Green and chemically synthesized zinc oxide nanoparticles: effects on <i>in-vitro</i> seedlings and callus cultures of <i>Silybum marianum</i> and evaluation of their antimicrobial and anticancer potential
Faryal Saeed, Muhammad Younas, Hina Fazal, Sadaf Mushtaq, Faiz Ur Rahman, Muzamil Shah, Sumaira Anjum, Nisar Ahmad, Mohammad Ali, Christophe Hano, Bilal Haider Abbasi
Abstract
Zinc oxide nanoparticles (ZnO-NPs) have been produced by physical and chemical methods. Here, the comparative evaluation of both chemically-synthesised ZnO-NPs (C-ZNPs) and in-vitro cultured S. marianum mediated green-synthesised ZnO-NPs (G-ZNPs) were investigated on seed germination frequency, root and shoot growth, callus induction and biochemical profile of medicinally important plant Silybum marianum. Of all the treatments, callus-mediated ZnO-NPs gave optimum results for seed germination (65%), plantlet’s root length (4.3 cm), shoot length (5.3 cm) and fresh and dry weights (220.4 g L−1 and 21.23 g L−1, respectively). Similarly, the accumulation of phenolic (12.3 µg/mg DW) and flavonoid (2.8 µg/mg DW) contents were also enhanced in callus cultures treated with G-ZNPs. We also observed maximum antioxidant activity (99%) in callus cultures treated with G-ZNPs, however, in case of plantlets, these activities were found highest for in-vitro whole plant-mediated ZnO-NPs. Moreover, G-ZNPs also enhanced total protein content (265.32 BSAE/20g FW) in callus cultures. G-ZNPs were further assessed for their effects on several multidrug resistant bacterial strains and human liver carcinoma (HepG2) cells and our findings revealed that callus extracts treated with G-ZNPs show ameliorated antibacterial (highest zone of inhibition (19 mm) against Klebsiella pneumonia) and anticancer (highest cytotoxicity of 64%) activities.