Green Synthesis of Zinc Oxide (ZnO) Nanoparticles Using Valeriana jatamansi Jones for Anticancer, Antimicrobial, Antidiabetic, and Antioxidant Activities

Abstract

Using plant extract for the production of metal oxide nanoparticles is a viable substitute for the traditional chemical process. This study utilized an extract of Valeriana jatamansi Jones to synthesize zinc oxide nanoparticles, which is a quick, economical, and environmentally friendly process. UV-Vis spectroscopy, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and energy-dispersive X-ray spectroscopy (EDX) were used to characterize the produced ZnO NPs. The creation of ZnO NPs with absorption maxima at 357 nm was preliminarily confirmed by UV-visible spectroscopy. FTIR results indicated the involvement of plant secondary metabolites of V. jatamansi as stabilizing materials. XRD analysis reported the crystalline nature of ZnO NPs with a crystallite size of 10.57 nm. FE-SEM analysis demonstrated hexagonal morphology with an average particle size of 82.39 nm. EDX analysis revealed the elemental composition of nanoparticles. The plant-assisted synthesized ZnO NPs were evaluated for their antioxidant, antibacterial, antifungal, antidiabetic, and cytotoxic activities. The NPs exhibited moderate inhibition on DPPH-free radical scavenging activities with an IC50 of 117.8 ± 1.2 μg/mL, with a 21 mm zone of inhibition, and the synthesized ZnO NPs demonstrated outstanding antibacterial efficacy against Klebsiella pneumoniae. It also displayed significant MIC and MBC of 3.12 mg/mL and 12.50 mg/mL against Staphylococcus aureus and Klebsiella pneumoniae, respectively. In contrast to the positive control, kanamycin, which showed a ZOI of 25 mm, the antifungal activity of ZnO NPs shows a promising antifungal agent with a ZOI of 21 mm against Candida albicans. ZnO NPs displayed good inhibitory activity against α-amylase, with an IC50 of 57.34 ± 1.06 μg/mL. Moreover, the ZnO NPs exhibit potent cytotoxicity of IC50 62.96 ± 3.67 μg/mL against cervical cancer cell lines. The production of ZnO NPs using the plant sample and exploring the anticancer and antibacterial activities are limited.