Fruit waste (peel) as bio-reductant to synthesize silver nanoparticles with antimicrobial, antioxidant and cytotoxic activities

Since last decade, biogenic synthesis of metal or metal-oxide nanoparticles is emerging as an alternative method, which is environment friendly, simple and safe to use. In this article, fruit waste (peel) extract (FWE) of three citrus fruits viz. Citrus limon, Citrus sinensis, and Citrus limetta were used as bio-reductant for green and sustainable synthesis of silver nanoparticles (AgNPs). As-synthesised AgNPs were characterized by using UV–vis spectroscopy, Dynamic light scattering, and High Resolution Transmission Electron Microscopy. TEM studies revealed 9–46 nm size range of synthesized AgNPs. The antimicrobial and antioxidant activities were also studied by using Agar well diffusion method and DPPH Assay, respectively. Nanoparticles showed good antimicrobial activity against both Gram positive (S. aureus) and Gram negative (E. coli) bacteria. Further, bioactivity assays revealed selective cytotoxicity (anticancer) of the nanoparticles against human lung cancer cell line A549. The nanoparticles are able to induce cancer cell specific apoptosis at G0/G1 phase of cell cycle. The results showed potential mechanism of action of nanoparticles via augmentation of antioxidant system in cancer cells. Over all, this study show multifaceted potential bioactivities of nanoparticles generated from fruit waste.