洗心汤通过增强神经保护作用和抑制神经炎症改善SAMP8学习记忆能力

Xixin Decoction improves learning and memory ability of SAMP8 by enhancing neuroprotective effect and inhibiting neuroinflammation

探讨洗心汤(Xixin Decoction,XXD)改善阿尔茨海默病(Alzheimer′s disease,AD)模型快速老化模型小鼠(senescence-accelerated mouse-prone 8,SAMP8)学习记忆能力的可能作用,以及在增强神经保护作用和减轻神经炎症方面的相关机制。40只SAMP8随机分为模型组(10 mL·kg^(-1)·d^(-1))、益生菌组(probiotics,0.39 g·kg^(-1)·d^(-1))、洗心汤颗粒高剂量组(5.07 g·kg^(-1)·d^(-1))、洗心汤颗粒中剂量组(2.535 g·kg^(-1)·d^(-1))、洗心汤颗粒低剂量组(1.2675 g·kg^(-1)·d^(-1)),8只相同周龄和相同品系的对抗快速老化小鼠(senescence-accelerated mouse-resistant 1,SAMR1)设为对照组(10 mL·kg^(-1)·d^(-1))。灌胃10周后,采用Morris水迷宫测试治疗后小鼠空间学习记忆能力变化,采用免疫荧光染色法检测小鼠海马CA1区人晚期糖基化终末产物受体(receptor for advanced glycation end products,AGER)、Toll样受体1(Toll-like receptors1,TLR1)和Toll样受体2(Toll-like receptors 2,TLR2)阳性表达水平,采用蛋白免疫印迹(Western blot)法检测小鼠海马沉默信息调节因子2相关酶1(silencing information regulator 2 related enzyme 1,SIRT1)、AGER、TLR1和TLR2蛋白表达水平,酶联免疫吸附测定(enzyme linked immunosorbent assay,ELISA)法检测海马中Aβ_(1-42)的表达水平以及血清和海马中核因子κB(nuclear factor kappa B,NF-κB)p65、NOD样受体蛋白3(NOD-like receptor protein 3,NLRP3)、肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)和白细胞介素^(-1)β(interleukin^(-1)β,IL^(-1)β)的水平。结果显示,与模型组相比,洗心汤可显著改善SAMP8的空间学习记忆能力,提高海马区神经保护因子的表达,降低神经炎症相关因子的水平,并抑制Aβ_(1-42)的表达。尤其是高剂量洗心汤显著增加了海马中SIRT1的表达,同时显著降低了SAMP8海马和血清中NF-κB p65、NLRP3、TNF-α、IL^(-1)β的水平,并降低了海马中AGER、TLR1和TLR2的表达(P<0.05或P<0.01)。综上,洗心汤可能通过增强神经保护作用和抑制神经炎症改善AD模型SAMP8空间学习记忆能力。

This study aimed to explore the possible effect of Xixin Decoction(XXD)on the learning and memory ability of Alzheimer's disease(AD)model senescence-accelerated mouse-prone 8(SAMP8)and the related mechanism in enhancing neuroprotective effect and reducing neuroinflammation.Forty SAMP8 were randomly divided into a model group(10 mL·kg^(-1)·d^(-1)),a probiotics group(0.39 g·kg^(-1)·d^(-1)),a high-dose group of XXD granules(H-XXD,5.07 g·kg^(-1)·d^(-1)),a medium-dose group of XXD granules(M-XXD,2.535 g·kg^(-1)·d^(-1)),and a low-dose group of XXD granules(L-XXD,1.2675 g·kg^(-1)·d^(-1)).Eight senescence-accelerated mouse-resistant 1(SAMR1)of the same age and strain were assigned to the control group(10 mL·kg^(-1)·d^(-1)).After ten weeks of intragastric administration,the Morris water maze was used to test the changes in spatial learning and memory ability of mice after treatment.Meanwhile,immunofluorescence staining was used to detect the positive expression of receptor for advanced glycation end products(AGER),Toll-like receptor 1(TLR1),and Toll-like receptor 2(TLR2)in the hippocampal CA1 region of mice.Western blot was employed to test the protein expression levels of silencing information regulator 2 related enzyme 1(SIRT1),AGER,TLR1,and TLR2 in the hippocampus of mice.Enzyme linked immunosorbent assay(ELISA)was applied to assess the levels of Aβ_(1-42)in the hippocampus of mice and the levels of nuclear factorκB p65(NF-κB p65),NOD-like receptor protein 3(NLRP3),tumor necrosis factor-α(TNF-α),and interleukin^(-1)β(IL^(-1)β)in the serum and hippocampus of mice.Compared with the model group,XXD significantly improved the spatial learning and memory ability of SAMP8,increased the expression of neuroprotective factors in the hippocampus,decreased the levels of neuroinflammatory factors,and inhibited the expression of Aβ_(1-42).In particular,H-XXD significantly increased the expression of SIRT1 in the hippocampus of mice,reduced the expression levels of NF-κB p65,NLRP3,TNF-α,and IL^(-1)βin the serum and hippocampus of mice,and decreased the expression of AGER,TLR1,and TLR2 in the hippocampus of mice(P<0.05 or P<0.01).XXD may improve the spatial learning and memory ability of AD model SAMP8 by enhancing the neuroprotective effect and inhibiting neuroinflammation.