Evaluation of five medicinal plants used in diarrhoea treatment in Nigeria

Five medicinal plants [Acacia nilotica, Acanthospermun hispidum, Gmelina arborea, Parkia biglobosa and Vitex doniana] used in diarrhoeal treatment in Kaduna State, Nigeria, were investigated. This study was carried out on perfused isolated rabbit jejunum and castor oil-induced diarrhoea in mice. The aqueous methanol extracts (0.5, 1.0, 2.0 and 3.0 mg/ml) were generally found to cause a dose-dependent response in the isolated rabbit jejunum, though this was not uniform in all the plants. Gmelina arborea and Vitex doniana showed concentration dependent relaxation at low doses (0.5, 1.0 mg/ml), but showed no significant relaxation at higher doses (2.0, 3.0 mg/ml). Other extracts showed biphasic effects. For example, Acacia nilotica at 3.0 mg/ml caused initial relaxation quickly followed by contraction. In the castor oil-induced diarrhoeal, 100% protections were shown by extracts of Acacia nilotica and Parkia biglobosa (100, 200 mg/kg) while Vitex doniana showed a dose-dependent effect. The least protection was shown by Acanthospermun hispidum, at the same dose, when compared with the other four plants. The results obtained revealed that the aqueous methanol extracts of all the five medicinal plants investigated have pharmacological activity against diarrhoea. This may explain their use in traditional medicine for the treatment of diarrhoea.     

Antidiarrhoeal and intestinal modulatory activities of Wei-Chang-An-Wan extract

Aim of the study

Wei-Chang-An-Wan (WCAW), a traditional pharmaceutical preparation, has been used for treating various gastrointestinal (GI) diseases for several decades, but it is still poorly understood how it works on those disorders. This study was to investigate the effects of WCAW extract on GI tract.

Materials and methods

The activities of the methanol extract (ME) of WCAW on castor oil-induced diarrhoea, gastrointestinal transit (GIT) in mice, and contractions of isolated rabbit jejunum were investigated. We further assessed the safety of ME in vivo. Additionally, a HPLC fingerprint of ME was appraised to ensure its chemical consistency.

Results

Ten peaks were identified in the HPLC fingerprint of ME. At the doses of 400 and 800 mg/kg, ME significantly protected mice against castor oil-induced diarrhoea as well as the number of faeces and wet faeces. Interestingly, administration of ME significantly accelerated GIT in normal mice and reduced stimulated GIT induced by neostigmine. ME also dose-dependently attenuated spontaneous contractions of the isolated rabbit jejunum, and those induced by acetylcholine (Ach) and neostigmine. Moreover, oral administration of ME up to 5 g/kg did not produce any toxic effects. Taken together, ME is able to inhibit diarrhoea, increase normal GIT, and decrease GIT induced by neostigmine, which indicate that ME might play a bidirectional role in GI tract.

Conclusions

Our study provides a scientific basis for the clinical use of WCAW.     

Antidiarrhoeal and antimicrobial activities of Emilia coccinea (Sims) G. Don extracts

Emilia coccinea (Sims) G. Don is reported to possess a number of medicinal properties including antidiarrhoeal and antimicrobial activities. The antidiarrhoeal effects of both methanol and aqueous extracts of the leaves of Emilia coccinea were studied in rats against castor oil-induced diarrhoea at the doses of 200, 400 and 600 mg/kg body weight. The methanol extract, and to a lesser extent the aqueous extract, significantly prolonged the time for diarrhoeal induction; it reduced the frequency of diarrhoea episodes and decreased the propulsion of charcoal meal through the gastrointestinal tract in a dose dependent manner. The aqueous extract did not have any antimicrobial activity at the tested concentration (5 mg/ml), but the methanol extract was most active on Escherichia coli. These results may support the fact that this plant is used traditionally to cure diarrhoea.     

Evaluation of the antidiarrhoeal activity of Byrsocarpus coccineus

Based on its use in traditional African medicine, the antidiarrhoeal activity of the aqueous leaf extract of Byrsocarpus coccineus, Connaraceae, was evaluated on normal and castor oil-induced intestinal transit, castor oil-induced diarrhoea, enteropooling and gastric emptying. The extract (50, 100, 200 and 400 mg/kg, p.o.) produced a significant (P<0.05) dose dependent decrease in propulsion in the castor oil-induced intestinal transit in mice. The mean peristaltic index (%) for these doses of extract, control (distilled water; 10 ml/kg, p.o.) and morphine (10 mg/kg, s.c.) were 55.27+/-1.86, 53.12+/-3.73, 38.60+/-3.79, 30.25+/-1.27, 89.33+/-5.62 and 20.29+/-3.38, respectively. The effect of the extract at the highest dose was significantly (P<0.05) lower than that of the standard drug. This effect was antagonised by yohimbine (1 mg/kg, s.c.) but not by isosorbide dinitrate (IDN, 150 mg/kg, p.o.). At 200 mg/kg, the extract produced a significant decrease in propulsion in normal intestinal transit. In a dose dependent manner, it delayed the onset of diarrhoea, produced a significant decrease in the frequency of defaecation, severity of diarrhoea and protected the mice treated with castor oil. Mean diarrhoea scores were 30.83+/-1.72, 22.40+/-1.71, 21.43+/-1.32, 13.80+/-0.33, 18.00+/-3.94 and 7.67+/-2.41 for control, extract (50, 100, 200 and 400 mg/kg) and morphine, respectively. This effect was not antagonized by IDN. The extract (400 mg/kg) significantly decreased the volume (ml) of intestinal fluid secretion induced by castor oil (0.60+/-0.23) compared with 1.27+/-0.12 for control. However, there was no significant effect on gastric emptying. The results obtained suggest that Byrsocarpus coccineus possesses antidiarrhoeal activity due to its inhibitory effect on gastrointestinal propulsion, mediated through alpha(2) adrenoceptors, and also inhibition of fluid secretion. Preliminary phytochemical analysis revealed the presence of alkaloids, tannins, saponins, reducing sugars, glycosides and anthraquinones.     

Anti-diarrhoeal and ulcer-protective effects of the aqueous root extract of Guiera senegalensis in rodents

The anti-diarrhoeal and ulcer-protective properties of the aqueous root extract of Guiera senegalensis, a popular herbal traditional medicine in Nigeria were investigated in rats and mice. Acute toxicity studies were also carried out. The intestinal transit in mice was significantly (P < 0.05) reduced and gastric emptying delayed. One hundred and Two hundred milligrams per kilogram (p.o.) of the extract elicited a greater anti-motility activity than 0.1 mg/kg of atropine. The extract exhibited ulcer-protective properties against ethanol-induced ulceration in rats with maximal anti-ulcer activity recorded at 100 mg/kg. Guiera senegalensis also exerted significant anti-enteropooling effects causing a dose-related inhibitory effect on castor oil-induced enteropooling in rats. A profound anti-diarrhoeal activity was observed when Guiera senegalensis was tested in diarrhoeic mice. The frequency of defaecation as well as the wetness of the faecal droppings was significantly reduced. Furthermore, the extract produced 100% inhibition of castor oil-induced diarrhoea in mice. The oral LD50 values obtained were > 5000 mg/kg in both mice and rats. The results support the folkloric applications of Guiera senegalensis for the treatment of diarrhoea and ulcer in Nigerian herbal traditional medicine.     

Anti-diarrhoeal and anti-microbial activity of Flos populi (male inflorescence of Populus tomentosa Carrière) aqueous extracts

Ethnopharmacological relevance

Flos populi (male inflorescence of Populus tomentosa Carrière) has been traditionally used in East Asian countries for the treatment of various inflammatory diseases, strengthening the spleen and stomach, anti-rheumatic, anti-tumor and anti-diarrhoeal.

Aim of the study

To evaluate the in vivo or in vitro anti-diarrhoeal and anti-microbial activity of Flos populi aqueous extract.

Materials and methods

Acute toxicity of Flos populi aqueous extract (FPAE) was investigated. Castor oil-induced diarrhoea method was used to evaluate the anti-diarrhoeal activity, inhibition of defecation and diarrhoea were determined in mice, effects on castor oil-induced enteropooling, intestinal transit and intestinal fluid secretion in rats or mice. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of FPAE against strains of three clinical bacterial isolates and one reference strain were used to test the anti-microbial activity.

Results

The FPAE reduced the frequency of diarrhoea episodes and decreased the propulsion of charcoal meal through the gastrointestinal tract in a dose dependent manner. FPAE (100–500 mg/kg, p.o.) produced dose-dependent and significant (P<0.01) protection of mice against castor oil-induced diarrhoea. FPAE, dose-dependently and significantly (P< 0.01) delayed the onset of castor-oil induced diarrhoea, decreased the frequency of defecation, and reduced the severity of diarrhoea. Compared with control animals, FPAE, dose-dependently and significantly (P< 0.01) decreased the volume of castor oil-induced intestinal fluid secretion, and reduced the number, weight and wetness of faecal droppings. There was no deaths or abnormalities in behaviour seen in the acute toxicity test. The aqueous extract displayed anti-microbial effects to three species of bacteria in anti-microbial test.

Conclusion

The findings of this study indicate that FPAE possesses anti-diarrhoeal property in rats and mice and confirm the ethnomedicinal use of Flos Populi as a valuable natural remedy for the treatment, management and/or control of diarrhoea. These results may support the fact that this plant is traditionally used to cure diarrhoea.     

Evaluation of some medicinal plant extracts for antidiarrhoeal activity

The antidiarrhoeal effect of seven plant extracts namely: the aerial parts of Euphorbia paralias L. (EP), Bidens bipinnata L. (BB), Cynachum acutum L. (CyAc), Diplotaxis acris (Forssk.) Boiss (DA), Convolvulus fatmensis (CF) and Schouwia thebaica Webb (ST) and the leaves of Plantago major L. (PM), was evaluated on castor oil-induced diarrhoea, gastrointestinal movement in rats (charcoal meal) and on the motility of duodenum isolated from freshly slaughtered rabbits. A significant antidiarrhoeal effect of the tested plant extracts against castor oil-induced diarrhoea in rats was achieved by 200 and 400 mg/kg. The tested plant extracts decreased the gastrointestinal movement as indicated by the significantly (p<0.05 to 0.001) decreased distance travelled by the charcoal meal. The large dose of the tested plant extracts was slightly more effective than the small one. The antidiarrhoeal effect was confirmed by the reported dose dependent inhibition of the motility of duodenum isolated from freshly slaughtered rabbits. The EP and PM methanol extract produced a transient stimulation followed by inhibition in doses of less than 0.05 and 1.6 mg/kg, respectively. Higher concentrations caused rapid muscle relaxation. Tannins, flavonoids, unsaturated sterols/triterpenes, carbohydrates, lactones and proteins/amino acids were reported as major active constituents of the tested plants.     

Antidiarrhoeal activity of seed extract of Albizzia lebbeck Benth

The antidiarrhoeal activity of the seed extract of Albizzia lebbeck (Benth.) was investigated employing conventional rodent models of diarrhoea, i.e. castor oil-induced diarrhoea, upper gastrointestinal transit (u.g.t.) and fluid secretion. It was found that the aqueous methanol extract of Albizzia lebbeck seeds (2.5-5 mg/kg i.p.) possessed antidiarrhoeal activity which strengthens the earlier use of the seeds in the treatment of diarrhoea and dysentery. The antidiarrhoeal dose of the extract was at least 10-30 times less than the LD(50) dose. The extract (2.5-5 mg/kg i.p.) potentiated the antidiarrhoeal activity of loperamide (1 mg/kg i.p.). Nalaxone (0.5 mg/kg i.p.) significantly inhibited the antidiarrhoeal activity of the extract as well as loperamide, thus indicating a role of the opioid system in the antidiarrhoeal activity of the extract.     

Anti-diarrhoeal activity of the aqueous extract of Mezoneuron benthamianum Baill (Caesalpiniaceae)

The effect of the aqueous extract of Mezoneuron benthamianum (MB) on experimentally induced diarrhoea, intestinal propulsive movement (IPM) and intestinal fluid accumulation (enteropooling) were investigated in rats and mice. The extract (400, 800 and 1600 mg/kg, orally) produced a significant (p<0.05) and dose-dependent reduction in propulsion in the castor oil-induced intestinal transit in mice. The mean peristaltic index (%) for these doses of extract, control, (distilled water, 10 ml/kg, p.o.) and morphine, (10 mg/kg, s.c.) were 73.48, 69.34, 57.27, 89.93 and 31.56, respectively. The effect of the extract at the highest dose was significantly (p<0.05) lower than that of the standard drug. This effect was antagonised by yohimbine (1mg/kg, s.c.). In a dose-dependent manner, the extract delayed the onset of diarrhoea, produced a significant decrease in the frequency of defaecation, severity of diarrhoea and protected the mice treated with castor oil. Total diarrhoea scores were 12.0+/-0.63, 10.3+/-2.06, 8.5+/-2.15, 7.1+/-0.91 and 5.8+/-0.79 for control, extract (400, 800 and 1600 mg/kg) and morphine, respectively. The extract significantly decreased the volume (ml) of intestinal fluid secretion induced by castor oil (1.75+/-0.02 to 0.93+/-0.04) compared with 1.90+/-0.05 for control. The inhibitory effect on fluid accumulation by the extract was also attenuated by yohimbine (1.0 mg/kg). Preliminary phytochemical screening revealed the presence of flavonoids, tannins, cardiac glycosides, anthraquinones and saponins. Administration of the extract up to 2 g/kg (orally) did not produce any toxic effect in the acute toxicity studies in mice. The LD(50) of the extract when given intraperitoneally was 1021.31 mg/kg. The results obtained show that MB possesses anti-diarrhoeal activity due to its inhibitory effects on gastrointestinal propulsion and intestinal fluid accumulation. The antagonistic actions of yohimbine in the experiments suggest a role for the a(2)-adrenergic receptor system.     

Preliminary pharmacological screening of Bixa orellana L. leaves

Preliminary pharmacological studies were performed on the methanol extract of Bixa orellana L. (Bixaceae) leaves to investigate neuropharmacological, anticonvulsant, analgesic, antidiarrhoeal activity and effect on gastrointestinal motility. All studies were conducted in mice using doses of 125, 250 and 500 mg/kg of body weight. In the pentobarbitone-induced hypnosis test, the extract statistically reduced the time for the onset of sleep at 500 mg/kg dose and (dose-dependently) increased the total sleeping time at 250 and 500 mg/kg dose. A statistically significant decrease in locomotor activity was observed at all doses in the open-field and hole-cross tests. In the strychnine-induced anticonvulsant test, the extract increased the average survival time of the test animals (statistically significant at 250 and 500 mg/kg). The extract significantly and dose-dependently reduced the writhing reflex in the acetic acid-induced writhing test. Antidiarrhoeal activity was supported by a statistically significant decrease in the total number of stools (including wet stools) in castor oil-induced diarrhoea model. A statistically significant delay in the passage of charcoal meal was observed at 500 mg/kg in the gastrointestinal motility test. The extract was further evaluated in vitro for antioxidant and antibacterial activity. It revealed radical scavenging properties in the DPPH assay (IC(50)=22.36 microg/ml) and antibacterial activity against selected causative agents of diarrhoea and dysentery, including Shigella dysenteriae.     

Anti-diarrhoea and analgesic activities of the methanol extract and its fractions of Jasminum amplexicaule Buch.-Ham. (Oleaceae)

Jasminum amplexicaule Buch.-Ham. (Oleaceae) has been commonly used in the traditional medicine in dysentery, diarrhoea and bellyache in China. In the present work, the methanol extract of Jasminum amplexicaule and different fractions of this extract were studied for anti-diarrhoea and analgesic activities. The anti-diarrhoea activities were investigated using castor oil-induced, magnesium sulphate-induced diarrhoea models, antienteropooling assay and gastrointestinal motility models in mice. The analgesic activities were studied using hot-plate, writhing and formalin models in mice. At the doses of 100, 200 and 400mg/kg, the methanol extract (ME) showed significant and dose-dependent anti-diarrhoea and analgesic activity in these models. The chloroform fraction (CHF), ethyl acetate fraction (EAF) and the residual methanol fraction (RMF) exhibited similar activity using a dose of 200mg/kg in these models. The pharmacological activities of the n-butanol fraction (BUF) were lesser than the ME extract and other fractions. These results may support the fact that this plant is traditionally used to cure diarrhoea and pain.     

Antidiarrhoeal activity of Geranium incanum Burm. f. (Geraniaceae) leaf aqueous extract in mice

Ethnopharmacological relevance

Geranium incanum Burm. f. (Geraniaceae) is used in South Africa especially in rural communities by traditional medicine practitioners to treat diarrhoea. However, scientific evidence does not exist in any literature to corroborate the claim of therapeutic success of the plant species in diarrhoea.

Aim of study

The study intended to investigate the antidiarrhoeal activity of the leaf aqueous extract of Geranium incanum in mice.

Materials and Methods

Castor oil induced diarrhoeal test was used to assess the antidiarrhoeal activity of Geranium incanum. Gastrointestinal tract transit of charcoal meal test was used to assess the antipropulsive activity of the plant extract while the acute toxicity study and phytochemical analysis were carried out using well established protocols and methods.

Results

The antidiarrhoeal activity of Geranium incanum was investigated by studying the effect of leaf aqueous extract of the plant species on castor oil-induced diarrhoea in mice. The leaf aqueous extract of Geranium incanum significantly reduced faecal output in castor oil -induced diarrhoea and also significantly reduced the number of diarrhoeal episodes. Geranium incanum significantly delayed the onset of diarrhoea induced by castor oil and significantly reduced the number of animals exhibiting diarrhoea. Loperamide, a standard antidiarrhoeal drug, produced similar effects to the leaf aqueous extract of Geranium incanum on castor oil-induced diarrhoea. Both Geranium incanum and loperamide significantly reduced the intestinal propulsion of charcoal meal in mice. The phytochemical analysis of the leaves revealed the presence of tannins, saponins particularly steroidal saponin, and flavonoids. The LD₅₀ of the plant species obtained was greater than 4000 mg/kg (p.o.).

Conclusion

The data obtained indicate that the leaf aqueous extract of Geranium incanum has both antidiarrhoeal and antipropulsive activities The data also show that the plant material given orally may be safe and/or non toxic in mice. However, further investigation on the acute toxicity and on the mechanism of the antidiarrhoeal effect of the plant species needs to be carried out.     

Pharmacological studies of anti-diarrhoeal activity of Gentianopsis paludosa

The pharmacological studies of anti-diarrhoeal activity of Gentianopsis paludosa were carried out. The 75% ethanol extract (100-400 mg/kg) of Gentianopsis paludosa inhibited castor oil-induced diarrhoea and also reduced gastrointestinal motility in the charcoal meal test in mice. In the rabbit-isolated ileum, the extract showed inhibitory effects not only on its spontaneous contraction, but also on acetylcholine (Ach, 0.1 mM)- and KCl (60 mM)-induced contractions. Furthermore, the ethanol extract (0.4-0.6 mg/ml) shifted the CaCl2 dose-effect curves to the right in a non-competitive manner and significantly reduced the acetylcholine-induced contraction of isolated ileum in Ca2+-free solution like verapamil (0.1 mM), which suggest that the extract interferes with Ca2+ movement. These results support the traditional use of Gentianopsis paludosa in the treatment of diarrhoea.     

Anti-diarrheal and spasmolytic activities and acute toxicity study of Soonkijangquebo, a herbal anti-diarrheal formula

The anti-diarrheal and spasmolytic activities of Soonkijangquebo (SKJQB), a Korean herbal anti-diarrheal formulation, were subjected to pharmacological evaluation. SKJQB, at a dose of 50-200 mg/kg, inhibited castor oil-induced diarrhea in mice. The median effective dose (ED50) for the anti-diarrheal effect was 93 mg/kg. In isolated rabbit jejunum preparations, SKJQB produced a spasmolytic effect by the relaxation of spontaneous contractions in a dose-dependent manner. The median effective concentration (EC50) for the spasmolytic effect was 3.6 mg/ml. In isolated guinea pig ileum preparations, SKJQB also produced a spasmolytic effect by reduction of acetylcholine-induced contractions. When tested against calcium channel blockade in rabbit jejunum, SKJQB caused a dose-dependent rightward shift in the Ca2+ dose-response curves, similar to that produced by verapamil, a well-known calcium antagonist. In an acute toxicity study in Sprague-Dawley rats, the median lethal dose (LD50) of SKJQB was greater than 2000 mg/kg, and no pathological changes were noticed in macroscopic examination by necropsy of rats treated with SKJQB. Thus, SKJQB may be safely used as a spasmolytic as well as an anti-diarrheal agent.     

Ocimum sanctum: an experimental study evaluating its anti-inflammatory, analgesic and antipyretic activity in animals

A methanol extract and an aqueous suspension of Ocimum sanctum inhibited acute as well as chronic inflammation in rats as tested by carrageenan-induced pedal edema and croton oil-induced granuloma and exudate, respectively. In both test procedures, the anti-inflammatory response of 500 mg/kg of methanol extract and aqueous suspension was comparable to the response observed with 300 mg/kg of sodium salicylate. Both the extract and suspension showed analgesic activity in the mouse hotplate procedure and the methanol extract caused an increase in the tail-withdrawal reaction time of a subanalgesic dose of morphine. Both preparations reduced typhoid-paratyphoid A/B vaccine-induced pyrexia. The antipyretic action of the methanol extract and aqueous suspension was weaker and of shorter duration than that of 300 mg/kg sodium salicylate. Oral premedication with the methanol extract and the aqueous suspension delayed castor oil-induced diarrhoea in rats.     

Antidiarrhoeal activity of Hypoxis hemerocallidea Fisch. & C. A. Mey. (Hypoxidaceae) Corm (‘African potato’) aqueous extract in rodents

This study investigated the antidiarrhoeal activity of Hypoxis hemerocallidea corm aqueous extract (APE) on experimentally‐induced diarrhoea, gastrointestinal motility, intestinal transit and enteropooling in rodents. H. hemerocallidea corm aqueous extract (APE, 50–400 mg/kg, p.o.) produced dose‐dependent and significant (p < 0.05–0.01) protection of rats and mice against castor oil‐induced diarrhoea, inhibited intestinal transit and delayed gastric emptying. Like atropine (1 mg/kg, p.o.), APE (50–400 mg/kg, p.o.) produced dose‐dependent and significant (p < 0.05–0.01) antimotility effect, and caused dose‐related inhibition of castor oil‐induced enteropooling in the animals. Like loperamide (10 mg/kg, p.o.), APE (50–400 mg/kg, p.o.) dose‐dependently and significantly (p < 0.05–0.01) delayed the onset of castor oil‐induced diarrhoea, decreased the frequency of defaecation and reduced the severity of diarrhoea in the rodents. Compared with control animals, APE (50–400 mg/kg, p.o.) dose‐dependently and significantly (p < 0.05–0.01) decreased the volume of castor oil‐induced intestinal fluid secretion, and reduced the number, weight and wetness of faecal droppings. APE (50–400 mg/mL) also produced concentration‐related and significant (p < 0.05–0.01) inhibitions of the spontaneous, pendular contractions of the rabbit isolated duodenum, and attenuated acetylcholine (ACh, 0.1–5.0 µg/mL)‐induced contractions of the guinea‐pig isolated ileum. Although the precise mechanism of the antidiarrhoeal activity of APE could not be established, the results of this study indicate that APE possesses antidiarrhoeal activity. This finding supports the use of ‘African potato’ as a natural supplementary remedy for the treatment, management and/or control of diarrhoea in some rural communities of southern Africa. Copyright © 2009 John Wiley & Sons, Ltd.     

Anti-diarrhoeal activity of methanol extract of Santalum album L. in mice and gastrointestinal effect on the contraction of isolated jejunum in rats

Ethnopharmacological relevance

Santalum album L., namely Sandalwood, honored as “Green Gold”, is a traditional Chinese herb which has the effects of anti-diarrhoeal and antibacterial activity. But there is limit scientific study on its activity and mechanism in gastrointestinal disorders.

Materials and methods

in vivo, after intragastric administration, the methanol extract of Sandalwood (SE) (200, 400 and 800 mg/kg) were studied in castor oil-induced diarrhoea mice. By the test of small intestinal hyperfunction induced by neostigmine, SE was studied on gastrointestinal transit including gastric emptying and small intestinal motility. Meanwhile, in vitro, the effects of SE (0.02, 0.05, 0.1, 0.2, 0.3, 0.4 mg/mL) on the isolated tissue preparations of rat jejunum were also investigated. The rat jejunum strips were pre-contracted with acetylcholine (Ach; 10⁻⁶ M), 5-hydroxytryptamine (5-HT, 200 μM) or potassium chloride (KCl; 60 mM) and tested in the presence of SE. In addition, the possible myogenic effect was analyzed in the pretreatment of the jejunum preparations with SE or verapamil in Ca²⁺-free high-K⁺ (60 mM) solution containing EDTA.

Results

At doses of 200, 400 and 800 mg/kg, SE showed significant anti-diarrhoeal activity against castor oil-induced diarrhoea as compared with the control. At the same doses, it also inhibited the gastric emptying and small intestinal motility in the mice of which small intestinal hyperfunction induced by neostigmine. It caused inhibitory effects on the spontaneous contraction of rat-isolated jejunum in dose-dependent manner ranging from 0.02 to 0.4 mg/mL, and it also relaxed the Ach-induced, 5-HT-induced and K⁺-induced contractions. SE shifted the Ca²⁺ concentration–response curves to right, similar to that caused by verapamil (0.025 mM).

Conclusions

These findings indicated that SE played a spasmolytic role in gastrointestinal motility which was probably mediated through inhibition of muscarinic receptors, 5-HT receptors and calcium influx. All these results provide pharmacological basis for its clinical use in gastrointestinal tract.     

Antidiarrhoeal and antiulcerogenic effects of methanolic extract of Asparagus pubescens root in rats

The effect of methanolic extract of Asparagus pubescens root on experimentally-induced diarrhoea and ulceration was investigated in rats. The extract (500-1500 mg/kg) dose-dependently, reduced significantly the intestinal propulsive movement, castor oil-induced diarrhoea and intestinal fluid accumulation. Yohimbine an alpha(2)-adrenoceptor blocker attenuated the antidiarrhoeal effect of the extract. The extract also reduced the ulcer indices induced by indomethacin and ethanol in a dose-related manner. The results indicate that its antidiarrhoeal and antiulcerogenic effects might in part be due to its alpha(2)-adrenoceptor stimulation and its active constituents respectively.     

Anti-diarrhoeal activity of aqueous extract of Ocimum kilimandscharicum

Ethnopharmacological relevance

Ocimum kilimandscharicum Baker ex Güerke, commonly referred to as Kapur Tulsi, is a medicinal herb that belongs to the family of Lamiaceae. It is traditionally popular for its gastroprotective effects, including its use as a digestive and anti-diarrhoeal.

Aim of the study

The present study aims to prove the anti-diarrhoeal activity of aqueous extract of leaves of Ocimum kilimandscharicum in animal models.

Materials and methods

The aqueous extract was tested at three different dose levels (100, 200 and 400 mg/kg, p.o. in rats and the corresponding doses in mice) against castor-oil induced diarrhoea model and castor oil induced enteropooling assay in rats; and charcoal meal test/intestinal motility test in mice. The parameters observed were the onset of defecation, cumulative faecal weight and consistency of faeces in the castor oil induced diarrhoea model; the weight of intestinal content in castor oil induced enteropooling assay; and the distance travelled by charcoal in the intestinal motility test.

Results

A significant delay in the onset of defecation (p<0.05), reduction in the cumulative faecal weight (p<0.001), along with a change in the faecal consistency from watery to solid form was observed at the dose of 200 mg/kg in the castor oil-induced diarrhoea model. Similarly, the extract at the doses of 100 mg/kg (p<0.01) and 200 mg/kg (p<0.001) significantly decreased the weight of intestinal content in castor oil induced enteropooling assay. In the charcoal meal test the extract at the dose of 280 mg/kg (corresponding to 200 mg/kg in rats) significantly (p<0.01) reduced the distance travelled by charcoal.

Conclusion

The aqueous extract of leaves of Ocimum kilimandscharicum showed anti-diarrhoeal activity, which may be due to its anti-motility and anti-secretory effects, which thus proved the traditional claims.     

花椒温经止痛和温中止泻药理研究

本实验发现花椒醚提物和水提液都能对抗乙酸提高小鼠腹腔毛细血管通透性,抑制二甲苯性小鼠耳壳肿胀和角叉菜胶性大鼠足跖肿胀,减少乙酸引起的小鼠扭体反应次数,醚提物还能延长热痛反应潜伏期。醚提物能迅速而存久地对抗蓖麻油引起的小鼠腹泻,但水提液对抗作用短而弱。然而醚提物不对抗番泻叶引起的小鼠腹泻,水提液却具持久的对抗作用。水提液还能抑制小鼠胃肠推进运动。