Comparative analysis of chemical composition and biological activities of Punica granatum L. Extracts: UPLC-MS/MS profiling, antioxidant capacity, enzyme inhibition, and molecular docking

Abstract

Pomegranate (Punica granatum L.) has been valued for its medicinal and nutritional benefits across traditional healing systems. This study investigated the phytochemical profile, antioxidant capacity, and enzyme inhibitory potential of mature pomegranate leaves. Methanol and ethanol extracts were prepared and analyzed using UPLC-MS/MS, multiple antioxidant assays (Fe3+ reduction, CUPRAC, FRAP, DPPH center dot, ABTS(center dot+), DMPD center dot+), and targeted enzyme inhibition tests. The methanol extract exhibited the highest phenolic and flavonoid content (409.44 mu g GAE/mg and 64.52 mu g QE/mg), with ellagic acid, gallic acid, syringic acid, and luteolin identified as major compounds. Both extracts showed concentration-dependent antioxidant activity, with the methanol extract demonstrating a significantly stronger Fe3+ reducing capacity (p < 0.05) and superior ABTS(center dot+) scavenging activity compared to standard antioxidants (p < 0.05). For carbonic anhydrase I and II, the extracts showed notable inhibition (IC50 = 0.0221, 0.0344 mu g/mL), although not reaching the efficacy of acetazolamide (IC50 = 0.0061, 0.0072 mu g/mL). Both extracts exhibited potent acetylcholinesterase inhibitory activity (IC50 = 0.0017 mu g/mL), closely approximating the efficacy of tacrine (IC50 = 0.0010 mu g/mL). The ethanol extract also showed remarkable alpha-glucosidase inhibition (IC50 = 0.0052 mu g/mL), being 2.8-fold more potent than the acarbose (IC50 = 0.0147 mu g/mL)-a noteworthy result, as natural compounds rarely exceed pharmaceuticals in such assays. Molecular docking confirmed ellagic acid's interaction with the target enzymes. These findings underscore pomegranate leaves as a valuable natural source of bioactive compounds, with promising applications in the management of diabetes, neurodegenerative disorders, and glaucoma -attributable to their rich phenolic content, strong antioxidant capacity, and notableenzyme inhibitory activities.