effect of silver nanoparticles on Staphylococcus epidermidis biofilm biomass and cell viability

Bacterial biofilm has been considered responsible for many deaths and high health costs worldwide. Their better protection against antibacterial agents compared to free living cells leads to poor treatment efficiency. Nanotechnology is promising approach to combat biofilm infections. The aim of the present study was to eradicate Staphylococcus epidermidis biofilm with silver nanoparticles [SNPs]. SNPs were used at different concentrations [two fold dilutions] and incubation times [24, 48, 72 h]. The crystal violet staining and pour plate assays were used to assess biofilm biomass and bacterial viability, respectively. The ability of SNPs on biofilm matrix eradication was assessed through optical density ratio [ODr]. Positive control was defined as an ODr =1.0. The crystal violet assay indicated that the biofilm matrixes were intact at different concentrations of SNOs and incubation times. There were no significant differences between these parameters [P >0.05]. Bacterial enumeration studies revealed that higher concentrations of SNPs were more effective in killing bacteria than lower ones. Although, longer incubation times led to enhancement of anti-biofilm activity of SNPs. The anti-biofilm activity of SNPs was concentration- and time-dependent. The results of this study highlighted that SNPs were effective against cell viability; however they were ineffective against biomass

comparative study of genotoxicity and oxidative stress before and after using lemon balm and cinnamon in subjects exposed to nickel welding fumes

By producing reactive oxygen and nitrogen species, metal-induced toxicity and carcinogenicity alter DNA bases, increase lipid peroxidation, and change calcium and sulfhydryl homeostasis. The purpose of the study was to investigate putative effects of Lemon balm and Cinnamomum zeylanicum on the blood markers of welding workers. We measured nickel and chromium levels, biochemical parameters, blood oxidative stress markers, total antioxidant capacity [TAC], Myeloperoxidase [MPO], lipid peroxidation [LPO], and DNA damage. The study was conducted on 55 male workers who worked in an industrial subjects exposed to Nickel Welding Fumes. The participants were administered Lemon balm and Cinnamon extract infusion 1.5 [0.12 extract] and 0.25[0.013 extract] g/100 mL, respectively, they have drunken twice a day for 30 days at 7:00 AM and 2:00 PM every day. In order to analyze the achieved data, paired t-test and Pearson correlation coefficient have been used. After using the extract infusion, a significant increase revealed in TAC [p= 0.007]. Also, administration of infusion decreased DNA damage but it was not statistically significant. After administration of infusion, a decrease in LPO and MPO were observed [p= 0.014, p=0.000 respectively]. Also there is positive correlation between ALP and Ni with 8-oH-dG and also, between Ni and TAC. The results indicate that using infusion causes to raise in a TAC and reduce in DNA damage