College of Veterinary Medicine , Nanjing Agricultural University , Nanjing 210095 , People's Republic of China.
J Agric Food Chem. 2018 Mar 7;66(9):2101-2107. doi: 10.1021/acs.jafc.7b05882. Epub 2018 Feb 22.
Eighteen lactating goats (38.86 ± 2.06 kg) were randomly allocated to three groups. One group was fed a low-concentrate (LC) diet (forage:concentrate = 6:4), while the other two groups were fed a high-concentrate (HC) diet (forage:concentrate = 4:6) or an HC diet supplemented with sodium butyrate (BHC) for 20 weeks. Samples of ruminal fluid, milk, hepatic blood plasma, and mammary gland tissue were prepared for the experimental analysis. The lipopolysaccharide (LPS) concentration, caspase-3 and -8 enzymatic activity, caspase-3 and -8 mRNA expression, and NF-κB (p65), phosphorylated-p65, bax, cytochrome c, and caspase-3 protein expression were higher in the HC group than those in the LC group; however, the levels of these parameters were lower in the BHC group than those in the HC group. Moreover, bcl-2 mRNA and protein expression was higher in the BHC group than that in the HC or LC groups, and no significant difference was observed between the HC and LC groups. Thus, feeding lactating goats an HC diet induces apoptosis in mammary cells, and supplementing the diet with sodium butyrate reduces the concentrations of LPS and proinflammatory cytokines, subsequently attenuating the activation of NF-κB and caspase-3 and eventually inhibiting apoptosis in mammary cells.
十八头泌乳山羊（38.86±2.06kg）被随机分为三组。一组饲喂低精料（LC）日粮（粗饲料：精料=6：4），另外两组饲喂高精料（HC）日粮（粗饲料：精料=4：6）或补充丁酸钠的 HC 日粮（BHC），持续 20 周。准备瘤胃液、奶样、肝血血浆和乳腺组织样本进行实验分析。HC 组的脂多糖（LPS）浓度、caspase-3 和 -8 酶活性、caspase-3 和 -8mRNA 表达、NF-κB（p65）、磷酸化-p65、bax、细胞色素 c 和 caspase-3 蛋白表达均高于 LC 组；然而，BHC 组的这些参数水平低于 HC 组。此外，BHC 组的 bcl-2mRNA 和蛋白表达高于 HC 或 LC 组，而 HC 和 LC 组之间无显著差异。因此，给泌乳山羊饲喂 HC 日粮会诱导乳腺细胞凋亡，日粮中补充丁酸钠可降低 LPS 和促炎细胞因子的浓度，从而减弱 NF-κB 和 caspase-3 的激活，最终抑制乳腺细胞凋亡。
