Anti-inflammatory mechanism of Kaempferia parviflora in murine macrophage cells (RAW 264.7) and in experimental animals

Ethnopharmacological relevance: The rhizomes of Kaempferia parviflora Wall. ex Baker have been used in Thailand for treatment of gout, apthous ulcer. peptic ulcer and abscesses. Aim of the study: In our previous study, the crude ethanol extract of Kaempferia parviflora and its compound (5,5-hydroxy-3,7,3',4'-tetramethoxyflavone), was reported to show nitric oxide (NO) inhibition in RAW 264.7 cells. The present study is thus investigated the anti-inflammatory mechanism of Kaempferia parviflora extract and compound 5 against inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) m RNA expressions. Materials and methods: The extract of Kaempferia parviflora and its compound were tested against NO and prostaglandin E-2 (PGE(2)) releases using RAW264.7 cells as well as studied on anti-inflammatory activity in carrageenan-induced rat paw edema and acute toxicity in mice. Results: The results revealed that the ethanol extract of Kaempferia parviflora markedly inhibited PGE2 release with an IC50 value of 9.2 mu g/ml. This plant extract and compound 5 also suppressed mRNA expression of iNOS in dose-dependent manners, whereas COX-2 mRNA expression was partly affected. According to the in vivo study, chloroform and hexane fractions greater decreased rat paw edema than ethanol, ethyl acetate and water fractions. Conclusion: The mechanisms for anti-inflammatory activity of Kaempferia parviflora and compound 5 are mainly due to the inhibition of iNOS mRNA expression but partly through that of COX-2 mRNA. (C) 2009 Elsevier Ireland Ltd. All rights reserved.