Studies On Effects Of Garlicin On Immune And Digestive Function In Crucian Carp(Carassius Auratus)

The crucian carp(Carassius auratus) was used as laboratory animal to study the effects of two different concentrations of garlicin on the immune and digestive function. Different concentrations of garlicin is added to the crucian carp based feed.The feeding trail was conducted for 42 days, feed containing garlicin during 1-28 days,feed not containing garlicin during 28-42 days. The experiment measured and observed the crucian carp non-specific immune parameters, erythrocyte count,antioxidant index, serum biochemical parameters and digestive enzyme activities and the physical structure of intestinal tissue, aimed to provide a theoretical basis for rational and scientific applications of garlicin in aquatic animals.1. The result on the nonspecific immune indexes of Carassius auratus showed that, compared with the control group, the serum C3 activity of 250 mg/kg garlicin test groups was increased very significantly(P<0.01); the serum C3, C4 activity of500 mg/kg garlicin test groups were decreased very significantly(P<0.01); the serum C4 activity was still declined significantly(P<0.05) after feeding basic diet without garlicin. Compared with the control group, the LZM activity of 250 mg/kg and 500mg/kg garlicin test groups were increased in serum, liver, kidney and spleen significantly(P<0.05); the LZM activity of experimental group fish returned to control levels in the first 42 days. the content NO of 250 mg/kg garlicin was increased in liver and spleen significantly(P<0.05); Compared with the control group, the content NO of 500 mg/kg garlicin test groups was increased in serum and spleen and was decreased in the liver significantly(P<0.05).2. The result on the antioxidant and blood indicators function of Carassius auratus showed that, compared with the control group: the SOD activity and T-AOC content of 250 mg/kg garlicin test groups were increased in serum and liver significantly(P<0.05), and the MDA content was declined significantly(P<0.05). the MDA content was still declined significantly(P<0.05) after feeding basic diet without garlicin. the SOD activity, T-AOC content and the MDA content of experimental group fish returned to control levels in the first two weeks after switched to the basic feed. The red blood cell count of 250 mg/kg garlicin test groups was increased significantly(P<0.05), and the GLB content was increased very significantly(P<0.01).The ALT and AST count of 250 mg/kg garlicin test groups were decreased significantly(P<0.05). The ALT count of 500 mg/kg garlicin test groups was decreased very significantly(P<0.01).3. The results on activity determination of intestinal digestive enzymes showed that, compared with the control group, the foregut, midgut and hindgut amylase activity of 250mg/kg garlicin was increased significantly(P<0.05). The midgut protease activity of 250mg/kg garlicin was increased significantly(P<0.05). The foregut protease activity of 500mg/kg garlicin was declined very significantly(P<0.01). It was still significantly declined in the first week after fed basic diet without garlicin(P<0.05).4. The observation on intestinal tissue physiology showed that: compared with the control group, intestinal tissue physiology observations suggest the foregut,midgut and hindgut villus height of 250 mg/kg garlicin were significantly increased(P<0.05); the foregut and midgut villus height of 500 mg/kg garlicin were declined significantly(P<0.05); the foregut, midgut and hindgut villus height of 250 mg/kg garlicin were still increased significantly(P<0.05) and that of 500 mg/kg were still declined significantly(P<0.05)after feeding basic diet without garlicin. The intestinal tissue slices on the 28 days show that, the foregut, midgut and hindgut villus structure of 250 mg/kg garlicin is intact and the arrangement is neat and tight; the villus height of 250 mg/kg garlicin changed shorter, and the villus tip changed sharpened.Conclusion: 250 mg/kg garlicin improves the immune and digestive function in crucian carp. Effect of 500 mg/kg garlicin on immune and digestive function in crucian carp is not completely consistent. Such as the C3 and C4 activities of serum were weakened, the NO content of liver was decreased, the antioxidant and protease activity were weakened in Carassius auratus at 500 mg/kg garlicin, but the LZM activities of test group were enhanced, and the NO content of serum and spleen were improved. After switched to the basal diet, immune and digestive function of the experimental group fish were no significant difference.