Polyherbal green-synthesised silver nanoparticle gel: in vitro antimicrobial activity and in vivo wound healing efficacy using mimosa pudica and tribulus terrestris extracts.

Abstract

Objective: To synthesize and evaluate a polyherbal silver nanoparticle (PH-AgNPs) gel using Mimosa pudica and Tribulus terrestris extracts for enhanced antimicrobial activity and wound-healing efficacy.

Significance: Wound infections remain a major clinical challenge due to rising antimicrobial resistance and cytotoxic limitations of conventional silver therapies. Green-synthesized PH-AgNPs offer a biocompatible and sustainable approach integrating antimicrobial and regenerative effects.

Methods: PH-AgNPs were synthesized via green methods and characterized using UV-Vis, DLS, FTIR, XRD, and SEM-EDX. Nanoparticles were incorporated into Carbopol gels (0.1% and 0.2% w/w). Antioxidant activity was assessed by DPPH assay, antibacterial activity by agar well diffusion, and in vivo wound healing was evaluated using a full-thickness excision model in Wistar rats. Biochemical (CAT, glutathione peroxidase, lipid peroxidation) and histopathological analyses were performed, with AgNO₃ gel as standard.

Results: The synthesized Silver Nanoparticles (AgNPs) exhibited a hydrodynamic diameter of 87 nm and a zeta potential of -25.4 mV. The polyherbal extract (PE) demonstrated 77.23% inhibition of DPPH radicals. Antibacterial testing showed inhibition zones of 14-15 mm against Escherichia coli (E. Coli) and Staphylococcus aureus (S. aureus). Biochemical analysis showed differences in antioxidant enzyme activities, including CAT and glutathione peroxidase, between the treatment groups and the control. The 0.2% w/w AgNPs gel achieved 94.25% wound contraction by day 15 compared with 48.35% in untreated controls.

Conclusion: PH-AgNPs gel exhibited effective antimicrobial activity and accelerated wound healing, suggesting potential as a safer alternative to conventional silver-based wound therapies.