Alpinia calcarata Roscoe: A potent antiinflammatory agent

Aim of the study: Alpinia calcarata Roscoe (Family: Zingiberaceae) rhizomes are often used in Sri Lankan traditional systems of medicine as a remedy for bronchitis, cough, respiratory ailments, diabetics, asthma and arthritis. Generally drugs that are used for arthritis have antinociceptive and antiinflammatory properties. However, validity of the antiinflammatory activity has not been scientifically investigated so far. Therefore, the aim of this study was to investigate the antiinflammatory potential of Alpinia calcarata rhizomes using hot water extract (AWE) and hot ethanolic extract (AEE). Materials and Methods: The antiinflammatory activity of Alpinia calcarata was evaluated by use of the carrageenan-induced paw oedema model in rats. In addition, the mechanism/s by which Alpinia calcarata is mediated the antinflammatory activity was assessed by determining its effects on (a) membrane stabilizing, (b) antihistamine and (c) prostaglandin synthesis inhibition activity. Results: All the tested doses of AWE and AEE (250, 500, 750, and 1000 mg/kg) produced a significant (P <= 0.05) inhibition of the inflammation, most pronounced at 4 h after the injection of carrageenan. The antiinflammatory effect induced by 500 mg/kg of AEE was superior than the reference drug, indomethacin at 4 h. Inhibition of histamine and prostaglandin synthesis production is probable mechanisms by which Alpinia calcarata mediates its antiinflammatory action. Conclusion: These findings rationalize the traditional usage of Alpinia calcarata as an antiinflammatory agent for the first time. (C) 2011 Elsevier Ireland Ltd. All rights reserved.