紫茎泽兰醇提物的毒理学研究

为确保以紫茎泽兰提取物为主要原药的植物源农药的安全性,对紫茎泽兰醇提物进行了小鼠经口急性毒性试验、大白兔急性皮肤和眼刺激试验、小鼠骨髓嗜多染红细胞微核计数及小鼠精子畸形试验等急性毒性和遗传毒性试验。结果表明,受试物对两种性别的小鼠经口急性毒性试验,LD50大于5000mg／kg,对大白兔皮肤无刺激性;小鼠骨髓嗜多染红细胞微核试验及小鼠精子畸形试验结果均为阴牲,受试物未见遗传毒性。     

运用蚕豆根尖细胞微核试验分析校园水体的污染

许多研究表明 ,饮用水及生活污水中存在具有致突性的有机化学物质 ,其水源污染主要来源于生活污染源、工业污染源以及微生物生长活动引起非活性化学物转化成致突物等 ,在这些致突物中 ,许多具有遗传毒性。目前 ,研究饮用水的遗传毒性可用许多短期遗传毒性试验 ,其中蚕豆根尖细胞微核试验作为致突性分析的一种测试系统已越来越受到人们的青睐和应用。1　蚕豆根尖微核试验原理环境污染物 (如物理、化学、生物污染源 )能诱发植物细胞的染色体畸变 ,染色体断片游离在细胞质中于分裂末期形成微核。蚕豆是对污染物较为敏感的植物品种 ,利用污染过…     

灵芝子实体醇提取物的毒理研究

本文主要研究灵芝子实体醇提物的毒理学并评价其安全性,利用小鼠急性毒性试验和遗传毒性试验(Ames试验、小鼠骨髓细胞微核试验、小鼠精子畸形试验)对灵芝醇提物的毒性进行考察。试验结果显示,小鼠对灵芝醇提取物的最大耐受量是15 000mg/(kg?bw);灵芝醇提取物在有或无S9的条件下,对鼠伤寒沙门氏菌的突变型菌株TA97、TA98、TA100及TA102均无潜在致突变性;灵芝醇提取物在小鼠骨髓细胞微核试验和小鼠精子畸形试验中均呈阴性反应,不同剂量的样品组与阴性对照组之间无显著性差异。该结果表明灵芝醇提取物基本无毒性,属实际无毒物质。本研究为灵芝醇提取物的产品开发和应用提供了科学研究。     

微核试验在中国的应用、发展与展望

微核试验是反映染色体损伤的重要试验方法,已广泛应用于遗传、食品、药物、环境等多领域的遗传毒性评估,以及作为有害职业和生活环境暴露人群遗传损害的生物标志物。我国开展微核试验已有二十余年的历史,本文通过检索《中国生物医学文献数据库》(1980~2000),共检索到有关微核的专题研究文献共1316篇,研究内容涉及微核的文献共2083篇。本文对微核的相关信息进行了分析,并结合作者自己的研究工作,回顾了微核试验在中国的应用和发展,总结了我国学者开展该项工作的优势与不足,对微核试验在我国的进一步发展进行了展望。     

吖啶橙荧光染色法和Giemsa染色法对微核的比较观察

微核试验是筛选环境诱变物和化学致癌物的一种快速、经济的测定方法。到目前为止,只有小鼠骨髓细胞微核试验发展为标准的试验方法。并为国际环境致突变物和致癌物防护委员会所肯定。近年来,日本国立卫生试验所林真等人研究了能     

嗜酸乳杆菌LA-G80的毒理学研究

目的对嗜酸乳杆菌的毒性进行研究。方法采用大、小鼠急性毒性试验、Ames试验、小鼠骨髓细胞微核试验、小鼠精子畸形试验和大鼠30 d喂养等对嗜酸乳杆菌进行安全性试验研究。结果急性经口毒性试验表明,大、小鼠灌胃给予嗜酸乳杆菌,最大耐受剂量雌雄两性别均大于20.0 g/kg体重,Ames试验、微核试验和精子畸形试验结果均为阴性。大鼠30 d喂养试验结果表明各项指标均未见明显毒性反应。结论在本次实验条件下,嗜酸乳杆菌未见遗传毒性。由此可初步判定,使用嗜酸乳杆菌是安全可靠的。     

黔西北马缨杜鹃花红色素的毒性试验

马缨杜鹃（ＲｈｏｄｏｄｅｎｄｒｏｎｄｅｌａｖａｙｉＦｒａｎｃｈ．）是贵州省分布较广的一种植物。为提高其利用价值,对花的红色素进行了毒性试验。结果表明：急性毒性试验属实际无毒范围,Ａｍｅｓ试验,骨髓细胞微核试验和精子畸形试验均未显示诱变作用。为开发马缨杜鹃花资源提供了科学依据     

Mix-G200益生菌粉安全性毒理学评价

目的通过对Mix-G200益生菌粉的安全性毒理学进行研究,为以后的应用提供科学依据。方法采用雌雄小鼠急性毒性试验、小鼠骨髓细胞微核试验、小鼠精子畸形试验、Ames试验和大鼠30天喂养试验等对Mix-G200益生菌粉进行安全性试验研究。结果急性经口毒性试验表明,Mix-G200益生菌粉对雌雄小鼠的急性经口LD50均大于21500 mg/kg,以急性毒性半数致死量毒性分级,属无毒级物质。小鼠骨髓细胞微核试验、小鼠精子畸形试验、Ames试验结果均为阴性。30天喂养试验结果表明,大鼠生长情况良好,血液学检查、生化学检查、主要脏体以及组织学检查结果与对照组相比,差异均无统计学意义。结论 Mix-G200益生菌粉未见遗传毒性,使用Mix-G200益生菌粉是安全可靠的。     

梨果仙人掌红花品系的毒性研究

通过对梨果仙人掌红花品系的小鼠急性毒性试验、小鼠骨髓嗜多染红细胞微核试验、小鼠精子畸形试验研究,梨果仙人掌红花品系雌、雄小鼠LD50均大于170．0g／kgBw,属无毒物质;小鼠骨髓嗜多染红细胞微核试验、小鼠精子畸形试验结果均为阴性。因此在本次实验条件下,梨果仙人掌红花品系为无毒物质,未显示有遗传毒性作用。     

变异白色红花总黄酮提取物安全性毒理学评价

本文通过急性毒性试验、三项遗传毒性试验和30 d喂养试验,对变异白色红花总黄酮提取物(TFES)进行安全性毒理评价。结果表明,TFES对小鼠急性毒性试验,LD5010.0 g/kg·BW,按急性毒性剂量分级,属实际无毒物质;三项遗传毒性试验即Ames试验、小鼠骨髓嗜多染红细胞微核试验、小鼠精子畸形试验结果均为阴性;TFES对大鼠30 d喂养试验,动物未见明显的中毒症状和死亡,TFES各剂量组大鼠体重、总食物利用率、血清生化指标、血液学指标、脏器系数指标以及病理组织学等指标与对照组比较,无显著性差异。TFES在本实验条件下,未观察到明显毒性作用,为其进一步开发应用提供了安全依据。     

Evaluation of genotoxicity using the micronucleus assay and nuclear abnormalities in the tropical sea fish Bathygobius soporator (Valenciennes, 1837) (Teleostei, Gobiidae)

The micronucleus and nuclear abnormalities assays have been used increasingly to evaluate genotoxicity of many compounds in polluted aquatic ecossystems. The aim of this study is to verify the efficiency of the micronucleus assay and nuclear abnormality assay in field and laboratory work, when using erythrocytes of the tropical marine fish Bathygobius soporator as genotoxicity biomarkers. Gill peripheral blood samples were obtained from specimens of Bathygobius soporator. In order to investigate the frequencies of micronuclei and to assess the sensitivity of species, the results were compared with samples taken at the reference site and maintained in the laboratory, and fish treated with cyclophosphamide. The micronucleus assay was efficient in demonstrating field pollution and reproducing results in the labotatory. There were significant higher frequencies of micronuclei in two sites subject to discharge of urban and industrial effluents. The nuclear abnormality assay did not appear to be an efficient tool for genotoxicity evaluation when compared with field samples taken at a reference site in laboratory, with a positive control.     

Genotoxic and mutagenic effects of diesel oil water soluble fraction on a neotropical fish species

Numerous spills and leakages involving petroleum and its derivatives have recently occurred in Brazilian rivers. Considering the lack of information regarding the genotoxic response of neotropical fish to these events and the predominance of information regarding saltwater fish, which offers no genuine comparisons, the present work aimed to evaluate the genotoxicity and mutagenicity of the diesel water soluble fraction (DWSF) on the neotropical fish Prochilodus lineatus under acute (6, 24 and 96h) and subchronic (15 days) exposures, using the comet (SCGE) and micronucleus assays. The results indicated genotoxic and mutagenic damage in erythrocytes of P. lineatus exposed to DWSF. Comet scores for fish exposed to DWSF in all experimental periods were significantly higher than the respective negative control groups (fish exposed to clean water for the same period). The relative frequencies of micronucleated erythrocytes for P. lineatus exposed to DWSF under acute and subchronic treatment were also significantly higher than their respective negative controls. Taken together these results showed that acute and subchronic exposures to DWSF produce mutagenic and genotoxic effects on the blood cells of P. lineatus and that the combination of comet and micronucleus assays proved to be both suitable and useful in the evaluation of the genotoxicity of diesel oil due to their complementary action.     

Genotoxic evaluation of the GH transgenic Synechocystis using mice and turbot (Scophthalmus maximus L.)

In the present paper, the genotoxicity of transgenic Synechocystis sp. PCC 6803 containing flounder (Paralichthys olivaceus) growth hormone gene has been assessed using micronucleus tests in mice and fish. No micronucleus inductions in bone marrow erythrocyte of mice were observed at three doses of transgenic Synechocystis (2.0, 5.0, and 10.0g/kg). The frequencies of micronucleus and other nuclear abnormalities in turbot (Scophthalmus maximus L.) fed with 0.2%, 0.5% and 1.0% transgenic Synechocystis were also not significantly different (P>0.05) from controls. In contrast, cyclophosphamide, used in detecting the sensitivity of the biological assays, significantly increased the frequencies of micronucleus and other nuclear abnormalities in mice and turbot. Results indicate that the flounder GH transgenic Synechocystis sp. PCC 6803 seems to have no genotoxic effects on fish.     

Genotoxic effects of Roundup on the fish Prochilodus lineatus

Glyphosate-based herbicides, such as Roundup, represent the most extensively used herbicides worldwide, including Brazil. Despite its extensive use, the genotoxic effects of this herbicide are not completely understood and studies with Roundup show conflicting results with regard to the effects of this product on the genetic material. Thus, the aim of this study was to evaluate the genotoxic effects of acute exposures (6, 24 and 96 h) to 10 mg L(-1) of Roundup on the neotropical fish Prochilodus lineatus. Accordingly, fish erythrocytes were used in the comet assay, micronucleus test and for the analysis of the occurrence of nuclear abnormalities and the comet assay was adjusted for branchial cells. The results showed that Roundup produces genotoxic damage in erythrocytes and gill cells of P. lineatus. The comet scores obtained for P. lineatus erythrocytes after 6 and 96 h of exposure to Roundup were significantly higher than respective negative controls. For branchial cells comet scores were significantly higher than negative controls after 6 and 24 h exposures. The frequencies of micronucleus and other erythrocyte nuclear abnormalities (ENAs) were not significantly different between Roundup exposed fish and their respective negative controls, for all exposure periods. In conclusion, the results of this work showed that Roundup produced genotoxic effects on the fish species P. lineatus. The comet assay with gill cells showed to be an important complementary tool for detecting genotoxicity, given that it revealed DNA damage in periods of exposure that erythrocytes did not. ENAs frequency was not a good indicator of genotoxicity, but further studies are needed to better understand the origin of these abnormalities.     

Formation of micronuclei in erythrocytes of the fathead minnow (Pimephales promelas) after acute treatment with mitomycin C or cyclophosphamide

Despite the widespread use of the fathead minnow in ecotoxicology, there have been relatively few studies on genotoxicity biomarkers in this small, warm-water fish species. Consequently, we investigated the effect of two known genotoxins, mitomycin C and cyclophosphamide, on micronucleus induction in spleen and peripheral blood erythrocytes of this species. Initially, 96-h experiments after intra-peritoneal (i.p.) injections of mitomycin C and cyclophosphamide were undertaken to determine the maximum tolerated dose (MTD). From these studies, MTDs of 10 and 400 mg/kg, respectively, were obtained: doses that were higher than those reported for other fish species. Next, an assessment of micronucleus induction at 1, 2, 4, 8 and 14 days after injection was undertaken for each compound at the MTD. Mitomycin C at 10 mg/kg significantly induced micronuclei in erythrocytes from the spleen, but not from the peripheral blood, at 8 and 14 days. In addition, the overall levels of micronuclei observed were lower than most previously published data from other fish species. In contrast to mitomycin C, treatment with 400 mg/kg cyclophosphamide failed to significantly induce micronuclei in erythrocytes from any of the tissues employed, in contrast to previous reports of significant induction in other species. The reasons for the apparent relative insensitivity of the fathead minnow to these clastogens, with respect to both MTDs and micronucleus induction, are not clear. The fathead minnow, however, has previously been described as relatively insensitive compared to other fish species with respect to selected carcinogens and cytochrome P450 inducers; the latter suggesting that the lack of a significant induction following cyclophosphamide exposure may be due to low metabolic activation in vivo. Consequently, further clarifying work is required to delineate the response shown, considering the extensive use of this species in ecotoxicology research and regulatory testing.     

汉口、汉阳两地空气细颗粒物PM2.5遗传毒性研究

目的：探究汉口、汉阳两地空气细颗粒物PM2.5的遗传毒性。方法：采用Ames波动实验和双核细胞微核实验评价PM2.5在基因和染色体水平是否具有遗传毒性。结果：Ames波动实验结果表明,汉口和汉阳PM2.5对鼠伤寒沙门苗TA100无致突变作用;而在双核细咆徽核实验中,两地PM2.5随浓度上升徽核率逐渐上升,呈剂量反应关系,对染色体有损伤作用。2项实验结果都显示,汉口和汉阳两地的颗粒物在致遗传性上无明显差异。结论：汉口、汉阳两地PM2.5具有一定的潜在遗传毒性。     

Chromosome aberrations in cultured central mudminnow heart cells and Chinese hamster ovary cells exposed to polycyclic aromatic hydrocarbons and sediment extracts

1. Genotoxicity experiments were conducted with cultured fish cells to determine if the high frequency of epidermal papillomas observed in lemon sole from Sturgeon Bank, where a sewage treatment plant discharges, could be correlated with contamination of the sediments with chemicals such as 3,4-benzopyrene. 2. The frequency of chromosome aberrations was measured in cultured Umbra limi heart (U1-H) and Chinese hamster ovary (CHO) cells following exposure to the polycyclic aromatic hydrocarbons (PAH) 3,4-benzopyrene (BP), 1,2,5,6-dibenzanthracene (DBA), 1,2-benzanthracene (BA), and pyrene (PY), activated using S9 prepared from rainbow trout liver. 3. An increase in the chromosome aberration frequency was only observed following exposure to fish S9-activated BP in both cell lines. 4. Following exposure of the cells to both Sturgeon Bank and Spanish Bank sediment extracts, it was determined that a higher level of toxic and genotoxic activity was associated with the Sturgeon Bank sediments. 5. Since the detection of PAH genotoxicity requires the presence of S9, and since a higher level of genotoxic activity was noted following sediment extract exposures with no S9 present, this suggests that the extracts contain a complex mix of chemicals, some of which express genotoxic activity. 6. An assessment using the micronucleus test failed to indicate in vivo genotoxicity in fish collected from Sturgeon and Spanish Banks. 7. It was, therefore, difficult to associate the observed sediment genotoxicity with the previously noted high incidence of epidermal papillomas in lemon sole from this area.     

Fish micronucleus assay to assess genotoxic potential of arsenic at its guideline exposure in aquatic environment

The exposure to arsenic, a potential genotoxic carcinogen in humans, via drinking water is a serious worldwide health hazard. The arsenic content of 10 μg L^?1 in drinking water, however, has been established as its guideline standard (maximum contaminant limit) that has been estimated to pose minimum risk to cancer. Since micronucleus induction in the erythrocytes of fish is a sensitive indicator of genotoxic agents in water, the piscine micronucleus assay was used in the present experiment to assess the genotoxic potential of arsenic at its various exposure levels including the guideline value for drinking water. The experiments were conducted in two different species of fishes, the pond murrel (Channa punctatus) and the goldfish (Carassius auratus). Significant increases in the frequency of micronucleated erythrocytes were documented in a dose-dependent manner in both Channa and Carassius. The fishes, however, exhibited variations in inter-specific sensitivity to micronucleus induction following arsenic exposure. The exposure level of arsenic at its guideline value for drinking water, therefore, exhibited marked genotoxicity in fishes.     

Mitigation by vitamin C of the genotoxic effects of nicotine in mice, assessed by the comet assay and micronucleus induction

Nicotine has been reported to cause acute toxicity and to present long-term risks, such as chromosomal damage and genetic instability. The genotoxicity of nicotine may be mediated partly by an oxidative mechanism. We have evaluated the effects of the antioxidant vitamin C on nicotine-induced genotoxicity in mice. The comet assay and the micronucleus test were used to assess the effects of nicotine (15mg/kg) at different exposure times (2, 4, and 24h in the comet assay; 24h in the micronucleus test). Pretreatment with vitamin C 24h before nicotine exposure strongly protected mice against nicotine-induced DNA damage.