Fungus-mediated synthesis of silver nanoparticles and evaluation of antitumor activity

Silver nanoparticles (AgNPs) were biologically synthesized using aqueous extract of Agaricus bisporus fungi. Physicochemical analysis of silver nanoparticles revealed that they are of spherical shape ranged size of 8-20 nm, and their zeta potential equal -7.23 mV. Silver nanoparticles showed a dose-dependent cytotoxic effect on MCF-7 breast cancer cells with LD₅₀ (50 μg/ml). Mice bearing Ehrlich solid tumor treated with AgNPs and exposed to gamma radiation significantly ameliorated superoxide dismutase and catalase activity and reduced glutathione with an increase in malondialdehyde and nitric oxide levels compared to tumor group. Gamma radiation with AgNPs induced apoptotic cell count in Ehrlich solid tumor cells from 68.3 (treated with AgNPs) to 98.1 % (treated with AgNPs with gamma radiation) via a mechanism involved caspase-3. Histological sections of tumor tissue of mice treated with AgNPs showed antiangiogenesis effect of AgNPs. The overall result indicates that AgNPs synergize with gamma radiation, promising a potential combined therapy of cancer.