The Antidiabetic Activity of Combining the Aqueous Extracts of Vernonia amygdalina Leaves and Tamarindus indica Fruit Pulp in Streptozotocin-Induced Wistar Rats

Background Many plants are used to reduce the side effects of diabetes mellitus. These plants (including Vernonia amygdalina and Tamarindus indica) are rich in phytochemical compounds that have the ability to reduce glycemia and the effect of diabetes-related oxidative stress. In this study, we aimed to investigate the antioxidant and antidiabetic activities of combining V. amygdalina leaves and T. indica pulp extracts. Methodology We prepared a mixture by combining V. amygdalina leaves and T. indica pulp extracts, and we assessed antioxidant properties via the capacity of both extracts to reduce ferric ions, 2,2-diphenyl-1-picryl-hydrazyl (DPPH) radicals, and hydroxyl radicals. We also assessed antidiabetic properties through the capacity of the extracts’ combination to inhibit alpha-amylase. We evaluated crude fiber, total phenols content (TPC), and total flavonoid content (TFC). Results From our findings, the combination at a concentration of 200 μg/mgE showed that a percentage of 55.17±1.2 could reduce DPPH radicals, 0.366±0.012 could scavenge ferric ions, and 0.233±0.0022 could reduce hydroxyl radicals. With regard to secondary metabolites, we obtained 16.96±0.17 mEGA/gE for total phenol content, 1.74±0.045 mECAT/gE for total flavonoid content, and crude fiber content in our combination at 6.87±1%. These results were obtained with a significant difference at the 5% threshold. The extract combination also showed an alpha-amylase inhibitory percentage of 23.56±4.6% at the concentration of 200 μg/mgE. Daily administration of the combination of extracts significantly lowered the fasting blood glucose, triglycerides, total cholesterol, LDL cholesterol, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, creatinine, and malondialdehyde. However, there was a significant increase in serum proteins and HDL cholesterol. We did not observe an antagonistic effect between our combination and glybenclamide. Conclusion Our formulation, therefore, presents antioxidant and antidiabetic activity and could be used for the management of diabetic patients.