Suppression of arachidonic acid metabolism and nitric oxide formation by kudzu isoflavones in murine macrophages

Abstract

Inhibitory effect of kudzu isoflavones on arachidonic acid metabolism and nitric oxide (NO) production in lipopolysaccharide activated RAW 264.7 macrophages were investigated. Isoflavone aglycones, such as daidzein, genistein, biochanin A, and formononetin significantly suppressed arachidonic acid release (50 microM). Biochanin A, which displayed the most active inhibition on arachidonic acid release in HT-29 human colon cancer cells, exhibited its most potent suppression in RAW 264.7 cell (by 86%) without showing cytotoxicity. However, isoflavone glucosides, puerarin and daidzin, showed lower inhibitory activities on the release of arachidonic acid and its metabolites. In NO formation, biochanin A showed marked inhibition, by 62% (50 microM), followed by genistein, daidzein, formononetin, and daidzin, 56, 39, 33, and 8%, respectively. 5,7-Dihydroxyl group in the A-ring of isoflavones could be a key functional group responsible for the strong inhibitory activity of biochanin A and genistein on NO production. These activities may contribute to the antiinflammatory and anticarcinogenic properties of kudzu isoflavones.

Anti-platelet effects of flavonoids and flavonoid-glycosides from Sophora japonica

“…Takano-Ishikawa et al (2006) suggested that flavonoids, such as genistein (3) and apigenin (8) strongly inhibit PGE 2 production through suppression of COX-2 protein expression. Antioxidant effect of biochanin A (1), irisolidone (2) and genistein (3) have also been reported (Jun et al, 2005;Kang et al, 2007;Rufer and Kulling, 2006). The inhibitory effects on enzymes, such as tyrosine kinase or COX, and the antioxidant effects of flavonoids may contribute to their effects on platelet aggregation.…”

Novel herbal flavonoids promote apoptosis but differentially induce cell cycle arrest in human colon cancer cell

“…Despite a few reports from mainland China that exemplified the antioxidative property of Astragalus flavonoids and saponins by inhibiting membrane lipid peroxidation, the anticarcinogenic effects of the former compound in human have not been clarified. Besides, formononetin is a major isoflavone constituent of Radix Astragali that has demonstrated beneficial metabolic [23], cardiovascular [24], antidiabetic [25], analgesic [26], antiinflammatory [27] and the proposed anticarcinogenic [28] effects. In the present study, we first evaluated the inhibitory effect exhibited by the total isoflavonoids extract AFT by MTT assay and observed the decrease of cell viability with increasing drug concentrations at different treatment times (Fig.…”

Kudzu root: Traditional uses and potential medicinal benefits in diabetes and cardiovascular diseases

“…Biochanin A exhibited the greatest suppression of the arachidonic acid release on macrophages by about 86% without any cytotoxic effects. Isoflavone glycosides, puerarin and daidzin, demonstrated less inhibitory effects on the release of arachidonic acid as compared with that of the aglycones (Jun et al, 2005). It is suggested that the declined activity of the isoflavone glycosides may be related to the higher hydrophilicity and steric hindrance of the additional sugar moiety, which reduces the uptake level into the cells (Kim et al, 1999).…”