Biosynthesis of nickel oxide nanoparticles from piper nigrum leaf Extract and their enhanced antioxidant, antibacterial, and enzyme Inhibition Activities

In recent years, the use of eco-friendly and sustainable methods for synthesizing nanoparticles has gained significant attention due to environmental concerns associated with conventional chemical approaches. This study explores the preparation of nickel oxide (NiO) NPs using Piper nigrum leaf extract sourced from Muzaffarabad Azad Kashmir, Pakistan a novel and environmentally benign approach. These NPs were studied using various techniques to determine their morphology, size, and structural properties. Furthermore, the biological activity of the freshly prepared NPs was evaluated, focusing on their inhibitory effect on alpha-amylase, a key enzyme related to diabetes management. The NPs exhibited excellent antioxidant properties, with a peak scavenging activity of 78% at 80 µg/mL, and an IC50 value of 28 µg/mL. In alpha-amylase inhibition assays, NiO NPs demonstrated significant enzyme inhibition with an IC50 of 1.18 µg/mL. Antibacterial tests revealed strong activity against Gram-positive bacteria, with peak inhibition zones of 18 mm for Streptococcus pyogenes and 13 mm for Staphylococcus aureus. These results highlight the NPs potential for biological applications.