Gastrointestinal stimulatory and uterotonic activities of dietary radish leaves extract are mediated through multiple pathways

Raphanus sativus, commonly known as radish, is a food plant known worldwide for its culinary and medicinal properties especially as a laxative and abortifacient. This study reports the gastrointestinal and uterine tone modulatory activities of the crude extract (Rl.Cr) of radish leaves. Rl.Cr, showing the presence of saponins and alkaloids, exhibited a spasmogenic effect (0.03-10 mg/mL) in isolated rabbit jejunum, rat stomach fundus and uterus which was partially blocked by atropine. In contrast, Rl.Cr was found to be devoid of any stimulatory effect in rat ileum, instead showed an inhibitory effect (0.1 mg/mL) on the ACh dose-response curves. A mild relaxant effect was also observed in rabbit jejunum at the lower doses (0.1-0.3 mg/mL) but not against K(+)-induced contractions, ruling out a calcium channel blocking effect. In guinea-pig ileum, Rl.Cr exhibited a stimulant effect resistant to atropine while sensitive to pyrilamine pretreatment. The aqueous fraction, showing a strong presence of saponins, was found to be more efficacious than the non-polar fractions in its spasmogenic effect. This study shows the presence of species-dependent gastrointestinal effects of radish mediated partially through cholinergic receptors in rabbit and rat tissues, but through histaminergic activation in the guinea-pig, providing a scientific basis for its use in gut and uterine affections while also giving a wider picture of the activity profile of radish by using different species of animals.     

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.     

Calcium Channel Blocking Activity in Desmostachya bipinnata (L.) Explains its use in Gut and Airways Disorders

Desmostachya bipinnata, despite of its popular medicinal uses, has not been widely studied for its effect in diarrhea, indigestion, and asthma. The aim of the present investigation was to provide scientific rationale for these applications. The crude aqueous‐methanolic extract of D. bipinnata (Db.Cr) was evaluated through in vivo and in vitro experiments. Db.Cr (100–500 mg/kg) protected mice against castor oil–induced diarrhea, similar to loperamide. When tested on gut preparations, Db.Cr produced an atropine‐sensitive spasmogenic effect in rabbit jejunum up to 5 mg/mL, followed by a partial relaxation at 10 mg/mL. With atropine preincubation, a verapamil‐like inhibitory effect was evident against spontaneous and high K⁺ (80 mM)–induced contractions. The maximum stimulant effect was comparable with the acetylcholine‐induced maximum contraction and was similarly reproducible in guinea pig ileum. Db.Cr inhibited carbachol (1 μM)‐induced contraction in rabbit trachea but caused an atropine‐sensitive accentuation of high K⁺–induced contraction at 0.003–0.3 mg/mL followed by inhibition at 1–5 mg/mL. On activity‐directed fractionation, inhibitory effect was concentrated on organic and stimulant effect in aqueous fraction. This study, suggesting the presence of calcium antagonist activity, possibly underlying its medicinal effect in hyperactive gut and respiratory disorders, and cholinergic activity, possibly underlying its digestive effect, provides rationale for these therapeutic uses of D. bipinnata. Copyright © 2012 John Wiley & Sons, Ltd.     

Pharmacological basis for the use of Fumaria indica in constipation and diarrhea

The crude extract of Fumaria indica whole plant (Fi.Cr) and its fractions were studied in vitro for spasmogenic and spasmolytic effects to rationalize some of the traditional uses. Fi.Cr (1.0-5.0 mg/mL) caused a moderate degree of atropine-sensitive spasmogenic effect in guinea-pig ileum. In spontaneously contracting rabbit jejunum, Fi.Cr (0.03-0.3 mg/mL) caused a mild spasmogenicity followed by relaxation at the higher doses. In the atropinized preparations, Fi.Cr inhibited spontaneous and K(+)-induced contractions at the similar doses (0.1-1.0 mg/mL), which suggests calcium channel blockade (CCB). CCB effect was confirmed when pretreatment of the tissue with the Fi.Cr produced a dose-dependent shift in the Ca(2+) dose-response curves to the right, similar to that produced by verapamil. Activity-directed fractionation revealed that the spasmolytic effect is concentrated in the petroleum ether fraction, while dichloromethane fraction contains both spasmogenic and spasmolytic constituents. These data indicate that the presence of cholinergic and CCB constituents in Fi.Cr may explain the respective traditional use of Fumaria indica in constipation and diarrhoea.     

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.     

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.     

Antispasmodic,bronchodilator and blood pressure lowering properties of Hypericum oblongifolium – possible mechanism of action

The crude extract of Hypericum oblongifolium (Ho.Cr), which tested positive for flavonoids, saponins and tannins caused concentration‐dependent (0.1–1.0 mg/mL) relaxation of spontaneous and high K⁺ (80 mM)‐induced contractions in isolated rabbit jejunum preparations, suggesting a Ca⁺⁺ antagonistic effect, which was confirmed when pretreatment of the tissue with Ho.Cr produced a rightward shift in the Ca⁺⁺ concentration‐response curves, like that caused by verapamil. Ho.Cr relaxed carbachol (1 μM) and high K⁺‐induced contractions in guinea pig tracheal preparations. It caused a dose‐dependent (3–100 mg/kg) fall in arterial blood pressure of rats under anesthesia. In isolated guinea pig atria, Ho.Cr caused inhibition of both atrial force and rate of spontaneous contractions. When tested in rabbit aortic rings, Ho.Cr exhibited a vasodilator effect against phenylephrine (1 μM) and high K⁺‐induced contractions. These results indicate that Ho.Cr possesses gastrointestinal, respiratory and cardiovascular inhibitory effects, mediated via a Ca⁺⁺ antagonist mechanism. Copyright © 2009 John Wiley & Sons, Ltd.     

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.     

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.     

Mechanisms underlying the antispasmodic and bronchodilatory properties of Terminalia bellerica fruit

AIM OF THE STUDY: The present investigation was carried out to provide the pharmacological basis for the medicinal use of Terminalia bellerica in hyperactive gastrointestinal and respiratory disorders. MATERIALS AND METHODS: Crude extract of Terminalia bellerica fruit (Tb.Cr) was studied in in vitro and in vivo. RESULTS: Tb.Cr caused relaxation of spontaneous contractions in isolated rabbit jejunum at 0.1-3.0mg/mL. Tb.Cr inhibited the carbachol (CCh, 1microM) and K(+) (80mM)-induced contractions in a pattern similar to that of dicyclomine, but different from nifedipine and atropine. Tb.Cr shifted the Ca(++) concentration-response curves to right, like nifedipine and dicyclomine. In guinea-pig ileum, Tb.Cr produced rightward parallel shift of acetylcholine-curves, followed by non-parallel shift at higher concentration with the suppression of maximum response, similar to dicyclomine, but different from nifedipine and atropine. Tb.Cr exhibited protective effect against castor oil-induced diarrhea and carbachol-mediated bronchoconstriction in rodents. In guinea-pig trachea, Tb.Cr relaxed the CCh-induced contractions, shifted CCh-curves to right and inhibited the contractions of K(+). Anticholinergic effect was distributed both in organic and aqueous fractions, while CCB was present in the aqueous fraction. CONCLUSIONS: These results indicate that Terminalia bellerica fruit possess a combination of anticholinergic and Ca(++) antagonist effects, which explain its folkloric use in the colic, diarrhea and asthma.     

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.     

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.     

Presence of cholinergic and calcium antagonist constituents in Saussurea lappa explains its use in constipation and spasm

This study was carried out to provide a scientific basis for the traditional use of Saussurea lappa, in constipation and spasms. Isolated tissue preparations were used to see if the aqueous-methanol crude extract of the S. lappa root (Sl.Cr) contains gut stimulatory and inhibitory constituents. In isolated guinea-pig ileum, a quiescent preparation, Sl.Cr caused a concentration-dependent (0.3-5.0 mg/mL) spasmogenic effect, with the maximum effect reaching 91% of the acetylcholine maximum. A further increase in concentration caused a declining effect, indicating the presence of spasmolytic constituent(s). The spasmolytic effect was more marked in the spontaneously contracting rabbit jejunum and in the atropinized preparations. The spasmolytic effect was mediated through calcium channel blocking (CCB) activity, as evident by its inhibitory effect against high K(+) (80 mm)-induced contraction and displacement of the Ca(++) concentration-response curves to the right. These data indicate that the crude extract of Sl.Cr contains gut stimulatory constituent(s) of cholinergic-type providing a scientific basis for its use in constipation. The presence of spasmolytic constituents of CCB-type more evident in the spontaneous contracting gut preparation may explain its use in spasms.     

Pharmacological basis for the medicinal use of Zanthoxylum armatum in gut,airways and cardiovascular disorders

This study describes the gut, airways and cardiovascular modulatory activities of Zanthoxylum armatum DC. (Rutaceae) to rationalize some of its medicinal uses. The crude extract of Zanthoxylum armatum (Za.Cr) caused concentration‐dependent relaxation of spontaneous and high K⁺ (80 mM)‐induced contractions in isolated rabbit jejunum, being more effective against K⁺ and suggestive of Ca⁺⁺ antagonist effect, which was confirmed when pretreatment of the tissues with Za.Cr shifted Ca⁺⁺ concentration‐response curves to the right, like that caused by verapamil. Za.Cr inhibited the castor‐oil‐induced diarrhea in mice at 300–1000 mg/kg. In rabbit tracheal preparations, Za.Cr relaxed the carbachol (1 μM) and high K⁺‐induced contractions, in a pattern similar to that of verapamil. In isolated rabbit aortic rings, Za.Cr exhibited vasodilator effect against phenylephrine (1 μM) and K⁺‐induced contractions. When tested in guinea pig atria, Za.Cr caused inhibition of both atrial force and rate of spontaneous contractions, like that caused by verapamil. These results indicate that Zanthoxylum armatum exhibits spasmolytic effects, mediated possibly through Ca⁺⁺ antagonist mechanism, which provides pharmacological base for its medicinal use in the gastrointestinal, respiratory and cardiovascular disorders. Copyright © 2009 John Wiley & Sons, Ltd.     

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.     

Studies on hepatoprotective, antispasmodic and calcium antagonist activities of the aqueous-methanol extract of Achillea millefolium

The crude extract of Achillea millefolium (Am.Cr) was studied for its possible hepatoprotective effect against d-galactosamine (d-GalN) and lipopolysaccharide (LPS) induced hepatitis in mice and antispasmodic effect in isolated gut preparations to rationalize some of the folklore uses. Co-administration of d-GalN (700 mg/kg) and LPS (25 microg/kg) produced 100% mortality in mice. Pre-treatment of animals with Am.Cr (300 mg/kg) reduced the mortality to 40%. Co-administration of d-GalN (700 mg/kg) and LPS (1 microg/kg) significantly raised the plasma alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels compared with values in the control group (p < 0.05). Pre-treatment of mice with Am.Cr (150-600 mg/kg) significantly prevented the toxins induced rise in plasma ALT and AST (p < 0.05). The hepatoprotective effect of Am.Cr was further verified by histopathology of the liver, which showed improved architecture, absence of parenchymal congestion, decreased cellular swelling and apoptotic cells, compared with the toxin group of animals. In isolated rabbit jejunum preparations, Am.Cr caused a concentration-dependent (0.3-10 mg/mL) relaxation of both spontaneous and K(+)-induced contractions as well as shifting the Ca(++) concentration-response curves (CRCs) to the right, similar to that caused by verapamil. These results indicate that the crude extract of Achillea millefolium exhibits a hepatoprotective effect, which may be partly attributed to its observed calcium channel blocking activity.     

Antispasmodic effect of Acorus calamus Linn. is mediated through calcium channel blockade

Acorus calamus Linn. (Araceae) is a native of Central Asia and Eastern Europe and has widespread use in the traditional system of medicine for gastrointestinal disorders such as colic pain and diarrhoea. This study was aimed at providing a possible pharmacological basis to the use of this plant as an antispasmodic and antidiarrhoeal. In the isolated rabbit jejunum preparation the crude extract (Ac.Cr), which tested positive for the presence of alkaloid, saponins and tannins, caused inhibition of spontaneous and high K(+) (80 mm)-induced contractions, with respective EC(50) values of 0.42 +/- 0.06 and 0.13 +/- 0.04 mg/mL (mean +/- SEM; n = 6-8), thus showing spasmolytic activity, mediated possibly through calcium channel blockade (CCB). The CCB activity was confirmed when pre-treatment of the tissue with Ac.Cr (0.3-1.0 mg/mL) caused a rightward shift in the Ca(++) dose-response curves similar to that caused by verapamil, a standard calcium channel blocker. Activity-directed fractionation revealed that the CCB activity was concentrated in the n-hexane fraction while the ethylacetate fraction was less potent. These results suggest that the spasmolytic effect of the plant extract is mediated through the presence of CCB-like constituent(s) which is concentrated in the n-hexane fraction and this study provides a strong mechanistic base for its traditional use in gastrointestinal disorders such as colic pain and diarrhoea.     

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 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.     

Antispasmodic and blood pressure lowering effects of Valeriana wallichii are mediated through K+ channel activation

Crude extract of Valeriana wallichii rhizome (Vw.Cr) and its fractions were studied for possible antispasmodic and blood pressure lowering activities to rationalize some of the folkloric uses. In rabbit jejunum preparations, Vw.Cr (0.1–3.0 mg/mL) caused relaxation of spontaneous contractions. When tested against high K⁺ (80 mM)-induced contractions it produced weak inhibitory effect, while caused complete relaxation of the contractions induced by low K⁺ (20 mM). In the presence of glibenclamide (3 μM), the inhibitory effect of low K⁺ was shifted to the right, similar to that produced by cromakalim while, verapamil caused no differentiation in its inhibitory effect against low and high K⁺-induced contractions. In guinea pig ileum, the plant extract produced similar results as in rabbit jejunum. Intravenous administration of Vw.Cr, produced fall in arterial blood pressure in normotensive anaesthetized rats and this effect was partially blocked by glibenclamide. In rabbit aortic preparations, plant extract also caused a selective and glibenclamide-sensitive relaxation of low K⁺ (20 mM)-induced contractions. Activity-directed fractionation studies revealed that the observed activity was distributed both in the chloroform and aqueous fractions. These results indicate that the antispasmodic and hypotensive effects of Valeriana wallichii are mediated possibly through K_ATP channel activation, which justify its use in gastrointestinal and cardiovascular disorders.