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

Multiple Mechanisms of Flaxseed: Effectiveness in Inflammatory Bowel Disease

Materials and Methods

Aqueous-methanolic crude extracts of Flaxseed (Fs.Cr) and Flaxseed oil were tested against 6% acetic acid- (AA-) induced colitis in BALB/c mice. Microscopic damage parameters of the hematoxylin and eosin-stained and periodic acid-Schiff-alcian blue-stained sections of the colon were scored to be assessed. Possible antispasmodic mechanism was studied on isolated rabbit jejunum, while antibacterial activity was assessed in vitro for microbes implicated in IBD.

Results

In AA-induced colitis, Flaxseed oil was found to be more effective in reducing mortality and colonic ulcers than Fs.Cr at 500 mg/kg dose. Fs.Cr was more efficacious in increasing mucin content as compared to oil, exhibiting slightly greater anti-inflammatory effect (50% vs 35%) and reducing depth of lesion (55% vs 42.31%, respectively). Antispasmodic activity of Fs.Cr (0.03 and 0.1 mg/ml) was mediated by phosphodiesterase inhibitors (PDEI, possibly PDE-4 subtype) with a resultant increase in cAMP levels. Flaxseed oil PDEI activity was mild (1 and 3 mg/ml). Fs.Cr (0.1 and 0.3 mg/ml) was potent in exhibiting anticholinergic activity, similar to dicyclomine, whereas Flaxseed oil showed anticholinergic effect at 1 and 3 mg/ml. Flaxseed oil (9 and 14 µg/ml) was bactericidal against enteropathogenic E.coli (EPEC), enterotoxigenic E.coli (ETEC), and enteroaggregative E.coli (EAEC), whereas Fs.Cr exhibited bactericidal effect against EPEC at 100 µg/ml.

Conclusions

Results of this study, taken together with previous studies, suggest that Flaxseed possesses anti-inflammatory, antibacterial, and antispasmodic action through multiple pathways and thus offers promising potential to be developed for IBD.

Strengthening antioxidant defense & cardio protection by Piper betle: An in-vitro study

Introduction

The purpose of this research work was to evaluate Piper betle ethyl acetate extract (PBEA) for its free radical scavenging, antioxidant, anti-apoptotic activities and its role in protecting against oxidative cardiac cell injury.

Methods

The Free radical scavenging activity and antioxidant potential of PBEA were evaluated using various non-cellular methods (1,1-Diphenyl-2-picrylhydrazyl, β-carotene bleaching, superoxide anion, hydroxyl radical, hydrogen peroxide_, Reducing power, Total phenolics and Total flavonoids). PBEA was standardized with Eugenol by GC-FID analysis. Furthermore, PBEA was also assessed for its cytotoprotective effect against 100μM H₂O₂ in H9c2 cells using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay. Intracellular reactive oxygen species scavenging and anti-apoptoic activity of PBEA was assessed by using 2′, 7′-Dichlorofluorescein diacetate and Annexin- Propidium Iodide, respectively.

Results

PBEA exhibited radical scavenging and antioxidant defense response at different magnitudes of potency. Eugenol, a cardiac protective bioactive molecule in PBEA was found to be 43.43 ± 1.46 mg/g of PBEA extract. Further, pre-incubation of H9c2 cells with 10 μg/ml PBEA for 24 h exhibited remarkable cytoprotective effect against H₂O₂ induced oxidative stress. PBEA at 10 μg/ml dose with 24 h contact with H9c2 cells significantly enhanced the activity of cellular defense system and significantly decreased intracellular ROS (P < 0.001) and apoptosis (P < 0.01) thereby protecting against the cytotoxic effects of H₂O₂.

Conclusion

These outcomes indicated that PBEA could shield against oxidative and apoptotic cardiac cell injury in invitro studies. Thus, PBEA might be a desirable antioxidant of natural origin that has future clinical implications in both health care and food industry.

Anti-cholinergic and Ca2+-antagonist mechanisms explain the pharmacological basis for folkloric use of Sisymbrium irio Linn. in gastrointestinal, airways and vascular system ailments

ETHNOPHARMACOLOGICAL RELEVANCE

Seeds of Sisymbrium irio Linn has been used traditionally in different regions of Pakistan for the treatment of gastrointestinal, airways and vascular system ailments. To insight the pharmacological basis, in vitro study was conducted in order to validate its folkloric uses.

MATERIAL AND METHODS

70% aqueous-methanolic extract of seeds from S. irio (Si.MEs) was tested on isolated rabbit aorta, jejunum and trachea strip hanged in tissue bath having physiological solutions aerated with carbogen and their responses were measured and recorded via Power Lab.

RESULTS

The Si.MEs exhibited the transient spasmogenic effect (0.01-1.0mg/mL) on spontaneous jejunum contractions, followed by the spasmolytic effect. The addition of atropine resulted in blocking in spasmogenic effect while the spasmolytic effect was originated, suggesting the presence of an antimuscarinic effect. Likewise verapamil, Si.MEs (0.03-5mg/mL) repressed the high concentration K⁺(80mM)-induced contraction and also drifted the Ca²⁺ concentration-response curves toward right (0.3-3.0mg/mL), possibly signifying the Ca²⁺ channel blockade. Furthermore, Si.MEs exhibited nonspecific relaxant effect on carbachol (1µM)- and high concentration K⁺(80mM)-induced tracheal contractions in a way comparable to dicyclomine, suggesting the coexistence of Ca²⁺-antagonistic and/or antimuscarinic properties. Additionally, Si.MEs also relaxed the phenylephrine(1µM)- and high concentration K⁺(80mM)-induced aortic contraction (0.01-3mg/mL), suggesting blockade of Ca²⁺ channel. Moreover, oral administration of Si.MEs, as high as 6g per kg, did not produce lethality among the treated groups of mice.

CONCLUSIONS

Aqueous-methanolic extract of seeds from S. irio (Si.MEs) exhibited the bronchodilator and gut modulator (spasmogenic and spasmolytic) activities, probably through dual blockade of muscarinic receptors and Ca²⁺ channels, whereas, vasodilator effect may be due to Ca²⁺ channels blockade.

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.

Anti-diabetic and spasmolytic potential of Farsetia hamiltonii Royle from Cholistan desert

ETHNOPHARMACOLOGICAL RELEVANCE

Folk herbal practitioners of the Cholistan desert claim Farsetia hamiltonii Royle (Brassicaceae) to treat diabetes, oxidative damages, diarrhea, fever, and abdominal cramps. The aim of this study was to scientifically find the potential of Farsetia hamiltonii in treating diabetes and gastrointestinal diseases.

MATERIALS AND METHODS

In vivo anti-diabetic activity of Farsetia hamiltonii was studied on alloxan induced diabetic rats to justify its traditional use. The in vitro antispasmodic activity on isolated tissues of rabbit jejunum was also evaluated. In addition, several enzyme inhibition studies (lipoxygenase, tyrosinase, acetylcholinesterase (AchE), carbonic II anhydrase and phosphodiesterase I) and antioxidant activity of plant extracts were also conducted.

RESULTS

In vivo experiments, Farsetia hamiltonii methanol extract (300 mg/kg) significantly lowered the fasting blood glucose (107.6 ± 1.249 mg/dL up to 4th day) comparable to positive control (Glibenclamide) throughout the study period. The in vitro antispasmodic activity on isolated tissues of rabbit jejunum on methanol extract showed concentration dependent (0.01-0.3 mg/ml) relaxation of spontaneous contractions with EC₅₀ value 0.011 µM and high K(+) (80 mM) induced contraction (0.01-0.1 mg/ml) with EC₅₀ value 0.066 mg/ml. Farsetia hamiltonii DCM and methanol extracts exhibited some antilipoxygenase activities while tyrosinase, acetylcholinesterase (AchE), carbonic II anhydrase, phosphodiesterase I, and antioxidant activity of plant extracts were not significant.

CONCLUSIONS

Our results validate the traditional use of Farsetia hamiltonii for the traditional therapeutic potential in treating diabetes and gastrointestinal diseases.

Pharmacological studies on the antispasmodic, bronchodilator and anti-platelet activities of Abies webbiana

This study evaluated the antispasmodic, bronchodilator and anti-platelet activities of Abies webbiana to rationalize some of its folk uses in gut and airways disorders and inflammation. The crude extract of A. webbiana (Aw.Cr) caused a complete relaxation of both spontaneous and K(+) (80 mM)-induced contractions in isolated rabbit jejunum in a concentration-dependent manner. Aw.Cr shifted the Ca(++) concentration-response curves (CRCs) to the right, in a fashion similar to verapamil, confirming its Ca(++) channel blocking (CCB) effect. In isolated rabbit tracheal preparations, it caused relaxation of carbachol (1 μM) and K(+) (80 mM)-induced contractions comparable to verapamil suggesting that the bronchodilatory effect may possibly be mediated through CCB activity. Aw.Cr was found to be the inhibitor of both ADP- and epinephrine-induced aggregation of human platelets thereby suggesting therapeutic potential in this plant against thrombo-embolic conditions. The exhibited anti-platelet effect was observed at low doses against epinephrine as compared to ADP. This study confirmed the presence of spasmolytic activity in Abies webbiana through possible blockade of Ca(++) channels providing evidence for its folkloric use in gut and respiratory disorders in addition to anti-platelet activity.

Antioxidant and relaxant activity of fractions of crude methanol extract and essential oil of Artemisia macrocephala Jacquem

Background

The current work is an attempt to know about additional chemical profile of Artemisia macrocephala. Antioxidant activity is performed as the plant is reported to contain flavonoids, which have antioxidant activity in general. Relaxant activity of fractions of crude methanol extract is performed to know in which fraction(s) the relaxant constituents concentrate as we have already reported that its crude methanol has relaxant activity. Antispasmodic activity of essential oil is also performed as the plant is rich with essential oil.

Methods

Phytochemical profile of the plant is performed. Free radical scavenging activity was performed using 2, 2-diphenyl-1-picrylhydrazyl (DPPH). Relaxation activity tests of fractions and essential oil of Artemisia macrocephala were performed on sections of rabbits’ jejunum. Calcium chloride curves were constructed to investigate the mode of action of plant extracts and its essential oil.

Results

We detected carbohydrates, flavonoids and saponins in A. macrocephala. At concentration 0.005 mg/ml, free radical scavenging activity of ethyl acetate fraction was 121.5 ± 2.02% of ascorbic acid.

n- hexane fraction relaxed spontaneous activity with EC₅₀ 0.74 ± 0.04 mg/ml. Essential oil relaxed spontaneous activity with EC₅₀ 0.8 ± 0.034 mg/ml. Chloroform and ethylacetate fractions relaxed both spontaneous and KCl-induced contractions suggesting its possible mode through calcium channels. Constructing calcium chloride curves, the test fractions showed a right shift in the EC₅₀. Essential oil at concentration 0.1 mg/ml produced right shift with EC₅₀ (log [Ca⁺⁺]M) -2.08 ± 0.08 vs. control with EC₅₀ -2.47 ± 0.07. The curve resembled the curves of verapamil, which caused a right shift at 0.1 μM, with EC₅₀ -1.7 ±0.07 vs. control EC₅₀ (log [Ca⁺⁺]M) -2.45 ± 0.06.

Conclusions

Crude methanol and its fractions (ethyl acetate, chloroform and butanol) are rich sources of antioxidant constituents. The relaxing constituents following calcium channel blocking mechanisms are more concentrated in n-hexane, chloroform and ethyl acetate fractions that warrant isolation.

Pharmacological Effects of Lactuca serriola L. in Experimental Model of Gastrointestinal, Respiratory, and Vascular Ailments

Lactuca serriola L. has traditionally been used in folkloric medicine to manage respiratory, gastrointestinal, and multiple other ailments. The present study was undertaken to explore the effect of methanol extract of L. serriola on isolated rabbit tissue preparations, that is, jejunum, trachea, and aorta in an attempt to validate its folkloric use in traditional medicine for gastrointestinal, respiratory, and vascular ailments. The application of the methanol extract to isolated rabbit jejunum preparations exhibited concentration-dependent spasmogenic effect (0.03 to 3.0 mg/mL), but interestingly further increase in concentration (5.0 mg/mL) resulted in complete spasmolytic effect. The pretreatment of the tissue preparations with atropine (0.1 μM) caused the suppression of the contractile response. Moreover, the same extract also caused relaxation of K⁺-(80 mM) induced spastic contractions of isolated rabbit jejunum preparations (5.0 mg/mL) and shifted the Ca⁺⁺ dose response curves towards right at concentration range of 0.3–1.0 mg/mL. Similarly, the extract application to isolated rabbit tracheal preparations relaxed the carbachol-(1 μM) induced (0.3–1.0 mg/mL) as well as K⁺-(80 mM) induced contractions (3.0 mg/mL). Furthermore, it relaxed the phenylephrine (1 μM)-induced contractions in isolated rabbit aorta preparations (3.0 mg/mL) and K⁺ (80 mM)-induced contractions (1.0 mg/mL). These effects were found comparable to that of dicyclomine, as an antagonist of muscarinic receptors as well as a possible Ca⁺⁺ channel blocker. The previously mentioned findings may partially justify the folkloric use of Lactuca serriola in the management of conditions pertaining to spasm of intestine, bronchioles, and vasculature.

Evaluation of gut modulatory and bronchodilator activities of Amaranthus spinosus Linn

BACKGROUND

The aqueous-methanolic extract of Amaranthus spinosus (A. spinosus Linn.,) whole plant, was studied for its laxative, spasmolytic and bronchodilator activities to validate some of its medicinal uses.

METHODS

The crude extract of A. spinosus was studied in-vivo for bronchodilator and laxative activities and in-vitro using isolated tissue preparations which were mounted in tissue baths assembly containing physiological salt solutions, maintained at 37°C and aerated with carbogen, to assess the spasmolytic effect and to find out the possible underlying mechanisms.

RESULTS

In the in-vivo experiments in mice, the administration of A. spinosus increased fecal output at doses of 100 and 300 mg/kg showing laxative activity. It also inhibited carbachol-induced bronchospasm in anesthetized rats at 1, 3, 10 and 30 mg/kg indicative of bronchodilator activity. When tested on isolated gut preparations, the plant extract showed a concentration-dependent (0.01-10.0 mg/ml) spasmogenic effect in spontaneously contracting rabbit jejunum and guinea-pig ileum. The spasmogenic effect was partially blocked in tissues pretreated with atropine (0.1 μM). When tested on K+ (80 mM)-induced sustained contractions in isolated rabbit jejunum, the plant extract caused complete relaxation and also produced a shift in the Ca++ concentration-response curves (CRCs) towards right, similar to diltiazem. In rabbit trachea, the plant extract completely inhibited K+ (80 mM) and carbachol (CCh, 1 μM)-induced contractions at 1 mg/ml but pretreatment of tissue with propranolol (1 μM), caused around 10 fold shift in the inhibitory CRCs of the plant extract constructed against CCh-induced contraction. The plant extract (up to 0.3 mg/ml) also increased both force and rate of spontaneous contractions of isolated guinea-pig atria, followed by relaxation at higher concentration (1.0-5.0 mg/ml). The cardio-stimulant effect was abolished in the presence of propranolol, similar to that of isoprenaline. Activity-directed fractionation revealed that the spasmolytic component(s) was separated in the organic fraction, whereas the spasmogenic component was concentrated in the aqueous fraction.

CONCLUSION

These results indicate that A. spinosus possesses laxative activity partially mediated through cholinergic action. The spasmolytic effect was mediated through calcium channel blocking (CCB), while bronchodilator activity through a combination of β-adrenergic and CCB pathways, which may explain the traditional uses of A. spinosus in gut and airways disorders.

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.

Isoliquiritigenin, a flavonoid from licorice, plays a dual role in regulating gastrointestinal motility in vitro and in vivo

Licorice root has been used for years to regulate gastrointestinal function in traditional Chinese medicine. This study reveals the gastrointestinal effects of isoliquiritigenin, a flavonoid isolated from the roots of Glycyrrhiza glabra (a kind of Licorice). In vivo, isoliquiritigenin produced a dual dose-related effect on the charcoal meal travel, inhibitory at the low doses, while prokinetic at the high doses. In vitro, isoliquiritigenin showed an atropine-sensitive concentration-dependent spasmogenic effect in isolated rat stomach fundus. However, a spasmolytic effect was observed in isolated rabbit jejunums, guinea pig ileums and atropinized rat stomach fundus, either as noncompetitive inhibition of agonist concentration-response curves, inhibition of high K(+) (80 mM)-induced contractions, or displacement of Ca(2+) concentration-response curves to the right, indicating a calcium antagonist effect. Pretreatment with N(omega)-nitro-L-arginine methyl ester (L-NAME; 30 microM), indomethacin (10 microM), methylene blue (10 microM), tetraethylammonium chloride (0.5 mM), glibenclamide (1 microM), 4-aminopyridine (0.1 mM), or clotrimazole (1 microM) did not inhibit the spasmolytic effect. These results indicate that isoliquiritigenin plays a dual role in regulating gastrointestinal motility, both spasmogenic and spasmolytic. The spasmogenic effect may involve the activating of muscarinic receptors, while the spasmolytic effect is predominantly due to blockade of the calcium channels.

Pharmacological study of antispasmodic activity of Mirabilis jalapa Linn flowers

INTRODUCTION

Mirabilis jalapa Linn is a well-studied plant. The indigenous people of Mexico use Mirabilis jalapa to cure many infirmities including dysentery, diarrhea, muscular pain and abdominal colic. In the present investigation, we have further characterized some pharmacological properties of an extract of Mirabilis jalapa flowers; therefore, we intend to contribute to understand the pharmacological effects and clarify the complex use of this medicinal plant.

RESULTS

The extract of Mirabilis jalapa (1-1000 mug/mL) exhibits an inhibitory effect (IC(50)=18+/-0.7 micorg/mL) on gut smooth muscle contractility whereas it stimulates the contraction of rabbit aortic muscle (EC(50)=11.60+/-0.26 micorg/mL) in a concentration-dependent manner.

CONCLUSIONS

These effects were not due to either ACh or HIS receptors blockage, IP(3), cAMP, cGMP, Ca(2+) release from intracellular storage, or protein kinase mediated contraction-relaxation mechanisms. The effects inducted by the Mirabilis jalapa extract may involve a serotoninergic mechanism, which, in turn, interacts with other adrenergic systems. Further studies are necessary to identify the active compounds within the extract and to elucidate the mechanism of action.

Gastrointestinal, selective airways and urinary bladder relaxant effects of Hyoscyamus niger are mediated through dual blockade of muscarinic receptors and Ca2+ channels

This study describes the spasmolytic, antidiarrhoeal, antisecretory, bronchodilatory and urinary bladder relaxant properties of Hyoscyamus niger to rationalize some of its medicinal uses. The crude extract of H. niger seeds (Hn.Cr) caused a complete concentration-dependent relaxation of spontaneous contractions of rabbit jejunum, similar to that caused by verapamil, whereas atropine produced partial inhibition. Hn.Cr inhibited contractions induced by carbachol (1 microM) and K(+) (80 mM) in a pattern similar to that of dicyclomine, but different from verapamil and atropine. Hn.Cr shifted the Ca(2+) concentration-response curves to the right, similar to that caused by verapamil and dicyclomine, suggesting a Ca(2+) channel-blocking mechanism in addition to an anticholinergic effect. In the guinea-pig ileum, Hn.Cr produced a rightward parallel shift of the acetylcholine curves, followed by a non-parallel shift with suppression of the maximum response at a higher concentration, similar to that caused by dicyclomine, but different from that of verapamil and atropine. Hn.Cr exhibited antidiarrhoeal and antisecretory effects against castor oil-induced diarrhoea and intestinal fluid accumulation in mice. In guinea-pig trachea and rabbit urinary bladder tissues, Hn.Cr caused relaxation of carbachol (1 microM) and K(+) (80 mM) induced contractions at around 10 and 25 times lower concentrations than in gut, respectively, and shifted carbachol curves to the right. Only the organic fractions of the extract had a Ca(2+) antagonist effect, whereas both organic and aqueous fractions had anticholinergic effect. A constituent, beta-sitosterol exhibited Ca(2+) channel-blocking action. These results suggest that the antispasmodic effect of H. niger is mediated through a combination of anticholinergic and Ca(2+) antagonist mechanisms. The relaxant effects of Hn.Cr occur at much lower concentrations in the trachea and bladder. This study offers explanations for the medicinal use of H. niger in treating gastrointestinal and respiratory disorders and bladder hyperactivity.

Species differences in the prokinetic effects of ginger

This study describes the prokinetic actions of the aqueous extract of ginger (Zingiber officinale). Ginger extract (Zo.Cr), which tested positive for saponins, terpenes, phenols, flavonoids and alkaloids, showed a spasmogenic effect in isolated guinea-pig ileum with 8-50 times more potency than in rabbit jejunum and ileum and rat stomach fundus and ileum. Spasmogenicity in all the gut preparations except in guinea-pig ileum was atropine-sensitive. Zo.Cr exhibited a stimulant effect in vivo in mice and enhanced the intestinal transit of charcoal meal. A spasmolytic effect, mediated via Ca2 + antagonist activity, was also exhibited by Zo.Cr, reflected in terms of inhibition of spontaneous contractions, K+ (80 mM)-induced contractions and displacement of Ca2 + dose-response curves. The ginger pure compounds (6-shogaol, 6-gingerol, 8-gingerol and 10-gingerol) also exhibited a spasmolytic activity, which reduced with the increasing size of the side chain in their chemical structures. The study showed that the aqueous extract of ginger exhibits species-specific spasmogenicity in gut tissues of rabbit and rat (muscarinic-type) while through an uncharacterized pathway in guinea-pig ileum, along with a dormant relaxant effect, mediated via the blockade of voltage-dependent Ca2 + channels.

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.

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.

Pharmacological basis for the medicinal use of ginger in gastrointestinal disorders

Ginger (rhizome of Zingiber officinale) has been widely used for centuries in gastrointestinal disorders, particularly dyspepsia, but its precise mode of action has yet to be elucidated. This study was undertaken to study the prokinetic action of ginger and its possible mechanism of action. Prokinetic activity of ginger extract (Zo.Cr) was confirmed in an in vivo test when it enhanced the intestinal travel of charcoal meal in mice. This propulsive effect of the extract, similar to that of carbachol, was blocked in atropine-pretreated mice, a standard cholinergic antagonist. Likewise, Zo.Cr showed an atropine-sensitive dose-dependent spasmogenic effect in vitro as well as in isolated rat and mouse stomach fundus tissues. In atropinized tissue, it showed spasmolytic activity as shown by the inhibition of 5-HT- and K+-induced contractions. A spasmolytic effect was also observed in other gut preparations either as noncompetitive inhibition of agonist dose-response curves, inhibition of high K+(80 mM)-induced contractions, or displacement of Ca2+ dose-response curves to the right, indicating a calcium antagonist effect. Phytochemical analysis revealed the presence of saponins, flavonoids, and alkaloids in the crude extract. These data indicate that Zo.Cr contains a cholinergic, spasmogenic component evident in stomach fundus preparations which provides a sound mechanistic insight for the prokinetic action of ginger. In addition, the presence of a spasmolytic constituent(s) of the calcium antagonist type may explain its use in hyperactive states of gut like colic and diarrhea.

Cardiovascular effects of ginger aqueous extract and its phenolic constituents are mediated through multiple pathways

Ginger is a world known food plant which is equally reputed for its medicinal properties. We report here the hypotensive, endothelium-dependent and independent vasodilator and cardio-suppressant and stimulant effects of its aqueous extract (Zo.Cr). Zo.Cr, which tested positive for saponins, flavonoids, amines, alkaloids and terpenoids, induced a dose-dependent (3.0-10.0 mg/kg) fall in the arterial blood pressure (BP) of anaesthetized rats which was partially blocked by atropine (1 mg/kg). In isolated endothelium-intact rat aorta, Zo.Cr (0.01-5.0 mg/ml) relaxed the phenylephrine (1 microM)-induced contractions, effect partially blocked by atropine (1 microM). Zo.Cr inhibited the K+ (80 mM)-induced contractions and also shifted the Ca++ dose-response curves to the right, similar to verapamil, indicating Ca++ antagonist activity. An atropine-resistant and l-NAME-sensitive vasodilator activity was also noted from ginger phenolic constituents 6-, 8- and 10-gingerol, while 6-shogaol showed a mild vasodilator effect. In guinea-pig atria, Zo.Cr (0.1-5.0 mg/ml) inhibited the force and rate of atrial contractions. Pretreatment with atropine blocked the inhibitory effect and a stimulatory effect was unmasked which was resistant to propranolol and verapamil but sensitive to ryanodine, blocker of Ca++ release from intracellular stores. Later at doses >or=1.0 mg/ml, the extract completely suppressed the atrial tissue, effect resistant to glibenclamide, pyrilamine, aminophylline and L-NAME. These data indicate that the aqueous ginger extract lowers BP through a dual inhibitory effect mediated via stimulation of muscarinic receptors and blockade of Ca++ channels and this study provides sound mechanistic basis for the use of ginger in hypertension and palpitations.

Trends in ethnopharmocology

The use of plants, plant extracts or plant-derived pure chemicals to treat disease is a therapeutic modality, which has stood the test of time. Indeed today many pharmacological classes of drugs include a natural product prototype. Aspirin, atropine, ephedrine, digoxin, morphine, quinine, reserpine and tubocurarine are a few examples of drugs, which were originally discovered through the study of traditional cures and folk knowledge of indigenous people. There is a revival of interest in herbal products (botanicals) at a global level and the conventional medicine is now beginning to accept the use of botanicals once they are scientifically validated. Ispaghula, Garlic, Ginseng, Ginger, Ginkgo, St. John's Wort, and Saw palmetto are a few examples of botanicals which are gaining popularity amongst modern physicians and this trend is likely to continue partly due to high cost involved in the development of patentable chemical drugs. There is growing evidence to show that medicinal plants contain synergistic and/or side-effects neutralizing combinations. Ethnopharmacology has already played important role in the development of conventional medicine and is likely to play more significant role in the years to come. A team work amongst ethnobotanists, ethnopharmacologists, physicians and phytochemists is essential for the fruitful outcome on medicinal plants research. While the ethnopharmacologists have a greater role to play in the rationalization of combination of activities, the phytochemist's role will slightly shift towards standardization of botanicals.

Studies on the antihypertensive, antispasmodic, bronchodilator and hepatoprotective activities of the Carum copticum seed extract

This study describes the antihypertensive, antispasmodic, bronchodilator and hepatoprotective activities of the aqueous-methanolic extract of Carum copticum Benth. seeds (CSE) to rationalize some of its traditional uses. CSE (3-100 mg/kg) caused a dose-dependent fall in arterial blood pressure in anaesthetized rats. In isolated rabbit aorta and jejunum preparations, CSE (0.1-3.0 mg/ml) caused an inhibitory effect on the K+-induced contractions. The calcium channel blocking (CCB) effect was confirmed when CSE shifted the Ca2+ dose-response curves (DRCs) to right similar to verapamil. In isolated guinea-pig tracheal preparations, it caused inhibition of carbachol and K+-induced bronchoconstriction at 0.1-1.0 mg/ml as well as shifted the dose-response curves (DRCs) of carbachol and histamine to the right with suppression of maximum response suggestive of non-specific bronchodilator effect mediated possibly through CCB. Pretreatment of rats with CSE (500 mg/kg orally for 2 days at 12 h intervals) prevented paracetamol (640 mg/kg) and CCl4 (150 ml/kg)-induced rise in serum alkaline phosphatase (ALP) and aminotransferases (AST and ALT). The same dose of CSE was able to prevent the CCl4-induced prolongation in pentobarbital-induced sleeping time in mice confirming its hepatoprotectivity. These results indicate the presence of calcium antagonist(s) in Carum copticum seeds and thus provides sound mechanistic basis for some of their folkloric uses.

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.

Pharmacological basis for the use of peach leaves in constipation

The aqueous crude extract (PPL.Cr) of peach leaves (Prunus persica) was studied for the possible presence of gut stimulatory constituent(s) to rationalize the folkloric use of the plant in constipation. PPL.Cr at the dose of 1-10 mg/ml caused a moderate degree of spasmogenic effect in isolated guinea-pig ileum. Pretreatment of the tissue with atropine (1 M) completely abolished the contractile effect of the plant extract similar to that of acetylcholine which is suggestive of a cholinergic mechanism. In isolated rabbit jejunum preparations, PPL.Cr produced a week spasmogenic effect followed by relaxation of the spontaneous contractions at higher doses. Bioassay-directed fractionation revealed that the spasmogenic activity was separated in the aqueous fraction, while the spasmolytic activity was concentrated in the ethyl acetate fraction. When tested against K(+)-induced contraction, both PPL.Cr and its ethyl acetate fraction (PPL.EtAc) caused a dose-dependent inhibition, suggesting calcium channel blockade (CCB). The presence of CCB in peach leaves was confirmed when pretreatment of the tissue with PPL.EtAc caused a dose-dependent rightward shift in the Ca(2+) dose-response curves, similar to that produced by verapamil. These data indicate that the plant contains spasmogenic (cholinomimetic) and spasmolytic (calcium antagonist) constituents, which are concentrated in the aqueous and ethyl acetate fractions, respectively. Furthermore, the laxative effect of the plant reported in the traditional system of medicine may be partially due to the cholinergic action, which was dominant over the spasmolytic component.