Effects of Strobilanthes crispus juice on activity of superoxide and dismutase and glutathione peroxidase in normal and streptozotocin-induced diabetic rats

Increased oxidative stress has been reported in patients with diabetes mellitus. Accumulating evidence suggests that oxidative cellular injury caused by free radicals contributes to the development of diabetes mellitus. Reactive oxygen species generated in the cells are scavenged by antioxidant enzymes. Moreover, diabetes also induces changes in the tissue content and activity of the antioxidant enzymes. This study was to determine the effect of Strobilanthes crispus juice on the activity of antioxidant enzymes such as superoxide dismutase (SOD) and glutathione peroxidase (GPx) in normal and streptozotocin-induced diabetic male albino Sprague dawley rats. This study was conducted on normal and streptozotocin-induced diabetic male Sprague dawley rats fed with basal diet and Strobilanthes crispus juice with difference doses 0.5, 0.75 and 1.0 ml/kg body weight for 21 days. A total of 54 male albino Sprague dawley rats (24 normal and 30 streptozotocin-induced diabetic rats), weight 150 -200 g were used. The rats were divided into 9 groups with 6 rats in each group. SOD and GPx were determined at day 0 (baseline) and day 21 by fully-automated spectrophotometric method. The results showed that the activity of SOD decreased significantly (p < 0.05) compared with baseline data, both in normal and diabetic group. A significant decrease in SOD activity were found in diabetic rats treated with 0.5 m1/kg b.w S.crispus juice (0.86 ± 0.04 units/L), 0.75 m1/kg b.w S.crispus juice (0.89 ± 0.28units/L)and 1.0 ml/kgb.w S.crispus juice (0.87 ± 0.08units/L). Significant decrease of SOD was also observed in the normal rats treated with 0.5 m1/kg b.w S.crispus juice (0.74 ± 0.26 units/l), 0.75 ml/kg b.w S.crispus juice 1.00 ± 0.80 units/L) and 1.0 m1/kg b.w S.crispus juice (0.91 ± 0.21 units/L). SOD activity in diabetic rats treated with S.crispus juice (0.5, 0.75 and 1.0 ml/kg b.w) was also low compared in diabetic control. GPx activity significantly increased (p < 0.05) in diabetic rats treated with 0.75 and 1.0 ml/kg b.w S.crispus juice (2506.14 ± 49.96 and 2701.96 ± 414.51 units/ml) when compared to diabetic control group (1914.88 ± 270.68 units/mI). GPx activity has no significant difference between treated and non treated in normal group. In conclusion, S. crispus juice which contains catechins, alkaloids, caffeine and tannin, may have a protective role for both GPx and SOD by replacing or compensating their activities in removing hydrogen peroxide and scavenging superoxide free radicals respectively.