ABSTRACT Heat stress induces oxidative stress, and reduces body antioxidant metabolite levels, which can affect poultry production performance. Dietary antioxidants protect birds against the adverse effects of heat stress. The effects of increasing concentrations of dietary curcumin on the antioxidant parameters of layers maintained under high-temperature conditions for nine weeks were evaluated. Roman laying hens (n = 336, 22 weeks old, 1420 g BW) were divided into three treatment groups. The first group served as a thermoneutral control (kept at 25 ± 1 °C). The second group was exposed to high temperatures (32 ± 1 °C, 6 h/d), given a basal diet. The third group was further divided into five treatment groups (100, 150, 200, 250, 300 mg/kg Curcumin) fed a basal diet (treatments H1, H2, H3, H4, H5) under high temperatures conditions (32 ± 1 °C, 6 hours/day). As a result of this study, total superoxide dismutase activity was significantly higher in H2 and H3 groups, and total antioxidant capacity was higher in H2, H3, and H5 groups. Catalase and glutathione peroxidase activity was significantly higher in the H3 group. Malondialdehyde concentration was lowered in curcumin supplemented hens compared with control groups hens. Laying hens in all curcumin treatment groups had slightly higher activities of CAT, SOD, GSH-Px, and T-AOC in the liver, heart, and lungs, compared with heat stressed control group. It was concluded that dietary curcumin given to laying hens under heat stress may enhance their antioxidant status, and alleviate the detrimental effects of stressful environmental conditions.

We aimed to study the renal injury and hypertension induced by chronic intermittent hypoxia (CIH) and the protective effects mediated by angiotensin 1-7 [Ang(1-7)]. We randomly assigned 32 male Sprague-Dawley rats (body weight 180-200 g) to normoxia control, CIH, Ang(1-7)-treated normoxia, and Ang(1-7)-treated CIH groups. Systolic blood pressure (SBP) was monitored at the start and end of each week. Renal sympathetic nerve activity (RSNA) was recorded. CTGF and TGF-β were detected by immunohistochemistry and western blotting. Tissue parameters of oxidative stress were also determined. In addition, renal levels of interleukin-6, tumor necrosis factor-α, nitrotyrosine, and hypoxia-inducible factor-1α were determined by immunohistochemistry, immunoblotting, and ELISA. TUNEL assay results and cleaved caspase 3 and 12 were also determined. Ang(1-7) induced a reduction in SBP together with a restoration of RSNA in the rat model of CIH. Ang(1-7) treatment also suppressed the production of reactive oxygen species, reduced renal tissue inflammation, ameliorated mesangial expansion, and decreased renal fibrosis. Thus, Ang(1-7) treatment exerted renoprotective effects on CIH-induced renal injury and was associated with a reduction of oxidative stress, inflammation and fibrosis. Ang(1-7) might therefore represent a promising therapy for obstructive sleep apnea-related hypertension and renal injury.

Obstructive sleep apnea is associated with inflammation and oxidative stress in lung tissues and can lead to metabolic abnormalities. We investigated the effects of angiotensin1–7 [Ang-(1–7)] on lung injury in rats induced by chronic intermittent hypoxia (CIH). We randomly assigned 32 male Sprague-Dawley rats (180–200 g) to normoxia control (NC), CIH-untreated (uCIH), Ang-(1–7)-treated normoxia control (N-A), and Ang-(1–7)-treated CIH (CIH-A) groups. Oxidative stress biomarkers were measured in lung tissues, and expression of NADPH oxidase 4 (Nox4) and Nox subunits (p22phox, and p47phox) was determined by Western blot and reverse transcription-polymerase chain reaction. Pulmonary pathological changes were more evident in the uCIH group than in the other groups. Enzyme-linked immunosorbent assays and immunohistochemical staining showed that inflammatory factor concentrations in serum and lung tissues in the uCIH group were significantly higher than those in the NC and N-A groups. Expression of inflammatory factors was significantly higher in the CIH-A group than in the NC and N-A groups, but was lower than in the uCIH group (P<0.01). Oxidative stress was markedly higher in the uCIH group than in the NC and N-A groups. Expression of Nox4 and its subunits was also increased in the uCIH group. These changes were attenuated upon Ang-(1–7) treatment. In summary, treatment with Ang-(1-7) reversed signs of CIH-induced lung injury via inhibition of inflammation and oxidative stress.

We investigated the effects of glucose and root exudates in combination with different nitrogen (N) forms on the spore germination rate and hyphal growth of the arbuscular mycorrhizal (AM) fungus Rhizophagus intraradices. Spores were cultured for 20 days at 26 ºC in agar medium containing either glucose or root exudates at different concentrations. Nitrogen was supplied in the form of 4 mM NaNO3, 4 mM NH4Cl, 4 mM NH4NO3 or 2 mM urea. Three different controls without added N were used: deionized water, glucose, and root exudates. After 20 days, Glucose concentrations of 10, 25, 40 and 50 g L-1 inhibited the spore germination; however, when the concentration of glucose was 5 g L-1, the mean hyphal length was longer than that in the control. Glucose plus different forms of N sources also has no positive effect on the germination as well as hyphal growth. The addition of root exudates significantly improved both the spore germination rate and hyphal lengths in all four media (root exudates +4 mmol NaNO3, root exudates +4 mmol NH4Cl, root exudates +4 mmol NH4NO3 and root exudates +2 mmol urea). After incubation for 20 days, the highest spore germination rates (80.33%) were detected in the root exudate + urea medium, while that in the root exudate + NaNO3 medium was lower than in the control. In all these four media, hyphal growth was initially rapid and slowed in the later stages of incubation. Finally, the greatest hyphal length (15. 15 mmspores-1 was observed in the root exudate + NH4NO3 medium, while the lowest was observed in the exudate + NaNO3 medium.

A newly formulated colistin sulphate solution was prepared in a previous study as a potential agent for intramuscular injection and its effectiveness, toxicity and pharmacokinetics were investigated. In order to provide more information to establish scientific guidance for safe use of this preparation, its residue depletion in swine tissues following intramuscular administration was investigated in this experiment. Fifty healthy cross-bred piglets (13.3 ± 0.9 kg) were used in this study. Five animals were kept as untreated controls and the other 45 animals were intramuscularly injected with the colistin preparation at a dose of 2.5 mg/kg of body weight. From the treated piglets, 5 animals were randomly selected and sacrificed at different withdrawal times. Liver, kidney and muscle tissues were sampled to examine the colistin residue levels by microbiological assay. The results showed that the colistin residue in liver and muscle decreased quickly and could not be detected at 1 day after the final dosing. However, the residue depletion in the kidneys was much slower than that in other tissues and even a small quantity of drug could be detected at 14 days after withdrawal. Using the method recommended by the Committee for Veterinary Medical Products (CVMP), a withdrawal time of 10 days was established for the safe use of the newly formulated colistin sulphate solution.