Abstract This research was directed to examine the influences of dietary silymarin supplementation in growth, intestinal mucosal permeability, histology and apical junctional complex (AJC) (including tight junction (TJ) and adherents junction (AJ)), as well as the appropriate level of silymarin supplementation to juvenile grass carp (Ctenopharyngodon idella). Fish was fed at 6 graded levels of silymarin (0, 20, 40, 60, 80 and 100 mg/kg) for 70 days. Our results showed that, dietary appropriate silymarin supplementation (1) enhanced growth performance and promoted intestinal growth of fish; (2) reduced intestinal mucosa permeability and improved intestinal apparent morphology of fish; (3) ameliorated intestinal AJC partly related to the enhancement of barrier-forming TJ-related proteins (TJs) and AJ-related proteins (AJs) mRNA levels and the reduction of pore-forming TJs mRNA levels through suppressing RhoA/ROCK signalling pathway (RhoA/ROCK/MLCK/NMII) in fish intestine. Interestingly, silymarin supplementation in diet did not affect the mRNA levels of ZO-2b (not in DI), claudin-7a, −7b, and -15b in fish intestine. Ultimately, based on the growth indicator PWG and intestinal mucosa permeability index serum D-lactate, the appropriate levels of silymarin supplementation to juvenile grass carp (24–223 g) were assessed to be 57.63 and 57.50 mg/kg diet, respectively.

中文翻译：

---

饲料中添加水飞蓟素可提高草鱼幼鱼（Ctenopharyngodon idella）的生长性能并改善肠道顶端连接复合体

摘要 本研究旨在检查膳食水飞蓟素补充剂对生长、肠粘膜通透性、组织学和顶端连接复合体 (AJC)（包括紧密连接 (TJ) 和粘附连接 (AJ)）的影响，以及适当水平的草鱼幼鱼（Ctenopharyngodon idella）的水飞蓟素补充剂。鱼以 6 个等级的水飞蓟素水平（0、20、40、60、80 和 100 毫克/千克）喂养 70 天。我们的研究结果表明，膳食中适当的水飞蓟素补充剂 (1) 提高了鱼类的生长性能并促进了肠道的生长；(2)降低肠黏膜通透性，改善鱼肠表观形态；(3) 改善肠道AJC 部分与通过抑制RhoA/ROCK 信号通路增强形成屏障的TJ 相关蛋白(TJs) 和AJ 相关蛋白(AJs) mRNA 水平和降低成孔TJs mRNA 水平有关。 RhoA/ROCK/MLCK/NMII) 在鱼肠中。有趣的是，饮食中补充水飞蓟素不影响鱼肠中 ZO-2b（不在 DI 中）、claudin-7a、-7b 和 -15b 的 mRNA 水平。最终，根据生长指标 PWG 和肠黏膜通透性指数血清 D-乳酸，评估草鱼幼鱼（24-223 克）的适当水飞蓟素补充水平分别为 57.63 和 57.50 毫克/千克饲料。饮食中补充水飞蓟素不影响鱼肠中 ZO-2b（不在 DI 中）、claudin-7a、-7b 和 -15b 的 mRNA 水平。最终，根据生长指标 PWG 和肠黏膜通透性指数血清 D-乳酸，评估草鱼幼鱼（24-223 克）的适当水飞蓟素补充水平分别为 57.63 和 57.50 毫克/千克饲料。饮食中补充水飞蓟素不影响鱼肠中 ZO-2b（不在 DI 中）、claudin-7a、-7b 和 -15b 的 mRNA 水平。最终，根据生长指标 PWG 和肠黏膜通透性指数血清 D-乳酸，评估草鱼幼鱼（24-223 克）的适当水飞蓟素补充水平分别为 57.63 和 57.50 毫克/千克饲料。