Effects of Stevia Leaf Extract on Blood Glucose and SOD Activity in Hyperglycemic Rats

Abstract

Background: Hyperglycemia is characterized by elevated blood glucose levels and may induce oxidative stress through excessive production of reactive oxygen species (ROS) that exceed the capacity of antioxidant defense systems. Stevia rebaudiana leaf extract (Stevia rebaudiana) contains antihyperglycemic and antioxidant compounds, including polyphenols and steviol glycosides. Objectives: This study aimed to determine the effect of Stevia leaf extract on blood glucose levels and Superoxide Dismutase (SOD) enzyme activity in hyperglycemic rats (Rattus norvegicus). Methods: This experimental study involved 35 rats divided into a negative control group (K−), a positive control group (K+), and three treatment groups (P1, P2, P3) receiving Stevia rebaudiana extract at doses of 100, 200, and 400 mg/kg body weight. Hyperglycemia was induced using alloxan. Blood glucose levels were measured using a digital analyzer, while SOD activity was assessed colorimetrically. Data were analyzed using the Kruskal–Wallis test followed by the Mann–Whitney test. Results: The mean blood glucose levels in groups K−, K+, P1, P2, and P3 were 93.2 mg/dL, 371.08 mg/dL, 134.3 mg/dL, 130.42 mg/dL, and 113.22 mg/dL, respectively. The mean SOD enzyme activity in groups K−, K+, P1, P2, and P3 were 14.92 U/mL, 13.53 U/mL, 14.57 U/mL, 14.74 U/mL, and 14.93 U/mL, respectively. The P3 group, which received a dose of 400 mg/kgBW, demonstrated the greatest effect on reducing blood glucose levels and increasing SOD activity. Conclusion: Stevia rebaudiana leaf extract significantly reduced blood glucose levels in hyperglycemic rats and showed a tendency to increase superoxide dismutase activity, although the differences in SOD activity were not statistically significant