Antioxidant status of serum, muscle, intestine and hepatopancreas for fish fed graded levels of biotin.

Lipid peroxidation, protein oxidation and antioxidant activities of muscle, intestine, hepatopancreas and serum in juvenile Jian carp (Cyprinus carpio var. Jian) were investigated after feeding graded levels of biotin (0.010, 0.028, 0.054, 0.151, 0.330, 1.540 and 2.680 mg kg(-1) diet) for 63 days. Both malondialdehyde and protein carbonyl content in all studied tissues and serum were the lowest in fish fed diets containing 0.151-0.330 mg biotin kg(-1) diet and then increased in fish fed the diet with 2.680 mg biotin kg(-1) diet (P < 0.05). Similarly, glutamate-oxaloacetate transaminase and glutamate-pyruvate transaminase activities in serum significantly decreased with biotin levels up to 0.151 mg kg(-1) diet (P < 0.05). Conversely, capacities of anti-hydroxyl radical (AHR) and anti-superoxide anion (ASA) in the detected tissues and serum significantly improved with biotin levels up to 0.054-1.540 mg kg(-1) diet and then decreased in 2.680 mg biotin kg(-1) diet group for muscle and intestinal AHR as well as hepatopancreas ASA (P < 0.05). Activities of superoxide dismutase in all studied tissues and serum significantly elevated with biotin levels up to 0.330 mg kg(-1) diet and then decreased when fish fed the diet with 2.680 mg biotin kg(-1) diet, except intestine (P < 0.05). Meanwhile, activities of catalase, glutathione peroxidase, glutathione-S-transferase and glutathione reductase and total thiol content in all studied tissues and serum showed the upward trend with biotin supplementations (P < 0.05). These results indicated that biotin improved antioxidant status and depressed lipid peroxidation and protein oxidation in all studied tissues and serum.