Biogenic synthesis of zinc oxide nanoparticles using mushroom fungus Cordyceps militaris: Characterization and mechanistic insights of therapeutic investigation

The present research demonstrates the Cordyceps militaris (a medicinal mushroom) mediated fabrication of zinc oxide nanoparticles ( Cor- ZnONPs) and its therapeutic investigation. The biosynthesized Cor- ZnONPs were characterized by UV–Visible spectroscopy, FT-IR, XRD, SEM with EDX, HRTEM, particle size, and zeta potential analysis and evaluated for their antidiabetic, antioxidant, and antibacterial potential by in-vitro methods. The nanoparticles showed SPR peak at 354 nm. FT-IR analysis exhibited a sharp peak at 432.05 cm −1 , demonstrating the distinctive Zn–O bond. Cor -ZnONPs had an average particle size of 1.83 nm with a polydispersity index of 0.29 and were crystalline as obtained from XRD analysis. Zeta potential of −6.42 mV indicates the moderate stability of nanoparticles. EDX analysis confirmed the presence of Zinc and Oxygen. Cor -ZnONPs expressed a 70–90% survival rate in brine shrimp lethality assay with 10–100 ppm concentrations and exhibited potent α-amylase and α-glucosidase inhibitory effect with an IC 50 of 46.29 ± 0.49 and 47.21 ± 0.19 μg/mL, respectively. Cor -ZnONPs showed moderate radical potency with DPPH, ABTS, hydroxyl radical, nitric oxide, and superoxide radical scavenging assays. Cor -ZnONPs revealed the highest antibacterial activity against Pseudomonas aeruginosa, followed by Shigella flexneri , Proteus vulgaris, and Rhodococcus equi . Moreover, a very low concentration of Cor -ZnONPs was required to inhibit the growth of studied bacterial strains. This study provides an informational insight into the Cordyceps militaris mediated synthesis of ZnONPs, and their antidiabetic, antioxidant, and antibacterial potential. Biosynthesized Cor -ZnONPs indicate a new application of nanoparticles in the development of therapeutic drugs.