Anti-inflammatory effects of zingiber officinale roscoe involve suppression of nitric oxide and prostaglandin E2 production

Abstract

Background and objective: Inflammation is a physiological response to injury and infection. However, chronic inflammation causes tissue damage and is a feature of most chronic diseases. Despite significant progress in developing therapies to target chronic inflammation over the years, almost all current therapies have serious side effects. The current investigation is to identify naturally-existing anti-inflammatory therapies with fewer side effects. Methods: The anti-inflammatory effects and mechanisms of action of extracts and fractions obtained using vacuum liquid chromatography (VLC) from ginger (Zingiber officinale) on the production of nitric oxide (NO) and prostaglandin E2 (PGE2) were investigated. NO and PGE2 production were induced by stimulating the mouse RAW264.7 monocyte/macrophage cell line with lipopolysaccharide (LPS). Levels of NO and PGE2 were determined using the Griess method and enzyme linked sorbent assay (ELISA), respectively. Results: Extracts of two Zingiber officinale species obtained with chloroform showed potent inhibitory effects on NO and PGE2 production. The extracts had a higher potency than N(G)-nitro-L-arginine methyl ester (L-NAME), a known specific inducible nitric oxide synthase (iNOS) inhibitor and were comparable in their effects on PGE2 with Indomethacin, a specific PGE2 inhibitor. Further, we identified a fraction (F6) that had most potent inhibitory effects. Conclusion: The study shows that extract of Zingiber officinale have strong inhibitory effects on key pro-inflammatory mediators involved in chronic inflammation. Both the extracts and F6 had better inhibitory effects than established pharmaceutical inhibitors of NO and PGE2.