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. Also, the biofilm of E. faecalis and S. aureus was greatly inhibited at 100 µg mL compared to E. coli and P. aeruginosa. The activity of α-amylase and α-glucosidase enzyme was inhibited at 100 µg mL demonstrating its antidiabetic potential. The larval and pupal development was delayed at 25 µg mL of Ws-ZnO NPs. A complete mortality (100%) was recorded at 25 µg mL. Ws-ZnO NPs showed least LC value (9.65 µg mL) compared to the uncoated ZnO NPs (38.8 µg mL) and leaf extract (13.06 µg mL). Therefore, it is concluded that Ws-ZnO NPs are promising to be used as effective antimicrobials, antidiabetic and insecticides to combat storage pests.