Antitussive Effect of Thymoquinone, a Constituent of Nigella Sativa Seeds, in Guinea Pigs

Abstract

The antitussive activity of thymoquinone, a constituent of Nigella sativa seeds, was evaluated using the nebulized solution of citric acid 20 % in guinea pigs. Thymoquinone and codeine were injected intraperitoneally. Thymoquinone (20 and 40 mg/kg) and codeine (5 mg/kg), a prototype antitussive agent, reduced the number of cough in animals. The antitussive effect of these agents was antagonized by pretreatment with naloxone (2 mg/kg), an opioid receptor antagonist. These results suggest that thymoquinone has antitussive