In vitro anti-oxidative and anti-inflammatory effects of solvent-extracted fractions from Suaeda asparagoides

Suaeda asparagoides Miq. (Chenopodiaceae: S. asparagoides) is a salt-marsh plant that has long been prescribed in traditional Oriental medicine for the treatment of hypertension and hepatitis. In order to elucidate the pharmacological mechanisms of the herb, we conducted an examination of the anti-oxidative and anti-inflammatory properties of solvent-extracts of S. asparagoides. All of the solvent fractions showed potent anti-oxidative effects, as assessed using a radical generation assay system (xanthine oxidase assay) and an electron-donating activity system (DPPH [2,2-diphenyl-I-picrylhydrazyl radical] assay), with IC₅₀ values ranging from 9 to 42 μg/ml. In agreement with this pattern, the total phenolic contents were widely distributed in the various solvent fractions, and ranged from 36.5 to 50.3 mg/g of dry weight. All of the solvent fractions significantly suppressed NO production in RAW264.7 cells induced by lipopolysaccharide (LPS, 0.1 μg/ml) and of the fractions, only the chloroform (CHC) fraction completely blocked the expression of inducible NO synthase (iNOS). Additionally, the hexane (HEX) and CHC fractions suppressed the mRNA expression of granulocyte/macrophage colony-stimulating factor (GM-CSF) and monocyte chemoattractant protein 1 (MCP-1), respectively, in the LPS-stimulated RAW264.7 cells. Therefore, these results suggest that the pharmacological action of S. asparagoides is due to its potent anti-oxidative effects and anti-inflammatory effects, and that therefore it can be applied to other diseases caused by oxidative stress and inflammation, such as cardiovascular diseases.