Exploring the Bioactive Potential of Persea americana Mill. Peel: Phytochemical Characterization, Antioxidant Activity, Digestive Enzyme Inhibition, and Antiglycation Effects

Abstract

Avocado peel is an underutilized fruit by-product that contains several classes of bioactive phytochemicals. The present study evaluated the phytochemical composition, antioxidant activity, carbohydrate-hydrolyzing enzyme inhibition, and antiglycation potential of a hydroethanolic extract of Persea americana Mill. peel. The dried peel was extracted with 70% ethanol by maceration. The extraction yield was 18.64% w/w. Preliminary phytochemical screening showed the presence of phenolics, flavonoids, tannins, saponins, terpenoids, steroids, and glycosides. The total phenolic and total flavonoid contents were 119.16 ± 0.94 mg GAE/g and 55.41 ± 0.73 mg QE/g dried extract, respectively. HPLC-DAD analysis confirmed chlorogenic acid, catechin, epicatechin, and quercetin as selected phenolic markers. Epicatechin showed the highest quantified level at 8.72 ± 0.16 mg/g extract. The extract showed concentration-dependent DPPH and ABTS radical-scavenging activities with IC₅₀ values of 105.6 and 82.7 µg/mL, respectively. The FRAP value was 730.27 ± 8.40 µmol Fe²⁺ equivalents/g extract. PA-PE also inhibited α-amylase and α-glucosidase with IC₅₀ values of 146.8 and 109.7 µg/mL, respectively. In the BSA-glucose model, the extract inhibited advanced glycation end-product formation with an IC₅₀ of 154.3 µg/mL. The reference compounds showed greater activity than the crude extract in their respective assays. Overall, the findings indicate that avocado peel is a phenolic-rich by-product with measurable antioxidant, digestive-enzyme inhibitory, and antiglycation activities under in-vitro conditions. Further studies are required to identify the major active constituents and establish their biological relevance.