Evaluation of antioxidant and antiinflammatory activity of ethanolic extracts of <i>Polygonum senticosum</i> in lipopolysaccharide-induced RAW 264.7 macrophages
Chul‐Hwan Kim, Buyng Su Hwang, Yong Pil Hwang, Young Taek Oh, Jin-Woo Jeong
Abstract
Abstract Objectives This study aimed to examine the antioxidant activity and antiinflammatory effects of ethanol extract of Polygonum senticosum (EPS) on lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. Methods Antioxidant activity of EPS was assessed by radical-scavenging effects on ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals. Proinflammatory markers produced by LPS-induced RAW 264.7 macrophages were quantified to assess the antiinflammatory activity of EPS. Results Our results showed that EPS significantly increased FRAP and DPPH radical-scavenging activity. Additionally, EPS reduced LPS-induced proinflammatory mediators, such as nitric oxide (NO) and prostaglandin E 2 (PGE 2 ), along with proinflammatory cytokines, including tumor necrosis factor (TNF)-α and interleukin (IL)-1β, without significant cytotoxicity. EPS significantly downregulated the expression of inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2), TNF-α, and IL-1β in LPS-stimulated RAW 264.7 macrophages. Positive correlations were noted between FRAP and DPPH radical-scavenging activity and antiinflammatory capacity. Conclusions Our results indicate that EPS downregulates the expression of pro-inflammatory mediators such as NO, PGE 2 , and cytokines (IL-1β and TNF-α) in LPS-stimulated RAW 264.7 macrophage cells. Further research is needed for its use as a treatment for inflammation and related diseases.