Phytoassisted synthesis of biogenic silver nanoparticles using Vernonia amygdalina leaf extract: characterization, antibacterial, anti-inflammatory, and acute toxicity profile

Nyuyfoni, G. F.; Nkana, B. P.; Deli, V.; Kedi, P. B. E.; Ntoumba, A. A.; Nanga, C. C.; Tchatchouang, G. C.; Djuidje, A. G.; Djimefo, T. A. K.; Evouna, I. D. M.; Malolo, E. F.-A.; Eha-Kang, C.; Kwati, L.; Ndzeidze, G. N.; Gbambie, A. P.; Francois, E. M.

doi:10.1101/2024.10.31.621348

bioRxiv · 10.1101/2024.10.31.621348

Phytoassisted synthesis of biogenic silver nanoparticles using Vernonia amygdalina leaf extract: characterization, antibacterial, anti-inflammatory, and acute toxicity profile

Nyuyfoni, G. F.·Nkana, B. P.·Deli, V.·Kedi, P. B. E.·Ntoumba, A. A.·Nanga, C. C.·Tchatchouang, G. C.·Djuidje, A. G.·Djimefo, T. A. K.·Evouna, I. D. M.·Malolo, E. F.-A.·Eha-Kang, C.·Kwati, L.·Ndzeidze, G. N.·Gbambie, A. P.·Francois, E. M.

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Abstract

Increasing antimicrobial resistance and pathological consequences from long-term anti-inflammatory drug use necessitate the urgent discovery and rational design of new, effective antimicrobial and anti-inflammatory agents. This study reports the antibacterial, anti-inflammatory, and acute toxicity profile of Vernonia amygdalina leaf extract-mediated silver nanoparticles (VA-AgNPs). VA-AgNPs were synthesized by mixing Ag+ ions with an aqueous leaf extract from Vernonia amygdalina and characterized using UV-Visible (UV-Vis) spectroscopy, powder X-ray diffraction (PXRD), and scanning electron microscopy (SEM). Antibacterial activity against Escherichia coli strains, carrageenan-induced rat paw edema, and oral acute toxicity assays were performed. The change in color from light brown to dark brown indicated the formation of VA-AgNPs, which was further confirmed by the surface plasmon resonance peaks between 400 and 450 nm in the UV-Vis spectrum. Stability studies showed increased VA-AgNPs formation at basic pH and with higher reactant quantities. The X-ray pattern showed nanocrystalline particles of Ag and AgCl with mean sizes of 13 and 18 nm, respectively. The SEM images depict aggregates of spherical shapes. The synthesized VA-AgNPs inhibited Escherichia coli growth with a minimum inhibition concentration of 0.125 mg/mL and rat paw edema with a maximum inhibition percentage of 96% at a dose of 0.4 mg/kg body weight. Oral administration of VA-AgNPs was not associated with any toxicity, supporting their use in the development of new effective antibacterial and anti-inflammatory drugs.

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Nyuyfoni, G. F., Nkana, B. P., Deli, V., Kedi, P. B. E., Ntoumba, A. A., Nanga, C. C., Tchatchouang, G. C., Djuidje, A. G., Djimefo, T. A. K., Evouna, I. D. M., Malolo, E. F.-A., Eha-Kang, C., Kwati, L., Ndzeidze, G. N., Gbambie, A. P., Francois, E. M.. 2024-11-03. Phytoassisted synthesis of biogenic silver nanoparticles using Vernonia amygdalina leaf extract: characterization, antibacterial, anti-inflammatory, and acute toxicity profile. https://doi.org/10.1101/2024.10.31.621348

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