Study On The Protection Effect Of Vitamin E On The Dietary Lipid Of Chinese Mitten Crab Eriocheir Sinensis

This study systematically disscussed the interaction between vitamin E and lipid, HUFA, oxidized oil, vitamin C, respectively, used Chinese mitten crab as objective. This study emphasize the protection effect of vitamin E on the dietary lipid of Chinese mitten crab. The results indicated that vitamin E can protect lipid during the utilization in vivo from oxidized efficiently and can alleviate the bad effect of oxidized oil on the crab, we also further discussed the anti-oxidant performance of vitamin E from molecular level. The results of this study will provide a solution for the lipid oxidized problem always met in the preparation of the Chinese mitten crab complete formula feed.1.Effect of dietary lipids and vitamin E on growth performance, body composition, anti-oxidative ability and resistance to Aeromonas hydrophila challenge of juvenile Chinese mitten crab Eriocheir sinensisVitamin E supplement is important in protecting lipid oxidation and enhancing immunity of aquatic animals. A10-week feeding trial was conducted to evaluate the effect of dietary lipid and vitamin E on juvenile Chinese mitten crab Eriocheir sinensis. The experimental diets included three levels of vitamin E (0,100and300mg kg-1diet) and two levels of lipid (6%and9%). The9%lipid diet significantly enhanced the body lipid of crabs compared to the6%lipid diet. The vitamin E concentration of hepatopancreas increased with the increase of vitamin E in the diets regardless of dietary lipid levels. The hepatopancreas fatty acids, especially PUFA (polyunsaturated fatty acid) and HUFA (highly unsaturated fatty acid), were significantly enhanced by vitamin E supplement or9%dietary lipid. Vitamin E supplement significantly increased the total antioxidant capacity (T-AOC), superoxide dismutase (SOD), lysozyme and phenoloxidase activities of crabs compared to those fed the diets without vitamin E supplement. The hepatopancreas malondialdehyde of crabs fed100mg vitamin E kg-1was significantly lower than those fed0or300mg vitamin E kg-1. The phenoloxidase activity of crabs fed the9%lipid diet was significantly higher than those fed6%lipid, irrespective of vitamin E levels. Vitamin E supplementation increased the bacterial resistance of juvenile crab. This study indicates that dietary lipid and vitamin E supplement do not affect crab growth and survival, but vitatmin E supplement at100mg kg-1can enhance immunity and antioxidant capacity of crab fed6%or9%dietary lipids.2. Growth performance, body composition, non-specific immune ability of Chinese mitten crab fed different levels vitmian E and C and highly unsaturated fatty acids (HUFA)Can vitamin E protect HUFA effectively from oxidized? A42-day feeding trial was conducted to explore the effect of growth performance, body composition, non-specific immune ability of juvenile Chinese mitten crab Eriocheir sinensis fed diets with different levels vitamin E and HUFA. The experiment diets were formulated with two levels of vitamin E (0and200mg kg-1diet) and HUFA (0and1%), designed as:-E-HUFA,-E+HUFA,+E-HUFA,+E+HUFA. The results showed crab fed+E+HUFA diet had significantly higher weight gain than those fed other diets. The body lipid deposition of crab fed+HUFA diets had a increase trend compared to those fed-HUFA diets. The hepatopancreas vitamin E concentration was positively related to the dietary vitamin E contents. The+E+HUFA diet resulted a significantly lower MDA contents in the hepatopancreas of crab than-E+HUFA diet. The+E+HUFA diets enhanced the respiratory burst activity of haemolymph. Highest lysozyme acitivity was found in+E+HUFA and+E-HUFA diets. The accumulative mortality of crab fed-E-HUFA diets were significantly higher than those fed other diets. This study indicated that vitamin E can protect the+HUFA from oxidization, the HUFA enhance the growth performance, non-specific immune ability and bacterial resistance capacity. 3. Effect of oxidized fish oil and a-tocopherol on growth, anti-oxidation status, serum immune enzyme activity and resistance to Aeromonas hydrophila challenge of Chinese mitten crab Eriocheir sinensisWill the vitamin E alleviate the bad effect of oxidized fish oil on the juvenile crab? The impact of dietary a-tocopherol on juvenile Chinese mitten crab Eriocheir sinensis fed different oxidized oil was experimentally evaluated in a10-week study. Crab were fed with nine diets including three levels of a-tocopherol (0,100and300mg kg-1diet) and three levels of fish oil oxidation:fresh, moderate and high) in triplicates. Fresh and moderate oil oxidization enhanced weight gain, but moderate and high oil oxidization lowered survival and feed efficiency. The100mg a-tocopherol kg-1diet resulted in lower hepatopancreas MDA than other a-tocopherol diets. High oil oxidization led to the lowest serum superoxide dismutase (SOD) and glutathione peroxidase (GPX). The serum SOD and GPX activities in crab fed100mg a-tocopherol were higher than those fed other a-tocopherol diets. The diet without a-tocopherol addition lowered lysozyme and phenoloxidase (PO) activities compared to other a-tocopherol dites. Fresh fish oil diet increased PO activity compared to oxidized oils. High oil oxidization caused significantly more mortality than fresh or moderate oxidization after7-d post challenge with Aeromonas hydrophila. Supplementation with a-tocopherol significantly enhanced resistance to bacterial infection. This study indicates that a-tocopherol can protect lipid from peroxidation and enhance disease resistance.4. The regulatory effect of vitamin E on the Hsp70, Trxl and Prx6gene expression level of crab fed oxidized oil dietsThe external stress can induce the Hsp70gene over expressed and the oxidative stress also can induce the Trxl and Prx6gene over expressed. The genes can be regulated by the functional nutritions. The results of vitamin E and the oxidized fish oil experiment indicated that highly oxidized oil significantly up-regulated the hepatopancreas Trx1, Prx6and Hsp70gene expression level and vitamin E supplement down-regulated the Trx1, Prx6and Hsp70gene expression level. In high oxidized oil group, the hepatopancreas Trxl, Prx6and Hsp70gene expression level of crab fed vitamin E unsupplemented diet were significantly higher than other groups. These genes were overexpressed under oxidative stress and the proper vitamin E addition can down-regulated these gene expression level, the probably reason may be vitamin E can alleviated the oxidative stress and regulated the above gene expression level indirectly.5. The interaction effect of vitamin E and vitamin C on the growth, anti-oxidative performance of Chinese mitten crab Eriocheir sinensis.An8-week feeding trial was conducted to evaluate the effect of vitamin E and vitamin C on the growth, anti-oxidative performance of Chinese mitten crab Eriocheir sinensis and the possible interaction between the two vitamins. The result indicated that the vitamin E and C concentrations in hepatopancreas were positively correlated with the vitamin E and C adding doses in the diets, however, the vitamin C concentration in hepatopancreas decreased with the increased vitamin E in the diets. The haemolymph respiratory burst activity of crab fed C100+E100diet was significantly higher than other groups, there was an interaction in the haemolymph respiratory burst activity. The hepatopancres SOD activity of crab fed C0+E50group and C300+E300group were significantly higher than other groups. C300+E100and VE100+VC100group had significantly DHA in hepatopancreas than other group. The EPA in hepatopancreas of crab fed C300+E50group was significantly higher than other groups. The hepatopancreas Trx1and Prx6gene expression level of crab were significantly influenced by vitamin E and vitamin C and the lowest gene expression level was found in E100+C100group. This study indicated that there was an interaction between vitamin E and vitamin C, vitamin C can spare vitamin E. Low level or too high level vitamin E and vitamin C all produce oxidized stress. The suggested dosge of vitamin E and C were100mg kg-1and100mg kg-1diet, repectively, based on the growth, anti-oxidant and non-specific immune parameters.