Biosynthesis of Nickel Nanoparticles using Shorea robusta Extract and Evaluation of their Antioxidant, Anti-bacterial, Anti-inflammatory, Wound healing, and Environmental Applications

The green synthesis of nickel nanoparticles (NiNPs) using Shorea robusta flower extract (SRFE) as a reducing and stabilizing agent. The formation of NiNPs was confirmed by UV-Vis, which revealed a strong absorption peak at ⁓279 nm, while FTIR identified functional groups of stretching bonds involved in capping. XRD patterns indicated predominantly amorphous structure with minor crystalline phases, while confirming the formation of NiNPs. FESEM micrographs showed irregular, spherical to semi-spherical particles with aggregation and EDAX confirmed the organic and elemental composition. Functionally, NiNPs exhibited significant antibacterial activity against E. coli, S. aureus, K. pneumoniae and B. subtilis in a dose-dependent manner. Antioxidant assays as DPPH (84.3% at 60 µg/mL), FRAP (94% at 100 µg/mL) and ABTS (88% at 50 µg/mL) demonstrated strong radical scavenging and ferric-reducing capacities comparable to standard compounds. Anti-inflammatory studies (BSA 93% and EA assay 90% at 80 µg/mL) showed concentration-dependent inhibition of protein denaturation, highlighting therapeutic potential. Wound healing assay at 300 µg/mL concentration of NiNPs including MTT, morphology and scratch tests confirmed enhanced fibroblast viability and migration. Furthermore, NiNPs demonstrated excellent photocatalytic activity in dye degradation under UV and visible light, establishing strong environmental applicability. Overall, the study highlights the biocompatible, multifunctional potential of using SRFE to synthesised NiNPs for biomedical and environmental applications. Green synthesis of NiNPs using Shorea robusta. Strong antioxidant and antimicrobial effects. Notable anti-inflammatory activity. Supports wound healing application. Effective photocatalytic dye removal.