Role of vitamin A oral supplementation on oxidative stress and inflammatory response in the liver of trained rats.
The use of dietary supplements to enhance the benefit of exercise training is a common practice. The liver is the organ where all substances are metabolized, and certain supplements have been associated with liver injury. Vitamin A (VA), a liposoluble vitamin stored in the liver, is commonly used as an antioxidant supplement. Here, we evaluated the effect of chronic VA supplementation on oxidative damage and stress parameters in trained rats. Animals were divided into the following groups: sedentary (SE), sedentary/VA (SE+VA), exercise training (ET), and exercise training/VA (ET+VA). During 8 weeks, animals were subjected to swimming (0%, 2%, 4%, 6% body weight) for 5 days/week and a VA daily intake of 450 retinol equivalents/day. Parameters were evaluated by enzymatic activity analysis, ELISA, and Western blotting. VA caused liver lipid peroxidation and protein damage in exercised rats and inhibited the increase in HSP70 expression acquired with exercise alone. The ET group showed higher levels of antioxidant enzyme activity, and VA inhibited this adaptation. Expression of the pro-inflammatory cytokines, interleukin (IL)-1β, and tumor necrosis factor-α was reduced in the ET+VA group, while the anti-inflammatory cytokine, IL-10, was increased. Western blotting showed that both exercised groups had lower levels of the receptor for advanced glycation end products, suggesting that VA did not affect this receptor. Our study demonstrated that, although VA caused oxidative damage, a controlled administration might exert anti-inflammatory effects. Further studies with higher VA doses and longer ET interventions would elucidate more the effects of the supplementation and exercise on liver parameters.
['Petiz|Lyvia Lintzmaier|LL|', 'Kunzler|Alice|A|', 'Bortolin|Rafael Calixto|RC|', 'Gasparotto|Juciano|J|', 'Matté|Cristiane|C|', 'Moreira|José Claudio Fonseca|JCF|', 'Gelain|Daniel Pens|DP|']
D000284:Administration, Oral D000410:Alanine Transaminase D000818:Animals D000975:Antioxidants D001219:Aspartate Aminotransferases D016207:Cytokines D019587:Dietary Supplements D004195:Disease Models, Animal D004305:Dose-Response Relationship, Drug D015227:Lipid Peroxidation D008099:Liver D008297:Male D018384:Oxidative Stress D010805:Physical Conditioning, Animal D051381:Rats D017208:Rats, Wistar D017382:Reactive Oxygen Species D013482:Superoxide Dismutase D013550:Swimming D017392:Thiobarbituric Acid Reactive Substances D014801:Vitamin A
vitamine A cytokines antioxidant enzymes, exercise, cytokines, liver dérivés réactifs de l’oxygène enzymes antioxydants exercice physique foie modèle de rat Wistar reactive oxygen species, vitamin A, Western blotting, Wistar rat model transfert de Western