In the present synthesis, study of nanoparticles of zinc oxide using ethanolic extract of Garcinia cambogia leaves extract. Using of zinc oxide nanoparticles as a precursor in leaf extracts of this plant for NPs synthesis. The optical properties and structural of NPs were investigated by ultraviolet-visible(UV-Vis) spectrophotometer ,scanning electron microscope (SEM), transmission electron microscopy (TEM) and dynamic light scattering (DLS).

Liquid Chromatography-Electrospray Ionization-Mass (LC-ESI-Mass) in negative ion mode of ethanolic extract demonstrates the presence of six bioactive compounds identified as guanosine, prephenic acid, tetrahydroxy-cholanic acid, limocitrin, 6,7-dihydroxycoumarin-6-glucoside and hydroxy citric acid which they responsible for providing electrons for reducing zinc nitrate hexahydrate to ZnO-NPs.

The antibacterial activity of both ethanolic extract and eco-friendly synthesis Of ZnO-NPs. by G.cambogia were tested against two pathogenic bacterial strains (Staphylococcus aureus ATCC6538 and Escherichia coli ATCC10536 ) by using disk diffusion method.

The ZnO-NPs showed antibacterial activity against S. aureus (40 mm) more than ethanolic extract (35 mm). The ZnO-NPs revealed significant antibacterial activity against E. coli (50 mm) compared to ethanolic extract (45 mm). Also, ZnO-NPs displayed more antibacterial activity than Ampicillin against S. aureus (266.6%) and E. coli (500%) and displayed more antifungal activity than Fluconazole against C. albicans (238.6%). However, ZnO-NPs showed higher antifungal activity against C.albicans (50.11 mm) than the ethanolic extract (45.37 mm).

Based on these findings, it is concluded that the synthesized ZnO-NPs is a more promising candidate than the alcoholic extract of G. Cambogia leaves against pathogenic bacterial, fungal strains.

The administration of G. cambogia and synthesized ZnO-Nps as a weight-reduction treatment is intended to give the important knowledge for both scholarly and broad public use regarding the effects of the plant.