Effects of Vitamin E with Different Levels or Sources of Dietary Lipid on the Growth and Expression of Inflammatory, Oxidative Stress, and Apoptotic Genes in the Head Kidney of Olive Flounder, <i>Paralichthys olivaceus</i>

Abstract

Abstract This study has assessed the effects of vitamin E (−E, +LE, +HE; 0, 100, 1000 mg/kg, respectively) in fish diets containing high levels ( HL ; 10%) of fish oil ( FO ) or mixed vegetable oils ( VO ) on the growth and inflammatory, oxidative stress, and apoptotic gene expression in the head kidney of olive flounder, Paralichthys olivaceus . Consequently, the highest weight gain was achieved in the FO group and the lowest in the HL‐VO + LE group. The gene expression levels of each group were compared to the 5% FO group. The 5% VO group showed higher expression levels of tumor necrosis factor ( TNF ) α, interleukin (IL)‐1β, and scinderin‐like ( ScinL ) genes. Although lysozyme gene expression was higher in the HL‐VO + LE group, the other gene expression levels of the HL‐FO / VO + LE groups were not different from those of the FO group. The HL‐FO / VO −E/+ HE groups showed a higher TNF α gene expression, but the cytochrome oxidase subunit III gene expression was higher in the HL‐FO −E and HL‐VO + HE groups. Lysozyme gene expression was higher in the HL‐FO −E and HL‐VO −E/+ HE groups. IL ‐6 and ScinL gene expression were higher in the HL‐VO ‐E and HL‐VO + HE groups, respectively. In conclusion, mixed VO and too high or too low vitamin E levels in fish diets may affect inflammatory, oxidative stress, and apoptotic gene expression in the head kidney of olive flounder.