Tangerine fruit peel extract mediated biogenic synthesized silver nanoparticles and their potential antimicrobial, antioxidant, and cytotoxic assessments

Abstract

The utilization of plant bioactive composites has concerned substantial attention due to their possible use in the development of novel antibiotics, containing the environmentally sustainable synthesis of nanoparticles. In the current study, a green and eco-friendly process was employed to synthesize silver nanoparticles (Ag-NPs) and to evaluate their anti-bacterial, anti-oxidant, and anti-cancer potentials. The characterization of the Ag-NPs involved UV-vis spectroscopy, Fourier-transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM). The UV-vis spectrum of Ag-NPs was 437 nm. The FTIR absorption peaks detected at 685.48 cm−1 confirmed their characteristics. The FESEM displayed that Ag-NPs have an average size of 30 nm. The TEM revealed that the Ag-NPs have an irregular spherical shape with 16 nm size distribution. The XRD results provided a strong indication that the green synthesized Ag-NPs was of high purity with crystalline nature. The anti-bacterial properties were investigated at different concentrations for both the ethanolic tangerine peel extract and Ag-NPs. The results of anti-bacterial activity showed that 100 µg·mL−1 was potent concentration, but the Ag-NPs were more effective than the ethanolic tangerine peel extract. For the ethanolic extract, the inhibition zone was 17.50 ± 0.20 mm for K. pneumoniae and 14.40 ± 0.20 mm for B. cereus. For the Ag-NPs, the inhibition zone was 25.50 mm for K. pneumoniae and 20.50 mm for B. cereus. Furthermore, the antioxidant examination revealed more potent free radical scavenging activity of the Ag-NPs than the ethanolic peel extract alone. The ethanolic extract ranged 46–77% while the Ag-NPs ranged 57–88%. Additionally, the anti-proliferative of the Ag-NPs against the lung cancer cell line (A549) was more potent than the ethanolic extract alone. The cytotoxic activity was 90.03% and 78.50%, respectively. The anti-proliferative effect of Ag-NPs is attributed to cell death, induced apoptosis, and enhanced generation of reactive oxygen species. Our findings highlight the potential and further utilization of Ag-NPs in medicinal applications particularly for cancer therapeutics.