Green synthesis of silver nanoparticles using cilinaphthalide c from justicia spicigera on HeLa and caski cancer cell lines

In this study, a new 1-aryl-2,3-naphthalide, 1-(4′,6′-dihydroxy-3′-methoxy)-phenyl-4,6,7-trimethoxy- 2,3-naphthalide (cilinaphthalide C) was first extracted from Justicia spicigera along with the known compounds allantoin, diphyllin, kaempferitrin and tuberculatin. Structures of these compounds were determined by spectroscopic methods. In the present study, we report the synthesis of silver nanoparticles (AgNPs) funcionalites with cilinaphthalide C (CC) isolated from J. spicigera. The synthesized CC-Ag-NPs were characterized by UV-vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), zeta potential, and transmission electron microscopy (TEM) analysis. The synthesized CC-AgNPs show an absorption peak at 417 nm in the UV-visible spectrum that reveals the surface plasmon resonance of the nanoparticles. TEM study revealed that the particles were mainly spherical and had a size ranging from 10 to 14 nm. The Z-average diameter of CC-AgNPs particle was 12 nm with a polydispersity index (PDI) of 0.241, and the Zeta potential analysis was -69 mV, suggesting the high stability of the nanoparticle. This research also showed the ability of CC-AgNPs in vitro against cervical cancer cell line (HeLa) and human cervical carcinoma (CaSki cells) at concentrations of 5 to 100 μg/ml. Both the isolated CC and the synthesized CC-AgNPs exert an in vitro cytotoxic effect on HeLa and CaSki cancer cell lines. However, cell viability in normal human liver HL-7702 cells was very low. These nanoparticles are involved in the activation of caspase-3-mediated apoptotic cell death.