Modulation of antioxidant and detoxification responses induced by lipoic acid in the Pacific white shrimp Litopenaeus vannamei (Boone, 1931) subjected to hypoxia and re-oxygenation

The effect of lipoic acid supplementation and moderate hypoxia (3 mg/L), followed by re-oxygenation, was analyzed in terms of antioxidant and oxidative damage responses in juvenile shrimp Litopenaeus vannamei. Lipoic acid (LA)-enriched rations (D1: 76.4 +/- 6.4; D2: 196.4 +/- 70.2; and D3: 397.2 +/- 79.97 mg LA/kg) were offered to shrimps. A control group without LA adding was also run. After 45 days, LA-enriched ration increased the activity of the detoxifying enzyme glutathione-S-transferase in gills. Total antioxidant capacity against peroxy radicals was augmented in gills and hepatopancreas at doses D2 and D3. Doses D1 and D2 of LA reduced the levels of oxidative damage (lipid peroxidation) in gills and hepatopancreas. The results showed that certain LA doses (particularly D2) improved not only antioxidant responses but also weight gain. It can be concluded that LA triggered antioxidant and detoxification protection in L. vannamei, allowing the shrimp to cope with environmental stressful factors.