Evaluation of Pulegone on Transit Time and Castor-Oil Induced Diarrhea in Rat

Background: Pulegone is an allelochemical widely occurring in plants of the Labiatae family. Pulegone has a pleasant mint like odor and therefore is used, directly or as a constituent of a variety of essential oils, in beverages and processed foods for human consumption. Methods: To evaluate the antidiarrheal activity of pulegone using various pharmacological models, the intestinal transit, castor oil induced diarrhea and enteropooling methods were used in this study. The acute toxicity and lethality of pulegone was determined using the Lorke?s method. Results: The pulegone was practically nontoxic administered p.o. The LD50 was 570 mg/kg given p.o. Pulegone (25–100 mg/kg, p.o.) produced insignificant reduction in propulsive movement in the normal and significant (P < 0.05) reduction in castor oil induced intestinal transit tests in rats. Peak effect was elicited at 25 mg/kg but this effect was higher than that produced by loperamide (3 mg/kg, p.o.). In the castor oil induced diarrhea test, high dose of pulegone significantly delayed the onset but did not decrease the frequency and severity of diarrhea. Pulegone at the dose of 25 mg/kg significantly reduced the volume of intestinal secretion induced by castor oil but produced no effect on diarrhea parameters. Conclusion: The results obtained in this study suggest that the pulegone did not possess antidiarrheal property due to weak inhibition of gastrointestinal propulsion and fluid secretion.