Diabetes is a chronic metabolic disorder that affects an increasing number of people worldwide, frequently managed with syn thetic drugs that have side effects and can be costly. Apteranthes tuberculata (N.E.Br.) Meve & Liede, a plant with traditional medicinal use in Pakistan to treat diabetes, but its antidiabetic potential has not been scientifically validated. This research assessed the phytochemicals, antioxidant properties, and dipeptidyl peptidase- 4 (DPP- 4) inhibitory activity of A. tuberculata's methanolic extract. The extract was assessed through in vitro antioxidant assays, DPP- 4 inhibition test, and metabolomic analy sis via Fourier- transform infrared (FTIR) spectroscopy and liquid chromatography–mass spectrometry (LC–MS). The study used computational tools to visualize compound structures, protein- ligand interactions, and to measure pharmacokinetic parameters. Phytochemical analysis revealed significant levels of total phenols (71.991 ± 0.78 mg/g gallic acid equivalents) and flavonoids (66.216 ± 0.09 mg/g quercetin equivalents). Results showed a robust total antioxidant capacity (70.900 ± 2 mg/g ascorbic acid), total reducing power (72.000 ± 2.00 mg/g gallic acid equivalents), and DPPH IC50 value of 96.54 μg/mL. FTIR spectra showed the presence of carbohydrates and glycosides. The extract exhibited 70% DPP- 4 inhibitory activity (IC50 value = 46.761 ± 0.043 μg/ mL), comparable to Sitagliptin at 78% (IC50 value = 20.474 ± 0.407 μg/mL). LC–MS identified 24 bioactive compounds, includ ing flavonoids and glycosides, with compounds like Kaempferol-3-O-rutinoside-7-O-glucoside and Kaempferol-7-O-rutinoside showing strong binding interactions with DPP- 4. These results underscore the therapeutic potential of A. tuberculata as a natural source of DPP- 4 inhibitors for managing diabetes.
