Antioxidant and Anti-inflammatory Activities of Butanol Extract of Melaleuca leucadendron L.

摘要

Melaleuca leucadendron L. has been used as a tranquilizing, sedating, evil-dispelling and pain-relieving agent We examined the effects of M. leucadendron L. extracts on oxidative stress and inflammation. M. leucadendron L. was extracted with methanol(MeOH) and then fractionated with chloroform (CHCI3) and butanol (BuOH). Antioxidant activity of the MeOH extract and BuOH fraction were higher than that of both a-tocopherol and but} rated hydroxy toluene (BHT). Total phenol content in the extracts of M. leucadendron L., especially the BuOH fraction, well correlated with the antioxidant activity. The anti-inflammatory activity of BuOH extracts were investigated by lipopolysaccharide (LPS)-induced nitric oxide (NO) and prostaglandin E2 (PGE2) production, and cyclo-oxygenase-2 (COX-2) expression in RAW 264.7 macrophages. The BuOH fraction significantly inhibited LPS-in-duced NO and PGE2 production. Furthermore, BuOH extract of M. leucadendron L. inhibited the expression of COX-2 and iNOS protein withoutan appreciable cytotoxic effect on RAW264.7 cells. The extract of M. leucadendron L. also suppressed the phosphorylation of inhibitor kBo. (IkBo) and its degradation associated with nuclear factor-kb (NF-kB) activation. Furthermore, BuOH fraction inhibited LPS-induced NF-kB transcriptional activity in a dose-dependent manner. These results suggested that M. leucadendron L. could be useful as a natural antioxidant and anti-inflammatory resource.