Phyllanthus niruri Linn. (Euphorbiaceae) is a small herb and is categorised as one of the rich medicinal plants throughout the world. This study aimed to evaluate the P. niruri L. whole plant extract (PNE) for secondary metabolite assay (total phenolic and terpenoid content) followed by the potential antioxidant activity (ABTS diammonium salt radical assay, DPPH· activity, superoxide anion (O2-) radicals' assay, and nitric oxide (NO) radical generation) and antidiabetic activity in vivo and in vitro in streptozotocin (STZ) induced albino mice. PNE showed good scavenging activity with a value of 286.45 ± 6.55 mg TE/g and 194.54 ± 4.64 mg TE/g in ABTS and DPPH assays respectively. In the superoxide anion assay, the PNE caused a dose-dependent inhibition at the lowest IC25 value of 0.17 ± 0.00 mg/mL compared to ascorbic acid (IC25 of 0.25 ± 0.02 mg/mL). The scavenging ability of PNE against nitric oxide showed an IC25 of 1.13 ± 0.04 mg/mL compared to ascorbic acid (IC25 4.78 ± 0.09 mg/mL). Unlike diabetic control mice, the PNE-treated diabetic mice presented significant amelioration of glycaemia and lipid dysmetabolism. Phytochemicals like Astragalin, Gallocatechin, Ellagic acid, Gallic acid, Brevifolin carboxylic acid, Phyllnirurin, and Hypophyllanthin showed significant docking score (> -4) of inhibitory potential with DPP-IV protein. Results indicated that PNE phytochemicals could be a promising antidiabetic agent by targeting DPP-IV.
Keywords: Antidiabetic; DPP-IV inhibition; Phyllanthus niruri; astragalin; phyllanthin.