Green synthesis palladium nanoparticles mediated by white tea (Camellia sinensis) extract with antioxidant, antibacterial, and antiproliferative activities toward the human leukemia (MOLT-4) cell line

Among nanoparticles used for medical applications, palladium nanoparticles (PdNPs) are among the least investigated. This study was undertaken to develop PdNPs by green synthesis using white tea (W. tea; Camellia sinensis) extract to produce the Pd@W. tea NPs. The Pd@W. tea NPs were characterized by UV-vis spectroscopy and X-ray diffractometry, and evaluated with transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The Pd@W. tea NPs were spherical (size 6-18 nm) and contained phenols and flavonoids acquired from the W. tea extract. Pd@W. tea NPs has good 1-diphenyl-2-picrylhydrazyl (DPPH), OH, and NO-scavenging properties as well as antibacterial effects toward Staphylococcus epidermidis and Escherichia coli. MTT assay showed that Pd@W. tea NPs (IC50 = 0.006 mu M) were more antipro-liferative toward the human leukemia (MOLT-4) cells than the W. tea extract (IC50 = 0.894 mu M), doxorubicin (IC50 = 2.133 mu M), or cisplatin (IC50 = 0.013 mu M), whereas they were relatively innocuous for normal human fibroblast (HDF-a) cells. The anticancer cell effects of Pd@W. tea NPs are mediated through the induction of apoptosis and G2/M cell-cycle arrest.