The negative effects of dietary cadmium on antioxidant capacity, immunity and intestine morphology of Macrobrachium nipponense and the alleviation effects of lipoic acid

The present experiment containing two dietary cadmium (Cd) levels (0 and 5 mg/kg) and two lipoic acid (LA) levels (0 and 600 mg/kg) was carried out to investigate the effects of dietary Cd on the growth, antioxidant capacity, immunity and intestine morphology of Macrobrachium nipponense and the alleviation effects of LA. We found that dietary Cd and LA had no significant effects on the growth of prawns. Dietary Cd significantly decreased the activity of antioxidant enzymes, resulting in a higher MDA level in the hepatopancreas. LA was added to diets that increased these antioxidant enzyme activities. Similarly, dietary Cd decreased the activity of lysozyme and content of NO in the serum, whereas dietary LA ameliorated these negative effects. Dietary Cd significantly increased the activities of GOT and GPT in the serum, and LA supplementation decreased the activities of these enzymes in the serum. The intestinal villus of prawns fed the diet containing Cd was partly detached from the basement membrane, and LA protected the integrity of the gut. In conclusion, dietary Cd depressed the antioxidant capacity and immunity, destroyed the intestine morphology of prawns and LA supplementation alleviated these negative effects caused by Cd.