In vitro pharmacological evaluation, phytochemical profiling, and in silico molecular docking of Duabanga grandiflora leaves and flowers

Duabanga grandiflora , a traditional medicinal plant of the Darjeeling Himalayan region, has not been broadly explored previously for its phytochemical and biological potential. The present study was performed to evaluate in vitro biological activities, the bioactive phytochemicals, and in silico molecular docking validation of D. grandiflora . For biological evaluation, TPC, TFC, the antioxidant (DPPH, metal chelating and reducing power), antidiabetic, anti-inflammatory activity, and cytotoxicity study were determined. The phytochemicals were measured by HPTLC analysis. The hydroalcoholic extract of leaves was found to have the highest phenolic (1093.87 ± 30.91 GAE/g DW) and the chloroform extracts of flowers were found to have the highest flavonoid (955.78 ± 37.01 mg QE/g DW) content. The result showed that hydroalcoholic extract exhibited significant DPPH in flowers (IC 50 :25.72 ± 1.58 µg/mL), metal chelating in leaves (IC 50 :71.25 ± 6.45 µg/mL), and α-amylase in flowers (IC 50 :26.24 ± 2.01 µg/mL) as compared to standards. The methanolic extract of leaves was considered to have significant anti-inflammatory activity (IC 50 :39.61 ± 2.17 µg/mL). Ethyl acetate extract of leaves exhibited high cytotoxicity activity (IC 50 : 7.29 µg/mL). HPTLC bioautography has identified gallic acid, caffeic acid, and naringenin as antioxidant potential. These compounds as identified by HPTLC were analyzed using in silico molecular docking studies to determine the binding affinity between the ligands and the enzymes (1J2E, 1PRG, 2H6D, 3E87, 3IOL, and 9ILB). It might be claimed from the study that D. grandiflora contains bioactive compounds which are responsible for not only antioxidant activity but also antidiabetic, anti-inflammatory activity, as indicated by in vitro and in silico studies.