Effects Of Dietary Angelica Sinensis Polysaccharide On Non-specific Immunity Of Epinephelus Malabaricus

To study the immunoregulatory effects of dietary Angelica sinensis polysaccharides on aquatic animals,differenet concentations(0 mg/kg,1500 mg/kg,3000 mg/kg,6000 mg/kg,12000 mg/kg and 24000 mg/kg)of Angelica sinensis polysaccharides were added in diet of Epinephelus malabaricus,and changes in biochemical indexes,antioxidative indexes and non-specific immunity function of E.malabaricus were investigated.Gene expressions of toll-like receptor 22 signaling pathway,as well as NBT-positive cells,albumin/globulin ratio and LZM activity were used to evaluate non-specific immunity function.The main results were presented as follows:Effects of dietary Angelica sinensis polysaccharides on biochemical index: Feeding Angelica sinensis polysaccharides increased HB content and activities of AKP,ACP,and decresed the activities of GPT and GOP significantly(P < 0.05).HB contents were the highest in 3000 mg/kg treatment at 28 d and 1500 mg/kg treatment at 56 d,respectively.At 28 d and 56 d,GPT activities in 6000mg/kg treatment and 1500mg/kg treatment reached to the lowest,respectively;GOT activities in 6000mg/kg treatment reached to the lowest at both 28 d and 56 d.AKP and ACP activities reached to the highest in 24000 mg/kg treatment at 28 d,6000 mg/kg treatment at 56 d.Effects of dietary Angelica sinensis polysaccharides on antioxidative index: Feeding Angelica sinensis polysaccharides increased T-SOD,CAT,GSH-Px activities and T-AOC level in plasma and tissues(liver,head kidney,posterior kidney and spleen)significantly(P < 0.05).MDA levels in plasma,liver,head kidney,posterior kidney and spleen decreased significantly(P < 0.05)after feeding Angelica sinensis polysaccharides.Effects of dietary Angelica sinensis polysaccharides on nonspecific immunology index: Feeding Angelica sinensis polysaccharides increased NBT-positive cells(P < 0.05)which reached to the highest in 24000mg/kg treatment at 28 d.NBT-positive cells were not affected significantly at 56 d(P > 0.05);feeding Angelica sinensis polysaccharides increased albumin/globulin ratio significantly(P < 0.05)which reached to the highest in 24000mg/kg treatment at 28 d and 56 d;feeding Angelica sinensis polysaccharides increased LZM activity significantly(P < 0.05)which reached to the highest in 6000mg/kg treatment at 28 d and 56 d.Gene expression of toll-like receptor 22 signaling pathway in different tissues: Gene expressions of TLR22、TRIF、IRF3、MyD88、TNF-α were all observed in head kidney,posterior kidney,liver,spleen,stomach,intestine and gill.The highest gene expressions of TLR22 and TNF-α appeared in spleen while the highest gene expressions of TRIF,IRF3 and MyD88 were observed in liver.Effects of dietary Angelica sinensis polysaccharides on gene expressions of toll-like receptor 22 signaling pathway: Feeding Angelica sinensis polysaccharides increased gene expressions of toll-like receptor 22 signaling pathway significantly(P < 0.05).At 28 d,gene expressions of TLR22,IRF3 and TNF-α in 12000mg/kg treatment were the highest while TRIF and MyD88 gene expressions reached to the highest in 6000mg/kg and 1500mg/kg treatments,respectively;At 56 d,all investigated five gene expressions reached the highest in 6000 mg/kg treatment.