山茱萸多糖对难治性癫痫幼鼠行为学和海马组织中多药耐药基因1b及主穹隆蛋白表达的影响

Effects of Cornus officinalis polysaccharide on behavior and multidrug resistance gene 1b and major vault protein expressions in hippocampus tissue of refractory epilepsy young rats

目的:探讨山茱萸多糖对难治性癫痫(RE)幼鼠行为学和海马组织中多药耐药基因1b(MDR1b)及主穹隆蛋白(MVP)的影响,并阐明其作用机制。方法:40只幼鼠建立RE模型,随机分为模型组(n=8)、低剂量山茱萸多糖组(n=9)、高剂量山茱萸多糖组(n=10)和阳性对照组(n=10),同时另设假手术组(n=10)。低和高剂量山茱萸多糖组幼鼠分别给予0.14和0.56 g·kg^(-1)山茱萸多糖灌胃,阳性对照组幼鼠给予154 mg·kg^(-1)拉莫三嗪灌胃,对照组和模型组幼鼠给予等量生理盐水灌胃。观察各组幼鼠癫痫行为学变化,HE染色观察各组幼鼠海马组织病理形态表现,酶联免疫吸附试验(ELISA)法检测各组幼鼠血清中肿瘤坏死因子α(TNF-α)和白细胞介素1β(IL-1β)水平,实时荧光定量PCR(RT-qPCR)和Western blotting法分别检测各组幼鼠海马组织中核因子κB(NF-κB)、MDR1b及MVP mRNA和蛋白表达水平。结果:与假手术组比较,模型组幼鼠癫痫发作总次数增加(P<0.05),总持续时间延长(P<0.05),血清中TNF-α和IL-1β水平、海马组织中NF-κB、MDR1b和MVP mRNA及蛋白表达水平升高(P<0.05)。与模型组比较,低和高剂量山茱萸多糖组及阳性对照组幼鼠癫痫发作总次数减少(P<0.05),总持续时间缩短(P<0.05),血清中TNF-α和IL-1β水平、海马组织中MDR1b、MVP mRNA和蛋白表达水平降低(P<0.05)。HE染色,假手术组幼鼠海马区细胞形态结构正常;模型组幼鼠海马区细胞排列紊乱,大量细胞呈空泡样变,可见大量核破裂和核固缩;低和高剂量山茱萸多糖组及阳性对照组幼鼠海马区细胞排列较为整齐,细胞轮廓较清晰,可见少量空泡变性、核破裂和核固缩。结论:山茱萸多糖可改善RE幼鼠癫痫发作情况,其机制可能与抑制MDR1b和MVP mRNA和蛋白表达有关。

Objective:To investigate the effects of Cornus officinalis polysaccharide on the behavior and the multidrug resistance gene 1 b(MDR1 b)and main vault protein(MVP)in hippocampus tissue of the refractory epilepsy(RE)young rats,and to clarify their mechanisms.Methods:A total of 40 young rats were used to establish the RE models and then they were randomly divided into model group(n=8),low dose of Cornus officinalis polysaccharide group(n=9),high dose of Cornus officinalis polysaccharide group(n=10),and positive control group(n=10);sham operation group was set up at the same time(n=10).The young rats in low and high doses of Cornus officinalis polysaccharide groups were given 0.14 and0.56 g·kg^(-1) Cornus officinalis polysaccharide by gavage,the young rats in positive control group were given 154 mg·kg^(-1) lamotrigine,and the young rats in control group and model group were given the same amount of normal saline.The epoleptic behavioral changes of the young rats in various groups were observed;the patholomorphology of hippocampus tissue of the young rats in various groups were observed by HE staining;the serum levels of tumor necrosis factor-α(TNF-α)and interleukin-1β(IL-1β)of the young rats in various groups were detected by ELISA method,and expression levels of nuclear factor-κB(NF-κB),MDR1 b,and MVP mRNA and proteins in hippocampus tissue of the young rats in various groups were detected by RT-qPCR and Western blotting methods.Results:Compared with sham operation group,the total number of seizures of the young rats in model group was increased(P<0.05),the total duration was prolonged(P<0.05),the serum levels of TNF-αand IL-1βwere increased(P<0.05),and the expression levels of NF-κB,MDR1 b,and MVP mRNA and proteins in hippocampus tissue of the young rats were increased(P<0.05).Compared with model group,the total number of seizures of the young rats in low and high doses of Cornus officinalis polysaccharide groups and positive control group was decreased(P<0.05),the total duration was shortened(P<0.05),the serum levels of TNF-αand IL-1βwere decreased(P<0.05),and the expression levels of MDR1 b,MVP mRNA and proteins in hippocampus tissue of the young rats were decreased(P<0.05).The HE staining results showed that the morphology and structure of the cells in hippocampus area of the young rats in sham operation group were normal;the cells in hippocampus area of the young rats in model group were arranged disorderly,a large number of cells showed vacuole-like changes,and a large number of nuclear ruptures and nuclear pyknosis were seen;the cells in hippocampus area of the young rats in low and high doses of Cornus officinalis polysacharide groups and positive control group were arranged neatly and the cell outline was clear,with a small amount of vacuolar degeneration,nuclear rupture,and nuclear pyknosis.Conclusion:Cornus officinalis polysaccharide can improve the seizure behavior of RE young rats,and its mechanism may be related to the inhibition of MDR1 b and MVP mRNA and protein expressions.