Suplementação dietética com nerolidol melhora a capacidade antioxidante e perfil de ácidos graxos musculares de Brycon amazonicus expostos a estresse por calor

Abstract

Aquaculture plays an important role in providing food for a growing world population, with fish being an important food item in the human diet throughout history. However, the increase in water temperature is a worrying factor, since temperature is a key environmental factor that determines the growth of key aquaculture species, such as matrinxã (Brycon amazonicus). The use of plant extracts has been considered an interesting approach to avoid/reduce the negative effects of exposure to high water temperatures, such as nerolidol, which has antioxidant activity when added to fish diets. Thus, the aim of this study was to determine whether dietary supplementation with nerolidol prevents or reduces muscle oxidative damage and compromised the fatty acid profile in fillet from matrinxãs exposed to heat stress. Seventy-two matrinxãs were transferred to 12 tanks and divided into four groups: basal diet; diet containing nerolidol; basal diet exposed to heat stress, and diet containing nerolidol exposed to heat stress. The basal diet and basal diet exposed to heat stress groups received the basal diet (without nerolidol), while the nerolidol-containing diet and nerolidol-containing diet exposed to heat stress groups received the basal diet supplemented with 1.0 mL of nerolidol/kg of ration for 14 days. After 14 days of diet, the basal diet exposed to heat stress and the nerolidol-containing diet exposed to heat stress groups were subjected to heat stress at 34 ºC for 72 h. The levels of espécies reativas de oxigênio (EROs) and peroxidação lipídica (LPO) in plasma and muscle were significantly higher in fish exposed to heat stress compared to fish not exposed to heat stress, while the activities of superóxido dismutase (SOD) and of glutationa peroxidase (GPx) were significantly lower in these tissues. The total of ácidos graxos saturados (SFA) content in the fillet was significantly higher in fish exposed to heat stress compared to fish not exposed to heat stress, while the total ácidos graxos poliinsaturados (PUFA) content was significantly lower. Nerolidol added to the diet prevented the increase in muscle LPO levels and plasma EROs and LPO levels in fish exposed to heat stress, and partially prevented the increase in muscle ROS levels. Nerolidol supplementation prevented the inhibition of muscle GPx activity in fish exposed to heat stress, and partially prevented the decrease in plasma GPx activity. Nerolidol supplemented the diet prevented the increase in fillet SFA in fish exposed to heat stress, while partially preventing the decrease in PUFA. Finally, we corroborate the data that heat stress at 34 ºC for 72 h causes oxidative damage and changes the fatty acid profile of matrinxã fillet, and we conclude that the diet containing 1.0 mL of nerolidol/kg of feed for 14 days can be considered a strategy to prevent oxidative damage induced by heat stress and impairment of muscle fatty acid profile.