Anti-inflammatory and analgesic effect of bromelain in mice and rats

Bromelain is a crude aquaeous extract obtained from both the stem and fruit of the pineapple plant, which contains a number of proteolytic enzymes. The analgesic and anti-inflammatory activities of bromelain were investigated. Bromelain was evaluated for anti-inflammatory effect by carrageen-induced rat paw edema. The analgesic activity was tested by acetic acid-induced writhing response and hot plate method in albino mice. Twenty adult male Balb/c mice (20-25 g) were used to evaluate the analgesic effect. And 25 male Sprague-Dawley rats (200-250 g) were used to study the anti-inflammatory activy. This study showed that bromelain in doses of 10; 20 and 40 mg/kg showed 11.3; 45.1 and 56.3% inhibition of paw edema respectively at the end of three hours, and the percentage of protection from writhing was 11.1; 23.4 and 40.8% respectively. In the hot plate model, the bromelain at 20 and 40 mg/kg increased the pain threshold significantly after 30 min, 1, 2 and 4 h of administration. Bromelain showed dose-dependent action in all the experimental models. These study suggest that bromelain has anti-inflammatory and analgesic properties.