Anti-inflammatory and antipyretic properties of Clerodendrum petasites S. Moore.

The methanol extract from Clerodendrum petasites S. Moore (CP extract) was assessed for anti-inflammatory and antipyretic activities on the experimental animal models. It was found that CP extract possessed moderate inhibitory activity on acute phase of inflammation in a dose-related manner as seen in ethyl phenylpropiolate-induced ear edema (ED(50)=2.34 mg/ear) as well as carrageenin-induced hind paw edema (ED(30)=420.41 mg/kg) in rats. However, CP extract did not elicit any inhibitory effect on arachidonic acid-induced hind paw edema in rats. In subchronic inflammatory model, CP extract provoked a significant reduction of transudation but had no effect on proliferative phase when tested in cotton pellet-induced granuloma model. CP extract also reduced the alkaline phosphatase activity in serum of rats in this animal model. Moreover, CP extract possessed an excellent antipyretic effect when tested in yeast-induced hyperthermic rats. It is postulated that the anti-inflammatory and antipyretic effects of CP extract are caused by the inhibition of the prostaglandin synthesis. Anyhow, CP extract did not possess any analgesic activity in acetic acid-induced writhing response in mice. The results obtained show that C. petasites has beneficial properties since it possesses potent antipyretic and moderate anti-inflammatory activities without ulcerogenic effect.