Piperine was extracted and isolated from Piper nigrum. Antidiarrhoeal effect of piperine and aqueous extract of Piper nigrum was examined in castor oil and magnesium sulphate induced diarrhoea in mice. Piperine has shown significant inhibition of diarrhoea when compared with antidiarrhoeal effect of aqueous extract of Piper nigrum. The results indicate that piperine is the active antidiarrhoeal constituent of Piper nigrum.
