Characterization, toxicological and antibacterial evaluation of green-synthesized silver nanoparticles using Bixa...

Biosynthesized nanoparticles are gaining prominence due to the physiologically active plant metabolites that aid in green synthesis and novel biological applications. The objective of this study was to use to synthesize silver nanoparticles from the aqueous seed extract of Bixa orellana, chemically characterize the nanoparticle, verify its effectiveness as antimicrobial agent. Further, we want to evaluate its in vitro toxicity toward breast cancer cell line and in vivo toxicity in mice. Biosynthesized Bixa orellana silver nanoparticles (BOAgNPs) were studied using diverse techniques, including UV-visible spectroscopy, dynamic light scattering (DLS), Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM). UV-vis confirms formation of Ag nanoparticle where the average grain size is 54 nm as per SEM studies. The XRD studies showed the size to be about 10.95nm nm. The FTIR data revealed the presence of several biomolecules in extracts, such as O-H stretching and aldehydic C-H stretching, were attributed to the peaks near 3452 cm^-1 and near 2920 cm^-1, respectively. The antibacterial properties have been confirmed by the presence of distinct inhibitory zones against Bacillus cereus, Bacillus subtilis, E. coli, and S. flexneri (p < 0.05). Assessment of the in vitro cytotoxicity on two distinct breast cancer cell lines reveals that the crude extract's IC50 was 2.05 mg/ml on MCF-7 cells, and in contrast, it was 16.09 µg/mL when BOAgNPs was added. On the MDA-MB-231 cell line, the crude extract's IC50 was 2.82 mg/mL, while it was 19.62 µg/mL when combined with BOAgNP. Chronic toxicity (30 days) in mice carried out in vivo revealed moderate changes in biomarkers of toxicity both in liver and serum as linked to the control group. Overall, the findings showed that the current green-synthesized BOAgNPs have excellent antibacterial, anti-cancerous and antioxidant potential and might be explored as a therapeutic agent.