Effects of 17beta‐estradiol in human lens epithelial cells

Abstract

Abstract Purpose Studies have shown that postmenopausal women have an increased incidence of cataract and it has been suggested that estrogen such as hormone replacement therapy may have protective effects against cataract. The purpose of this study was to investigate the effects of 17beta‐estradiol in cultured human lens epithelial cells (HLEC). Methods HLEC were exposed to 17beta‐estradiol for 24h and cell number, apoptosis, peroxides, superoxides, glutathione (GSH) and membrane potential were measured using MTT and fluorescent probes for detection of reactive oxidative species (ROS) and caspase‐3 activity. Cells were also simultaneously incubated with 17beta‐estradiol and 25µM H202 for 24h after which the levels of ROS, GSH and the change in mitochondrial potential was measured. Results Higher concentrations of 17beta‐estradiol (10 µM) showed increased levels of peroxides, superoxides, caspase‐3, MTT, propidium iodide and decreased levels of GSH. Lower concentrations of 17beta‐estradiol (0.1‐10nM) increased the membrane potential and decreased the level of propidium iodide. Low concentrations of 17beta‐estradiol also showed protective effects against oxidative stress induced by H202, which was shown by the reduced production of both peroxides and superoxides. Conclusion Low concentrations of estrogen may have an antioxidative effect against H202 in cultured HLEC, whereas high concentrations of estrogen alone may induce oxidative damage.