Freeze Dried extracts ofBidens biternata(Lour.) Merr. And Sheriff. show significant Antidiarrheal activity in ‐vivo Models of Diarrhea
Authors: Kinuthia Dennis Gacigi , Muriithi Anne W. , Mwangi Peter Waweru 
Published: March 2016

Ethnopharmacological relevance of the study

Diarrhea remains one of the main killers of children aged below five years. Traditional antidiarrheal remedies form a potentially viable source of novel low cost efficacious antidiarrheal remedies in low resource settings. There is therefore a pressing to scientifically evaluate these remedies.

Aim of the study

This study aimed to investigate thein vivoandin vitroantidiarrheal activity ofBidens biternataa herb species used in traditional Ayurvedic medicine in the management of diarrhea.

Materials and Methods

In the castor oil test twenty (20) adult Sprague-Dawley rats were randomized to the negative control (normal saline), positive control (5 mg/kg loperamide), (200 mg/kgBidens biternataextract) and (400 mg/kgBidens biternataextract) groups (n=5 in each group). Castor oil (4 ml/kg) was then administered to the animals one hour after administration of the respective treatments after which the total mass of fecal output excreted after four (4) hours was determined.

In the charcoal meal test fifteen (15) Sprague Dawley rats were randomized to the negative control (normal saline 5 ml/kg orally), the positive control (atropine sulphate 0.1 mg/kg i.p) and test (400 mg/kgBidens biternataextract) groups (n=5). Charcoal meal was then administered via oral gavage to each rat thirty (30) minutes after the administration of the various treatments. The distance covered by the charcoal meal from the pylorus was then determined after sacrifice of the animals.

In the enteropooling test twenty (20) Sprague-Dawley rats were randomized to the negative control (5% v/v ethanol in normal saline), positive control (5 mg/kg loperamide) and test (400 mg/kgBidens biternataextract) groups and prostaglandin E2 (PGE2) (100μg/kg) administered immediately after the treatments. The animals were then sacrificed half an hour later and the volume of the small intestine contents determined. The effects of different concentrations ofBidens biternataextract (0.5. 1.0, 2.0, 3.0 and 5.0 mg/ml) on jejunal contraction were investigated and a dose-response curve constructed using the experimental data after which The ED50 dose determined. The effect of tamsulosin (α1 adrenergic blocker), yohimbine (α2 adrenergic blocker), propranolol (β adrenergic blocker) and naloxone (μ opioid blocker) on the contractile activity of the extract were also investigated.

The experimental data were expressed as mean ± standard error of mean (SEM) and then analyzed using one way ANOVA followed by Tukey’s post hoc test in cases of significance (set at p<0.05).

Results

The freeze dried extracts ofBidens biternatahad significant antidiarrhealeffects in the castor oil induced diarrhea model (p=0.0075) with maximal activity being observed at the 400mg/kg dosage level (1.66± 0.81g vs. 4.54 ± 0.51 g negative control, p=0.01).Bidens biternataextract had significant effects on intestinal motility in the charcoal meal test compared to the control group (43.61 ± 4.42% vs. 60.54 ± 3.33%: p= 0.02).Bidens biternataextract had a significant effect on PGE2 induced enteropooling (3.06 ± 0.07 ml vs. 4.74 ± 0.10 ml; p<0.001).

The freeze dried extracts ofBidens biternatahad a significant negative effect on the contractility of the isolated rabbit jejunum (p<0.001). The effects of the extract were significantly attenuated by tamsulosin (53.94 ± 4.20% vs. 80.57 ± 4.09%; p=0.0067) and naloxone (53.94 ± 4.20% vs. 73.89 ± 7.26 %; p=0.0358). Yohimbine (p=0.4598) and propranolol (p=0.5966) however did not have any significant effect on the contractile activity of the extract.

Conclusions

The freeze dried extract ofBidens biternatapossess significant antidiarrhealactivity in bothin vitroandin vivomodels which appears to be mediated by modulating both the intestinal motility as well as the secretory activity. The results of this study also validate its traditional use as an antidiarrheal remedy.