Effect of taurine-enriched diets on the Hsp expression, MAPK activation and the antioxidant defence of the European sea bass (Dicentrarchus labrax)

This study aimed to identify and characterize the cellular and metabolic response in vital organs of Dicentrarchus labrax, after feeding on soy-based diets enriched with different taurine concentrations (T0.2, T0.5, T1.0 w/w). Molecular responses (expression of Hsp70, Hsp90, phosphorylation of p38 mitogen-activated protein kinase-p38MAPK and extracellular signal-regulated kinases-ERK1/2) were addressed. Metabolic and antioxidant capacities such as activities of citrate synthase (CS), malate and lactate dehydrogenase (MDH, L-LDH), superoxide dismutase (SOD), catalase (CAT) and levels of thiobarbituric acid-reactive substances (TBARS) were assessed. The most intense changes were detected in the liver and in the anterior intestine showing that taurine induces important protective biochemical mechanisms. Specifically, in the liver and the anterior intestine, Hsp and MAPK levels, as well as L-LDH activity levels were up-regulated under the effect of taurine diets. T diet had no major effect on the activity levels of CS, SOD and TBARS, except for MDH in the liver and catalase in the anterior intestine, where activity levels of these enzymes were increased under the effect of T0.2 and T1.0, respectively. These results may facilitate monitoring of adequate health status of farmed fish, exploiting the beneficial T effects and could assist at the formulation of aquaculture feeding strategies.