Camellia sinensis Silver Nanoparticles Inhibit Proliferation and Induce PARP-Dependent Apoptosis in A549 Cells: Formulation, Characterization, and Biological Evaluation

In this work, the potential anti-cancer activity of silver nanoparticles (AgNPs-CS) prepared using Camellia sinensis, C. sinensis (CS) aqueous extract and its pro-apoptotic effects on human lung adenocarcinoma alveolar (A549) cells were investigated. AgNPs-CS were prepared by reduction of AgNO3 using C. sinensis aqueous extract, CSaq. Furthermore, they were characterized for their size, polydispersity index (PDI), ζ-potentials, morphology, and antioxidant activity. of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), acridine orange/ethidium bromide (AO/EB) staining, and Western blotting techniques were used to measure cell proliferation, apoptosis, and poly (ADP-ribose) polymerase, PARP cleavage. AgNPs-CS had a size, PDI and ζ-potential of 101 nm, 0.12, and -21 ± 1.2 mV, respectively. Furthermore, they are spherical with a core size of ∼20-40 nm and have significant antioxidant activity compared with quercetin. A sigmoidal dose-response curve exhibiting significant concentration-dependent reductions in cell viability was obtained. AgNPs-CS had an IC50 of 6.5 µg/ml and a significant level of apoptosis (∼57%) compared to CSaq and doxorubicin (Dox). Western blot analysis showed a higher level of cleaved PARP, with cPARP/β-actin ratios of 1.8 and 2.9 for CSaq and AgNPs-CS, respectively, confirmed the caspase-dependent apoptosis. AgNPs-CS is a promising green-based nanotherapeutic for treating lung cancer with an enhanced ability to kill cells and cause apoptosis in A549 cells.