Although the benefits of oleic acid (OA) have been established in mammals, its effects on fish remain understudied. The aim of this study was to evaluate the antioxidant potential of OA in the liver, intestine, and muscle of European sea bass juveniles fed diets containing different lipid levels. For that purpose, six diets with 16 or 22% lipids and 0, 1, and 2% OA were formulated and triplicate groups of European sea bass juveniles (21.4 g) were fed with these experimental diets for 9 weeks. Increasing dietary lipid levels or OA supplementation did not affect antioxidant enzyme activity in the liver and muscle. Superoxide dismutase (SOD) activity in the intestine increased with both the dietary lipid and OA levels, while glucose 6 phosphate dehydrogenase (G6PDH) activity increased only with dietary OA supplementation. Reduced glutathione (GSH) and total glutathione (tGSH) content were higher in the liver and intestine of fish fed the low-lipid diets, while in the high-lipid diets it was lower in the muscle than in the liver and intestine. Present findings suggest that OA plays a role in the antioxidant defense mechanisms of European sea bass, particularly at the intestine level, but additional research is required to further assess the potential benefits of incorporating OA into the diets.

尽管油酸 (OA) 对哺乳动物的益处已得到证实，但其对鱼类的影响仍未得到充分研究。本研究的目的是评估饲喂含有不同脂质水平饮食的欧洲鲈鱼幼鱼的肝脏、肠道和肌肉中 OA 的抗氧化潜力。为此，配制了六种含有 16% 或 22% 脂质和 0%、1% 和 2% OA 的饲料，并用这些实验饲料喂养三组欧洲鲈鱼幼鱼（21.4 克），为期 9 周。增加膳食脂质水平或补充 OA 不会影响肝脏和肌肉中的抗氧化酶活性。肠道中的超氧化物歧化酶 (SOD) 活性随着膳食脂质和 OA 水平的增加而增加，而葡萄糖 6 磷酸脱氢酶 (G6PDH) 活性仅随着膳食 OA 的补充而增加。低脂饲料喂养的鱼的肝脏和肠道中还原型谷胱甘肽（GSH）和总谷胱甘肽（tGSH）含量较高，而高脂饲料中肌肉中的还原型谷胱甘肽（GSH）和总谷胱甘肽（tGSH）含量低于肝脏和肠道。目前的研究结果表明，OA 在欧洲鲈鱼的抗氧化防御机制中发挥着重要作用，特别是在肠道水平，但需要进行更多研究来进一步评估将 OA 纳入饮食中的潜在益处。