Microwave-assisted extraction enhances the antioxidant and anti-diabetic activities of polyphenol-rich Phyllanthus emblica fruit extract

Diabetes mellitus (DM) is a globally prevalent metabolic disorder marked by chronic high blood glucose levels, typically arising from inadequate insulin production, impaired insulin function, or both. This study evaluated the antioxidant and anti-diabetic potential of Phyllanthus emblica fruit extract obtained via microwave-assisted extraction (MAE). The optimized conditions (70.14% ethanol, 432.22 W, and 13.57 min) resulted in total flavonoid and phenolic contents of 42.85 ± 0.81 mg QE/g d.w. and 69.23 ± 0.95 mg GAE/g d.w., respectively, as determined using Box-Behnken Design (BBD) and response surface methodology (RSM). LC–HRMS analysis identified eleven phenolic compounds, including quercetin, kaempferol, and rutin. The extract exhibited strong antioxidant activity in DPPH, ABTS, and H₂O₂ scavenging assays, and significantly inhibited α-amylase and α-glucosidase enzymes in vitro. In vivo studies using streptozotocin-induced diabetic rats demonstrated that oral administration of the extract (400 mg/kg/day) for 30 days significantly reduced fasting blood glucose and HbA1c levels, increased superoxide dismutase (SOD) activity, and improved pancreatic histoarchitecture. These results indicate that Phyllanthus emblica fruit extract represents a valuable natural candidate for antioxidant and antidiabetic activities, offering potential for development in both therapeutic and functional food applications.