Supplementation of adult rats with moderate amounts of β-carotene modulates the redox status in plasma without exerting pro-oxidant effects in the brain: a safer alternative to food fortification with vitamin A?

Carlos Eduardo Schnorr,Leonardo Da Silva Bittencourt,Fares Zeidán-Chuliá,André Simões-Pires,José Cláudio Fonseca Moreira,Maurilio Da Silva Morrone

doi:10.3390/nu6125572

Carlos Eduardo Schnorr, Leonardo Da Silva Bittencourt + Show 4 more

Open Access

https://doi.org/10.3390/nu6125572

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Journal: Nutrients	Publication Date: Dec 1, 2014
Citations: 51	License type: CC BY 4.0

Affiliation: Universidade Federal do Rio Grande do Sul

Abstract

Despite the antioxidant potential of vitamin A, recent studies reported that chronic retinol ester supplementation can also exert pro-oxidant effects and neurotoxicity in vivo and raises the mortality rates among healthy subjects. Our aim was to find evidence for a safer (i.e., less toxic) molecule with provitamin A activity. Therefore, we investigated whether chronic supplementation of healthy Wistar rats with β-carotene (0.6, 3, and 6 mg/kg/day) would demonstrate antioxidant characteristics without leading to pro-oxidant side effects in the brain. Total reactive antioxidant potential (TRAP), thiobarbituric reactive species level (TBARS), and total reduced thiol content (SH) were evaluated in plasma. TBARS and SH were additionally evaluated in selected brain regions together with superoxide dismutase (SOD) and catalase (CAT) activity. In the present study, we show that β-carotene is able to exert antioxidant activity in plasma without triggering pro-oxidant events in the brain, providing evidence that may justify its further evaluation as a safer nutritional supplement with provitamin A activity.

Highlights

Food fortification and dietary supplementation with retinol esters are commonly used to mitigate the impacts of hypovitaminosis A
The animals supplemented with β-carotene showed no treatment-related clinical signs of toxicity and no differences in body weight gain (Figure 1) during the experimentation
The plasma collected from the β-carotene-supplemented groups showed an increase in antioxidant activity, as demonstrated by the decrease in the AUC of the Total reactive antioxidant potential (TRAP) assay when compared to the control group (Figure 2A), but only the effect of the supplementation at 6 mg/kg/day was statistically significantly (p < 0.01) (Figure 2B). β-carotene supplementation at 0.6 (p < 0.05), 3 (p < 0.05), and 6 (p < 0.05) mg/kg/day reduced the lipid peroxidation levels (TBARS) in the plasma, but did not affect the total thiol content (Figure 2C,D, respectively)

Summary

Introduction

Food fortification and dietary supplementation with retinol esters are commonly used to mitigate the impacts of hypovitaminosis A. Increasing interest in fortified foods and vitamin A supplements is leading to a large percentage of the healthy population being constantly exposed to a higher intake of vitamin A than recommended [1]. Excessive consumption of vitamin A can have a severe adverse impact on human health. Even without any manifestation of clinical signs of hypervitaminosis A, neurotoxic effects may occur in adults due to excessive vitamin A intake because vitamin A readily enters the central nervous system (CNS) [3]. The harmful effects of retinol ester supplementation to the brain have been investigated using experimental animal models. The search for safer sources of vitamin A seems to be timely and necessary

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