羟基红花黄色素A对大鼠避水应激所致结肠高动力的抑制作用及其机制

目的通过体内和体外研究探讨羟基红花黄色素(hydroxy safflower yellow A,HSYA)在大鼠应激性结肠高动力中的作用及其可能的作用机制。方法将15只雄性Wistar大鼠分为3组,分别为:SWAS(假性避水应激)组、WAS(避水应激)组、WAS+HSYA组,每组5只。WAS组和SWAS组大鼠连续10 d每天分别暴露于避水应激和假性避水应激中1 h,建立大鼠模型;WAS+HSYA组大鼠于每天进行避水应激前半小时,以60 mg/kg的HSYA灌胃,而WAS组以相同的生理盐水灌胃,SWAS组则不做处理。整个实验期间,分别记录各组大鼠的每天粪球排出量。于实验第11天,大鼠处死后取近端结肠制备肌条,以张力换能器测定结肠平滑肌肌张力变化。另取正常大鼠离体近端结肠制备肌条,以张力换能器测定结肠平滑肌肌张力变化,当出现一段规律收缩信号后,分别进行其他的相关处理:(1)加入浓度梯度的HSYA溶液(终浓度分别为0.6、1.2、1.8 mol/L),观察并记录其自发性收缩活性变化;(2)用1μmol/L TTX孵育肌条10 min,再以浓度梯度的HSYA溶液处理肌条,观察并记录其自发性收缩活性变化;(3)用30μmol/L Tak-242孵育肌条15 min,再以浓度梯度的HSYA溶液处理肌条,观察并记录其自发性收缩活性的变化。采用SPSS 26.0统计软件、Graphpad 8.0软件对实验所得数据进行分析。结果避水应激诱发大鼠结肠动力亢进。HSYA明显抑制结肠肌条收缩活性,这种作用未被TTX阻断,而TLR4受体拮抗剂Tak-242能显著阻断HSYA对结肠肌条收缩活性的抑制作用。结论 HSYA能逆转应激性结肠动力亢进,这种效应可能与TLR4受体通路有关。

Inhibitory effect of hydroxy safflower yellow A on colon hypermotility induced by water avoidance stress in rats and its mechanism

Objective To investigate the role of hydroxy safflower yellow A(HSYA) in stress hypermotility of the colon in rats and its possible mechanism through in vivo and in vitro studies. Methods Fifteen male Wistar rats were divided into 3 groups: SWAS(sham water avoidance stress) group, WAS(water avoidance stress) group, WAS+HSYA group, 5 rats in each group. Rats in WAS group and SWAS group were exposed to water avoidance stress and pseudo water avoidance stress for 1 hour each day for 10 consecutive days, respectively, to establish rat models. The rats in WAS+HSYA group were gavaged with 60 mg/kg HSYA half an hour before the daily water avoidance stress, while the rats in WAS group were gavaged with the same normal saline, and the rats in SWAS group were not treated. During the whole experiment, the daily fecal pellet output of rats in each group was recorded. On the 11 th day of the experiment, muscle strips were prepared from the proximal colon of the rats after death, and the changes in muscle tension of the colon smooth muscle were measured with a tension transducer. In addition, muscle strips were prepared from the proximal colon of normal rats in vitro, and the changes in muscle tension of colon smooth muscle were measured with a tension transducer. When a regular contraction signal appeared, other related processing could be performed respectively:(1) adding HSYA solution with a concentration gradient(the final concentration was 0.6, 1.2, 1.8 mol/L, respectively) to observe and record the changes in its spontaneous contractile activity;(2) the muscle strips were incubated with 1 μmol/L TTX for 10 minutes, and then treated with HSYA solution with concentration gradient. The changes of spontaneous contractile activity were observed and recorded;(3) the muscle strip was incubated with 30 μmol/L Tak-242 for 15 minutes, and then treated with HSYA solution with concentration gradient. The changes of spontaneous contractile activity of the muscle strip were observed and recorded. SPSS 26.0 statistical software and Grappad 8.0 were used to analyze the experimental data. Results HSYA significantly inhibited the contractile activity of colon muscle strips, which was not blocked by TTX, while the inhibitory effect of HSYA on the contractile activity of colon muscle strips was significantly blocked by TLR4 receptor antagonist Tak-242. Conclusion HSYA can reverse stress-induced hyperdynamic colon, and this effect may be related to the TLR4 receptor pathway.