In vitro antioxidant and ptp inhibitory activity of methanolic extract of Anogeissus acuminata leaf and bark

Objective: Anogeissus acuminata is a plant rich in tannins and flavonoids. Various parts of the plant are used in traditional medicine for diabetes mellitus and inflammatory conditions. In the present study, methanolic extracts of leaf and bark are evaluated for their in vitro antioxidant and PTP 1B inhibitory activity. Methods: In vitro antioxidant activity was analyzed by 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay, reducing power assay and TBA (thiobarbituric acid) assay, using vitamin C as a standard. Moreover, antidiabetic potential was evaluated using in vitro protein tyrosine phosphatase 1B (PTP1B) inhibition assay using Suramin as a standard. Results: IC50 values for Vitamin C, leaf and bark of the plant in DPPH assay were 45.51 ± 6.657, 111.9 ± 5.534 and 80.9 ± 5.329 ìg/ml, respectively. The extracts also exhibited significant reducing powers and inhibition of lipid peroxidation comparable to that by Vitamin C (P <0.01). Both extracts also demonstrated significant PTP 1B inhibitory activity with IC50 values 20.7± 7.6 and 11.59 ± 7.8 ìg/ml for leaf and bark extracts respectively. Conclusion: Leaf and bark extracts of Anogeissus acuminata demonstrated potent in vitro anti-oxidant and PTP1B inhibitory activity.