Effects of standardized methanol extract of Andrographis paniculata on guinea pig tracheal cyclooxygenase and rat paw inflammation

Abstract

Extracts of Andrographis paniculata Nees is used in traditional medicine for the treatment several diseases including inflammation, asthma and common cold. The aim of this study was to investigate the possible effects of a clinical dose of the methanol extract of A. paniculata (AP) on tracheal cyclooxygenase and inflammation in animals. Ovalbumin (OA) sensitized guinea pigs were orally treated daily for 21 consecutive days with water, 2.86 mg/kg AP, or 10 mg/kg prednisolone. At the end of treatment tracheae were excised and assayed for cyclooxygenase enzyme. The same dose of AP was tested on acute inflammation in rat using 10 mg/kg indomethacin as the positive control. Although 2.86 mg/kg of AP did not significantly reduce guinea pig tracheal cyclooxygenase activity when compared with control it significantly (P < 0.05) reduced rat paw size within the first hour of induction of inflammation. The clinical dose of AP used for the study possesses anti-inflammatory property but higher doses may be more effective in the inhibition of airway cyclooxygenase.

Keywords: Andrographis paniculata; Methanol extract; Asthma; Inflammation; Cyclooxygenase