Abstract:

Objective  To investigate the effects of melatonin(MLT) in preventing hydrogen peroxide-induced cataract in rats. Methods  The lenses of the cultured normal Wistar rats in vitro were randomly divided into 3 groups: the control group (group A ), the group treated by hydrogen peroxide(group B), and the group treated by hydrogen peroxide and melatonin(10, 30, 50, 100 and 200μmol/L) (group C1, group C2,  group C3, group C4 and group C5). At the end of the study period (24th hour), the lenticular opacification of lenses was examined and the mean densities of black bands under the lenses were analyzed by Image-Pro Plus（IPP）6.0 software .At the same time, the levels of protein, glutathione(GSH), malondialdehyde(MDA), total antioxidiation ability(TAOC), superoxide dismutase(SOD) and catalase (CAT) were tested. Results  The lenses were observed with slit-lamp microscope after 24 hours of incubation, and there were differences in lenticular opacification between each group. The mean density of lenses in Group C was significantly higher than lenses in Group B (P<0.05). To compare with the biochemical parameters of group B, the levels of GSH, T-AOC, SOD and CAT of group C increased statistically; the level of MDA reduced statistically(P<0.05). Conclusion  Melatonin can effectively enhance antioxidant ability of the oxidative damaged lense, and also can inhibit the development of hydrogen peroxideinduced cataract of rats in vitro.

Key words: Melatonin; Cataract; Lens; Lens epithelial cells; Rats,Wistar