Rapid action of oestradiol against hydrogen peroxide-induced oxidative stress in cataractous lens epithelium: an in vitro study.
OBJECTIVE
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 17beta-oestradiol for varying time intervals from 1 to 5 min followed by treatment with H(2)O(2) (5 x 10(-6) M) in the culture medium. Catalase activity was measured to access the oxidative stress levels.


RESULTS
LECs exposed to H(2)O(2) (5 x 10(-6) M) showed a fourfold increase in catalase activity (407.03+/-89.11 U/microg protein) after 6 h when compared to cultured unexposed LECs (97.124+/-9.4 U/microg protein). When the cultured LECs were treated with oestradiol (5 x 10(-8) M) before H(2)O(2) 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).


CONCLUSIONS
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.
Gajjar
D
D
Department of Molecular Biology, Iladevi Cataract and IOL Research Centre, Ahmedabad, Gujarat, India.
Patel
D
D
Alapure
B
B
Praveen
M R
MR
Patel
A
A
Johar
K
K
Vasavada
A R
AR
D000368:Aged; D000975:Antioxidants / Q000378:metabolism; D002374:Catalase / Q000378:metabolism; D002386:Cataract / Q000188:drug therapy* / Q000201:enzymology; D002478:Cells, Cultured; D004847:Epithelial Cells / Q000187:drug effects* / Q000201:enzymology; D004958:Estradiol / Q000494:pharmacology*; D004967:Estrogens / Q000494:pharmacology*; D005260:Female; D006801:Humans; D006861:Hydrogen Peroxide; D007908:Lens, Crystalline / Q000166:cytology* / Q000201:enzymology; D015227:Lipid Peroxidation / Q000187:drug effects; D008297:Male; D008875:Middle Aged; D016877:Oxidants; D018384:Oxidative Stress / Q000187:drug effects*; D020011:Protective Agents / Q000494:pharmacology
D000975:Antioxidants; D004967:Estrogens; D016877:Oxidants; D020011:Protective Agents; D004958:Estradiol; D006861:Hydrogen Peroxide; D002374:Catalase