INVITRO EVALUTION OF ANTIOXIDENT AND ANTIDIABETIC ACTIVITY OF MELIA DUBIA LEAF EXTRACT

Kuludeep T. S.*, Ahalya Devi K. H., Dr. Suresha B. S., Dr. T. Balasubramanian

Background: Diabetes mellitus is a chronic metabolic disorder characterized by persistent hyperglycemia and is frequently associated with oxidative stress. Medicinal plants are considered valuable sources of bioactive compounds with antioxidant and antidiabetic properties. Melia Dubia Cav. (Malabar neem) is a medicinally important tree rich in phytochemicals that may contribute to its therapeutic potential. Objective: The present study was undertaken to evaluate the phytochemical constituents and investigate the in-vitro antioxidant and antidiabetic activities of the ethanolic leaf extract of Melia Dubia. Methods: Preliminary phytochemical screening was performed using standard qualitative methods. Antioxidant activity was assessed by DPPH free radical scavenging, phosphomolybdenum, and reducing power assays using ascorbic acid as the reference standard. In vitro antidiabetic activity was evaluated by α-amylase and α-glucosidase enzyme inhibition assays using acarbose as the standard drug. Percentage inhibition and EC₅₀ values were determined for each assay. Results: Phytochemical screening confirmed the presence of alkaloids, flavonoids, tannins, saponins, steroids, proteins, amino acids and carbohydrates in the ethanolic leaf extract. The extract exhibited concentration-dependent antioxidant activity in the DPPH assay with an EC₅₀ value of 107.13 μg/mL, while the standard showed an EC₅₀ of 71.92 μg/mL. The phosphomolybdenum and reducing power assays further demonstrated appreciable antioxidant capacity. In the α-amylase inhibition assay, the extract showed dose-dependent inhibition with an IC₅₀ value of 220.84 ± 5.18 μg/mL, whereas acarbose exhibited an IC₅₀ of 158.67 ± 10.94 μg/mL. Similarly, the extract displayed significant α-glucosidase inhibitory activity with an IC₅₀ value of 101.84 ± 4.56 μg/mL, although its activity was lower than that of the standard acarbose (IC₅₀ 68.42 ± 3.36 μg/mL). Conclusion: The ethanolic leaf extract of Melia Dubia demonstrated promising antioxidant and in-vitro antidiabetic activities, which may be attributed to its diverse phytochemical constituents. These findings support the traditional medicinal use of Melia Dubia and suggest that it could serve as a potential natural source for the development of antioxidant and antidiabetic agents. Further isolation of active constituents and in-vivo studies are warranted to validate its therapeutic efficacy and safety.