Lycopene Affects Hepatic Gene Expression of the Main Antioxidant Enzymes in Gilts

The objective of this work was to evaluate the effects of lycopene 10 % extract levels in the diet of pigs, barrows and gilts, on the gene expression of antioxidant enzymes in the liver. 15 Barrows and 15 gilts (Piétrain x Landrace x Large White) with an initial weight of 75.23 ± 1.13 kg were used. Animals were distributed in a randomized block design with three replicates, using a 2 x 5 factorial scheme consisting of two sexes (male and female), five levels of lycopene (0, 125, 250, 375, 500 mg/kg feed). Gene expression of the enzymes glutathione peroxidase (GPX), superoxide dismutase (SOD) and catalase were measured in the liver by quantitative polymerase chain reaction in real time. The F test was applied to the means obtained for the sex. The degrees of freedom related to the lycopene levels were unfolded in orthogonal polynomials to obtain the regression equations. There was a significant interaction between lycopene levels and sex for SOD (P=0.018) and catalase (P=0.001). A linear reduction in the gene expression of SOD and catalase in the gilts’ liver was observed as the lycopene levels increased in the diet, adjusting the equations Ŷ = - 0.00125x + 0.9155 (R²= 0.50) e Ŷ = - 0.00024x + 0.2418 (R²= 0.64), respectively. Gene expression of SOD was lower (P=0.001) in gilts with a supplementation of 500 mg of lycopene/kg of feed. Likewise, catalase was less expressed in gilts at levels of 0, 125 and 500 mg of lycopene, in relation to barrows. Lycopene levels did not influence (P>0.050) the GLPx gene expression in the liver of the pigs, but the gilts presented a lower gene expression (P=0.001) in relation to the barrows. These results indicate that lycopene may reduce the expression of antioxidant enzymes as a result of an adjustment of the cellular redox state due to the consumption of an exogenous antioxidant. It was concluded that lycopene reduced the gene expression of SOD and catalase enzymes in gilts’ liver.