Yang Liu, Yuan Yajing, Wu Yue
Department of Anesthesiology, the First Affiliated Hospital of Dalian Medical University, Dalian 116021, Liaoning, China.
Department of Anesthesiology, Tianjin Medical University Cancer Institute and Hospital, Tianjin 300000, China. Corresponding author: Wu Yue, Email:
Zhonghua Wei Zhong Bing Ji Jiu Yi Xue. 2019 Jun;31(6):746-749. doi: 10.3760/cma.j.issn.2095-4352.2019.06.017.
To investigate the protective effect of Polyphyllin I (PPI) on myocardial ischemia/reperfusion (I/R) injury in rats and its mechanism.
The 6-month-old Sprague-Dawley (SD) rats were divided into sham operation group (Sham group), I/R model group, and low, medium, high dose PPI groups according to the random number table method, with 10 in each group. The rat myocardial I/R model was prepared by ligating the left anterior descending branch of the coronary artery by 30 minutes and reperfusion by 120 minutes. Sham group was exposure to open chest without ligation. Low, medium, high dose PPI groups were injected with PPI 75, 150, 300 mg×kg×d in front of the film for 4 weeks; dimethyl sulfoxide (DMSO) was gastric infused in the I/R model group. After the end of reperfusion, the myocardial infarction area (IA) was determined by triphenyltetrazole (TTC) and Evans blue (EB) staining; the apoptosis of myocardial cells was detected by TdT-mediated dUTP nick end labeling stain (TUNEL); the expressions of apoptosis related protein (Bax, Bcl-2), and cytoplasmic and nucleus expressions of P65 in nuclear factor-ΚB (NF-ΚB) signal pathway were detected by Western Blot.
Compared with the Sham group, the myocardial IA was significantly increased in the I/R model group, the apoptosis rate of myocardial cells was significantly increased, the expression of Bcl-2 was significantly decreased, and the expression of Bax was significantly increased, and the intranuclear transfer of P65 was significantly increased. Compared with the I/R model group, low, medium and high dose PPI pretreatment could significantly reduce the myocardial IA [(21.6±0.9)%, (14.3±1.6)%, (15.0±0.8)% vs. (29.6±1.4)%], the apoptosis rate of myocardial cells was significantly decreased [(38.6±1.9)%, (24.3±2.6)%, (26.3±2.8)% vs. (56.8±2.4)%], the protein expression of Bcl-2 was significantly increased, while the protein expression of Bax was significantly decreased (Bcl-2/GAPDH: 0.24±0.07, 0.36±0.02, 0.34±0.09 vs. 0.13±0.04; Bax/GAPDH: 0.39±0.10, 0.21±0.08, 0.23±0.06 vs. 0.53±0.12); and P65 nuclear transfer was significantly decreased after middle and high dose PPI pretreatment [nuclear P65/Histone 3: 0.49±0.09, 0.51±0.06 vs. 0.83±0.11; cytoplasmic P65/GAPDH: 0.31±0.03, 0.30±0.05 vs. 0.22±0.07], with statistically significant differences (all P < 0.05). However, there was no significant difference in each index between the medium and high dose PPI groups (all P > 0.05).
PPI alleviates myocardial I/R injury in rats via NF-ΚB signal pathway, and the PPI effect of 150 mg×kg×d is most especially significant.
探讨重楼皂苷Ⅰ（PPI）对大鼠心肌缺血/再灌注（I/R）损伤的保护作用及其机制。
将6月龄Sprague-Dawley（SD）大鼠按随机数字表法分为假手术组（Sham组）、I/R模型组、PPI低、中、高剂量组，每组10只。采用结扎冠状动脉左前降支30分钟再灌注120分钟的方法制备大鼠心肌I/R模型。Sham组仅开胸不结扎血管。PPI低、中、高剂量组于造模前4周分别给予PPI 75、150、300mg·kg·d灌胃；I/R模型组给予二甲基亚砜（DMSO）灌胃。再灌注结束后，用三苯基四氮唑（TTC）和伊文思蓝（EB）染色法测定心肌梗死面积（IA）；采用TdT介导的dUTP缺口末端标记染色法（TUNEL）检测心肌细胞凋亡；用蛋白质免疫印迹法检测凋亡相关蛋白（Bax及Bcl-2）表达及核因子-κB（NF-κB）信号通路中P65的胞质及核内表达。
与Sham组比较，I/R模型组心肌IA显著增大，心肌细胞凋亡率显著升高，Bcl-2表达显著降低，Bax表达显著升高，P65核转位显著增加。与I/R模型组比较，PPI低、中、高剂量预处理均可显著降低心肌IA[（21.6±0.9）%、（14.3±1.6）%、（15.0±0.8）%比（29.6±1.4）%]，显著降低心肌细胞凋亡率[（38.6±1.9）%、（24.3±2.6）%、（26.3±2.8）%比（56.8±2.4）%]，显著增加Bcl-2蛋白表达，显著降低Bax蛋白表达（Bcl-2/GAPDH：0.24±0.07、0.36±0.02、0.34±0.09比0.13±0.04；Bax/GAPDH：0.39±0.10、0.21±0.08、0.23±0.06比0.53±0.12）；中、高剂量PPI预处理后P65核转位显著降低[核内P65/组蛋白3：0.49±0.09、0.51±0.06比0.83±0.11；胞质P65/GAPDH：0.31±0.03、0.3
