Microbial mediated silver nanoparticles enhance the potential of bioactive metabolites in the medicinal plant Linum usitatissimum

Abstract

Medicinal plants contain phytochemicals that confer therapeutic potentials, allowing plants to perform various biologically significant functions. However, the therapeutic potential of these bioactive metabolites against multidrug-resistant bacteria is limited. Hence, the potential use of rhizopheric bacteria to isolate silver nanoparticles to enhance the potential of bioactive metabolites has been adopted by researchers. Therefore, this research aimed to biogenically produce silver nanoparticles using the rhizospheric soil of Aloe barbadensis miller and to evaluate its impact in regulating the potential of bioactive metabolites produced from the medicinal plant Linum usitatissimum. The powder extract of Linum usitatissimum was macerated under four different environmental conditions including cold maceration, warm maceration, fermented, and unfermented for extraction of metabolites. Macerated extracts were then evaluated for phytochemical detection of bioactive metabolites like alkaloids, steroids, phenols, and saponins. Biogenic AgNPs were primarily confirmed by visible color change from colorless to brown and were further characterized using UV-vis spectroscopy, giving two absorbance peaks at 440 nm and 445 nm. Functional groups attached to biogenic AgNPs were detected by Fourier transform infrared (FTIR) analysis. The crystalline nature of biogenic AgNPs was evaluated by X-ray diffraction (XRD) giving a diffraction peak at angles of around 36°, 46°, 67°, and 77°. The particle size and morphological appearance of biogenic AgNPs were confirmed by Scanning Electron Microscopy (SEM). The total phenolic content of biogenic AgNPs and bioactive metabolites was estimated by the Folin–Ciocalteu (F–C) assay. The antimicrobial efficacy of biogenic AgNPs and bioactive metabolites against MDR bacterial strains was accessed. This research shows that biogenic AgNPs can be used as a strong agent in enhancing the antimicrobial potential of bioactive metabolites against MDR bacteria and they can be investigated for further experimental findings.