Biochemical and histopathological studies to assess chronic toxicity of triazophos in blood, liver and brain tissue of rats

Triazophos, O,O-diethyl-1-H-1,2,4-triazol-3-yl phosphorothioate, (TZ) is an organophosphorus pesticide which is extensively used in agriculture for controlling insect pests. Except a FAO/WHO report no study has investigated its short-term toxicity with respect to its potential to cause biochemical and histopathological alterations. The present study was designed to identify the effect of TZ at different doses (1.64, 3.2 and 8.2 mg/kg) on the oxidative stress parameters in blood as well as organs involved in xenobiotic metabolism (liver and brain) following chronic exposure for 90 days. Moreover, the study also delineates the effect of TZ on the histo-architecture of these organs. The results indicated a dose dependent induction (p < 0.001) of oxidative stress, as evident by increased malondialdehyde (MDA) level and compromised antioxidant defense including glutathione S transferase (GST) activity, glutathione (GSH) content and ferric reducing ability of plasma (FRAP) in blood, and increased MDA level with concomitantly decreased GSH content in tissues, following chronic exposure to TZ. The ratio of MDA: FRAP in blood was found to be increased following chronic exposure to TZ and may serve as a suitable indicator of severity of oxidative damage. Onset of such biochemical alterations is one of the early adaptive responses to TZ exposure which leads to histopathological alterations in terms of diffuse fatty changes expanding from mid-zonal area to whole lobule in liver. However, increased oxidative stress did not bring any morphological alteration in brain. The present study concludes that induction of oxidative stress, leading to subsequent histopathological alterations in liver, is an important mechanism underlying the TZ induced chronic toxicity.     

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.     

光辐射对农业土壤的影响

核爆炸产生的光辐射，能量大，发射率高，在一定数值内可使土壤表层熔融，沸腾，并随着光冲量值的减弱轻。表层熔融的土壤，机械组成有微小的变化，有机质，全氮量有部分减少，但不影响整个耕层土壤的耕作性能，在此土壤上种植农作物，生长良好，产量正常。     

Effects of Waterlogging on Photosynthesis and Antioxidant Enzyme Activities of Six Barley Genotypes with Different Waterlogging Tolerance

A field experiment was carried out to study genotypic difference in the effect of waterlogging on photosynthesis, chlorophyll content and antioxidative enzyme activities in barley. Waterlogging caused a rapid decline in net photosynthetic rate (Ph) and stomatal conductance (gs), and little change in chlorophyll content during early days of the treatment. A dramatic increase in malondialdehyde (MDA) content, superoxide dismutase (SOD) and peroxidase (POD) in waterlogged plants in the early days of the experiment was found, indicating the occurrence of oxidative stress in barley plants exposed to waterlogging. There was a highly significant difference in the changed extent of all these parameters among genotypes.Franklin and Yongjiahong Liuleng Damai, which were relatively sensitive to waterlogging in terms of growth, photosynthesis and chlorophyll content, accumulated much more MDA than the other two relatively tolerant genotypes (93-3143 and QS).After removal of waterlogging, the genotypic difference became much greater in recovering of these examined parameters.Yongjiahong Liuleng Damai showed higher recovery, while Franklin only recovered to 50% of the control at the 14 day after waterlogging removal. It may be concluded that it is the difference in anti-oxidative stress caused by waterlogging that account for the major difference in photosynthesis among barley genotypes.     

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.     

Effects of the commercial extract of aronia on oxidative stress in blood platelets isolated from breast cancer patients after the surgery and various phases of the chemotherapy

Since the extract from berries of Aronia melanocarpa presents antioxidative properties in plasma and in blood platelets, not only from healthy group, but also from patients with benign breast diseases and in patients with invasive breast cancer before surgery, the aim of our present study was to evaluate the oxidative stress by measuring the level of various biomarkers of this process such as the generation of superoxide anion radicals (O(2)(-·)), the amount of carbonyl groups and 3-nitrotyrosine in proteins or the amount of glutathione in blood platelets isolated from breast cancer patients after the surgery and after various phases of the chemotherapy in the presence of A. melanocarpa extract (Aronox) in vitro. We demonstrated in platelet proteins from patients with invasive breast cancer (after the surgery and after various phases of the chemotherapy) higher level of carbonyl groups than in control healthy group. The level of 3-nitrotyrosine in platelet proteins from patients with invasive breast cancer was also significantly higher than in healthy subject group. We observed an increase of other biomarkers of oxidative stress such as O(2)(-·) and a decrease of GSH in platelets from patients with breast cancer (after the surgery and after various phases of the chemotherapy) compared to the healthy group. In model system in vitro our results showed that the commercial extract from berries of A. melanocarpa due to antioxidant action, significantly reduced the oxidative/nitrative stress in platelets from patients with invasive breast cancer caused by the surgery and various phases of the chemotherapy.     

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.     

Effect of N‐Acetylcysteine Supplementation on Intracellular Glutathione,Urine Isoprostanes,Clinical Score,and Survival in Hospitalized Ill Dogs

Background

Antioxidant depletion and lipid peroxidation have been correlated with disease severity and associated with poor outcomes.

Hypothesis/Objectives

Supplementing dogs with N‐acetylcysteine (NAC) during the first 48 hours of hospitalization will increase cysteine, normalize glutathione concentrations, and decrease the degree of lipid peroxidation associated with illness.

Animals

Sixty systemically ill hospitalized client‐owned dogs and 14 healthy control dogs.

Methods

Randomized investigator‐blinded, placebo‐controlled prospective study. Dogs were randomized to treatment with NAC (n = 30) versus placebo (n = 30). Antioxidants, urine 8‐isoprostane/creatinine (IP/Cr), and clinical score were determined before and after treatment with NAC. Glutathione, cysteine, and vitamin E concentrations were quantified using high‐performance liquid chromatography. Atomic absorption spectroscopy and enzyme‐linked immunosorbent assays were used to quantify selenium and isoprostane concentrations, respectively.

Results

Ill dogs had significantly lower vitamin E concentrations (27 versus 55 μg/mL; P = .0005) as well as elevated IP/Cr ratios (872 versus 399 pg/mg; P = .0007) versus healthy dogs. NAC supplementation significantly increased plasma cysteine (8.67 versus 15.1 μM; P < .0001) while maintaining glutathione concentrations. Dogs in the placebo group experienced a statistically significant decrease in glutathione concentrations (1.49 versus 1.44 mM; P = .0463). Illness severity and survival were unchanged after short duration NAC supplementation.

Conclusions

Ill dogs experience systemic oxidative stress. Supplementation with NAC during the first 48 hours of hospitalization stabilized erythrocyte glutathione concentrations. The clinical impact of this supplementation and glutathione concentration stabilization was undetermined.     

The pulp and paper properties of Sirex noctilio infested and fire-damagedthermomechanically pulped,South African grown Pinus patula

Pinus patula is the softwood species most extensively planted in South Africa. However, large portions of these plantings are under threat from Sirex noctilio infestation and occasional forest fires. In this exploratory investigation, the effects of tree age, Sirex noctilio infestation and fire damage to wood from Pinus patula trees on their pulp and paper properties were evaluated. Pulp was produced using the thermomechanical pulping (TMP) process. The energy consumption required to pulp the different pulpwood materials was determined. Pulps were beaten for five different time periods to investigate the development of the fibre properties in response to increasing energy input. Paper properties such as burst, tear strength and breaking length were determined on handsheets manufactured from unbeaten and beaten pulps. Box and line plots and canonical variate analysis biplots were used to statistically analyse the data. It was found that the burst strength of paper produced from healthy trees was significantly higher than that from sirex-infested or fire damaged (burnt) trees. Similarly, the tear strength of paper from healthy and burnt trees was significantly better than from sirex-infested or young trees. No significant differences in breaking length were evident between the pulpwood materials and an increase in beating time did not lead to any improvements. From this study it can be concluded that wood from dead or dying, sirex-infested and young trees produced paper with consistently lower strength properties compared to wood obtained from healthy 12-year-old trees.