The dual roles of Ganoderma antioxidants on urothelial cell DNA under carcinogenic attack

Aims of the study: Ganoderma lucidum possesses significant antioxidant and anti-cancer properties. The effects of Lingzhi antioxidants on oxidative DNA damage and oxidative stress were investigated, in order to understand their roles in bladder chemoprevention. Materials and methods: Antioxidant-enhanced extracts were tested, in terms of ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH·) inhibition, hydrogen peroxide (H2O2) and 8-hydroxy-2′-deoxyguanosine (8-OHdG) concentrations, and cytotoxicity, using an in vitro pre-cancerous human uroepithelial cell (HUC-PC) tumorigenic model. Results: Water-soluble extract (GLw) possesses relatively higher antioxidant capacities than the water-insoluble counterpart (GLe); however, under the challenge of carcinogenic 4-aminobiphenyl (ABP), GLw reduced the 8-OHdG concentration in HUC-PC culture, while GLe induced the formation of H2O2and 8-OHdG in a dose-dependent manner. The modern theory of antioxidant-oxidant balance seems to obey the theory of Yin-Yang in traditional Chinese medicine (TCM). Conclusions: Water-soluble and water-insoluble components of Ganoderma lucidum exhibited dual roles in oxidative DNA damage. Oxidative DNA damage may be an underlying mechanism of Lingzhi-induced apoptosis in bladder chemoprevention.