ABSTRACT
Rumex acetosa is a folk medicine for gastritis and gastric ulcers. In our previous study, the ethanol extract of R. acetosa inhibited gastric ulcers and protected gastric tissue in mice induced with HCl/ethanol from gastric ulcers. Moreover, we isolated six anthraquinone compounds from this plant and evaluated their antiHelicobacter pylori activity. Therefore, this study was conducted to identify further the related antioxidant and anti-inflammatory activities and the bioactive constituents. Five fractions of n-hexane, methylene chloride, ethyl acetate, n-butanol, and aqueous fractions were obtained from the total ethanolic extract from whole parts of R. acetosa that had exhibited antioxidant and anti-inflammatory activities. The ethyl acetate fraction contained the highest total phenol and flavonoid contents among the five fractions and exhibited the most potent antioxidant effect on 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay. Among the six compounds, emodin showed the most potent antioxidant activity. Next, we induced inflammation in the LPS-induced RAW 264.7 cell line. The methylene chloride fraction showed the strongest reducing nitric oxide production activity among the fractions. In addition, the methylene chloride fraction suppressed the phosphorylation of ERK and JNK, and the expression of cyclooxygenase-2 in a dose-dependent manner. These physiological activities of the fraction and the compounds could be involved in the anti-gastric ulcer activity of R. acetosa