The anti-inflammatory effects of a methanolic extract from Radix Isatidis in murine macrophages and mice

Abstract

Radix Isatidis is the dried root of the plant Isatidis indigotica Fort (family Cruciferae) and traditionally used as an anti-viral, anti-bacterial, anti-endotoxic, and immune regulatory agent in the folk medicine of Korea and China. The aim of the present study was to determine the anti-inflammatory effects of methanolic extracts of Radix Isatidis (RIME) in lipopolysaccharide (LPS)-stimulated murine macrophages and in a TPA-induced ear edema animal model. Anti-inflammatory effects of RIME were examined in LPS-stimulated RAW 264.7 macrophages. In order to investigate the effects of RIME in vivo, activation of myeloperoxidase, and histological assessment were examined in the 12-O-tetradecanoyl-phorbol-13-acetate (TPA)-induced mouse ear edema model. RIME significantly inhibited the release from macrophages of inflammatory mediators such as nitric oxide, prostaglandin E(2), and pro-inflammatory cytokines. Topical administration of RIME at 1-5 mg/ear resulted in reduction of ear inflammation in mice. Thus, our results indicate that the anti-inflammatory effects of RIME involve decreased production of inflammatory mediators, which suggests that RIME may have therapeutic potential in a variety of inflammation-related diseases.