[Evaluation of calcium dobesilate for its anti-cataract potential in experimental rat models].

OBJECTIVE: To investigate the preventive and therapeutic effects of agent calcium dobesilate(CDO) with different doses on the galactose cataract of rats. METHODS: We chose fifty Wistar rats at 20- day old. Then, they were divided into 3 groups at random. Choose 10 rats as the control group and gave normal diet; 10 rats as the model group and fed with Gal solution ( drink 12.5% Gal solution from 1 to 7 days and 10%Gal solution from 8 to 21 days except for normal diet ) ; 30 rats as the treatment group and fed with the same Gal solution as the model group, besides they were divided into high dosage group, medium dosage group and low dosage group equally and gave 300 mg×kg(-1)×d(-1), 150 mg×kg(-1)×d(-1), 75 mg×kg(-1)×d(-1) dose of calcium dobesilate respectively from the first day to the end of experiment. The experiment lasts 21 days. Lens opacity were observed and recorded by slit-lamp examination regularly. Activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-px) and content of malondialdehyde (MDA) were determined to estimate the effect of CDO . Lens fibers changes and Histological changes were observed by scanning electron microscope (SEM) and light microscope (LM) separately. The apoptosis rate of lens epithelium were determined by TUNEL assay. RESULTS: The appearance of Lens opacity in model group was more quickly than that in treatment group in model group, 3 eyes in degree IV, 7 eyes in degree V, while in treatment group, 5 eyes in degree III, 3 eyes in degree IV, 2 eyes in degree V (H = 7.12, P < 0.05). The activity of SOD and GSH-px in treatment group is higher than mode group, but lower than control group on 8th day, there was difference noticed in the activity of SOD (50.01 ± 1.19), (39.39 ± 1.70) , treatment group (46.57 ± 1.09, 46.42 ± 0.87, 45.70 ± 1.46) U/mgProt (F = 88.70, P < 0.05) and the activity of GSH-px (42.92 ± 0.97) , (12.70 ± 1.17) , treatment group (29.16 ± 1.05, 29.08 ± 0.98, 28.25 ± 0.98) nmol/mgprot (F = 1071.89, P < 0.05) ]in 3 groups. The content of MDA in model group (3.43 ± 0.15)nmol/mgprot is higher than treatment group (2.89 ± 0.11, 2.99 ± 0.12, 2.99 ± 0.09)nmol/mgprot (F = 64.62; P < 0.05). There were no statistic significant differences among high dosage group, medium dosage group and low dosage group . The texture of lens fibres detected by SEM in the rats of model was more disorder than treatment group. After HE staining, Lens epithelial cell detected by LM in control group have a clear structure, however, Lens epithelial cell both in model group and treatment group have changed from the initial single layer to multi-storey. Junction between lenses fibers became decreased even disappeared . The apoptosis rate of lens epithelium in treatment group[(2.37 ± 0.17)%, (2.46 ± 0.26)%, (2.79 ± 0.41)%] is higher than control group (0.23 ± 0.07) %, but is much fewer than model group (4.99 ± 0.51) % (χ(2) = 40.41;P < 0.05). CONCLUSION: CDO with different doses could protect lens of rats against galactose damage and there were no significant differences among the different doses of groups.