Effect of fomesafen on glutathione S-transferase and cellulase activity and DNA damage in the earthworm (Eisenia fetida)

Biochemical responses and DNA damage of earthworm (Eisenia fetida) exposed to various concentrations of fomesafen (0, 10, 100, and 500 μg kg^?1) for 3, 7, 14, 21, and 28 days were investigated in vivo. Glutathione S-transferase (GST) activity was significantly stimulated upon treatment with 500 μg kg^?1 fomesafen for 21 days, while the cellulase activity was markedly inhibited after 14 days of treatment. On day 28, the activities of GST and cellulase had recovered to the level similar to that of controls. Low or mild DNA damage in earthworm was induced within 14 days of exposure, and the damage was reduced or disappeared with the extension of exposure.     

Genotoxicity study of phenol and o-cresol using the micronucleus test and the comet assay

Phenol and cresols are common toxic environmental pollutants. In this study, the micronucleus assay and the alkaline single cell gel electrophoresis (SCGE) technique have been used to investigate the genotoxic activity of phenol and o-cresol. The result of experiments revealed that phenol and o-cresol were both evident genotoxins, and the genotoxic activity of o-cresol was stronger. In the micronucleus assay, phenol and o-cresol could both cause a significant increase in the micronucleus (MN) frequencies (p?p?p?p?相似文献   

Intervention research on influence of biomass briquette on human health

Raw coal (RC) is the main fuel in many, especially rural parts of China. Biomass briquette (BB), which has less SO₂ emission, was developed as a cleaner alternative for RC. In this research, the cooking fuel of a group of countrywomen was switched from RC to BB and studied for health effects. Five biological indices percent of comet cell (COMET), lysozyme saliva (LYS), malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GSH-PX) were chosen. All indices were measured three times during the 18-month experiment. Statistical analysis shows that there are significant changes in the indices. Using BB as a cooking fuel improves the function of anti-oxidation system and the nonspecific immune system, and reduces the DNA damage, which is negatively related to LYS and SOD.     

Modeling toxic endpoints for improving human health risk assessment of polycyclic aromatic hydrocarbons – parent compounds and simple mixtures

Risk assessments for mixtures of polycyclic aromatic hydrocarbons (PAH) are problematic due to the lack of available potency and toxicity data on individual compounds and mixtures. This article examines the toxicity of parent compounds and designed mixtures of PAH in order to bridge the gap between component assessment and mixture assessment for this class of ubiquitous compounds. The objective for this study was to test seven parent PAH compounds and four PAH mixtures in a set of three bioassays to evaluate the toxicity of parent compound PAH and binary mixtures of PAH. PAH and mixtures were examined in the Salmonella/microsome mutagenicity assay, a Gap Junction Intercellular Communication assay, and the 7-ethoxyresorufin-O-deethylase assay. These assays were chosen for their ability to measure specific toxic endpoints related to the carcinogenic process (i.e. initiation, promotion, and progression). Two compounds similar in structure, benzo(a) pyrene (BAP) and benzanthracene, consistently produced positive results in all three bioassays. Conversely, a linear PAH, anthracene, produced negative results in all three bioassays. An antagonistic response was observed for the mixtures in all three bioassays. Chemical structure was important in explaining the observed responses. Using chemical structure–activity relationships with the steps of the carcinogenic process may be used to improve estimates of toxicity for compounds and mixtures for human health risk assessments.     

Genotoxic assessment of anthracene and benzo [a] pyrene to milkfish Chanos chanos

Mutagenic and genotoxic effects of polycyclic aromatic hydrocarbons, anthracene and benzo [a] pyrene (BaP), in milkfish Chanos chanos were determined using micronucleus (MN) test and comet assay (CA). Distinct mean frequencies of nuclear abnormalities such as MNs; binucleated micronuclei, nuclear bud, and fragmented apoptotic cells were measured. Significant increase in DNA damage with five classes of damage level was observed and expressed in terms of arbitrary unit (AU). Mean frequencies of total nuclear abnormalities were 0.5?±?0.25 cells in control; 0.67?±?0.33 cells in solvent control; 70?±?9.60 cells in 0.176?mg?L^?1 anthracene, and 91.83?±?6.25 cells in 0.031?mg?L^?1 BaP. The greatest DNA damage of 170AU was observed in 0.176?mg?L^?1 anthracene-exposed group and 182AU was observed in 0.031?mg?L^?1 BaP-treated fish. This study confirmed that the CA and MN assays are useful tools in determining potential genotoxicity of water pollutants and might be appropriate as a part of monitoring program.     

Molecular level toxicological evaluation of a dental composite implanted in albino rats

Dental composite (DC) resins are synthetic resins which are used as restorative material or adhesives in dentistry. Monomers and other components released into the oral environment from the DC material even after polymerization might affect the surrounding tissues and even the whole body gradually. Biocompatibility of DC has to be stringently evaluated since the fillings are in close contact with mucosa, tooth, and pulp. Common difficulties with various current dental materials include allergies, chemical leakage from the material, and pulpal irritation which are due to the byproducts of chemical reactions during different stages of material hardening. Dental Products Laboratory of Sree Chitra Tirunal Institute for Medical Sciences and Technology developed a new BIS-GMA-based DC. In this study the oxidative stress induced by this DC material in vivo was tested for a period of 1, 4, 8, 26, or 52 weeks in albino rats. Dental materials were implanted intramuscularly into the gluteus muscle and oxidative biomarkers such as lipid peroxidation, 8-oxo-deoxyguanosine (8-OHdG) concentration, and total glutathione content analyzed. Data showed no significant changes in antioxidant defense system and 8-OHdG levels in nuclear DNA of the tissue. Serum biochemical results confirmed that animals were in normal functioning physiological state.     

植物彗星实验及其在生态毒理监测中的应用

植物彗星实验(Comet assay)是近几年发展起来的一项检测DNA损伤的新技术,具有快速、简便、灵敏性高和可靠性强等特点.本文总结了近年来国内外植物彗星实验的研究成果,详细介绍了植物彗星实验方法及其在生态毒理学中的应用.     

人血淋巴细胞检测浊漳河地表水的遗传毒性

为评价浊漳河水体中有机污染物的致突变性,采用单细胞凝胶电泳(SCGE)技术,研究了浊漳河水体3个不同样点的有机提取物对人外周血淋巴细胞DNA损伤效应。结果显示,各水样中的有机提取物均能引起DNA损伤,且随剂量的增高,有机物对DNA的损伤加重;细胞DNA损伤与对照组相比均有显著性差异(p<0.01)。这表明人外周血淋巴细胞对水体有机污染物的毒作用非常敏感。细胞彗星尾部DNA含量(%DNAT)和染毒剂量呈极显著正相关(R2>0.8547,p<0.01)。以上结果表明,浊漳河水体受到一定程度的有机物污染,这些有机污染物可诱导淋巴细胞DNA损伤,具有遗传毒性。SCGE技术作为一种简便、快速和灵敏的检测方法在水环境遗传毒性监测方面具有较大的应用价值。     

彗星实验技术及其应用

彗星实验是瑞典科学家Ostling和Johanson于1984年发明的检测毒物DNA损伤效应的方法。它经历了从最初的微电泳技术、中性彗星实验、碱性彗星实验、酶切彗星实验和双向垂直彗尾彗星实验等不断完善的发展过程。在毒理学、遗传学和环境生态科学等领域有着重要的应用,是经济合作与发展组织(OECD)和欧洲食品安全局等国际组织推荐的测定遗传毒性的方法之一。彗星实验的关键点包括单细胞悬液的制备、细胞裂解液的成分与比例,低熔点琼脂糖凝胶的浓度,电泳条件等。在典型应用领域,如蚯蚓、鱼、两栖动物、鼠和人的彗星实验很难找到标准实验方案。成功的彗星实验还需关注,实验设计时必须包括阳性对照,结果表述时必须有图为证,实验方案可能因物种或细胞而异。