摘要
本试验旨在探讨黄芩苷对脂多糖(LPS)诱导的小鼠空肠炎症和氧化应激的缓解作用及其分子机制。将36只小鼠随机分为对照组、阴性对照组、模型组以及低、中、高剂量黄芩苷组,每组6只。适应性生长7 d后开始试验。对照组小鼠不作处理,阴性对照组和模型组小鼠每天灌胃0.2 mL磷酸盐缓冲液(PBS),黄芩苷组小鼠每天灌胃黄芩苷药液0.2 mL(根据小鼠体重计算黄芩苷用量,低剂量组为100 mg/kg BW,中剂量组为200 mg/kg BW,高剂量组为400 mg/kg BW),连续灌胃7 d,第7天给模型组、黄芩苷组小鼠腹腔注射0.2 mL LPS(3.5 mg/kg BW)。注射LPS 24 h后处死小鼠,取空肠进行形态学观察,检测空肠中炎性因子mRNA表达量和含量以及核因子-κB(NF-κB)和核因子-E2相关因子2(Nrf2)/血红素氧合酶-1(HO-1)信号通路关键蛋白表达量的变化。结果显示:相比于对照组,模型组小鼠空肠组织绒毛结构损伤,绒毛高度与隐窝深度比值显著降低(P<0.05),空肠中Toll样受体4(TLR4)的mRNA表达量显著升高(P<0.05),炎性因子[白细胞介素-6(IL-6)、白细胞介素-1β(IL-1β)、肿瘤坏死因子-α(TNF-α)]的mRNA表达量和含量显著升高(P<0.05),P65的蛋白表达量、磷酸化NF-κB抑制蛋白α(P-IκBα)/NF-κB抑制蛋白α(IκBα)和磷酸化P65(P-P65)/P65比值显著升高(P<0.05),超氧化物歧化酶(SOD)活性和HO-1的蛋白表达量显著降低(P<0.05)。相对于模型组,黄芩苷组小鼠空肠组织结构得到明显改善,绒毛高度与隐窝深度的比值显著升高(P<0.05),TLR4和炎性因子的mRNA表达量显著下降(P<0.05),P-65、P-IκBα的蛋白表达量显著降低(P<0.05);高剂量黄芩苷组空肠中SOD的活性显著升高(P<0.05);中、高剂量黄芩苷组空肠中HO-1和醌氧化还原酶-1(NQO-1)的mRNA表达量显著升高(P<0.05),HO-1和胞核Nrf2的蛋白表达量显著升高(P<0.05)。综上可知,在LPS构建的小鼠空肠炎症模型中,黄芩苷在适宜剂量内可以通过抑制NF-κB信号通路发挥抗炎症作用,通过激活Nrf2信号通路发挥抗氧化作用,推荐剂量为200 mg/kg BW。
This study mainly explored the alleviation effect and molecular mechanisms of baicalin on lipopolysaccharide(LPS)induced jejunal inflammation and oxidative stress in mice. Thirty-six mice were randomly divided into control group,negative control group,model group,low-dose baicalin group,medium-dose baicalin group and high-dose baicalin group with six mice in each group. Mice in the control group did not make any treatment,mice in the negative control group and model group were separately treated by continuous 7 days gavage with 0.2 mL phosphate buffer saline(PBS),and mice in baicalin groups were separately treated by continuous 7 days gavage with 0.2 mL different doses of baicalin(low-dose group,100 mg/kg BW;mediumdose group,200 mg/kg BW;high-dose group,400 mg/kg BW)solution,followed by intraperitoneal injection of 3.5 mg/kg BW LPS to construct the jejunal inflammation model of mice in the model group and the baicalin groups. The mice were sacrificed 24 h later,and the jejunum was harvested for morphological observation,and the expression level changes and the contents of inflammatory factors in the jejunum,and the expression level changes of key proteins of nuclear factor-κB(NF-κB)and nuclear factor E2-related factor 2(Nrf2)/heme oxygenase-1(HO-1)signaling pathways in the jejunum were detected. The results showed that compared with the control group,the jejunal tissue of mice in the model group had damage to the villus structure,and the villus height to crypt depth ratio was significant decreased(P<0.05),the Toll-like receptor 4(TLR4)mRNA expression level in the jejunum was significant increased(P<0.05),the inflammatory factors interleukin-6(IL-6),interleukin-1β (IL-1β),tumor necrosis factor-α (TNF-α)mRNA expression levels and contents were significantly increased(P<0.05),the P65 protein expression level,and the ratios of phosphorylated inhibitor of nuclear factor-kappa Bα (P-IκBα)/inhibitor of nuclear factor-kappa Bα (IκBα)and phosphorylated P65(P-P65)/P65 were significantly increased(P<0.05),and the superoxide dismutase(SOD)activity and HO-1 protein expression level were significantly reduced(P<0.05). Relative to the model group,the histological structure of the jejunum in mice was obviously improved in the baicalin groups,with a significant higher ratio of villus height to crypt depth,and the mRNA expression levels of TLR4 and inflammatory factors(P<0.05),and the protein expression levels of P-65 and P-IκBαwere significantly decreased(P <0.05);the SOD activity in the jejunum in high-dose baicalin group was significantly increased(P<0.05);the mRNA expression levels of HO-1 and quinone oxidoreductase-1(NQO-1)in the jejunum in the high-dose baicalin group and medium-dose baicalin group were significantly increased(P<0.05),and the protein expression levels of nuclear Nrf2 and HO-1 were significantly elevated(P<0.05). In conclusion,in a jejunal inflammation model of mice introduced by LPS,baicalin at an optimum dose can exert anti-inflammatory function by inhibiting NF-κB pathway and play antioxidant function by activating Nrf2 signaling pathway. The recommended dose is 200 mg/kg BW.[Chinese Journal of Animal Nutrition,2022,34(2):1217-1229]
作者
鲍明隆
孙心怡
梁梅
巨向红
雍艳红
马兴斌
于志超
郭依莹
刘晓曦
BAO Minglong;SUN Xinyi;LIANG Mei;JU Xianghong;YONG Yanhong;MA Xingbin;YU Zhichao;GUO Yiying;LIU Xiaoxi(Department of Veterinary Medicine,College of Coastal Agricultural Sciences,Guangdong Ocean University,Zhanjiang 524000,China)
出处
《动物营养学报》
CAS
CSCD
北大核心
2022年第2期1217-1229,共13页
CHINESE JOURNAL OF ANIMAL NUTRITION
基金
国家自然科学基金青年科学基金项目(31902314)
广东省自然科学基金项目(2019A1515011142)
深圳市基础研究专项面上项目(JCYJ20190813142005766)
广东海洋大学南海学者计划(002029002005)
广东海洋大学博士启动费及研究生培养项目(101402/R17088)
广东海洋大学“创新强校”工程专项(GDOU230419057)
广东海洋大学2020年校级大学生创新训练项目(CXXL2020170)。
关键词
小鼠
黄芩苷
信号通路
空肠炎症
氧化应激
mice
baicalin
signaling pathway
jejunal inflammatory
oxidative stress
