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1.
The compound VAM2‐6 (1‐methyl‐7‐nitro‐4‐(5‐(piperidin‐1‐yl)pentyl)‐3,4‐dihydroquinoxalin‐2(1H)‐one) has previously been shown to have an in vitro efficacy of 100% at a concentration of 100 µg ml–1 against Trichomonas vaginalis, a protozoon parasite that causes the sexually transmitted disease trichomoniasis. Because VAM2‐6 is a quinoxaline derivative and given the lack of studies on the genotoxic activity of this compound, the present study was undertaken to evaluate its ability to induce DNA damage in the peripheral blood of mice using single‐cell gel electrophoresis (SCGE or comet assay) and the micronucleus (MN) assay. Cell viability was assessed using a fluorochrome‐mediated viability test. The compound was tested on CD1 mice at 60, 40 and 10 mg kg–1 body weight administrated intraperitoneal (i.p.) in a single dose. Peripheral blood samples were collected 24 and 48 h after treatment. N‐Ethyl‐N‐nitrosourea (ENU) was used as a positive control for the comet and micronucleus assays. The results showed that i.p. VAM2‐6 induced single‐strand DNA breaks and increased the average number of micronuclei in the treated mice in a dose‐dependent manner at 60, 40 and 10 mg kg–1. Cell viability decreased at 24 h but recovered at 48 h for all three evaluated doses. Therefore, the chemical structure of VAM2‐6 should be modified to reduce its genotoxic potential. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

2.
Baccharis dracunculifolia (Asteraceae), the main botanical source of green propolis, is a shrub of the Brazilian ‘cerrado’. In folk medicine it is used as an anti‐inflammatory agent, mainly for the treatment of gastrointestinal diseases. The aim of the present study was to evaluate the genotoxic and antigenotoxic effects of B. dracunculifolia ethyl acetate extract (Bd‐EAE) on Chinese hamster lung fibroblasts (V79 cells) by the comet assay. Methyl methanesulfonate (MMS; 200 μM ) was used as an inducer of DNA damage. Genotoxicity was evaluated using four different concentrations of Bd‐EAE: 12.5, 25.0, 50.0 and 100.0 μg ml?1. Antigenotoxicity was assessed before, simultaneously, and after treatment with the mutagen. The results showed a significant increase in the frequency of DNA damage in cultures treated with 50.0 and 100.0 μg ml?1 Bd‐EAE. Regarding its antigenotoxic potential, Bd‐EAE reduced the frequency of DNA damage induced by MMS. However, this chemopreventive activity depended on the concentrations and treatment regimens used. The antioxidant activity of phenolic components present in Bd‐EAE may contribute to reduce the alkylation damage induced by MMS. In conclusion, our findings confirmed the chemopreventive activity of Bd‐EAE and showed that this effect occurs under different mechanism. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

3.
《Pharmaceutical biology》2013,51(6):930-934
Abstract

Context: Bothrops moojeni Hoge (Viperidae) venom is a complex mixture of compounds with therapeutic potential that has been included in the research and development of new drugs. Along with the biological activity, the pharmaceutical applicability of this venom depends on its toxicological profile.

Objective: This study evaluates the cytotoxicity and genotoxicity of the Bothrops moojeni venom (BMV).

Material and methods: The in vitro cytotoxicity and genotoxicity of a pooled sample of BMV was assessed by the MTT and Comet assay, respectively. Genotoxicity was also evaluated in vivo through the micronucleus assay.

Results: BMV displayed a 50% cytotoxic concentration (CC50) on Vero cells of 4.09?µg/mL. Vero cells treated with 4?µg/mL for 90?min and 6?h presented significant (p?<?0.05, ANOVA/Newman–Keuls test) higher DNA damage than the negative control in the Comet assay. The lower DNA damage found after 6?h compared with the 90?min treatment suggests a DNA repair effect. Mice intraperitoneally treated with BMV at 10, 30, or 80?µg/animal presented significant genotoxicity (p?<?0.05, ANOVA/Newman–Keuls test) in relation to the negative control after 24?h of treatment. Contrary to the in vitro results, no DNA repair seemed to occur in vivo up to 96?h post-venom inoculation at a dose of 30?µg/animal.

Discussion and conclusion: The results show that BMV presents cyto- and genotoxicity depending on the concentration/dose used. These findings emphasize the importance of toxicological studies, including assessment of genotoxicity, in the biological activity research of BMV and/or in the development of BMV-derived products.  相似文献   

4.
Nerolidol is a sesquiterpenoid component of essential oil used as a flavor and aroma enhancer. It has also been studied as a topical skin penetration enhancer, and has inhibitory activities against S. aureus and E. coli, among other activities. The objective of this study was to evaluate the ability of a single nerolidol treatment to induce DNA damage in peripheral blood and liver cells of mice and micronuclei in polychromatic erythrocytes of bone marrow cells of the same animals. In the dose range‐finding assays, the maximum tolerated dose was higher than 2000 mg kg?1. The doses used in the experiments were 250, 500 and 2000 mg kg?1, administered by gavage in a single dose. Peripheral blood cells were collected 4 and 24 h after the treatments and liver cells 24 h after. At least 100 nucleoids per cell type/animal were analyzed to determine the DNA damage scores and 2000 PCEs per animal for micronuclei in PCEs. The positive control was N‐nitroso‐N‐ethylurea 50 mg kg?1. Cytotoxicity was assessed by scoring 200 consecutive total polychromatic (PCE) and normochromatic (NCE) erythrocytes (PCE:NCE ratio). The results showed that nerolidol induced weak levels of dose‐related DNA damage in both types of cells analyzed, and enhanced the average number of micronucleated cells in the two high doses tested. The PCE:NCE ratio showed no cytotoxicity for the three doses of the compound. The data obtained support the view that nerolidol induces clastogenicity and very weak genotoxicity in the mouse cells tested. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

5.
We used well-characterized and positively charged nanoparticles (NP+) to investigate the importance of cell culture conditions, specifically the presence of serum and proteins, on NP+ physicochemical characteristics, and the consequences for their endocytosis and genotoxicity in bronchial epithelial cells (16HBE14o-). NP+ surface charge was significantly reduced, proportionally to NP+/serum and NP+/BSA ratios, while NP+ size was not modified. Microscopy studies showed high endocytosis of NP+ in 16HBE14o-, and serum/proteins impaired this internalization in a dose-dependent manner. Toxicity studies showed no cytotoxicity, even for very high doses of NP+. No genotoxicity was observed with classic comet assay while primary oxidative DNA damage was observed when using the lesion-specific repair enzyme, formamidopyrimidine DNA-glycosylase (FPG). The micronucleus test showed NP+ genotoxicity only for very high doses that cannot be attained in vivo. The low toxicity of these NP+ might be explained by their high exocytosis from 16HBE14o- cells. Our results confirm the importance of serum and proteins on nanoparticles endocytosis and genotoxicity.  相似文献   

6.
ABSTRACT

Cecropia pachystachya

leaves are popularly used to treat asthma and diabetes. Despite the widespread consumption of this plant, there are few scientific studies regarding its toxicological potential. In order to conduct a thorough study concerning the potential adverse effects, the aim of this study was to assess acute and subacute toxicity tests of crude aqueous extract from C. pachystachya leaves (CAE-Cp) using in vivomodel, as well as in vitro cytotoxicity, genotoxicity and antioxidant activity. In addition, genotoxicity, and cytotoxicity of chlorogenic acid (CGA) and cytotoxicity of isoorientin (ISOO) were also evaluated. The antioxidant activity was verified by DPPH, cytotoxicity using sulforhodamine B (SRB) assay and genotoxicity by comet assay on V79 cells. The phytochemical analysis of CAE-Cp detected flavonoids and tannins, CGA and ISOO as the major compounds utilizing HPLC. The total flavonoid content (6.52 mg/g EQ) and antioxidant activity (EC50 = 62.15 µg/ml) of CAE-Cp were determined. In vitro evaluations with CAE-Cp showed genotoxic effects at 0.31 to 2.5 mg/ml and an expressive cytotoxicity on HT-29 (IC50 = 4.43 µg/ml) cells. CGA was genotoxic against V79 cells at 0.07 mg/ml and cytotoxic against to HT-29 (IC50 = 71.70 µg/ml), OVCAR-3 (IC50 = 80.07 µg/ml), MCF-7 (IC50 = 45.58 µg/ml) and, NCI-H460 (IC50 = 71.89 µg/ml) cancer cell lines. Wistar rats treated with a single dose (2,000 mg/kg) CAE-Cp decreased hemoglobin levels after 14 days, although no significant toxicity was observed in animals after 28 days. In view of the in vitro cytotoxicity and genotoxicity detected, further studies are necessary to establish the safe use of CAE-Cp.  相似文献   

7.
Rosmarinic acid (RA) is a naturally occurring phenolic compound, which contributes to the beneficial and health‐promoting effects of herbs, spices and medicinal plants. RA has shown several biological activities, such as hepatoprotective, anti‐inflammatory, antiangiogenic, antitumor, antidepressant, antineurodegenerative, HIV‐1 inhibitory and antioxidant effects. The aim of this study was to investigate the ability of RA to prevent chemically induced chromosome breakage or loss and primary DNA damage using the micronucleus and comet assays with V79 cells, respectively. The chemotherapeutic agent doxorubicin (DXR; 0.5 µg ml?1) was used as the DNA‐damaging agent. The cultures were treated with different concentrations of RA (0.28, 0.56 and 1.12 mm ) alone or in combination with DXR. The results showed that RA exerted no genotoxic effect, but significantly reduced the frequency of micronuclei and the extent of DNA damage induced by DXR at the three concentrations tested. The antioxidant activity of RA might be involved in the reduction of DXR‐induced DNA damage observed in the present study. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

8.
The physicochemical characteristics of silver nanoparticles (AgNPs) may greatly alter their toxicological potential. To explore the effects of size and coating on the cytotoxicity and genotoxicity of AgNPs, six different types of AgNPs, having three different sizes and two different coatings, were investigated using the Ames test, mouse lymphoma assay (MLA) and in vitro micronucleus assay. The genotoxicities of silver acetate and silver nitrate were evaluated to compare the genotoxicity of nanosilver to that of ionic silver. The Ames test produced inconclusive results for all types of the silver materials due to the high toxicity of silver to the test bacteria and the lack of entry of the nanoparticles into the cells. Treatment of L5718Y cells with AgNPs and ionic silver resulted in concentration-dependent cytotoxicity, mutagenicity in the Tk gene and the induction of micronuclei from exposure to nearly every type of the silver materials. Treatment of TK6 cells with these silver materials also resulted in concentration-dependent cytotoxicity and significantly increased micronucleus frequency. With both the MLA and micronucleus assays, the smaller the AgNPs, the greater the cytotoxicity and genotoxicity. The coatings had less effect on the relative genotoxicity of AgNPs than the particle size. Loss of heterozygosity analysis of the induced Tk mutants indicated that the types of mutations induced by AgNPs were different from those of ionic silver. These results suggest that AgNPs induce cytotoxicity and genotoxicity in a size- and coating-dependent manner. Furthermore, while the MLA and in vitro micronucleus assay (in both types of cells) are useful to quantitatively measure the genotoxic potencies of AgNPs, the Ames test cannot.  相似文献   

9.
This study evaluated the toxicity of 1-methyl-3-octylimidazolium chloride ([C8mim]Cl) on Paramisgurnus dabryanus by enzyme analysis, comet assay, and apoptosis analysis. The study showed that [C8mim]Cl had an obvious toxic effect inducing oxidative stress, genotoxicity, and cytotoxicity to fish liver cells. [C8mim]Cl also induced changes in the activities of superoxide dismutase and catalase, and the glutathione content and malondialdehyde level in fish exposed at 20–80 mg L−1. With increased exposure concentration and time, the four antioxidant enzyme activities, three different comet parameters and apoptosis rates of tested cells were significantly increased, with significant differences (P < 0.05 or P < 0.01) observed between control group and each treatment group. This study shows that [C8mim]Cl could be a threat to aquatic organism health when accidentally released into aquatic ecosystems.  相似文献   

10.
Genotoxicity of Ceratonia siliqua extracts, was investigated by assessing their capacity to induce nucleus DNA degradation of murine leukaemia cells L1210, using the “Comet assay”. The ability of total oligomer flavonoids (TOF) and aqueous extracts to protect cell DNA against oxidative stress induced by H2O2, was performed by pre- co or post-treatment of cells with the before mentioned extracts for different periods preceding exposure to H2O2 stress. No significant genotoxic effect was detected at different exposure times, except at the lowest concentration of TOF extract (16.25 μg/ml). It appears that extracts decreased DNA damage, induced by H2O2.Both of TOF and aqueous extracts exhibited cellular antioxidant capacity, with EC50 values of respectively <16.25 and < 35 μg/ml, as well as, a protective capacity against lipidperoxidation inducing using L1210 cells line as a cellular model. MDA inhibition percentages reached 88.43% and 90.52% with respectively 35.5 μg/ml of TOF extract and 70 μg/ml of aqueous extract.Antioxidant properties of carob leaf extracts revealed by our study make a good antioxidant protection and thus a good candidate as food addition component.  相似文献   

11.
Hydrogels are three‐dimensional, crosslinked networks of hydrophilic polymers swollen with a large amount of water or biological fluids, without dissolving. Dextrin, a low‐molecular‐weight carbohydrate composed by glucose residues, has been used to develop an injectable hydrogel for biomedical applications. Dextrin was first oxidized to introduce aldehyde groups, which then reticulate with adipic acid dihydrazide, forming the dextrin‐based hydrogel (HG). The HG and its components were tested for cyto‐ and genotoxicity according to the International Standard ISO 10993‐3 on the biological evaluation of medical devices. To assess genotoxicity, a battery of in vitro genotoxicity tests employing both eukaryotic and prokaryotic models was performed: comet assay, cytokinesis‐block micronucleus assay and Ames test. Our data revealed that the HG (IC50 = 2.8 mg/mL) and oxidized dextrin by itself (IC50 = 1.2 mg/mL) caused a concentration‐dependent decrease in cellular viability of human lymphoblastoid TK6 cells after 24 hours of exposure to the test agents. However, these concentrations are unlikely to be reached in vivo. In addition, no significant increase in the DNA and chromosomal damage of TK6 cells exposed to non‐cytotoxic concentrations of the HG and its isolated components was detected. Furthermore, neither the HG nor its metabolites exerted a mutagenic effect in different of Salmonella typhimurium strains and in an Escherichia coli mix. Our data demonstrated the genocompatibility of the HG (up to 3.5 mg/mL) for biomedical applications. To our best acknowledge, this is the first report with a detailed genotoxicity assessment of an aldehyde‐modified polysaccharide/adipic acid dihydrazide hydrogel.  相似文献   

12.
Solanum lycocarpum St.-Hil (Solanaceae) is a hairy shrub or small much-branched tree of the Brazilian Cerrado, popularly known as “fruit-of-wolf”. Considering that the induction of chromosomal mutations is involved in the process of carcinogenesis, and that S. lycocarpum is often used in folk medicine, it becomes relevant to study its effect on genetic material. In this sense, the aim of present study was to determine the possible cytotoxic, genotoxic and antigenotoxic potentials of S. lycocarpum fruits glycoalkaloid extract (SL) in Chinese hamster lung fibroblasts (V79 cells). The cytotoxicity was evaluated by the colony forming assay, apoptosis and necrosis assay, Trypan blue exclusion dye method and mitotic index. Genotoxic and antigenotoxic potential were evaluated by comet and chromosomal aberrations assays. Four concentrations of SL (4, 8, 16 and 32 μg/mL) were used for the evaluation of its genotoxic potential. The DNA damage-inducing agent methyl methanesulfonate (MMS, 22 μg/mL) was utilized in combination with extract to evaluate a possible protective effect. The results showed that SL was cytotoxic at concentrations above 32 μg/mL by the colony forming assay. For apoptosis and necrosis assay, the concentration of 64 μg/mL of SL showed statistically significant increase in cell death by apoptosis and necrosis, while the concentrations of 128 and 256 μg/mL of SL demonstrated statistically significant increase in cell death by necrosis, compared with the control group. Analysis of cell viability by Trypan blue exclusion indicated >96% viability for treatments with concentrations up to 32 μg/mL of SL. No significant differences in MI were observed between cultures treated with different concentrations of SL (4, 8, 16 and 32 μg/mL) alone or in combination with MMS and the negative control, indicating that these treatments were not cytotoxic. The comet and chromosomal aberrations assays revealed that SL does not display genotoxic activity. Moreover, the different concentrations of SL showed protective effect against both genomic and chromosomal damages induced by MMS.  相似文献   

13.
In Deok Kim  Bae Jin Ha   《Toxicology in vitro》2009,23(6):1014-1019
LPS is one of the major constituents of the outer membrane of Gram-negative bacteria. LPS-induced activation of macrophage results in the nitrite (NO) production and the secretion of a pro-inflammatory mediator such as PGE2. Excessive NO reacts with the superoxide anion to generate a selective oxidant and nitrating agent, peroxynitrite, which interacts with biological molecules and damages the cell membranes of them, being able to result in the cell death. We evaluated the protective effects of paeoniflorin (PF) against LPS-induced toxicity by measuring its dose-dependent effects on cell viability in MTT assay, NO production in NO assay, PGE2 production in prostaglandin E2 (PGE2) assay, and DNA damage in comet assay in LPS-treated RAW 264.7 macrophages. In the comet assay, we also analyzed tail length, tail DNA, and tail moment as the markers of DNA strand breaks. PF-treatment significantly protected RAW 264.7 macrophages against LPS-induced toxicity with the increase of viable cells, the decrease of NO and PGE2, and the repair of DNA damage.  相似文献   

14.
关木通两种提取液对V79细胞DNA的损伤作用   总被引:5,自引:0,他引:5  
目的 探讨关木通对DNA的损伤作用。方法 应用单细胞凝胶电泳技术(彗星实验)研究中药关木通的两种提取液对中国仓鼠肺成纤维细胞(V79)的DNA损伤情况。结果 关木通的两种提取液在一定浓度下均能导致V79细胞产生彗星现象,并且存在的剂量-反应关系。结论 提示关木通过V79细胞DNA具有损伤作用。  相似文献   

15.
Acrylamide (ACR) and glycidyl methacrylate (GMA) are structurally related compounds used for making polymers with various properties. Both chemicals can be present in food either as a byproduct of processing or a constituent of packaging. We performed a comprehensive evaluation of ACR and GMA genotoxicity in Fisher 344 rats using repeated gavage administrations. Clastogenicity was measured by scoring micronucleated (MN) erythrocytes from peripheral blood, DNA damage in liver, bone marrow and kidneys was measured using the Comet assay, and gene mutation was measured using the red blood cell (RBC) and reticulocyte Pig-a assay. A limited histopathology evaluation was performed in order to determine levels of cytotoxicity. Doses of up to 20 mg/kg/day of ACR and up to 250 mg/kg/day of GMA were used. ACR treatment resulted in DNA damage in the liver, but not in the bone marrow. While ACR was not a clastogen, it was a weak (equivocal) mutagen in the cells of bone marrow. GMA caused DNA damage in the cells of bone marrow, liver and kidney, and induced MN reticulocytes and Pig-a mutant RBCs in a dose-dependent manner. Collectively, our data suggest that both compounds are in vivo genotoxins, but the genotoxicity of ACR is tissue specific.  相似文献   

16.
It is reported that salidroside, the main component of a traditional Chinese medicine, Rhodiola rosea, has the efficacy of protecting Coxsackie virus impairment. As part of a safety evaluation on salidroside for use in the treatment of viral myocarditis, the present study evaluated potential genotoxicity of salidroside by using the standard battery of tests (i.e., bacterial reverse mutation assay, chromosomal aberrations assay, and mouse micronucleus assay) recommended by the State Food and Drug Administration of China. The results showed that salidroside was not genotoxic under the conditions of the reverse mutation assay, chromosomal aberrations assay, and mouse micronucleus assay conditions. The anticipated clinical dose seems to be smaller than the doses administered in the genotoxicity assays. With confirmation from further toxicity studies, salidroside would hopefully prove to be a safe anti-Coxsackie virus agent.  相似文献   

17.
The use of plants for the treatment of diseases continues to rise although there are few studies providing proof of these effects. One of these plants is the Anacardium occidentale, popularly known as the cashew. The present study evaluated the possible genotoxic and protective activities of cashew stem bark methanolic extract, in vitro, using methyl methanesulfonate (MMS) as a positive control, to compare possible mechanisms of DNA damage induction in the Comet assay. The antigenotoxicity protocols used were pre, simultaneous and post-treatment in relation to MMS. In genotoxicity and antigenotoxicity assessments, besides MMS, PBS was used as the negative control and three concentrations of the A. occidentale extract (500 μg/mL, 1000 μg/mL and 2000 μg/mL) were used on Chinese hamster lung fibroblasts (V79 cells). The Comet assay revealed that the two lowest concentrations tested presented no genotoxic activity, whereas the highest presented genotoxicity. All of the concentrations showed protective activity in simultaneous and post-treatment in relation to MMS. Further studies are required to identify the substances that comprise the extract and more clearly comprehend the antigenotoxic mechanism detected in this study.  相似文献   

18.
Benzalkonium chloride (BAC) acts as a preservative in numerous nasal preparations. Possible genotoxic and cytotoxic effects of BAC in human respiratory epithelial BEAS-2B cells should be investigated in vitro.

Cell cultures were exposed for 2 h to BAC in concentrations ranging from 0.002% to 0.05%. Methyl methanesulfonate served as positive control, PBS as negative control. The tail moment of single-cell gel-electrophoresis (SCGE) was used to assess BAC-induced DNA damage. Cell viability was measured by trypan blue dye exclusion staining. Additionally, the critical micellar concentration (CMC) of BAC in PBS was detected.

The tail moment increased dose dependently with the maximum value at 0.02%, and declined for higher concentrations. Nearly all cells died at low BAC concentrations up to 0.01%. Above this concentration cell viability increased. The CMC of BAC in PBS was estimated to be 0.02%.

BAC caused relevant DNA changes in respiratory epithelial cells in vitro at concentrations commonly employed in commercially available nasal preparations. Some of the exposed cells survived. In further studies it could be considered to look whether these cells would still be able to proliferate and possibly fix the damage that they have possibly accumulated into an actual mutation using for example the induction of micronuclei.  相似文献   


19.
It is reported that dehydrocavidine (DC), the main component of a traditional Chinese medicine, Yanhuanglian (YHL), can protect hepatic tissue against HBV and HAV impairment. As part of a safety evaluation on YHL-DC for use in the treatment of HBV, the present study evaluated the potential genotoxicity of YHL-DC by using the standard battery of tests (i.e., bacterial reverse mutation, chromosomal aberrations, and mouse micronucleus assays) recommended by the State Food and Drug Administration of China. The results showed that YHL-DC was not genotoxic under the conditions of the reverse mutation, chromosomal aberrations, and mouse micronucleus assay conditions. The anticipated clinical dose should be smaller than the doses used in the genotoxicity assays. With confirmation from further toxicity studies, YHL-DC would hopefully prove to be a useful anti-HBV agent.  相似文献   

20.
Leather manufacturing has a high potential for environmental pollution due to hides and chemicals that are not completely absorbed during the tanning process. This study aims to investigate the mutagenic potential of surface water samples from Cadeia and Feitoria rivers (RS, Brazil) in areas influenced by tanneries and leather footwear industry. Micronucleus assays using V79 cells and human lymphocytes were used. Cells were exposed to surface water collected bimonthly from three sites for a year, totaling six samples. Significant MN induction in human lymphocytes was shown by 83% of samples from sites FEI001 and CAD001 located downstream from the industrial area, followed by FEI004 (33%), upstream. Only a single sample from site FEI004 showed a positive response for MN in V79 cells. Thirteen discordant and five concordant responses were found between the two in vitro tests. Mutagenic agents were found at the sites where chemical quality was worst, corroborating studies on chronic toxicity, oxidative stress and mutagenicity performed in this area. The assay using human lymphocytes was more sensitive than V79 cells to detect the contaminants from this area, showing that it is an excellent biomarker of environmental genotoxicity.  相似文献   

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