Unveiling the Therapeutic Potential: Cylicodiscus gabunensis (FABACEAE) Aqueous Stem Bark Extract Derived Silver Nanoparticles for Enhanced Anti-inflammation in Wistar Rats

Abstract

Background: Medicinal plants and green-synthesized silver nanoparticles have gained increasing attention as potential alternatives to conventional anti-inflammatory therapies due to their bioactivity, biocompatibility, and reduced toxicity. Aims: The present study investigates the anti-inflammatory activity of silver nanoparticles (AgNPs) biosynthesized using the aqueous stem bark extract of Cylicodiscus gabunensis. The aqueous extract was prepared by infusion and reacted with silver nitrate to generate AgNPs. Study Design: Experimental. Place and Duration of Study: Department pharmaceutical Sciences, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Cameroon, between November 2021 and June 2022. Methodology: Comprehensive physicochemical characterization was carried out using UV-Vis spectrophotometry to confirm nanoparticle formation, Fourier-transform infrared spectroscopy (FTIR) to identify functional groups at the metal-biomolecule interface, powder X-ray diffraction (XRD) to assess crystallinity and purity, scanning electron microscopy (SEM) to examine morphology, and energy-dispersive X-ray spectroscopy (EDX) to determine elemental composition.Acute toxicity was evaluated in accordance with OECD Guideline 425, while anti-inflammatory activity was assessed in vitro using the bovine serum albumin (BSA) denaturation assay and in vivo using the carrageenan-induced rat paw edema model. Results: The synthesized AgNPs were stable, crystalline, composed of elemental silver, and no signs of acute toxicity were observed. Notably, the AgNPs exhibited pronounced anti-inflammatory activity, achieving 95% inhibition of BSA denaturation at 200 µg/mL in vitro and 91% inhibition of paw edema at 400 µg/kg in vivo. Conclusion: Overall, silver nanoparticles biosynthesized from Cylicodiscus gabunensis stem bark demonstrated potent anti-inflammatory effects coupled with low toxicity, highlighting their promise as a plant-derived, biocompatible alternative for the management of inflammatory disorders.