Jun Jiang

Bio: Jun Jiang is an academic researcher from Sichuan Agricultural University. The author has contributed to research in topics: Grass carp & Glutathione peroxidase. The author has an hindex of 50, co-authored 242 publications receiving 6865 citations. Previous affiliations of Jun Jiang include Chinese Ministry of Education.

Soybean β-conglycinin induces inflammation and oxidation and causes dysfunction of intestinal digestion and absorption in fish.

Abstract: β-conglycinin has been identified as one of the major feed allergens. However, studies of β-conglycinin on fish are scarce. This study investigated the effects of β-conglycinin on the growth, digestive and absorptive ability, inflammatory response, oxidative status and gene expression of juvenile Jian carp (Cyprinus carpio var. Jian) in vivo and their enterocytes in vitro. The results indicated that the specific growth rate (SGR), feed intake, and feed efficiency were reduced by β-conglycinin. In addition, activities of trypsin, chymotrypsin, lipase, creatine kinase, Na+,K+-ATPase and alkaline phosphatase in the intestine showed similar tendencies. The protein content of the hepatopancreas and intestines, and the weight and length of the intestines were all reduced by β-conglycinin. β-conglycinin increased lipid and protein oxidation in the detected tissues and cells. However, β-conglycinin decreased superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferase (GST), glutathione peroxidase (GPx) and glutathione reductase (GR) activities and glutathione (GSH) content in the intestine and enterocytes. Similar antioxidant activity in the hepatopancreas was observed, except for GST. The expression of target of rapamycin (TOR) gene was reduced by β-conglycinin. Furthermore, mRNA levels of interleukin-8 (IL-8), tumor necrosis factor-α (TNF-α), and transforming growth factor-β (TGF-β) genes were increased by β-conglycinin. However, β-conglycinin increased CuZnSOD, MnSOD, CAT, and GPx1b gene expression. In conclusion, this study indicates that β-conglycinin induces inflammation and oxidation, and causes dysfunction of intestinal digestion and absorption in fish, and finally reduces fish growth. The results of this study provide some information to the mechanism of β-conglycinin-induced negative effects.

Effects of Dietary Copper on Growth, Digestive, and Brush Border Enzyme Activities and Antioxidant Defense of Hepatopancreas and Intestine for Young Grass Carp (Ctenopharyngodon idella)

Abstract: To investigate the effects of dietary copper (Cu) on fish growth, digestive and absorptive enzyme activities, and antioxidant status in the hepatopancreas and intestine, young grass carp (Ctenopharyngodon idella) (282±2.8 g) were fed six diets containing 0.74 (basal diet), 2.26, 3.75, 5.25, 6.70, and 8.33 mg Cu /kg diet for 8 weeks. Results showed that percentage weight gain (PWG) and feed intake were increased with dietary Cu levels up to 3.75 mg/kg diet. In addition, the positive effects of dietary Cu at a level 3.75 or 5.25 mg/kg diet on trypsin, chymotrypsin, and lipase activities in the hepatopancreas and of Na+, K+-ATPase, alkaline phosphatase, creatine kinase, and γ-glutamyl transpeptidase activities in three intestine segments produced significantly (P<0.05) better feed efficiency (FE). However, amylase activity in the hepatopancreas was decreased by dietary Cu levels up to 3.75 mg/kg diet (P<0.05). In addition, dietary Cu at 3.75 or 5.25 mg/kg diet decreased malondialdehyde and protein carbonyl content partly by significantly (P<0.05) increasing the activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glutathione-S-transferase, and glutathione content in the hepatopancreas and intestine. Collectively, dietary Cu improved growth and digestive and absorptive capacity and decreased lipid peroxidation and protein oxidation partly by enhancing antioxidant defense in the hepatopancreas and intestine. The dietary Cu requirement for PWG, plasma ceruloplasmin activity, and FE of young grass carp (282–688 g) were 4.78, 4.95, and 4.70 mg/kg diet, respectively.