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 400mg/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 200mg/kg in the castor oil-induced diarrhoea model. Similarly, the extract at the doses of 100mg/kg (p<0.01) and 200mg/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 280mg/kg (corresponding to 200mg/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.