茶多酚抗辐射制剂安全毒理学研究

为检测茶多酚抗辐射制剂的食用安全性,通过急性毒性试验、遗传毒性试验（Ames试验、小鼠骨髓微核试验、小鼠精子畸形试验）、30d喂养试验进行毒理学研究。结果表明,雌雄两性大、小鼠经口MTD均大于20.0g/kg,Ames试验、小鼠骨髓微核试验、小鼠精子畸形试验3项遗传毒性试验结果均为阴性,显示无致突变性。30d喂养试验（5.00g/kg）未见动物出现中毒症状。试验结果显示,茶多酚抗辐射制剂急性毒性分级属无毒级、无遗传毒性,食用安全性高。     

茶多酚西洋参制剂安全性毒理学研究

根据《保健食品检验与评价技术规范》对茶多酚西洋参制剂安全性进行了评价。急性毒性试验结果表明,制剂内容物经口LD50>10.0g/kg·Bw;3项致突变试验结果均为阴性;大鼠30d喂养试验中,各剂量组动物生长发育良好,对体重、食物利用率无不良影响;各剂量组血常规,血清生化测定结果与对照组比较无显著差异;脏器比值与对照差异不明显。肝、心、脾、肾、胃肠、睾丸、卵巢等器官外观和组织切片与对照比均未发现实质性病理改变。结果表明茶多酚西洋参制剂无毒,无遗传毒性,使用安全性高。     

Impacts of chloramine‐T treatment on antioxidant enzyme activities and genotoxicity in rainbow trout,Oncorhynchus mykiss (Walbaum)

Juvenile rainbow trout Oncorhynchus mykiss (Walbaum) were exposed to therapeutic, and higher concentrations of chloramine‐T (Cl‐T) to assess the effects of this chemical on the antioxidant enzyme system and genetic structure. Red blood cells acetylcholinesterase, ?‐aminolevulinic acid dehydratase, paraoxonase and liver glutathione S‐transferase activity were increased at 10 and 20 mg L^?1 Cl‐T‐exposed fish, while they were decreased at 30 mg L^?1 Cl‐T‐exposed fish. On the other hand, liver catalase activity and liver protein levels increased at 10 mg L^?1 and decreased at 20 and 30 mg L^?1 concentrations of Cl‐T. Liver super‐oxide dismutase activity decreased at 10 mg L^?1 and 20 mg L^?1 Cl‐T and increased at 30 mg L^?1 of Cl‐T. Compared to control, comet assay indicated that Cl‐T did not cause significant DNA damage to red blood cells of the fish. Results indicate that 10 or 20 mg L^?1 Cl‐T can be safely used to prevent or treat external parasitic and bacterial infection of rainbow trout.     

Proposal of a testing strategy and assessment criteria for the ecotoxicological assessment of soil or soil materials

Background and Scope  Information on a potential contamination of soils or soil materials are derived by chemical analysis which takes place specifically for a given substance. For a comprehensive assessment, information on the bioavailable and mobile contaminant fraction, including all metabolites, is desirable. During the last years several research projects were initiated in Germany, to supplement the chemical analyses and to elaborate a suitable testing strategy. The main goal of this contribution is to elucidate the results of these research projects and to summarize the test strategy, which is recommended based on these results. Results and Conclusion  Ecotoxicological tests, which are standardized for the assessment of chemicals, were regarded as a suitable starting basis for a cost effective, pragmatic approach. Aquatic tests (testing of aqueous soil extracts) focus on the retention function of soils and terrestrial tests (testing of soil) on the habitat function. Suitable reference systems for the terrestrial tests and assessment criteria for both test types (terrestrial and aquatic) were elaborated. On the basis of a round robin test and a laboratory comparison test, a minimal test battery was established. This minimal test battery can be supplemented by further tests if more or specific information is required. Outlook  The recommendations should encourage the discussion regarding the application of biological methods for the assessment of soil quality. Such an assessment is or at least can be required by soil protection laws which have been adopted in some European countries within the last years.     

Validation of Microplate Bioassays for the Assessment of Contaminated and Remediated Sites

Background, Goal and Scope  Bioassays are frequently used to investigate the water extractable ecotoxicological and genotoxicological potential of contaminated soil samples. A laboratory intercomparison study was performed for validation of miniaturised biological test systems for the assessment of contaminated and remediated sites. The successful performance of this study resulted in an optimisation of microplate assays with respect to the testing of chemicals and environmental samples. Methods  For this purpose, miniaturised bioassays were chosen, which, because of their stage of development, are suitable for routine application in the characterisation of the water extractable ecotoxicological and genotoxicological potential of soils. These ecotoxicological and genotoxicological assays were performed with contaminated soil samples by three institutions at the same time. Results and Discussion  The toxicological assessment of the contaminated and remediated soil samples using LID-values, as a rule, was highly uniform. Some minor deviations could, for the most part, be explained by the heterogeneity of the soil samples and, to a lesser extent, by methodical aspects. The difference in sensitivity towards contaminants of the two bacteria Vibrio fischeri and Pseudomonas putida was pointed out. In the algae test with Desmodesmus subspicatus, the influence of the highest sample concentrations on the growth controls became obvious. It was recommended to modify the experimental setup of the microtitration plate, i.e. to place growth controls located next to both the lowest and the highest dilution steps of the sample. The Ames-test did in some cases provide new information on the genotoxicity of the samples, but is not considered useful in a test battery for the evaluation of the genotoxic potential because of its great expense in time and work. Conclusions  The investigations in this laboratory-intercomparison study for the assessment of the water extractable toxic potential of soil samples show that different bioassays are needed, which, in contrast to chemical-analytical methods, can detect the complete effects of all present pollutants in contaminated and remediated soils and solid substrates path-specifically. Recommendations and Outlook  If the recommended modifications for the performance of the bacterial and algae growth inhibition assays on microplates are taken into consideration, these tests can substitute the tests performed on a macro scale. The usefulness of the umu-test and the NM2009-test for the investigation of the genotoxic potential has been proven. Although the tests performed on microplates require much lower sample amounts, it is recommended that sample amounts be eluted in accordance with current guidelines to ensure representativity of the sample. Further work should focus on toxicity identification studies in the future by combining chemical and toxicological analyses.     

阿特拉津污染胁迫对典型细菌DNA损伤研究

采用随机扩增多态性DNA标记(RAPD)方法,研究阿特拉津浓度为0、25、50、75、100和125 mg·L-1污染胁迫条件下对阿特拉津高效降解菌Arthrobacter sp.DNS10和Acinetobacter sp.DNS32与非阿特拉津降解菌Escherichia coli K12和Micrococcus luteus N19生长影响及基因组DNA损伤情况。结果表明,在阿特拉津污染胁迫24 h后,随阿特拉津浓度增高,Escherichia coli K12和Micrococcus luteus N19生长速度受抑制强度逐渐明显。利用随机引物对上述四种细菌基因组DNA进行PCR扩增。结果表明,菌株Escherichia coli K12和Micrococcus luteus N19处理组与对照组之间RAPD指纹图谱存在明显差异,在阿特拉津浓度为100 mg·L-1时,基因组模板稳定性(GTS)分别降至52.3%和61.2%。同一浓度下,阿特拉津降解菌Acinetobacter sp.DNS32基因组模板稳定性为82.9%,Arthrobacter sp.DNS10基因组模板稳定性为92.1%。研究表明,阿特拉津胁迫对Escherichia coli K12和Micrococcus luteus N19基因组DNA产生损伤;阿特拉津降解菌Arthrobacter sp.DNS10和Acinetobacter sp.DNS32对阿特拉津胁迫有较高耐受性,适于阿特拉津降解。