Anti-inflammatory and antioxidant effects of methanol extract of Sedum latiovalifolium in LPS-stimulated RAW 264.7 cells

Abstract

Regulating overactive inflammatory responses with plant-derived substances to circumvent side effects is a new strategy for treating chronic inflammatory diseases such as rheumatoid arthritis, Crohn’s disease, and cancer. Excess ROS generation in response to inflammatory reactions is involved in the progression of these diseases. Therefore, in this study, the anti-inflammatory and antioxidant activities of methanol extract of Sedum latiovalifolium (MESL) were investigated in LPS-stimulated RAW 264.7 cells. MESL treatment decreased LPS-induced NO production and decreased the RNA and protein expression levels of iNOS, a NO producer. In addition, MESL treatment decreased the secretion of major inflammatory cytokines, such as TNF-α and MCP-1, and the RNA expression of TNF-α, MCP-1, IL-6, and IL-1β. NF-κB, a crucial transcription factor for inflammation, was inactivated through the inhibition of phosphorylation of its regulators, IκB and IKK. In addition, the phosphorylation levels of MAPKs, an upstream factor of NF-κB, was decreased in the MESL-treated group. Compared to that in the treatment with ascorbic acid at the same concentration, there was a 60% radical scavenging activity and increased expression of HO-1. Therefore, MESL can suppress the inflammatory response by regulating inflammatory factors and by increasing the expression of antioxidant enzymes in LPS-induced RAW 264.7 cells. These results suggested that MESL can be used a promising therapeutic for treating inflammation-related disease.