GSR and prostate cancer: In a model of hormone- and carcinogen-induced prostate cancer in Sprague‒Dawley rats, supplementation of quercetin during prostate cancer initiation resulted in increased levels of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GSR) compared to the control group without quercetin supplementation [100].