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.     

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.     

Blood pressure lowering,cardiovascular inhibitory and bronchodilatory actions of Achillea millefolium

Achillea millefolium Linn. (Asteraceae) is used in folk medicine for the treatment of overactive cardiovascular and respiratory ailments. This study describes its hypotensive, cardio‐depressant, vasodilatory and bronchodilatory activities. The crude extract of Achillea millefolium (Am.Cr) caused a dose‐dependent (1–100 mg/kg) fall in arterial blood pressure of rats under anaesthesia. In spontaneously beating guinea‐pig atrial tissues, Am.Cr exhibited negative inotropic and chronotropic effects. In isolated rabbit aortic rings, Am.Cr at 0.3–10 mg/mL relaxed phenylephrine (PE, 1 µm ) and high K⁺ (80 mm )‐induced contractions, as well as suppressed the PE (1 µm ) control peaks obtained in Ca⁺⁺‐free medium, like that caused by verapamil. The vasodilator effect of Am.Cr was partially blocked by N_ω‐nitro‐l ‐arginine methyl ester in endothelium intact preparations. In guinea‐pig tracheal strips, Am.Cr inhibited carbachol (CCh, 1 µm ) and K⁺‐induced contractions. These results indicate that Achillea millefolium exhibits hypotensive, cardiovascular inhibitory and bronchodilatory effects, thus explaining its medicinal use in hyperactive cardiovascular and airway disorders, such as hypertension and asthma. Copyright © 2010 John Wiley & Sons, Ltd.     

Antidiarrheal and Antispasmodic Activities of Buddleja polystachya are Mediated Through Dual Inhibition of Ca++ Influx and Phosphodiesterase Enzyme

This study describes the antidiarrheal and antispasmodic activities of the hydro‐alcoholic extract of Buddleja polystachya (Bp.Cr) with possible mode of action explored along with activity‐directed fractionation. Bp.Cr and its aqueous (Bp.Aq) and organic fractions, petroleum ether (Bp.Pet), dichloromethane (Bp.DCM), ethylacetate (Bp.EtAc) and butanol (Bp.But), were tested using the in‐vivo and in‐vitro assays. The crude extract (100–300 mg/kg) showed 20 and 60% protection of castor oil‐induced diarrhea in mice. In isolated rabbit jejunum, Bp.Cr like papaverine inhibited spontaneous and high K⁺ (80 mM)‐induced contractions equi‐potently. In guinea‐pig ileum, Bp.Cr showed a moderate spasmogenic effect. The activity‐directed fractionation revealed that the spasmolytic activity was concentrated in the organic fractions and spasmogenic component in the aqueous fraction. Amongst the organic fractions, BP.DCM and Bp.Pet inhibited spontaneous and high K⁺‐induced contractions equi‐potently, while Bp.But, like verapamil was more potent against high K⁺. The crude extract and its organic fractions caused rightward shift in the Ca⁺⁺‐concentration response curves (CRCs), similar to verapamil, and all except Bp.But potentiated the isoprenaline‐inhibitory CRCs to the left, similar to papaverine. The results of this study indicate that the crude extract of B. polystachya possesses antidiarrheal and antispasmodic activities, mediated possibly through dual inhibition of Ca⁺⁺ influx and phospodiesterase enzyme. Copyright © 2015 John Wiley & Sons, Ltd.     

Studies on Bronchodilator Activity of Salvia officinalis (Sage): Possible Involvement of K+ Channel Activation and Phosphodiesterase Inhibition

The aqueous methanolic extract of the aerial parts of Salvia officinalis (So.Cr) was studied to provide possible underlying mechanism(s) for its medicinal use in asthma using the in vivo bronchodilatory assay and isolated tracheal preparations. S. officinalis (1–10 mg/kg) dose‐dependently inhibited carbachol (CCh)‐induced bronchospasm in anesthetized rats with three‐fold greater potency than the positive control, aminophylline. In tracheal preparations, So.Cr inhibited the low K⁺ (25 mM)‐induced contractions. Pretreatment of the tissues with 4‐aminopyridine reversed the inhibitory effect of the plant extract against low K⁺, whereas glibenclamide did not show any effect, thus showing the involvement of voltage‐sensitive K⁺ channels. When tested against the CCh‐induced pre‐contractions for the involvement of any additional mechanism, interestingly, the extract showed a dose‐dependent (0.03–0.1 mg/mL) inhibitory effect and shifted the inhibitory concentration response curves of isoprenaline to the left, thus showing phosphodiesterase enzyme inhibitory‐like action, similar to that of papaverine. These results indicate that the crude extract of S. officinalis possesses bronchodilatory activity mediated predominantly via activation of voltage‐dependent K⁺ channels and inhibition of phosphodiesterase enzyme; thus, this study provides sound pharmacological basis for its medicinal use in hyperactive airways disorders such as asthma and cough. Copyright © 2015 John Wiley & Sons, Ltd.     

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.     

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.     

Study on the mechanism of the bronchodilatory effects of Cynodon dactylon (Linn.) and identification of the active ingredient

Ethnopharmacological relevance

In the traditional medicine, Cynodon dactylon (Linn.) is used in asthma, but scientific studies to provide evidence for medicinal uses are sparse. Thus this study was undertaken to provide evidence for medicinal use in asthma as a bronchodilator, and to identify active ingredient(s).

Materials and methods

In vivo, acetylcholine (Ach)-induced bronchospasm was conducted in guinea pig while isolated rat tracheal strip was suspended in organ bath to measure the concentration response curve using multichannel data acquisition system.

Results

The chloroform extract of Cynodon dactylon (CECD) protected against Ach-induced bronchospasm in guinea pigs, similar to atropine. In the in vitro studies, CECD relaxed carbachol (CCh) and high K⁺-induced contraction of rat tracheal strip, similar to atropine and verapamil respectively, suggesting antimuscarinic and calcium channel blocking (CCB) activities, which were confirmed by right ward shifting of CCh and Ca⁺² concentration response curve (CRC). The phosphodiestrase (PDE) inhibitory activity was confirmed by potentiation of isoprenaline-induced inhibitory response, similar to papaverine. Densitometry analyses led to the identification of scopoletin as an active ingredient. Effectively, it significantly inhibited high K⁺, and Ca⁺² induced contractile response, similar to verapamil. The phosphodiestrase (PDE) inhibitory activity was confirmed by direct evidence of potentiation of isoprenaline-induced inhibitory response, similar to papaverine.

Conclusions

These results suggest that the bronchodilator activity of CECD is partly due to presence of scopoletin, and mediated possibly through CCB and PDE inhibition.     

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.