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

Abstract

BackgroundIntervention studies have shown an increased mortality in patients who received beta-carotene. However, the mechanisms involved in this phenomenon are still unknown. ObjectiveEvaluate the influence of beta-carotene on oxidative stress and the expression of connexin 43 in rat hearts. MethodsWistar 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. ResultsBeta-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. ConclusionBeta-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.

Effects of titanium dioxide nanoparticles on the myocardium of the adult albino rats and the protective role of β-carotene (histological, immunohistochemical and ultrastructural study)

“…This suggests possible protection provided by β-carotene against the harmful effects of TiO 2 NPs on the ventricular muscle. These results of β-carotene on the hearts of Wistar rats registered by Novo et al (2013) who mentioned that β-carotene has a positive effect on the ventricular myocardium characterized by the increased intercellular communication and improvement of the antioxidant defense system. Regarding this study, there were some limitations due to unavailable resources which affected the methodological tools that were not adequate to quantifying immunohistochemical results.…”

Disease Prevention and Treatment Using β-Carotene: the Ultimate Provitamin A

“… In vitro studies have demonstrated a stimulation of cellular communication through gap junctions (Sies and Stahl 1997 ). A study concluded the positive effect of β-carotene leading to increased intercellular communications in rats (Novo et al 2013 ). The degree of conversion of the consumed provitamin A carotenes to retinol is the essential measure to which the deficiency of vitamin A, common in children, can be treatable.…”

“…In vitro studies have demonstrated a stimulation of cellular communication through gap junctions (Sies and Stahl 1997 ). A study concluded the positive effect of β-carotene leading to increased intercellular communications in rats (Novo et al 2013 ).…”

Nutrition and Cardiology: An Interface not to be Ignored

“…The study by Novo et al has shown that supplementation with beta-carotene to rats has beneficial effects, characterized as increased intercellular communication, with a potential to reduce arrhythmias and to enhance the antioxidant defense system 12 .…”

“…Beta-carotene is a carotenoid with provitamin A activity and other functions, present in the human diet in colored fruits and vegetables. The study by Novo et al has shown that supplementation with beta-carotene to rats has beneficial effects, characterized as increased intercellular communication, with a potential to reduce arrhythmias and to enhance the antioxidant defense system 12 .…”