil induced diarrhoea in mice. As the inhibition of contractile overactivity of the ileum is the base of the treatment of some gastrointestinal disorders such as colic, SHEO may have clinical benefits for treatment of these conditions.     

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 100 mg/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 (0.1-1 mg/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.