Anti-inflammatory action of γ-irradiated genistein in murine peritoneal macrophage

• Genistein was irradiated at the various doses of 50, 100, and 150 kGy.
• Gamma-irradiated genistein was less toxic to macrophage than non-irradiated genistein.
• Gamma-irradiated genistein treatment reduced NO production and TNF-α and IL-6 release.

This present study was to examine the cytotoxicity and anti-inflammatory activity of gamma (γ)-irradiated genistein in murine peritoneal macrophage. Inflammation to macrophage was induced by adding the lipopolysaccharide (LPS). γ-Irradiated genistein significantly decreased the cytotoxicity to murine peritoneal macrophage in dose ranges from 5 to 10 µM than that of non-irradiated genistein. Anti-inflammatory activity within the doses less than 2 µM showed that γ-irradiated genistein treatment remarkably reduced the lipopolysaccharide-induced inflammation by decreasing the nitric oxide (NO) and cytokines (TNF-α, IL-6) production. In a structural analysis through the high pressure liquid chromatography (HPLC), γ-irradiated genistein showed a new peak production distinguished from main peak of genistein (non-irradiated). Therefore, increase of anti-inflammatory activity may closely mediate with structural changes induced by γ irradiation exposure. Based on the above result, γ-irradiation could be an effective tool for reduction of toxicity and increase of physiological activity of biomolecules.