渗透胁迫诱导水稻幼苗的氧化伤害

水稻幼苗在渗透胁迫下，随着胁迫强度的增加及时间的延长，O2和H2O2大量产生，膜脂过氧化加剧，细胞膜的完整性受到破坏，离子大量外泄；严重渗透胁迫亦使叶绿素——蛋白质复合体结合松弛，叶绿素含量明显降低。活性氧清除剂α-生育酚、抗坏血酸及甘露醇可阴抑渗透胁迫所诱导的丙二醛增生，减少叶绿素的氧化破坏。这些结果表     

DNA damage and effects on antioxidative enzymes in earthworm (Eisenia foetida) induced by atrazine

To evaluate atrazine (2-chloro-4-ethylamino-6-isopropylamino-1, 3, 5-triazine) ecotoxicology in soil, the effect of atrazine on the activity of antioxidative enzymes (superoxide dismutase, SOD; catalase, CAT; and guaiacol peroxidase, POD) and DNA damage induced by atrazine were investigated in earthworms. Atrazine was added to artificial soil at rates of 0, 2.5, 5 and 10 mg per kg of soil. Earthworm tissues exposed to each treatment were collected on the 7th, 14th, 21st, and 28th day of the treatment. Compared to the controls, the CAT activity was stimulated at 2.5 mg kg⁻¹ treatment except on the 14th day, and inhibited at 5, 10 mg kg⁻¹ atrazine except 5 mg kg⁻¹ on the 28th day and 10 mg kg⁻¹ on the 21st day; the overall SOD activity was inhibited, while the POD activities were stimulated by all atrazine concentrations in 28 days. The olive tail moments of single-cell gel electrophoresis of coelomocytes, as an indication of DNA damage, were increased after treatment with different doses of atrazine on the 7th, 14th, 21st, and 28th day, and significant differences were found compared to the controls. In conclusion, atrazine induces oxidative stress and DNA damage on earthworms, and the adverse effects may be the important mechanisms of its toxicity to earthworms.     

Protective effect of BNDF on vascular endothelial cells with H2O2-induced oxidative injury

AIM: To study the protective effect of brain-derived neurotrophic factor (BDNF) on vascular endothelial cells with H₂O₂-induced oxidative injury. METHODS: Human umbilical vein endothelial cells (HUVECs) were cultured in vitro, and the oxidation injury model of HUVECs was established by treatment with H₂O₂. The oxidatively injured HUVECs were cultured with different concentrations (1, 10 and 100 μg/L) of BDNF. At the same time, the control group (no injury), PBS treatment after H₂O₂ injury group and TrkB inhibitor group (with 100 μg/L BDNF and 1: 1 000 TrkB inhibitor) were also set up. The viability of the HUVECs was detected by MTT assay. The levels of LDH, MDA, SOD and GSH were measured. The releases of NO, ET-1 and ICAM-1 were analyzed by ELISA. The changes of ROS production and cell apoptosis were evaluated by flow cytometry. The protein levels of TrkB, p-TrkB, cleaved caspase-3, Bcl-2 and Bax were determined by Western blot. RESULTS: Compared with uninjured control group, in H₂O₂ oxidative injury plus PBS treatment group, the viability of the cells was decreased significantly, the LDH and MDA levels were increased significantly and the activities of SOD and GSH were decreased significantly. The NO secretion was decreased, and the ET-1 and ICAM-1 concentrations were increased significantly. The ROS content and apoptotic rate were increased significantly. The protein levels of cleaved caspase-3 and Bax were increased but Bcl-2 protein expression was decreased significantly. Compared with PBS treatment group, in H₂O₂-injured HUVECs treated with different concentrations of BDNF, the cell viability was gradually increased, the LDH and MDA levels were decreased and the activities of SOD and GSH were increased gradually. The secretion of NO was increased but ET-1 and ICAM-1 were decreased gradually. The ROS content and apoptotic rate were decreased significantly. The TrkB and p-TrkB levels were significantly increased significantly, the protein expression of cleaved-caspase 3 and Bax was decreased gradually and the Bcl-2 protein expression increased gradually. The role of BDNF was inhibited by TrkB inhibitor. CONCLUSION: BDNF protects HUVECs from oxidative injury by binding with TrkB to activate the BDNF-TrkB signaling pathways.     

Subacute chlorpyrifos-induced oxidative stress in rat erythrocytes and the protective effects of catechin and quercetin

This study examined the effects of chlorpyrifos in the rat erythrocyte antioxidant system and evaluated the ameliorating effects of catechin and quercetin on the oxidative damage induced by chlorpyrifos. Sexually mature male Wistar rats were given chlorpyrifos (5.4 mg/kg, 1/25 of the oral LD₅₀), catechin (20 mg/kg), quercetin (20 mg/kg), catechin plus chlorpyrifos, and quercetin plus chlorpyrifos daily via gavage for four weeks. No statistical differences were found in the catechin-only and quercetin-only groups compared with the control group. By the end of the fourth week, chlorpyrifos alone increased the levels of malondialdehyde (MDA) and decreased superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) activities compared with the control group in rat erythrocytes. In the catechin-plus-chlorpyrifos and quercetin-plus-chlorpyrifos groups, there were statistically significantly decreased MDA levels and increased SOD, CAT, and GPx activities compared with the chlorpyrifos-only group. Thus, it appears that catechin and quercetin ameliorate chlorpyrifos-induced oxidative stress in rat erythrocytes in vivo.     

近40年雷公藤生殖毒性研究概述

该研究通过雷公藤甲素 (TP) 损伤TM4细胞构建生殖细胞损伤模型,探究了香港牡蛎 (Crassostrea hongkongensis) 酶解超滤组分对TP诱导的TM4小鼠 (Mus musculus) 睾丸支持细胞氧化损伤的保护作用,并检测了牡蛎酶解超滤组分的分子量分布与微量金属元素含量,比较分析了各个超滤组分对TP诱导的TM4细胞存活率以及还原型谷胱甘肽 (GSH)、丙二醇 (MDA) 和活性氧 (ROS) 水平的影响。结果表明,牡蛎酶解超滤组分富含铜 (Cu)、锌 (Zn)、锰 (Mn) 和硒 (Se) 等微量金属元素;经超滤分级,小分子与大分子物质得到有效分离;与模型组相比,各个超滤组分均不同程度地提高了经TP诱导的TM4细胞存活率,其中<3、3~5和5~10 ku超滤组分的细胞存活率高于>10 ku超滤组分;而<3 ku超滤组分可有效抵抗TP诱导的TM4细胞氧化应激损伤,减少细胞内ROS产生和脂质过氧化,增强TM4细胞的抗氧化能力。     

Determination of the oxidative burst chemiluminescent response of avian and murine-derived macrophages versus corresponding cell lines in relation to stimulation with Salmonella serotypes.

In contrast to mammalian systems, avian species lack a resident or harvestable macrophage population in the abdominal exudate. Peritoneal macrophages in the chicken can be elicited if an inflammatory agent such as sephadex is injected. This study examines the kinetics of different macrophage populations, derived by different methods of isolation and from different hosts, with respect to the elicited oxidative burst upon infection with host-adapted Salmonella serotypes.

The nature of the oxidative burst elicited by murine and avian-derived and cell line macrophages was determined after stimulation with phorbol myristate (PMA), zymosan A, and Salmonella serotypes. Both murine and chicken peritoneal macrophages, chicken blood monocytes and corresponding cell lines, J774A.1 and HD-11, were unable to produce a detectable chemiluminescent (CL) response after interaction with Salmonella using the luminescent probe luminol. However, both PMA and zymosan A induced a CL response in all cell types, with PMA eliciting a higher and earlier peak response (pkH) than zymosan A. Lucigenin-enhanced CL in both murine and chicken macrophages was achieved with PMA, zymosan A and Salmonella serotypes. In this case, zymosan A induced higher responses than PMA. In the peritoneal macrophages of both hosts, there were no significant differences in the oxidative burst induced by the different Salmonella serotypes. However, the J774A.1 (murine) cells demonstrated significant differences, with S. enterica serotype Choleraesuis (S. choleraesuis and S. gallinarum producing the highest response. In the HD-11 (chicken) cells, S. choleraesuis and S. dublin elicited the higher CL. With both cell lines, S. abortusovis failed to induce an appreciable CL response.

In these experiments it was demonstrated that oxidative burst was not detectable in monocytes/macrophage populations using luminol, which suggests a link to the lack of a myeloperoxidase system in these cells. Lucigenin-enhanced CL appeared independent from the myeloperoxidase system, indicating production of another oxidative species compared with luminol. No discernable effect of host specificity with regard to Salmonella serotype and respective host was seen in host-derived or cell line macrophages, and cell line macrophages displayed altered functional characteristics with regard to oxidative burst in comparison with their primary counterparts.     

Effect of α tocopherol and selenium on antioxidant status, lipid peroxidation and hepatopathy induced by malathion in chicks

The objective of the present study was to investigate the role of α tocopherol and selenium on malathion induced hepatic damage, and antioxidant defense in chicks. The chicks were divided into three groups. First group received malathion 10 mg/kg BW, orally for 60 days, the second group received the same dose of malathion but was supplemented with α tocopherol and selenium for 60 days and the third group served as the control. A compromised antioxidant capacity as evidenced by increased levels of erythrocytic lipid peroxidation and decreased concentration of vitamin E and decreased activity of glutathione peroxidase was observed in chicks following the administration of malathion. An improved antioxidant status was observed in chicks of second group with α tocopherol and selenium supplementation including higher concentration of vitamin E, increased activity of glutathione peroxidase and lower levels of lipid peroxidation. Histopathological studies of liver in the chicks which received malathion exhibited, moderate to severe degenerative and necrotic changes in the hepatocytes. The correlation of decreased antioxidant status of chicks with degenerative changes in liver suggests that lipid peroxidation may be one of the important mechanism in the chronic toxicity of malathion. The results indicate that α tocopherol and selenium were effective in partially alleviating degenerative changes induced by malathion in the liver of chicks by attenuating processes leading to lipid peroxidation.     

Behavioral, morphological deformities and biomarkers of oxidative damage as indicators of sublethal cypermethrin intoxication on the tadpoles of D. melanostictus (Schneider, 1799)

Concerns have been raised that the amphibian larval stages are particularly at risk and may be vulnerable to adverse effects of pesticides. The present study reports acute toxicity of cypermethrin at 24, 48, 72 and 96 h through static renewal bioassay test for Duttaphrynus melanostictus. The LC₅₀ values were 5.15, 4.55, 3.95, and 3.34 μg/L for 24, 48, 72, and 96 h respectively. At sublethal concentration (0.33 μg/L) behavioral, morphological and biochemical changes were studied. The behavioral and morphological anomalies observed in the present study are typical signs of cyano pyrethroid poisoning. Significant changes were observed in total, soluble, and structural proteins. The depletion of all the protein fractions observed in this investigation led to progressive protein oxidation and catabolism of proteins. Decreased protein level has resulted in a marked elevation of free amino acid levels at all time intervals. The induction of catalase, glutathione-S-transferase activities and elevation in the levels of hydrogen peroxide, reduced glutathione, and malondialdehyde eventually lead to oxidative damage of biomolecules, showing that the generation of reactive oxygen species and oxidative stress are involved in the toxicity induced by cypermethrin. Indicating increased susceptibility of tadpoles. Thus, an exposure to cypermethrin at sublethal concentration had catastrophic effect on tadpoles of D. melanostictus.     

Influence of the Site of Cultivation on Chétoui Olive (Olea europaea L.) Oil Quality

Abstract

A comparative study was conducted to evaluate the effect of location on the chemical composition and quality of monovarietal virgin olive oils obtained from the Chétoui cultivar in relation to the fruit ripening stages. Three sites representative of two Tunisian olive growing regions were examined, Selten (region I (RI): original site of plantation of Chétoui variety in the north of the country), Ousletia and Jelma (region II (RII): in the central part of the country away from the original plantation site). In this study, Chétoui olive cultivar was found to have different responses to environmental conditions. Chétoui olive oils showed lower values in phenol and o-diphenol contents and were less stable to oxidation (weaker oxidative stability and antioxidant activity levels) when the olive trees were cultivated away from the original plantation site. These Chétoui olive oils are also characterized by decreased oil content and higher values of quality parameters such as free acidity, peroxide value and UV absorbance due probably to the drought during the flowering and olive ripening periods. Furthermore, many analytical parameters, i.e., chlorophyll pigments, carotenoids, oleic acid contents, total phenol and o-diphenol amounts, oxidative stability, antioxidative capacity and quality parameters showed nearly the same changes during fruit ripening but in different degrees depending on the site of the plantation.     

Assessment of biodegradability and oxidation stability of mineral, vegetable and synthetic oil samples

This study proposes to evaluate rapid methodologies to estimate oxidative stability and biodegradability for mineral, vegetable and synthetic oil samples, using quick and simple experiments. The synthetic oil sample was obtained from castor oil, so the vegetable oil chosen for this evaluation was a sample of the crude castor oil source. The oxidative stability tests described enabled the comparison of synthetic lubricant samples and showed that their stability was lower than that of petroleum-based oil. However, the physico-chemical properties, such pour points and viscosity index, were improved and potentially interesting for lubricant applications. The biodegradability experiments were carried out using a model of bio-kinetics. These studies proved that synthetic lubricant samples were easily degradable (similar to crude castor oil) and showed half-life significantly lower than those of the mineral oil samples.