In vivo antidiarrheal activity of the ethanolic leaf extract of Catharanthus roseus Linn. (Apocyanaceae) in Wistar rats

Catharanthus roseus is a medicinal plant with various pharmacological properties. In this study, we investigated the in vivo antidiarrheal activity of C. roseus ethanolic leaf extract in Wistar rats. Castor oil was used to induce experimental diarrhea in rats pretreated with extracts administered at 200 and 500 mg/kg to determine antidiarrheal effect. Loperamide and atropine sulphate were used as standard drugs in the two experiments. Preliminary phytochemical screening of the extract revealed the presence of alkaloids, tannins, triterpenes, flavonoids and saponins. The antidiarrheal effect of ethanolic extract of C. roseusrevealed a dose dependant inhibition of castor oil induced diarrhea at doses of 200 and 500 mg/kg. On comparison of the extract with the negative control, there was a significant difference at 200 mg/kg (P < 0.05) and a more significant difference at 500 mg/kg (P < 0.001). Test extract’s effect was further evaluated on intestinal transit and it exhibited dose dependant inhibition of transit motility of charcoal meal. The results indicated that the ethanol extract of C. roseus possesses significant antidiarrheal effect and corroborate the use of this herbal remedy as non-specific treatment for diarrhea in folk medicine. Key words: Catharansu roseus, antidiarrheal, ethanolic, phytochemical.