人参皂苷Rb3联合β-细辛醚对血管性痴呆模型小鼠的改善作用及其机制研究

Study on the Improvement Effect of Ginsenoside Rb Combined withβ-asarone on Vascular Dementia Model Mice and Its Mechanism

目的:研究人参皂苷Rb3联合β-细辛醚对血管性痴呆(VD)模型小鼠的改善作用及其机制。方法:将ICR小鼠随机分为模型组、人参皂苷Rb3组(10 mg/kg)、β-细辛醚组(10 mg/kg)、联合用药组(人参皂苷Rb310 mg/kg+β-细辛醚10 mg/kg)、阳性对照组(盐酸多奈哌齐1 mg/kg)和蛋白激酶B(Akt)抑制剂组(LY294002,1 mg/kg),并设假手术组,每组10只。除假手术组外,其余各组小鼠均按四血管阻断法复制VD模型。造模后,假手术组和模型组小鼠灌胃等体积生理盐水,Akt抑制剂组腹腔注射相应药物,其余各组均灌胃相应药物,每日2次,连续30 d。末次给药后,采用避暗实验检测各组小鼠的学习记忆能力,酶联免疫吸附测定法检测其海马组织中4-羟基壬烯酸(4-HNE)、8-羟基脱氧鸟苷(8-OHdG)、活性氧(ROS)含量,实时荧光定量聚合酶链式反应技术检测海马组织中B细胞淋巴瘤2(Bcl-2)及其X蛋白(Bax)mRNA的表达,免疫荧光法检测皮质中Bcl-2蛋白的表达,Western blotting法检测海马组织中Bcl-2、Bax蛋白的表达。结果:与假手术组比较,模型组小鼠的避暗潜伏期显著缩短,错误次数显著增多,4-HNE、8-OHdG、ROS含量以及Bax mRNA、蛋白的表达水平均显著升高,Bcl-2 mRNA、蛋白的表达水平均显著降低(P<0.01)。与模型组比较,人参皂苷Rb3组、β-细辛醚组、联合用药组和阳性对照组小鼠的避暗潜伏期均显著延长,错误次数均显著减少,4-HNE、8-OHdG、ROS含量以及Bax m RNA、蛋白的表达水平均显著降低,Bcl-2 mRNA、蛋白的表达水平均显著升高,且联合用药组的效果最为显著(P<0.05或P<0.01);而Akt抑制剂组小鼠的避暗潜伏期显著缩短,错误次数显著增多,4-HNE、8-OHdG、ROS含量以及Bax mRNA、蛋白的表达水平均显著升高,Bcl-2 mRNA、蛋白的表达水平均显著降低(P<0.05)。结论:人参皂苷Rb3联合β-细辛醚对VD模型小鼠学习记忆能力具有一定改善作用,且效果优于各化合物单用。这种作用可能与抗氧化应激、抗海马组织凋亡有关。

OBJECTIVE:To study the improvement effects of ginsenoside Rb3 combined withβ-asarone on vascular dementia(VD)model mice and its mechanism.METHODS:ICR mice were randomly divided into model group,ginsenoside Rb3 group(10 mg/kg),β-asarone group(10 mg/kg),drug combination group(ginsenoside Rb310 mg/kg+β-asarone 10 mg/kg),positive control group(donepezil hydrochloride 1 mg/kg)and Akt inhibitor group(LY294002,1 mg/kg),and sham operation group was set up,with 10 mice in each group.Except for sham operation group,VD model was induced by four vessel occlusion method in other groups.After modeling,sham operation group and model group were given constant volume of normal saline,Akt inhibitor group was given relevant medicine intraperitoneally,and other groups were given relevant medicine intragastrically,twice a day,for consecutive 30 d.After last administration,the learning and memory ability of mice was detected by avoiding darkness test.The contents of 4-hydroxydecenoic acid(4-HNE),8-hydroxydeoxyguanosine(8-OHdG)and reactive oxygen species(ROS)in hippocampus was detected by ELISA.RT-PCR assay was used to detect the mRNA expression of Bcl-2 and Bax in hippocampus.The protein expression of Bcl-2 in cortex was detected by immunofluorescence method.Western blotting assay was used to detect the protein expression of Bcl-2 and Bax in hippocampus.RESULTS:Compared with sham operation group,the incubation period of avoiding darkness test in model group was shortened significantly;and the number of errors was increased significantly;4-HNE,8-OHdG and ROS contents,mRNA and protein expression of Bax were increased significantly,and mRNA and protein expression of Bcl-2 was decreased significantly(P<0.01).Compared with model group,the incubation period of avoiding darkness test was prolonged significantly in ginsenoside Rb3 group,β-asarone group,drug combination group and positive control group,the number of errors was decreased significantly;4-HNE,8-OHdG,ROS contents,mRNA and protein expression of Bax were decreased significantly,and mRNA and protein expression of Bcl-2 were increased significantly,especially in drug combination group(P<0.05 or P<0.01).But the incubation period of avoiding darkness test was shortened significantly in Akt inhibitor group,and the number of errors was increased significantly;4-HNE,8-OHdG,ROS contents,mRNA and protein expression of Bax were increased significantly,and mRNA and protein expression of Bcl-2 were decreased significantly(P<0.05).CONCLUSIONS:Ginsenoside Rb3 combined withβ-asarone has a protective effect on VD model mice,and the effect was better than that of each compound alone.The mechanism of which may be associated with antioxidative stress and anti-apoptosis of hippocampus.