Rapid action of oestradiol against hydrogen peroxide-induced oxidative stress in cataractous lens epithelium: an in vitro study

Purpose To evaluate the short-term protective effects of oestradiol against damages because of oxidative stress in human lens epithelial cells (LECs). Methods The central zone of human lens epithelium was obtained from the cataract surgery and cultured in MEM culture medium. These cultured LECs were treated with 17 beta-oestradiol for varying time intervals from 1 to 5 min followed by treatment with H2O2 (5 x 10(-6) M) in the culture medium. Catalase activity was measured to access the oxidative stress levels. Results LECs exposed to H2O2 (5 x 10(-6) M) showed a fourfold increase in catalase activity (407.03 +/- 89.11 U/mu g protein) after 6 h when compared to cultured unexposed LECs (97.124 +/- 9.4 U/mu g protein). When the cultured LECs were treated with oestradiol (5 x 10(-8) M) before H2O2 treatment, the increase in catalase activity was inhibited, whereas simultaneous and post-treatments showed no effect. The catalase activity of LECs pretreated with oestradiol for 1, 2, 3, and 5 min was 259.92 +/- 18.37, 200.24 +/- 14.39, 140.50 +/- 19.83, and 110.01 +/- 14.66, respectively (P < 0.0001). Conclusion Antioxidative enzymes are synthesized in response to the oxidative stress signal. Upon treatment with oestrogen catalase is not synthesized. The pretreatment time of oestrogen required for its antioxidative effect can be seen within 5 min indicating non-genomic mode of action of oestrogen. Eye (2009) 23, 1456-1463; doi:10.1038/eye.2008.284; published online 19 September 2008