White mushroom Agaricus bisporus extract inhibits oxidative DNA damage in human lymphocytes as assessed by comet assay

Abstract

White mushroom Agaricus bisporus, one of the many known medicinal mushrooms, Agaricus bisporus contains antioxidant activities. The antioxidant effects of the mushroom may be partly explained by protection of cell components against free radicals. We evaluated the effect of aqueous Agaricus bisporus extracts for their potential for protecting against oxidative damage to DNA in human lymphocytes. Cells were pretreated with various concentrations (10, 50, 100 and 500 μg/mL) of the extract (Sclerotium and Mycelium) for 1 h at 37 ^oC. Cells were then treated with 100 μM of H₂O₂ for 5 min as an oxidative stress. Evaluation of oxidative damage was performed using single-cell gel electrophoresis for DNA fragmentation (Comet assay). Using image analysis, the degree of DNA damage was evaluated as the DNA tail moment. Cells pretreated with Agaricus bisporus extract showed over 30% reduction in DNA fragmentation compared with the positive control (100 μmol H₂O₂ treatment). Thus, Agaricus bisporus treatment affords cellular protection against endogenous DNA damage produced by H₂O₂.