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BIBTEX RIS

Effect of Beta-Carotene on Oxidative Stress and Expression of Cardiac Connexin 43

2013; Sociedade Brasileira de Cardiologia (SBC); Linguagem: Inglês

10.5935/abc.20130160

ISSN

1678-4170

Autores

Rosângela Novo, Paula S. Azevedo, Marcos Ferreira Minicucci, Leonardo A. M. Zornoff, Sérgio Alberto Rupp de Paiva,

Tópico(s)

Air Quality and Health Impacts

Resumo

Background: Intervention studies have shown an increased mortality in patients who received beta-carotene.However, the mechanisms involved in this phenomenon are still unknown.Objective: Evaluate the influence of beta-carotene on oxidative stress and the expression of connexin 43 in rat hearts.Methods: Wistar rats, weighing approximately 100 g, were allocated in two groups: Control Group (n = 30), that received the diet routinely used in our laboratory, and Beta-Carotene Group (n = 28), which received beta-carotene (in crystal form, added and mixed to the diet) at a dose of 500 mg of beta-carotene/kg of diet.The animals received the treatment until they reached 200-250g, when they were sacrificed.Samples of blood, liver and heart were collected to perform Western blotting and immunohistochemistry for connexin 43; morphometric studies, dosages of beta-carotene by high-performance liquid chromatography as well as reduced glutathione, oxidized glutathione and lipids hydroperoxides were performed by biochemical analysis.Results: Beta-carotene was detected only in the liver of Beta-Carotene Group animals (288 ± 94.7 µg/kg).Levels of reduced/ oxidized glutathione were higher in the liver and heart of Beta-Carotene Group animals (liver -Control Group: 42.60 ± 1.62; liver -Beta-Carotene Group: 57.40 ± 5.90; p = 0.04; heart: -Control Group: 117.40 ± 1.01; heart -Beta-Carotene Group: 121.81 ± 1.32 nmol/mg protein; p = 0.03).The content of total connexin 43 was larger in Beta-Carotene Group.Conclusion: Beta-carotene demonstrated a positive effect, characterized by the increase of intercellular communication and improvement of anti-oxidizing defense system.In this model, mechanism does not explain the increased mortality rate observed with the beta-carotene supplementation in clinical studies.(

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