Hypericum perforatum is on of the members of Hypericaciea family and from long time ago it had been used for treatment of many diseases such as hair and skin lesions, children anureses, depression and mental disorders. Nowadays in many countries including Germany it is used frequently in making soft drinks and a ariety of drugs have been drived from it in the form of tablet, ointment, syrup and etc.The aim of this study was to assess the GENOTOXICITY effects of alcohol extract of the plant.Aines test along with two strains of Salmonella typhymorium TA98 ,TA100, because of their high sensitivity, were chosen to carry out this research. At first the two strains checked from view point of existence or lack of mutations and additional plasmids of rfa,uvrb,PKM101,then alcohole extract obtained from dry top branches and both the strains were cultured in minimum glucose agar culture and exposed at different volumes of 10,20,50,100,200,250 and 300 microliters and hen created clonies were counted after 48 hours in condition of 37°C.Regarding the criteria of evaluation, the alcohol extract of Hypericum perforatum using two bacterial strains of TA98, TA100 and by use of Ames is not mutagen.

Background: In a world of nanotechnology, the first concern is the potential environmental impact of nanoparticles. An efficient way to estimate nanotoxicity is to monitor the responses of bacteria exposed to these particles.Objectives: The current study explored the antimicrobial properties of nZVI (zero-valent Iron nanoparticles) on the Gram-negative bacterial systems Erwinia amylovora, Xanthomonas oryzae and the Gram-positive bacterial systems Bacillus cereus and Streptomyces spp. The GENOTOXICITY potential of nZVI was also assayed.Materials and Methods: The toxicity of nZVI was tested by two different methods: Growing bacteria in liquid (broth dilution) and agar media (challenge test) containing different nZVI concentrations for 24-72 hours. The GENOTOXICITY of nZVI was assessed using the preincubation version of the Ames test.Results: The lowest concentrations of nZVI that inhibited the visible growth (MIC) of E. amylovora, X. oryzae, B. cereus and Streptomyces spp. were 625, 550, 1250 and 1280 ppm, respectively. The minimum bactericidal concentration (MBC) for E. amylovora and X. oryzae were 10, 000 and 5, 000 ppm of nZVI, respectively. MBC was not observed for the Gram positive bacteria. No bacteriostatic and bactericidal effects were observed for oxidized nZVI. Mutant frequency did not increase according to the vehicle control at the concentrations assayed, indicating a lack of mutagenicity associated with nZVI.Conclusions: nZVI nanoparticles are not mutagenic at low concentrations, therefore they can be used without detrimental effects on soil bacteria.

Introduction: The aim of the present in vitro study was to evaluate the GENOTOXICITY of mineral trioxide aggregate (MTA) after adding different concentrations of disodium hydrogen phosphate and silver nanoparticles using the Ames test. Methods and Materials: TA100 strain of Salmonella typhimurium was used to evaluate mutagenicity of experimental materials with and without S9 mix fraction. The materials tested in this study consisted of MTA, MTA/disodium hydrogen phosphate and MTA/silver nanoparticles at 0. 1, 0. 01, 0. 001 and 0. 0001 concentrations. Negative and positive control groups consisted of 1% dimethyl sulfoxide and sodium azide with 2-aminoanthracene, respectively. The number of colonies per plate was determined. If the ratio of the number of histidine-revertant colonies to spontaneous revertants of the negative control colonies was *2, the material was regarded a mutagenic agent. Results: In all the concentrations of the three tested materials, the Ames test failed to detect mutations. Conclusion: Under the limitations of the present study, MTA/disodium hydrogen phosphate and MTA/silver nanoparticles were biocompatible in relation to mutagenicity.

Cisplatin is one of the most useful chemotherapeutics which performs its cytotoxic effect via accumulation of platinum resulting in oxidative stress, and destruction of cell DNA. This could probably cause secondary cancers in healthy tissues. Lipocalin2 (Lcn2) is a protein which its expression is increased in oxidative stresses. Therefore, the present study was performed to evaluate the protective effects of Lcn2 up-regulation on cisplatin GENOTOXICITY. In order to up-regulate Lcn2 expression, HEK293 cells were transfected with pcDNA3.1-Lcn2 vector. Afterwards, stable cells consistently expressing Lcn2 were selected via screening with G418 antibiotic. Next, overexpression of Lcn2 was evaluated by RT-PCR and ELISA, comparing to the control non-transfected cells. Then, in order to evaluate the cytoprotective effects of Lcn2 overexpression, transfected and non-transfected cells were subjected to cisplatin treatment followed by MTT and alkaline Comet assays. RT-PCR and ELISA assays confirmed up-regulation of Lcn2 by the stable cells. MTT assay of the Lcn2 over-expressing cells showed higher IC50 values comparing to the non-transfected cells. Furthermore, the Comet assay confirmed Lcn2 protective effects on the cisplatin (1 mg/mL) induced GENOTOXICITY. In the present study, for the first time, we showed the protective effect of Lcn2 on cisplatin induced GENOTOXICITY. Therefore, one of the probable mechanisms of Lcn2 cytoprotctive effects under oxidative stress conditions could be due to the prevention of GENOTOXICITY. However, further evaluations in this regard must be considered.