Preliminary Evaluation of Different Components of Bacopa monnieri for Laxative Effect

Bacopa monnieri (B. monnieri) has been used for various therapeutic purposes in traditional medicine including treatment of constipation and stomach disorders. The aim of the present study was to investigate and identify the fractions of B. monnieri extract with maximal laxative effect. Three different types of Bacopa fractions and one extract were prepared: Fraction 1 (non-polar fraction), Fraction 2 (approx. 60-70% bacosides containing fraction), Fraction 3 (polar fraction) and Extract 4 (40% bacosides containing extract). In Study 1, rats and mice were given p.o. different doses of the four different test substances (40, 120 and 500 mg/kg b. wt.). Vehicle, loperamide (5 mg/kg b. wt.) and castor oil (2 ml/rat and 0.4 ml/mouse) were used for comparison. The stools were observed and graded. Animals given vehicle were observed to have normal stools, while all animals showed diarrhea with castor oil and loperamide caused constipation. Significant diarrhea (p < 0.05) was observed in rats administered with Fraction 1 and 2 (100%, and 71% respectively) at a dose of 500 mg/kg. Diarrhea was observed in one mouse administered Fraction 1 at 500 mg/kg. In Study 2, when the four different test substances were given in combination with loperamide, Fraction 1 (500 mg/kg) resulted in non significant diarrhea in 29% of rats. Studies on the rate of small intestine propulsion in mice also indicate that Fraction 1 showed the maximal distance traversed by carbon black (p < 0.05). It could be noted here that Fraction 1 (non-polar fraction) exhibited the maximum diarrhea while Fraction 3 (polar fraction) exhibited no diarrhea.