Effect of garlic (Allium sativum L.) stems on inflammatory cytokines, iNOS and COX-2 expressions in Raw 264.7 cells induced by lipopolysaccharide

In this study, the anti-oxidant and anti-inflammatory activities of water extract (ASSW) and 70% ethanol extract (ASSE) of Allium sativum L. stems were investigated using Raw 264.7 cells induced by lipopolysaccharide (LPS). ABTS radical scavenging activities of ASSW and ASSE at concentration were 96.9% and 97.8%, respectively. In order to investigate the potential anti-inflammatory effects of ASSW and ASSE, nitric oxide (NO), pro-inflammatory cytokines, interleukin-6 (IL-6), and tumor necrosis factor including (TNF-), interleukin- (IL-), and prostaglandin-E2 (PGE2) were measured. ASSW and ASSE at concentration showed inhibitory effects against NO production by 18% and 23%, respectively. Production of IL- and IL-6 after treatment with ASSW and ASSE at decreased by approximately 28% and 15% for ASSW and 17% and 12% for ASSE, respectively. In addition, production of TNF- after treatment of of ASSW and ASSE decreased by 24% and 23%, respectively. In addition, the treatment of of ASSW and ASSE showed inhibitory expressions against PGE2 by 45.47% and 33.87%, respectively. These results suggested that ASSE showed greater inhibitory activity than that of the ASSW by the suppression of inflammatory mediators, including NO, IL-6, TNF- and PGE2 production, and the expressions of iNOS and COX-2 in macrophages. In conclusion, ASSW and ASSE may have some ancillary effects on inflammatory factors as potential anti-inflammatory agents.