ABSTRACT
Following the increasing antibiotic resistance of pathogenic bacteria, the use of medicinal herbs as antibacterial agents has attracted growing attention. Pseudomonas aeruginosa is a human opportunistic pathogen that uses quorum sensing for regulating virulence gene expression [pyocyanin, protease, and elastase production and biofilm formation]. This study examined the anti-quorum sensing activity of Quercus infectoria, Zataria multiflora and Trachyspermum copticum extracts on standard P. aeruginosa strain. The minimum inhibitory concentration [MIC] of Q. infectoria, Z. multiflora and T. copticum extracts for standard P. aeruginosa strain was determined through micro dilution. Microtiter plates were used to evaluate the anti-quorum sensing effects of the three extracts [at a sub-MIC concentration] on pyocyanin, protease, and elastase production and biofilm formation. The acetone extract of Q. infectoria showed the highest anti-quorum sensing activity and reduced the pyocyanin, protease, and elastase production and biofilm formation by 89.1%, 78%, 73.3%, and 70.1%, respectively. The corresponding values were 88.2%, 72.1%, 69%, and 61.1% for the methanol extract of Z. multiflora and 70.6%, 63.42%, 60.1%, and 59.1% for the methanol extract of T. copticum. Considering the high anti-quorum sensing activity of the studied extracts, especially the acetone extract of Q. infectoria, these herbs can be used as antipathogenic drugs
ABSTRACT
Recently, applications of nanoparticles in many fields of medicine have been developed, due to their specific physical and chemical properties. Therefore assessment of their toxicity specially in the in vivo condition is necessary. The aim of this study is to evaluation the effect of Fe[3]O[4] nanoparticles coating by biocompatible compounds on their toxicity and also comparison by noncoated nanoparticles. Wetted chemical method was used in order to synthesize Fe[3]O[4] nanoparticles. The synthesized nanoparticles were coated by BSA [Bovine Serum Albumin] and DMSA [Dimercaptosuccinic Acid] and the coating interactions were investigated by FTIR. Magnetic and structure properties of Fe[3]O[4] and coated Fe[3]O[4] nanoparticles were evaluated by AGFM [Alternating Gradient Force Magnetometer], TEM [Transmission Electron Microscope] and XRD [X Ray Diffraction]. Toxicity assessment of Fe[3]O[4] and coated Fe[3]O[4] nanoparticles were studied in mice by intra peritoneally injections during a month. Liver enzymes [SGPT, SGOT, ALP, and LDH] were measured 7, 15 and 30 days post injection. The synthesized nanoparticles are single phase and have the spinel structure which their size distribution in the net from is around 5 to 11 nm and in the coated form is 17 to 25 nm. Some liver enzymes were changed due to the injection of both uncoated and coated nanoparticles to mice [especially in groups who received concentrations more than 100 mg per kg of mice weight]. The liver enzymes changes were more considerable in the groups received DMSA or DMSA coated in comparison with the groups received BSA or BSA coated. Chemical toxicity studies showed that there is not any irreversible effect in concentrations less than 200 mg/kg for all control and treated groups. The results indicate that, liver enzymes were changed during 7 and 15 days post injection measurements especially in high doses [200 mg/kg]. The results of 30 days post injection measurements were changed less in comparison with the control and this is indicates that there is not any irreversible effect in liver. Moreover, DMSA coated nanoparticles were more toxic in comparison with BSA coated nanoparticles