知母皂苷元对谷氨酸引起的皮层神经元损伤的保护作用研究

目的观察知母皂苷元(Sarsasapogenin,SAR)对谷氨酸引起的皮层神经元损伤的保护作用。方法大鼠乳鼠大脑皮层神经元,培养7 d后用于实验。倒置相差显微镜观察神经元树突生长发育情况;用MTT法测定细胞活力;Ho-echst33258核染色观察细胞凋亡的形态学改变;Western印迹法检测神经元SYP、caspase-3、钙蛋白酶Ⅰ蛋白表达水平。结果形态学观察结果显示谷氨酸可明显抑制神经元树突的生长发育,表现为神经元树突总长度明显降低、一级树突数目明显减少、最大分支级数明显减少及胞体面积缩小。SAR(10、30、100μmol.L-1)可明显抑制谷氨酸对神经元树突生长发育的抑制作用,并呈明显浓度依赖。MTT和Ho-echst33258核染色结果显示谷氨酸可降低神经元细胞活力及增加神经元细胞凋亡百分比。SAR(10、30、100μmol.L-1)能明显对抗谷氨酸引起的神经元细胞活力降低及细胞凋亡百分比增加。Western印迹结果显示谷氨酸可明显降低SYP蛋白表达水平及增加活性caspase-3、钙蛋白酶Ⅰ蛋白表达水平。SAR(10、30、100μmol.L-1)可明显对抗谷氨酸引起SYP蛋白表达降低及活性caspase-3、钙蛋白酶Ⅰ蛋白表达增加。结论知母皂苷元能够明显对抗谷氨酸引起的皮层神经元损伤作用。     

吡格列酮对谷氨酸诱导的皮质神经元损伤的保护作用

目的观察吡格列酮对谷氨酸所致培养皮质神经元损伤的保护作用及其机制。方法乳大鼠大脑皮质神经元,培养7d后用于实验。实验分为对照组,加入0.1%二甲亚砜;谷氨酸损伤组,加入谷氨酸100μmol·L-1作用2h或24h;吡格列酮组,先分别加入吡格列酮0.01,0.1和1μmol·L-1作用1h,然后加入谷氨酸;谷氨酸+吡格列酮+GW9662组,先加入GW966210μmol·L-1作用30min,然后加入吡格列酮1μmol·L-1,作用1h后加入谷氨酸。MTT法测定细胞存活率;Hoechst33258核染色观察细胞凋亡的形态学改变;Western印迹法检测Bcl-2蛋白、钙蛋白酶Ⅰ蛋白和磷酸化c-Jun氨基端激酶1(JNK1)表达水平;免疫荧光染色法检测钙蛋白酶Ⅰ及磷酸化活化转录因子2(ATF2)表达。结果谷氨酸作用24h可使体外培养神经元细胞存活率明显下降,从对照组的(100.0±15.4)%降低至(71.5±6.1)%;细胞凋亡百分率明显增加,从对照组的(8.7±1.3)%增加至(35.4±6.9)%;磷酸化JNK1、钙蛋白酶Ⅰ蛋白和磷酸化ATF2表达增加,Bcl-2蛋白表达水平降低。吡格列酮0.1及1μmol·L-1明显对抗谷氨酸引起的神经元损伤,神经元细胞存活率分别为(91.1±4.7)%和(96.6±3.4)%;细胞凋亡百分率分别为(15.5±3.8)%和(9.2±0.9)%。过氧化物酶体增殖物激活受体γ(PPARγ)的特异性阻断剂GW9662不能拮抗吡格列酮对神经元的保护作用,谷氨酸+吡格列酮+GW9662组细胞存活率为(91.3±6.7)%,细胞凋亡百分率为(10.2±1.8)%。单独应用GW966210μmol·L-1对细胞存活率和细胞凋亡百分率没有影响。吡格列酮也可抑制谷氨酸引起的磷酸化JNK1、磷酸化ATF2、钙蛋白酶Ⅰ表达增多及Bcl-2蛋白表达减少。结论吡格列酮对谷氨酸引起的培养皮质神经元损伤具有明显的保护作用,可能与吡格列酮抑制磷酸化JNK1和钙蛋白酶Ⅰ表达,以及增强Bcl-2蛋白表达有关,与PPARγ激活无关。     

吡格列酮对Aβ_(25-35)引起的皮层神经元损伤保护作用部分机制的研究

目的研究吡格列酮对抗淀粉样β蛋白片段25-35(Amyloid-β,Aβ25-35)所致培养皮层神经元损伤作用的机制。方法取培养7d大鼠乳鼠大脑皮层神经元,Aβ组加入Aβ25-35(20μmol.L-1)作用24h;吡格列酮组和各种阻断剂组,先加入吡格列酮(0.1、1、10μmol.L-1)或各种阻断剂作用1h,然后加入Aβ25-35(20μmol.L-1)作用24h;正常对照组加入等量培养基。MTT法测定细胞存活率;免疫荧光染色法测定活性的caspase-3细胞内定位;Westernblot检测活性的caspase-3表达水平;Griess法测定培养细胞上清液中一氧化氮(NO)含量。结果神经元经NSE和NF200免疫荧光鉴定,其阳性率可达90%以上。Aβ25-35(20μmol.L-1)可使神经元细胞存活率下降、caspase-3表达明显增加,同时神经元培养液中的NO含量也明显增加。吡格列酮可明显抑制Aβ25-35诱导的神经元细胞存活率下降、抑制caspase-3表达的增加,吡格列酮还可明显抑制Aβ25-35诱导的神经元培养液中NO含量增加,且呈浓度依赖性。GW9662(10μmol.L-1)能明显对抗吡格列酮对Aβ25-35诱导的神经元细胞存活率下降、活性的caspase-3表达增加、NO增加的抑制作用。SP600125(5μmol.L-1)、SB203580(20μmol.L-1)和SMT(1mmol.L-1)可明显对抗Aβ25-35诱导的神经元细胞存活率下降及培养液中NO含量增加。结论吡格列酮能够明显的抑制Aβ25-35引起的皮层神经元损伤作用,这种作用可能与激活PPARγ受体、抑制JNK信号传导通路和p38MAPK信号传导通路有关。     

葛根素保护双氧水诱导的SH-SY5Y细胞凋亡

目的探讨葛根素对双氧水(H_2O_2)诱导的SH-SY5Y细胞凋亡的保护作用及其机制。方法建立体外神经元损伤模型,MTT法观察细胞存活率;Hoechst 33342染色观察细胞核改变;JC-1染色检测细胞线粒体膜电位的改变;酶活性检测线粒体caspase-3和caspase-9的变化;Western blot检测细胞中Bcl-2、Bax、p-Akt、Akt蛋白的表达。结果与H_2O_2模型组相比,葛根素预处理能明显改善H_2O_2诱导的SHSY5Y细胞存活率下降(P<0.05),缓解H_2O_2引起的线粒体膜电位的下降(P<0.01),抑制caspase-3和caspase-9的酶活性(P<0.01),减少H_2O_2诱导的细胞凋亡。此外,葛根素还促进细胞内p-Akt、Bcl-2蛋白表达,抑制Bax蛋白表达,而这种作用能被PI3K/Akt的抑制剂LY294002所抑制。结论葛根素可保护H_2O_2诱导的SH-SY5Y细胞凋亡,这种保护作用可能是通过激活PI3K/Akt信号通路实现的。     

阿托伐他汀对人胃癌AGS细胞增殖、自噬和糖代谢的影响及机制

目的 探究阿托伐他汀对人胃癌AGS细胞增殖、自噬和糖代谢的影响及机制。方法 通过预实验考察低、中、高浓度（12.5、25、50μmol/L）阿托伐他汀对AGS细胞活力的影响,筛选作用浓度。正式实验分为对照组（不做干预）、阿托伐他汀组（25μmol/L）、阳性对照组（50 mg/L 5-氟尿嘧啶）、抑制剂组[25μmol/L阿托伐他汀+10μmol/L磷脂酰肌醇-3-激酶（PI3K）/蛋白激酶B(Akt)信号通路抑制剂LY294002]和激活剂组（25μmol/L阿托伐他汀+10μmol/L PI3K/Akt信号通路激活剂SC79）,干预24 h,检测细胞糖代谢情况（葡萄糖和乳酸含量）和细胞增殖率,以及细胞中自噬相关蛋白轻链3(LC3)Ⅰ、LC3Ⅱ及PI3K/Akt信号通路相关蛋白的表达。结果 中、高浓度阿托伐他汀均能显著抑制AGS细胞活力（P<0.05）,正式实验选择25μmol/L阿托伐他汀进行后续实验。与对照组相比,阳性对照组和阿托伐他汀组细胞中葡萄糖和乳酸含量、细胞增殖率以及p-PI3K/PI3K、p-Akt/Akt比值均显著降低（P<0.05）,LC3Ⅰ、LC3Ⅱ蛋...     

知母皂苷元对高糖引起的体外培养大鼠海马神经元损伤的保护作用

目的探讨知母皂苷元(sarsasapogenin,Sar)对高糖引起的海马神经元损伤是否有保护作用。方法选用出生0～24 h Sprague-Dawley(SD)大鼠乳鼠,取海马,进行海马神经元体外培养,培养7 d用于实验。实验分为正常对照组、高糖组、高糖+Sar(10、30、100μmol.L-1)组;对照组:加入等量含0.1%DMSO培养基;高糖处理组:分别加入葡萄糖(30、50、100 mmol.L-1)作用48 h;高糖+Sar(10、30、100μmol.L-1)组:先加入不同浓度Sar(10、30、100μmol.L-1)作用1 h,然后加入葡萄糖(50 mmol.L-1)作用48 h;应用MTT方法观察细胞活力,免疫荧光和Western免疫印迹方法观察神经元突触素表达的改变。应用Hoechst 33258核染色检测神经元凋亡。应用Western免疫印迹方法观察caspase-3和多聚ADP核糖聚合酶(PARP)蛋白表达改变。结果加入葡萄糖(30、50、100 mmol.L-1)作用48 h可使培养神经元细胞活力明显降低,神经元突触素蛋白表达明显降低。另外高糖也可引起神经元凋亡细胞百分比和活性caspase-3、PARP蛋白表达水平也较对照组明显提高。在加入高糖前加入不同浓度Sar(10、30、100μmol.L-1)可明显对抗高糖引起的这些变化。培养海马神经元突触素蛋白表达较高糖组(50 mmol.L-1)明显增加,神经元凋亡细胞百分比和活性caspase-3、PARP蛋白表达水平也较高糖组明显降低。结论 Sar对高糖引起的海马神经元损伤具有明显的保护作用。     

17β雌二醇对氯胺酮诱导皮层神经元凋亡的影响

目的研究17β雌二醇对氯胺酮诱导的原代培养皮层神经元凋亡的影响。方法原代培养大鼠皮层神经元,分别给予不同浓度的氯胺酮及17β雌二醇培养24 h,MTT法检测神经元的存活率,显微镜下观察神经元的形态变化,TUNEL法检测神经元调亡,Western blot法测定pAkt蛋白的表达。结果与对照组比较,氯胺酮能剂量依赖性降低神经元存活率。与氯胺酮组比较,17β雌二醇能剂量依赖性提高神经元的存活率。100μmol·L-1氯胺酮组显微镜下神经元数量减少,胞体立体感消失,细胞轮廓不清,神经元轴突断裂,TUNEL阳性神经元明显增加,pAkt表达明显降低。0.1μmol·L-117β雌二醇与100μmol·L-1氯胺酮共处理改善了氯胺酮引起的神经元损伤,TUNEL阳性神经元明显下降,pAkt表达增加。PI3K抑制剂LY294002拮抗了17β雌二醇的保护作用,TUNEL阳性神经元较0.1μmol·L-117β雌二醇与100μmol·L-1氯胺酮共处理组明显增加,pAkt表达明显下降。结论 17β雌二醇可以保护神经元免受氯胺酮导致的凋亡,其保护作用可能是通过激活PI3K-Akt信号通路实现的。     

七氟烷激活PI_3-K/Akt/P~(70S6K)信号转导通路抑制缺血/再灌注损伤神经元的凋亡

目的研究七氟烷对神经元缺血/再灌注损伤后PI3-K/Akt/P70S6K信号转导通路的影响,探讨七氟烷脑保护机制。方法将96孔和6孔培养板上培养7d的海马神经元随机分为6组:正常培养组(C组)、缺血/再灌注组(I/R组)、缺血/再灌注+2%Sevoflurane组(Sevo组)、缺血/再灌注+2%Sevoflurane+10μmol.L-1LY294002(PI3-K拮抗剂)组(LY组)、缺血/再灌注+2%Sevoflurane+10μmol.L-1Tric irib in(Akt拮抗剂)组(Tri组)、缺血/再灌注+2%Sevoflurane+10 nmol.L-1Rapamyc in(P70S6K拮抗剂)组(Rap组)。C组神经元按正常培养方法培养。Sevo组在神经元缺糖缺氧的同时接受2%Sevoflurane麻醉。LY组、Tri组和Rap组在神经元进行缺糖同时分别加入LY294002、Tric irib in或Rapamyc in使其终浓度分别为10μmol.L-1、10μmol.L-1或10 nmol.L-1后同Sevo组处理。96孔培养板的神经元进行细胞存活力的检测。6孔培养板的神经元进行神经元纯度鉴定、神经元凋亡和PI3-K、Akt和P70S6K蛋白表达的检测。结果Sevo组PI3K、Akt、P70S6K蛋白表达增加,神经元存活率增加、神经元凋亡率降低(vsI/R组,P<0.01)。LY组PI3K、Akt和P70S6K表达降低,神经元存活率降低、神经元凋亡率增加(vsSevo组,P<0.05或P<0.01);Tri组Akt和P70S6K表达降低,神经元存活率降低、神经元凋亡率增加(vsSevo组,P<0.05或P<0.01);Rap组P70S6K表达降低,神经元存活率降低、神经元凋亡率增加(vsSevo组,P<0.01)。结论Sevoflurane激活了PI3-K/Akt/P70S6K信号通路,在海马神经元缺血/再灌注损伤过程中抑制了神经元凋亡,保护了神经元。     

PI3K/Akt信号通路在硫化氢保护PC12细胞对抗化学性缺氧损伤的作用

目的探讨硫化氢(H2S)对PC12细胞PI3K/Akt信号通路的影响及该通路在H2S神经保护中的作用。方法Western blot法检测H2S供体硫氢化钠(NaHS)处理PC12细胞诱导Akt磷酸化的水平;CCK-8比色法检测细胞存活率;应用碘化丙啶(PI)染色流式细胞术检测细胞凋亡率。结果应用不同浓度NaHS处理PC12细胞30 min,在50～400μmol.L-1浓度范围内,呈浓度依赖性地上调Akt磷酸化的水平,但随着NaHS浓度的增加,磷酸化Akt表达量逐渐下降;Ly294002明显抑制了NaHS对Akt磷酸化水平的上调作用。NaHS预处理可以保护PC12细胞对抗600μmol.L-1CoCl2诱导的损伤,使细胞存活率提高及细胞凋亡率降低。而在预处理前使用PI3K/Akt信号通路抑制剂Ly294002,则明显地减弱了H2S的神经细胞保护作用。结论 H2S可通过激活PI3K/Akt信号通路保护PC12细胞对抗化学性缺氧损伤。     

毒胡萝卜素诱导大鼠皮层神经元内质网应激及丹红注射液的干预作用

目的：探讨毒胡萝卜紊诱导大鼠皮层神经元内质网应激凋亡的机制及丹红注射液的干预作用。方法：体外培养SD乳鼠皮层神经元，免疫组织化学、免疫荧光染色鉴定神经元纯度。流式细胞术Annexin V、PI双标检测凋亡率及活性caspase-3、caspase-8、caspase-7、caspase-9表达，Western Noting免疫印迹分析caspase-12、GRP78、Bcl-2、细胞色素C蛋白表达，Fura-2／AM法荧光分光光度计检测细胞内钙浓度（[Ca^2＋]i）。结果：SD乳鼠皮层神经元可纯化体外培养。2μmol／L毒胡萝卜素作用神经元24、48h细胞凋亡率分别是17.88％、21.38％，丹红治疗组分别是6．30％、6．11％，两组比较差异有统计学意义（P〈0．05）。毒胡萝卜素诱导神经元GRP78表达上调，剪切活化caspase-3、caspase-8、caspase-9、caspase-12，使细胞色素C表达增加，Bcl-2表达减少。丹红注射液促进细胞Bcl-2表达，抑制细胞色素C释放，减少活化的caspase-3、caspase-8、caspase-9含量，稳定游离钙浓度。结论：毒胡萝卜素诱导神经元内质网应激反应性凋亡。丹红注射液能抑制体外培养神经元内质网应激所致凋亡。     

Neuroprotection by sodium ferulate against glutamate-induced apoptosis is mediated by ERK and PI3 kinase pathways

Aim： To investigate whether sodium ferulate （SF） can protect cortical neurons from glutamate-induced neurotoxicity and the mechanisms responsible for this protection. Methods： Cultured cortical neurons were incubated with 50 μmol/L glutamate for either 30 min or 24 h, with or without pre-incubation with SF （100, 200, and 500 pmol/L, respectively）. LY294002, wortmannin, PD98059, and U0126 were added respectively to the cells 1 h prior to SF treatment. After incubation with glutamate for 24 h, neuronal apoptosis was quantified by scoring the per- centage of cells with apoptotic nuclear morphology after Hoechst 33258 staining. After incubation with glutamate for either 30 rain or 24 h, cellular extracts were prepared for Western blotting of active caspase-3, poly （ADP-ribose） polymerase （PARP）, μ-calpain, Bcl-2, phospho-Akt, phosphorylated ribosomal protein S6 pro- tein kinase （p70S6K）, phospho-mitogen-activated protein kinase kinase （MEK1/2） and phosphorylated extracellular signal-regulated kinase （ERK） 1/2. Results： SF reduced glutamate-evoked apoptotic morphology, active caspase-3 protein expression, and PARP cleavage and inhibited the glutamate-induced upregulation of the ~-calpain protein level. The inhibition of the phosphatidylinositol 3-kinase （P13K） and the MEK/ERK1/2 pathways partly abrogated the protective effect of SF against glutamate-induced neuronal apoptosis. SF prevented the glutamate- induced decrease in the activity of the PI3K/Akt/p70S6K and the MEK/ERK1/2 pathways. Moreover, incubation of cortical neurons with SF for 30 min inhibited the reduction of the Bcl-2 expression induced by glutamate. Conclusion： The results indicate that PI3K/Akt/p70S6K and the MEK/ERK signaling pathways play important roles in the protective effect of SF against glutamate toxicity in cortical neurons.     

The neuroprotective action of pyrroloquinoline quinone against glutamate-induced apoptosis in hippocampal neurons is mediated through the activation of PI3K/Akt pathway

Pyrroloquinoline quinone (PQQ), a cofactor in several enzyme-catalyzed redox reactions, possesses a potential capability of scavenging reactive oxygen species (ROS) and inhibiting cell apoptosis. In this study, we investigated the effects of PQQ on glutamate-induced cell death in primary cultured hippocampal neurons and the possible underlying mechanisms. We found that glutamate-induced apoptosis in cultured hippocampal neurons was significantly attenuated by the ensuing PQQ treatment, which also inhibited the glutamate-induced increase in Ca2+ influx, caspase-3 activity, and ROS production, and reversed the glutamate-induced decrease in Bcl-2/Bax ratio. The examination of signaling pathways revealed that PQQ treatment activated the phosphorylation of Akt and suppressed the glutamate-induced phosphorylation of c-Jun N-terminal protein kinase (JNK). And inhibition of phosphatidylinositol-3-kinase (PI3K)/Akt cascade by LY294002 and wortmannin significantly blocked the protective effects of PQQ, and alleviated the increase in Bcl-2/Bax ratio. Taken together, our results indicated that PQQ could protect primary cultured hippocampal neurons against glutamate-induced cell damage by scavenging ROS, reducing Ca2+ influx, and caspase-3 activity, and suggested that PQQ-activated PI3K/Akt signaling might be responsible for its neuroprotective action through modulation of glutamate-induced imbalance between Bcl-2 and Bax.     

Neuroprotection of Ilex latifolia and caffeoylquinic acid derivatives against excitotoxic and hypoxic damage of cultured rat cortical neurons

Ilex latifolia (Aquifoliaceae), one of the primary components of "Ku-ding-cha", has been used in Chinese folk medicine to treat headaches and various inflammatory diseases. A previous study demonstrated that the ethanol extract of I. latifolia could protect against ischemic apoptotic brain damage in rats. The present study investigated the protective activity of I. latifolia against glutamate-induced neurotoxicity using cultured rat cortical neurons in order to explain a possible mechanism related to its inhibitory effect on ischemic brain damage and identified potentially active compounds from it. Exposure of cultured cortical neurons to 500 μM glutamate for 12 h triggered neuronal cell death. I. latifolia (10-100 μg/mL) inhibited glutamate-induced neuronal death, elevation of intracellular calcium ([Ca(2+)](i)), generation of reactive oxygen species (ROS), the increase of a pro-apoptotic protein, BAX, and the decrease of an anti-apoptotic protein, BcL-2. Hypoxia-induced neuronal cell death was also inhibited by I. latifolia. 3,4-Dicaffeoylquinic acid (diCQA), 3,5-diCQA, and 3,5-diCQA methyl ester isolated from I. latifolia also inhibited the glutamate-induced increase in [Ca(2+)](i), generation of ROS, the change of apoptosis-related proteins, and neuronal cell death; and hypoxia-induced neuronal cell death. These results suggest that I. latifolia and its active compounds prevented glutamate-induced neuronal cell damage by inhibiting increase of [Ca(2+)](i), generation of ROS, and resultantly apoptotic pathway. In addition, the neuroprotective effects of I. latifolia on ischemia-induced brain damage might be associated with the anti-excitatory and anti-oxidative actions and could be attributable to these active compounds, CQAs.     

阿魏酸钠对抗谷氨酸诱导的鼠皮层神经元凋亡作用的影响

目的探讨MEK/ERK信号转导通路是否参与了阿魏酸钠(SF)对抗谷氨酸诱导的鼠皮层神经元凋亡作用。方法以谷氨酸诱导大鼠皮层神经元凋亡为模型。采用Westernblot观察Bcl-2、caspase-3、磷酸化ERK1/2表达的改变。结果阿魏酸钠能够显著降低谷氨酸诱导的神经细胞caspase-3的表达,提高Bcl-2、磷酸化ERK1/2的表达。PD98059可以减弱SF的保护作用。结论 MEK/ERK1/2通路参与阿魏酸钠对抗谷氨酸诱导的鼠皮层神经元凋亡。     

Neuroprotective effect of Alpinia oxyphylla Miq. fruits against glutamate-induced apoptosis in cortical neurons

The protective effect of ethanol extract from the fruits of Alpinia oxyphylla on glutamate-induced neuronal apoptosis was examined in primary cultured mouse cortical neurons. After exposure of cortical neurons to 30 microM glutamate for 24 h, cortical neurons exhibited remarkable apoptotic-like death as evidenced by multi-indices including morphological features, cell viability assay, DNA fragmentation on agarose gel and flow cytometric analysis. Co-treatment of the neurons with A. oxyphylla fruits extract (AFEx) (80-200 microg/ml) in the presence of glutamate significantly elevated cell viability, reduced the number of apoptotic cells and decreased the intensity of glutamate-induced DNA fragmentation. These results suggest the neuroprotective potential of A. oxyphylla fruits against glutamate-induced neuronal apoptosis.     

17β‐Oestradiol Protects Primary‐Cultured Rat Cortical Neurons from Ketamine‐Induced Apoptosis by Activating PI3K/Akt/Bcl‐2 Signalling

Numerous studies in rodents have indicated that exposure to ketamine during the period when synaptogenesis is highly active induces neurodegeneration. Thus, there is a growing need to develop strategies to prevent ketamine‐induced brain injury in the developing brain. Oestradiol is a neuroactive steroid that prevents neuronal cell death in different experimental models by activating cell survival signals and inhibiting apoptotic signals. The main goal of this study was to investigate the neuroprotective effects of 17β‐oestradiol against ketamine‐induced apoptotic neurodegeneration in primary‐cultured cortical neurons. The data revealed that 17β‐oestradiol (0.1 μM) in combination with ketamine (100 μM) increased cell viability in the MTT assay and reduced the number of apoptotic cells detected by TUNEL and Hoechst 33258 staining. To elucidate a possible mechanism by which 17β‐oestradiol exerts its neuroprotective effect, we investigated the PI3K pathway using an inhibitor of PI3K, LY294002. The protective effects of 17β‐oestradiol were abrogated by LY294002. Furthermore, we found that 17β‐oestradiol not only induced phosphorylation of the PI3K substrate Akt, but also increased the expression of Bcl‐2, which down‐regulated ketamine‐induced caspase‐3 activity and inhibited neuronal apoptosis. These data demonstrate that 17β‐oestradiol exerts a neuroprotective effect against ketamine‐induced neuronal apoptosis by activating the PI3K/Akt/Bcl‐2 signalling pathway. Therefore, 17β‐oestradiol appears to be a promising agent in preventing or reversing ketamine's toxic effects on neurons at an early developmental stage.     

Hyperoside protects primary rat cortical neurons from neurotoxicity induced by amyloid β-protein via the PI3K/Akt/Bad/Bcl(XL)-regulated mitochondrial apoptotic pathway

Amyloid β-protein (Aβ), which is deposited in neurons as neurofibrillary tangles, is known to exert cytotoxic effects by inducing mitochondrial dysfunction. Additionally, the PI3K/Akt-mediated interaction between Bad and Bcl(XL) plays an important role in maintaining mitochondrial integrity. However, the application of therapeutic drugs, especially natural products in Alzheimer's disease therapy via PI3K/Akt/Bad/Bcl(XL)-regulated mitochondrial apoptotic pathway has not aroused extensive attention. In the present study, we investigated the neuroprotective effects of hyperoside, a bioactive flavonoid compound from Hypericum perforatum, on Aβ(25-35)-induced primary cultured cortical neurons, and also examined the potential cellular signaling mechanism for Aβ detoxication. Our results showed that treatment with hyperoside significantly inhibited Aβ(25-35)-induced cytotoxicity and apoptosis by reversing Aβ-induced mitochondrial dysfunction, including mitochondrial membrane potential decrease, reactive oxygen species production, and mitochondrial release of cytochrome c. Further study indicated that hyperoside can activate the PI3K/Akt signaling pathway, resulting in inhibition of the interaction between Bad and Bcl(XL), without effects on the interaction between Bad and Bcl-2. Furthermore, hyperoside inhibited mitochondria-dependent downstream caspase-mediated apoptotic pathway, such as that involving caspase-9, caspase-3, and poly ADP-ribose polymerase (PARP). These results demonstrate that hyperoside can protect Aβ-induced primary cultured cortical neurons via PI3K/Akt/Bad/Bcl(XL)-regulated mitochondrial apoptotic pathway, and they raise the possibility that hyperoside could be developed into a clinically valuable treatment for Alzheimer's disease and other neuronal degenerative diseases associated with mitochondrial dysfunction.