Size-Dependent Antibacterial, Antidiabetic, and Toxicity of Silver Nanoparticles Synthesized Using Solvent Extraction of Rosa indica L. Petals

In this study, silver nanoparticles (AgNPs) are synthesized through a green approach by employing Rosa indica L. petal (RE) extracts as reducing and stabilizing agents, which are extracted using three different solvents: ethanol (Et), acetone (Ac), and water (Aq). The phase formation of the AgNPs is confirmed using X-ray diffraction (XRD). Morphological analysis is performed using a field-emission scanning electron microscope (FESEM), which reveals that the AgNPs are spherical in shape. The size is estimated using ImageJ software, which is found to be ~12, 18, and 770 nm for RE-Ac-Ag, RE-Et-Ag, and RE-Aq-Ag, respectively. The phytochemicals of Rosa indica L. petals involved in the formation of the AgNPs are studied using Fourier transform infrared spectroscopy (FTIR). Finally, these materials are studied for their antibacterial, antidiabetic, antioxidant, and hemolytic activity, as well as cell toxicity properties. The materials, RE-Ac-Ag and RE-Et-Ag, are found to be more effective than RE-Aq-Ag in inhibiting E. coli (Gram-negative bacteria) and S. aureus (Gram-positive bacteria). Hemolytic studies reveal that all of the samples show concentration-dependent activity up to 50 µg/mL. RE-Ac-Ag and RE-Et-Ag exhibit nonhemolytic behavior, whereas RE-Aq-Ag remains nonhemolytic until 100 µg/mL. The antidiabetic ability of the AgNPs is evaluated using α-amylase inhibition assay (DNSA assay) and α-glucosidase inhibition assay. The results are found to be effective, with IC(50) values of α-amylase and α-glycosidase being 50, 50, and 75 µg/mL for RE-Et-Ag, RE-Ac-Ag, and RE-Aq-Ag, respectively. DPPH assay shows that the AgNPs inhibited the antioxidants well, with IC(50) values of 40 µg/mL for RE-Et-Ag and RE-Ac-Ag and 60 µg/mL for RE-Aq-Ag. The toxicity study reveals that the AgNPs show size- and concentration-dependent behavior. Overall, it is realized from the findings that RE-Ac-Ag, RE-Et-Ag, and RE-Aq-Ag show size-dependent antibacterial, antidiabetic, and toxicity properties.