In vitro Evaluation of Antidiabetic, Antioxidant, Cytotoxic Activities and Phytochemical Screening of Methanolic Extracts of Thevetia peruviana Bark and Solanum viarum fruit

North Eastern State Tripura is enriched with different types of natural plant resources. Tribal people use various traditional methods to treat various types of diseases with such unearthed plant resources. Thevetia peruviana bark and Solanum viarum fruit are used by the tribal people of Tripura to treat diabetes. In this study an attempt is made to verify the claim of the tribal people of Tripura by performing various analytical tests. The bark extract of T. peruviana and fruit extract of S. viarum were prepared by Soxhlet apparatus with methanol, ethanol and water. Extracted materials were evaluated for phytochemical analysis, in vitro antioxidant by DPPH and HRSA method, antidiabetic activity by inhibition assay for α-glucosidase and α-amylase enzyme as well cytotoxicity against HePG2 cells. Results revealed that methanolic extract of T. peruviana bark (mTp) and S. viarum (mSv) fruit were in light to dark brown in color with yield of 22 % and 38% respectively. The mSv showed highest antioxidant activity of 50.996±0.084% and 80.786±0.126% compared to mTp of49.122±0.914% and 79.832±0.786% in DPPH and HRS assay. In comparing the in vivo antidiabetic activity, both mSv and mTp showed significant α-glucosidase, α-amylase inhibitory potential with IC₅₀ values of 65.72%, 68.81% and 61.61%, 66.61% respectively. The cytotoxicity study revelated that mTp was significantly inhibited the viability of HepG2 cellswith IC₅₀ of 155.89±2.11μg/mL than mSv of 232.47±4.22μg/mL at 48hours treatment. Taken together, these finding suggested that methanolic extract of T. peruviana bark and S. viarum fruit can be castoff as a latent source of antidiabetic, antioxidant and cytotoxic agents which has further supported the scientific validation of folklorepractices by the Tribal people of Tripura.