Effect of α-Tocopherol on Antioxidants, Lipid Peroxidation, and the Incidence of Pulmonary Hypertension Syndrome (Ascites) in Broilers

Abstract

Research has demonstrated a compromised antioxidant capacity in broilers with pulmonary hypertension syndrome (PHS). Thus, the objective of the present study was to assess the effects of vitamin E on PHS-induced mortality, tissue antioxidants, and plasma lipid peroxides in male broilers. Control broilers were provided normal ventilation but others, maintained under low ventilation conditions to induce PHS, were randomly assigned to nonimplanted (NI), placebo (PL), or vitamin E (VE) implanted groups. The VE implant released a total of 15 mg of alpha-tocopherol from 0 to 3 wk of age. Tissues and blood samples were obtained at 3 and 5 wk of age from birds with (PHS+) and without (PHS-) PHS. Five-week PHS cumulative mortality was lowered by alpha-tocopherol with mortality rates of 3.6, 4.2, 11.9, and 11.8%, for Controls, VE, NI, and PL groups, respectively. The PHS+ birds exhibited lower body weights, higher hematocrit, right ventricular hypertrophy, lower alpha-tocopherol and glutathione (GSH) concentrations in liver and lung, as well as indicators of oxidative stress, including elevated plasma lipid peroxides and lower oxidized GSH in liver and erythrocytes, at 5 wk of age. All birds exhibited lower erythrocyte catalase activity at 5 than at 3 wk of age. An improved antioxidant capacity was observed in VE birds, including higher liver and lung alpha-tocopherol at 3 and 5 wk, higher liver GSH at 3 wk, and lower plasma lipid peroxide values at 5 wk of age. Direct correlations observed between body weight and plasma lipid peroxides at 3 wk (r = .45) and between right ventricular hypertrophy and plasma lipid peroxides at 5 wk (r = .48), suggests that lipid peroxidation plays a role in the etiology of PHS. The results indicate that the VE implant was effective in lowering PHS-induced mortality in broilers apparently by attenuating processes leading to lipid peroxidation.

Endothelial Cell Energy Metabolism, Proliferation, and Apoptosis in Pulmonary Hypertension

“…For example, the antioxidant dimethylthiourea inhibits right heart dysfunction usually induced by a 10-day exposure to hypoxia in rats (54,70,73) and significantly abrogates the pulmonary hypertensive response (54). PH syndrome in avian species, with reduced respiratory chain coupling, inefficient use of oxygen, and higher generation of ROS (25,57,126), is successfully treated by implanting nonenzymatic antioxidant pellets of vitamin E after chickens hatch (20). In vitamin E-treated chickens, the incidence of avian PH syndrome is decreased and antioxidant capacity increased (20).…”

“…PH syndrome in avian species, with reduced respiratory chain coupling, inefficient use of oxygen, and higher generation of ROS (25,57,126), is successfully treated by implanting nonenzymatic antioxidant pellets of vitamin E after chickens hatch (20). In vitamin E-treated chickens, the incidence of avian PH syndrome is decreased and antioxidant capacity increased (20). Similarly, N-acetyl-l-cysteine, which serves as a precursor to the nonenzymatic antioxidant glutathione, reduces PH, right ventricular hypertrophy, and pulmonary vascular media thickening in a hypoxia-induced rodent model of PH (55).…”

Oxidative‐Stress Biomarkers in Patients with Pulmonary Hypertension

“…Early studies conducted in the mid-1990s suggested the beneficial effects of antioxidants on lipid peroxidation and the incidence of pulmonary hypertension syndrome in broilers. 1 A growing number of in vitro studies have reported beneficial effects of retinoids on cell migration, proliferation, apoptosis, matrix remodeling, fibrinolysis, coagulation, and inflammation, all of which are involved with vascular disease. 2 There is a rich literature on human PAH oxidative stress showing associations between increased oxidant-injury markers and poorer clinical outcomes.…”

Lipid Peroxidation in the Plasma, Lungs, Heart and Liver of Broilers Fed a Grape Seed Extract and Raised at 2278 m of Altitude

“…Vitamin E is a well-recognized natural antioxidant used for the prevention of biological oxidation, and was shown to reduce mortality due to ascites (Bottje et al, 1995). However, the addition of high concentrations of VE increases the cost of the diet (Kennedy et al, 1992), leading to the search of new more affordable sources of antioxidant compounds, such as grape seed extract (GSE).…”

“…Bakonyi & Radak (2004) reported that exposure to high altitude increases the formation of reactive oxygen species (ROS) and reactive nitrogen species, and ROS cause lipid peroxidation in heart and liver of broilers (Díaz-Cruz et al, 1996). Bottje et al (1995) reported that oxidative stress is associated with AS. Rodríguez-Ortega et al (2014) observed that ad libitum feeding decreases antioxidant activity in lungs, heart, and liver of broilers.…”