Antioxidant and Anti‐Inflammatory Effects of Herbal Formula SC‐E3 in Lipopolysaccharide‐Stimulated RAW 264.7 Macrophages

SC‐E3 is a novel herbal formula composed of five oriental medicinal herbs that are used to treat a wide range of inflammatory diseases in Korean traditional medicine. In this study, we sought to determine the effects of SC‐E3 on free radical generation and inflammatory response in lipopolysaccharide‐ (LPS‐) treated RAW 264.7 macrophages and the molecular mechanism involved. The ethanol extract of SC‐E3 showed good free radical scavenging activity and inhibited LPS‐induced reactive oxygen species generation. SC‐E3 significantly inhibited the production of the LPS‐induced inflammatory mediators, nitric oxide and prostaglandin E2, by suppressing the expressions of inducible nitric oxide synthase and cyclooxygenase‐2, respectively. SC‐E3 also prevented the secretion of the proinflammatory cytokines, IL‐1β, TNF‐α, and IL‐6, and inhibited LPS‐induced NF‐κB activation and the mitogen‐activated protein kinase (MAPK) pathway. Furthermore, SC‐E3 induced the expression of heme oxygenase‐1 (HO‐1) by promoting the nuclear translocation and transactivation of Nrf2. Taken together, these results suggest that SC‐E3 has potent antioxidant and anti‐inflammatory effects and that these effects are due to the inhibitions of NF‐κB and MAPK and the induction of Nrf2‐mediated HO‐1 expression in macrophages. These findings provide scientific evidence supporting the potential use of SC‐E3 for the treatment and prevention of various inflammatory diseases.