Toxicity of endophyte-infected ryegrass hay containing high ergovaline level in lactating ewes

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Ergovaline in tall fescue and its effect on health, milk quality, biochemical parameters, oxidative status, and drug metabolizing enzymes of lactating ewes

International audienceErgovaline (EV) produced by symbiotic association of Epichloë coenophiala with tall fescue (Lolium arundinaceum) causes toxicoses in livestock. In this study, 16 lactating ewes (BW 76.0 ± 0.6 kg) were used to determine the effects of feeding endophyte-infected (FE+) or endophyte free (FE−) tall fescue hay on animal health and performances and to investigate the putative mechanisms of action of EV. The mean EV concentrations in FE+ and FE− diets were 497 ± 52 and <5 µg/kg DM, respectively. Decreased hay consumption and BW were observed in the FE+ group. Prolactin (PRL) concentrations decreased (P < 0.02) in the FE+ group from d 3 to 28 of the study compared to the FE− group, but no consequences were observed on milk quantity or quality. Skin temperature and the thermocirculation index were lower (P < 0.05) in the FE+ than in the FE− group from d 3 to 7, but this effect disappeared from d 14 to 28. Hematocrit, mineral and biochemical, and enzymatic analyses of plasma revealed no differences between the 2 groups. Measurement of oxidative damage and antioxidant enzyme activities revealed a decrease in the activities of plasma catalase (P < 0.05), kidney glutathione reductase and peroxidase and in kidney total glutathione and malo-ndialdehyde contents (P < 0.02) in ewes fed FE+. Hepatic flavin monooxygenase enzyme activities decreased (P < 0.01) in ewes fed FE+, except for a marked increase in the demethylation of erythromycin. This activity is linked to cytochrome P4503A content and is known to be involved in ergot alkaloid metabolism. Glutathione S-transferase activity in the kidneys decreased (P < 0.02) in the FE+ group, whereas no difference was observed in uridine diphosphate-glucuronosyltransferase activity in the liver or kidneys. The reversibility of the effect of FE+ hay on skin temperature and the increase in erythromy-cin N-demethylase activity may contribute to the relative resistance of ewes to EV toxicity

Dietary polyunsaturated fatty acids and heme iron induce oxidative stress biomarkers and a cancer promoting environment in the colon of rats

International audienceThe end products of polyunsaturated fatty acid (PUFA) peroxidation, such as malondialdehyde (MDA), 4-hydroxynonenal (HNE), and isoprostanes (8-iso-PGF2alpha), are widely used as systemic lipid oxidation/oxidative stress biomarkers. However, some of these compounds have also a dietary origin. Thus, replacing dietary saturated fat by PUFAs would improve health but could also increase the formation of such compounds, especially in the case of a pro-oxidant/antioxidant imbalanced diet. Hence, the possible impact of dietary fatty acids and pro-oxidant compounds was studied in rats given diets allowing comparison of the effects of heme iron vs. ferric citrate and of omega-6- vs. omega-3-rich oil on the level of lipid peroxidation/oxidative stress biomarkers. Rats given a heme iron-rich diet without PUFA were used as controls. The results obtained have shown that MDA and the major urinary metabolite of HNE (the mercapturic acid of dihydroxynonane, DHN-MA) were highly dependent on the dietary factors tested, while 8-iso-PGF2alpha was modestly but significantly affected. Intestinal inflammation and tissue fatty acid composition were checked in parallel and could only explain the differences we observed to a limited extent. Thus, the differences in biomarkers were attributed to the formation of lipid oxidation compounds in food or during digestion, their intestinal absorption, and their excretion into urine. Moreover, fecal extracts from the rats fed the heme iron or fish oil diets were highly toxic for immortalized mouse colon cells. Such toxicity can eventually lead to promotion of colorectal carcinogenesis, supporting the epidemiological findings between red meat intake and colorectal cancer risk. Therefore, the analysis of these biomarkers of lipid peroxidation/oxidative stress in urine should be used with caution when dietary factors are not well controlled, while control of their possible dietary intake is needed also because of their pro-inflammatory, toxic, and even cocarcinogenic effects

The approaches to diagnosis of chronic forms of Epstein-Barr virus infections in adults based on comprehensive evaluation of clinical and immunological indicators

В статье проанализированы отдаленные исходы инфекционного мононуклеоза у взрослых и усовершенствована диагностика хронических форм ЭБВ-инфекции у взрослых. на основе комплексной динамической оценки клинико-лабораторных показателей, серологических, молекулярно-биологических маркеров и характера изменений иммунного статуса; The long-term outcomes of infectious mononucleosis in adults is analyzed and diagnostic approaches to chronic EBV infection in adults is improved, based on a comprehensive dynamic assessment of clinical and laboratory parameters, serological, molecular biological markers, and the changes in immunological status