High synergistic antibacterial,antibiofilm, antidiabetic and antimetabolic activity of Withania somnifera leaf extract-assisted zinc oxide nanoparticle

Nanotechnology is currently gaining immense attention to combat food borne bacteria, and biofilm. Diabetes is a common metabolic disease affecting majority of people. A better therapy relies on phytomediated nanoparticle synthesis. In this study, W. somnifera leaf extract-assisted ZnO NPs (Ws-ZnO NPs) was synthesized and characterized. From HR-TEM analysis, it has been found that the hexagonal wurtzite particle is 15.6 nm in size and − 12.14 mV of zeta potential. A greater antibacterial effect of Ws-ZnO NPs was noticed against E. faecalis and S. aureus at 100 µg mL⁻¹. Also, the biofilm of E. faecalis and S. aureus was greatly inhibited at 100 µg mL⁻¹ compared to E. coli and P. aeruginosa. The activity of α-amylase and α-glucosidase enzyme was inhibited at 100 µg mL⁻¹ demonstrating its antidiabetic potential. The larval and pupal development was delayed at 25 µg mL⁻¹ of Ws-ZnO NPs. A complete mortality (100%) was recorded at 25 µg mL⁻¹. Ws-ZnO NPs showed least LC₅₀ value (9.65 µg mL⁻¹) compared to the uncoated ZnO NPs (38.8 µg mL⁻¹) and leaf extract (13.06 µg mL⁻¹). Therefore, it is concluded that Ws-ZnO NPs are promising to be used as effective antimicrobials, antidiabetic and insecticides to combat storage pests.