phytoestrogens and Diabetic-Retinopathy

Diabetes-induced oxidative stress is vital in initiating neuronal damage in the diabetic retina, leading to diabetic retinopathy (DR). This study investigates the possible effects of coumestrol (CMS) on streptozotocin (STZ)-induced DR. First, we established a rat model of DR by STZ injection and a cell model involving high-glucose (HG) exposure of human retinal microvascular endothelial cells (hRMECs). We characterized the expression patterns of oxidative stress indicators, pro-inflammatory cytokines, and pro-apoptotic proteins in hRMECs. Polymerase chain reaction showed sirtuin 1 (SIRT1) to be poorly expressed in the retinal tissues of STZ-treated rats and HG-exposed hRMECs, but its expression was upregulated upon treatment with CMS treatment. Furthermore, CMS treatment attenuated the STZ-induced pathologies such as oxidative stress, inflammation, and cell apoptosis. Consistent with the

Topics: Animals; Apoptosis; Coumestrol; Diabetes Mellitus, Experimental; Diabetic Retinopathy; Disease Models, Animal; Endothelial Cells; Glucose; Humans; Inflammation; Oxidative Stress; Phytoestrogens; Rats; Retina; Retinal Vessels; Sirtuin 1

There is growing evidence that soy isoflavones exert hormonal and antioxidant effects in postmenopausal women. In the present study, 12 postmenopausal Korean women with diabetic retinopathy consumed 2 g of genistein combined polysaccharides (GCP), containing 120 mg of genistein and 57 mg of daidzein, daily for 12 weeks. Blood was collected prior to and after 12 weeks of GCP supplementation for analysis of fasting blood glucose, insulin, lipid profiles, sex hormone-binding globulin (SHBG), estradiol, testosterone, free testosterone, and osteocalcin and activities of glutathione peroxidase (GSH-Px), catalase, and paraoxonase. After GCP supplementation, blood glucose, insulin, total cholesterol, triglyceride, high-density lipoprotein, and low-density lipoprotein cholesterols did not change significantly. However, there were significant increases in SHBG (P < .05) and testosterone (P < .05) and a decrease in estradiol (P < .01). Free testosterone levels were not significantly affected by GCP supplementation. After supplementation, osteocalcin decreased, but the difference was not statistically significant. Although activities of catalase and paraoxonase were unchanged, GSH-Px activity (P < .01) was increased significantly. These findings suggest that GCP supplementation may change the levels of some hormones and improve antioxidant status in postmenopausal Korean women with diabetic retinopathy.

Topics: Antioxidants; Blood Glucose; Diabetic Retinopathy; Dietary Supplements; Estrogens; Female; Genistein; Glutathione Peroxidase; Humans; Insulin; Isoflavones; Korea; Lipids; Middle Aged; Osteocalcin; Phytoestrogens; Postmenopause; Sex Hormone-Binding Globulin; Surveys and Questionnaires; Testosterone