螺旋藻多糖提取物对凡纳滨对虾免疫、抗氧化功能及亚硝酸盐应激的影响OA

This experiment aimed to investigate the effects of Spirulina polysaccharide extract on the immune,and antioxidant function,and nitrite stress of Litopenaeus vannamei.A total of 1 800 Litopenaeus vannamei were randomly divided into six groups,with three replicates per group and 100 shrimp per replicate.The blank control group and the nitrite stress control group were fed the basal diet.The high-dose,medium-dose,and low-dose groups received basal diets supplemented with 4.0,2.0,and 1.0 g/kg of Spirulina polysaccharide extract,respectively.The positive control group(Astragalus polysaccharide group)supplemented with 2.0 g/kg of Astragalus polysaccharide in the basal diet.The pre-test period was seven days,and the formal test period was 30 days.After the feeding test concluded,a 72-hour nitrite stress test was conducted.The results showed that the activities of acid phosphatase(ACP),alkaline phosphatase(ALP),and superoxide dismutase(SOD)in the high-dose,medium-dose,and low-dose groups were higher than those in the blank control group.After 24 hours of nitrite stress,the activities of ACP,ALP,phenoloxidase(PO),aspartate aminotransferase(AST),and total antioxidant capacity(T-AOC)in the nitrite stress control group were significantly higher than those in the blank control group(P<0.05),while ACP,ALP activities,and T-AOC in the high-dose and medium-dose groups were significantly lower than those in the nitrite stress control group(P<0.05).After 48 hours of stress,the ACP,ALP activities,and T-AOC in the nitrite stress control group were significantly lower than those in the blank control group(P<0.05),and the ALP activity and T-AOC in the medium-dose group were significantly higher than those in the nitrite stress control group(P<0.05).The study show that Spirulina polysaccharide extract enhances nonspecific immune and antioxidant function,regulates physiological and biochemical responses under stress,and alleviates nitrite-induced damage in Litopenaeus vannamei.