Six-shogaol inhibits production of tumour necrosis factor alpha, interleukin-1 beta and nitric oxide from lipopolysaccharide-stimulated RAW 264.7 macrophages

Objective: We previously reported that 6-shogaol, a phenolic compound from ginger, has anti-inflammatory properties in a Complete Freund's Adjuvant (CFA) model of mono-arthritic rats. In the present study, we investigated the effects of 6-shogaol on the production of inflammatory mediators from lipopolysaccharide (LPS) activated RAW 264.7 macrophages. These mediators (TNF-α, IL-1-β and NO) and their output from macrophages are involved in various pathophysiological events of chronic inflammation and arthritis. Methods: Effects of 6-shogaol were investigated on the production of the mediators TNF-α, IL-1-β and NO (measured as nitrate) from macrophages. Lipopolysaccharide activated RAW 264.7 macrophages were cultured in the presence and absence of 6-shogaol (2μM, 10μM and 20μM) and ELISA was used to quantify the output of the mediators. Results: 6-shogoal (2μM, 10μM and 20μM) significantly inhibited the production of nitric oxide (NO), IL-1β and TNF-α from the LPS activated RAW264.7 macrophages. Conclusion: The results suggest that macrophages are targets for the anti-inflammatory effects of 6-shogaol. Also, the inhibitory effects against TNF-α, IL-1β and NO production from LPS activated macrophages are cellular mechanisms by which 6-shogaol produced its anti-inflammatory effects. These mechanisms provide an explanation of the protection by 6-shogaol against development of joint inflammation and cartilage degradation in CFA induced mono-arthritis that we previously demonstrated (1). Based on these results with 6-shogaol, there is evidence that it exhibits exploitable anti-inflammatory properties.