Cytotoxic Effect of Palladium Nanoparticles Synthesized From Syzygium aromaticum Aqueous Extracts and Induction of Apoptosis in Cervical Carcinoma

Among the various nanoparticles explored for diverse biological applications, palladium nanoparticles still remain far too behind in the field of cancer therapeutics. Nanoparticles synthesized by chemical methods aggregate in physiological conditions hindering their biomedical applications. Therefore, in the present study, a plant mediated green synthesis approach for palladium nanoparticle preparation from Syzygiumaromaticum was reported and the biocompatibility and anticancer activity of the eco-friendly synthesized palladium nanoparticles against human cervical carcinoma was evaluated. The as-synthesized palladium nanoparticles were characterized by various analytical techniques such as, UV–vis spectroscopy, transmission electron microscope, dynamic light scattering, zeta potential, energy dispersive X-ray spectroscopy, X-ray diffraction and fourier transform infrared spectroscopy. The biocompatibility of palladium nanoparticles were verified by incubating with RBCs and cytotoxic studies revealed a dose dependent cytotoxic effect with half maximal inhibitory concentration values of 15 ± 0.5 µg/mL against HeLa cells at 48 h incubation. Further, the induction of apoptosis was evidenced by fluorescence microscopic study. Semi-quantitative RT-PCR analysis evidenced the activation of cytochrome c and caspase 3 and down regulation of Bcl-2 and Bcl-xL. In vivo antitumor studies showed significant suppression of tumor growth against HeLa tumor xenograft models. The results suggest that palladium nanoparticles can be synthesized using clove buds; they are biocompatible possessing significant anticancer activity against human cervical carcinoma, indicating the great potential of palladium nanoparticles in relevant biomedical applications.