Inhibition of nitric oxide production and mRNA expressions of proinflammatory mediators by xylarinic acid A in RAW 264.7 cells

Mushrooms possess vast and yet unknown source of powerful new pharmaceutical products, which contain active biomolecules. Xylarinic acid A isolated from a mushroom, Xylaria polymorpha, has been reported to have free radicals scavenging property and anti-fungal activity. However, information of its anti-inflammatory activity is scarce. Therefore, the objective of this study was to examine the effect of the compound on the gene expression levels of inflammatory mediators and pro-inflammatory cytokines. MTT assay, NO assay, semi-quantitative reverse transcription-polymerase chain reaction (RT- PCR) and quantitative real time PCR (qPCR) were performed to determine the effect of xylarinic acid on cell viability, NO production and mRNA expression levels in LPS-treated RAW 264.7 mouse macrophage-like cells. As such, xylarinic acid A inhibited nitric oxide production and mRNA expressions of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), interleukin-1β (IL-1β) and interleukin-6 (IL-6) in a concentration dependant pattern without cytotoxicity effect. Our preliminary result indicates that xylarinic acid A might have anti-inflammatory property.