Carotenoids from malanga (Xanthosoma sagittifolium) leaves protect cells against oxidative stress in rats

Abstract

The present study investigated the effect of malanga leaf powder and its carotenoids oil extract on oxidative damage in rat tissues. A group of rats received AIN-93G diet devoid of vitamin A (AD) and three other groups were treated with AD diet supplied with synthetic beta-carotene (beta-car) or malanga leaf powder (MP) or malanga carotenoids extract (CE). The diets' carotenoids bioavailability was determined through carotenoids intake/liver retinol content. Lipid thiobarbituric acid reactive substances (TBARS) and protein (carbonyl) oxidation, and reduced (GSH) and oxidized (GSSG) glutathione concentrations were determined in liver, heart, and brain. Synthetic beta-carotene bioavailability was higher than that of pro-vitamin A carotenoids from MP and CE diets, and no difference was observed between the latter two groups. Liver and heart lipid peroxidation was lower in the beta-car and CE groups than the AD group, while no difference was observed for the MP group. The beta-car, MP, and CE groups showed lower liver protein oxidation than the AD group, and only the CE group had lower heart protein oxidation in relation to AD. The MP group had a lower liver GSSG concentration and higher GSH/GSSG ratio than the AD group, while no difference was observed for heart glutathione concentration among the groups. The results indicate that at physiological levels, beta-car, malanga carotenoids extract, and malanga leaf powder have antioxidant effects in rats.