[Abstract unavailable

This work investigated the cytotoxicities of three silver nanoparticles (SNPs) SNP-5, SNP-20 and SNP-50 with different sizes ( approximately 5 nm, approximately 20 nm and approximately 50 nm) using four human cell models (A549, SGC-7901, HepG2 and MCF-7). Endpoints included cell morphology, cell viability, cellular membrane integrity, oxidative stress and cell cycle progression. Observable deleterious effects on the cell morphologies and membrane integrity were induced by SNP-5 and SNP-20. SNPs elevated the ROS levels in cells and arrested the cells at S phase. Apoptosis occurred for 4-9% of the exposed cells. All these cellular responses as well as EC50 values were found to be size-dependent for the tested SNPs. Ultrastructural observations confirmed the presence of SNPs inside cells. Elemental analysis of silver in cells by ICP-MS showed that smaller nanoparticles enter cells more easily than larger ones, which may be the cause of higher toxic effects. The findings may assist in the design of SNP applications and provide insights into their toxicity.

Luteolin, a common dietary flavonoid, has been found to have antitumor properties and therefore poses special interest for the development of preventive and/or therapeutic agent for cancers. E-cadherin, a marker of epithelial cells, mediates cell-cell adhesion. Decreased expression of E-cadherin results in a loss of cell-cell adhesion and an increased cell invasion. Many studies have shown the antiproliferative activities of luteolin on cancer cells. However, the effects of luteolin on invasion of cancer cells remain unclear. In this article, we show that luteolin inhibits invasion of prostate cancer PC3 cells through E-cadherin. We found that Luteolin induced expression of E-cadherin through mdm2. Overexpression of mdm2 or knockdown of E-cadherin could restore invasion of PC3 cells after luteolin treatment. Luteolin inhibits mdm2 through AKT and overexpression of active AKT attenuated luteolin-induced expression of E-cadherin, suggesting that luteolin regulates E-cadherin through AKT/mdm2 pathway. The in vivo experiments showed that luteolin inhibited spontaneous lung metastasis of PC3 cells implanted onto the nude mice. These findings provide a new sight into the mechanisms that luteolin is against cancer cells, and suggest that molecular targeting of E-cadherin by luteolin may be a useful strategy for treatment of invasive prostate cancers.

Due to the increasing applications of nanomaterials and nanotechnology, potential danger of nanoparticle exposure has become a critical issue. However, recent nanotoxicity studies have mainly focused on the health risks to healthy adult population. The nanotoxicity effects on susceptible populations (such as pregnant, neonate, diseased, and aged populations) have been overlooked. Due to the alterations in physiological structures and functions in susceptible populations, they often suffer more damage from the same exposure. Thus, it is urgent to understand the effects of nanoparticle exposure on these populations. In order to fill this gap, the potential effects of nanoparticles to pregnant females, neonate, diseased, and aged population, as well as the possible underlying mechanisms are reviewed in this article. Investigations show that responses from susceptible population to nanoparticle exposure are often more severe. Reduced protection mechanism, compromised immunity, and impaired self-repair ability in these susceptible populations may contribute to the aggravated toxicity effects. This review will help minimize adverse effects of nanoparticles to susceptible population in future nanotechnology applications.