Effect of two different formulations of Zincovit tablets on galactose induced cataract in rats

Diabetes is one of the major cause for development of early cataract. Control of blood sugar and enhancement of antioxidant defense remain important goals in the prevention of diabetic cataract. Multivitamins may prevent or delay the development of cataract by their antioxidant action. Hence a commercially available nutrient supplement namely Zincovit tablet along with grape seed extract was tested against experimentally induced diabetic cataract. A total of 48 rats were used in this experiment. Diabetic cataract was induced in 42 rats by administration of 0.5 ml of 50% galactose for 45 days. All the animals including normal control were divided into eight groups (n=6). The rats were given two formulations of Zincovit tablets (40, 80 and 160 mg/kg) along with 0.5 ml of 50% galactose orally to their respective groups for 45 days. Eye was examined daily to check cataract formation. On 46^th day, the rats were sacrificed and lens was separated for estimation of glutathione peroxidase (GPx) activity, superoxide dismutase (SOD) activity, catalase, glucose-6-phosphate dehydrogenase (G6PD) activity, adenosine triphosphate (ATP) level, aldose reductase (AR) level and sorbitol dehydrogenase (SDH). Data showed that there was significant increase in glutathione peroxidase (p=0.010), adenosine triphosphate (p=0.002) and significant decrease (p < 0.001) in aldose reductase level in Zincovit treated animals when compared with galactose induced diabetic cataract control animals. But, there was no significant change in reduced glutathione (GSH), protein thiol, superoxide dismutase, catalase, malondialdehyde, glucose-6-phosphate dehydrogenase and sorbitol dehydrogenase level when compared to control group. Zincovit tablet (vitamin A: 5000 IU with grape seed extract was better in delaying the onset of cataract when compared to other groups.