Green synthesis of ZnO nanoparticles using pomegranate husk extract: comparative evaluation of antioxidant, enzyme inhibition, and cytotoxic properties

The prevalence of obesity has risen sharply in recent years, prompting the need for safer and more biocompatible therapeutic alternatives to conventional anti-obesity drugs. In this study, zinc oxide nanoparticles (ZnO NPs) were synthesized using pomegranate husk extract via two green approaches: conventional heating and microwave-assisted synthesis. Structural and morphological characterizations confirmed successful nanoparticle formation. Microwave-assisted ZnO nanoparticles (MA-ZnO NPs) exhibited smaller particle dimensions and narrower polydispersity compared with conventionally synthesized ZnO NPs. Both types of ZnO NPs demonstrated notable antioxidant activity (>62% scavenging in DPPH and ABTS assays) and strong inhibitory effects against pancreatic lipase and α-amylase (>70%), comparable to standard drugs such as orlistat and acarbose. Cytotoxicity assays using Vero cells confirmed high biocompatibility, with >60% cell viability. This work presents a comparative evaluation of two green synthesis methods and highlights the potential of biogenic ZnO NPs as multifunctional agents for oxidative stress reduction and enzyme inhibition in obesity management.