Triterpenoid Saponins from Leaves and Stems of Panax Quinquefolium L

In the chemical investigation on the saponin composition of leaves and stems of Panax quinquefolium L., two new minor dammarane saponins, quinquenoside L₁ (1) and L₂ (2) have been isolated. By means of physico-chemical evidences and spectral analysis their structures were established as 3-O-[β-D-glucopyranosyl-(1-2)-β-D-glucopyranosyl]-20-O-β-D-glucopyranosy-dammara-23,25-diene-3β, 12β, 20(S)-triol (1) and 3-O-[β-D-glucopyranosyl-(1-2)-β-D-glucopyranosyl]-20-O-β-D-D-glucopyranosyl-(24Z)-dammar-24-ene-3β, 12β, 20(S), 26-tetraol (2).     

番茄红素调节Keap1/Nrf2/ARE信号通路对精神分裂大鼠认知障碍和氧化应激反应的影响

目的 探究番茄红素调控Kelch样环氧氯丙烷相关蛋白1(Keap1)/核因子E2相关因子2(Nrf2)/抗氧化反应元件（ARE）通路,影响精神分裂症大鼠的氧化应激反应和认知功能。方法 构建精神分裂症大鼠模型,将大鼠随机分为对照组、氯丙嗪组、模型组以及番茄红素高、低剂量组和番茄红素+Nrf2抑制剂组,每组各10例。Morris水迷宫实验检测各组大鼠认知功能;Tunel染色观察并计算各组大鼠海马组织中神经元凋亡率;酶联免疫吸附测定法（ELISA）检测大鼠血清中过氧化氢酶（CAT）、谷胱甘肽过氧化物酶（GSH-Px）、超氧化物歧化酶（SOD）水平;Western blotting法检测各组大鼠海马组织中Keap1、Nrf2和ARE下游抗氧化蛋白HO-1的表达水平。结果 与模型组相比,番茄红素组大鼠水迷宫实验中逃避潜伏期明显缩短（2～5 d）,海马组织细胞凋亡率显著降低,血清CAT、GSH-Px、SOD水平和海马组织Keap1、Nrf2、HO-1蛋白表达量显著升高（P<0.05）;与番茄红素高剂量组相比,番茄红素低剂量组、番茄红素+Nrf2抑制剂组大鼠水迷宫实验中逃避潜伏期明显延长（2～...     

Triterpenoid Saponins from Leaves and Stems of Panax Quinquefolium L

Abstract

In the chemical investigation on the saponin composition of leaves and stems of Panax quinquefolium L., two new minor dammarane saponins, quinquenoside L₁ (1) and L₂ (2) have been isolated. By means of physico-chemical evidences and spectral analysis their structures were established as 3-O-[β-D-glucopyranosyl-(1-2)-β-D-glucopyranosyl]-20-O-β-D-glucopyranosy-dammara-23,25-diene-3β, 12β, 20(S)-triol (1) and 3-O-[β-D-glucopyranosyl-(1-2)-β-D-glucopyranosyl]-20-O-β-D-D-glucopyranosyl-(24Z)-dammar-24-ene-3β, 12β, 20(S), 26-tetraol (2).     

Panax notoginseng saponins attenuate atherosclerosis in rats by regulating the blood lipid profile and an anti-inflammatory action

Previous studies have reported on the anti-atherosclerotic effects of Panax notoginseng saponins (PNS). The aim of the present study was to explore the molecular mechanisms responsible for the anti-atherosclerotic effects of PNS and the inflammatory response. Thirty rats were randomly divided into three groups, namely a control group, a group, in which zymosan A was used to induce inflammation (Zym group) and a PNS-treated group. Rats in the three groups were administered liquid paraffin (i.p.), zymosan A (20 mg/kg, i.p., once every 3 days) or zymosan A and PNS (100 mg/kg, i.p., once daily), respectively. All animals were fed a high-fat diet for 9 weeks. At scheduled times, rats were killed, blood was collected and the aorta was removed. Pathological changes in aortas were observed using Sudan IV staining and transmission electron microscopy. Serum lipids were measured enzymatically. Whole-blood viscosity was observed at different shear rates. The expression of cardiovascular disease-specific genes was determined using GEArray (SuperArray, Frederick, MA, USA). Western blotting was used to evaluate the expression levels of nuclear factor (NF)-kappaB/p65 and its inhibitor IkappaBalpha in the aortic wall. In the present study, typical pathological changes associated with atherosclerosis in rats following induction by zymosan A were alleviated by PNS treatment. In the PNS-treated group, there was a marked reduction in total serum cholesterol, triglycerides and blood viscosity. In addition, PNS treatment significantly decreased the gene expression of some inflammatory factors, such as integrins, interleukin (IL)-18, IL-1beta and matrix metalloproteinases 2 and 9. The expression of NF-kappaB/p65 was attenuated, whereas the expression of IkappaBalpha was significantly increased, after treatment with PNS. In conclusion, it appears that PNS exerts its therapeutic effects on atherosclerosis through an anti-inflammatory action and regulation of the blood lipid profile and that an NF-kappaB signalling pathway is involved.     

Changing paradigm to target microglia in neurodegenerative diseases: from anti-inflammatory strategy to active immunomodulation

Introduction: The importance of microglia in most neurodegenerative pathologies, from Parkinson’s disease to amyotrophic lateral sclerosis and Alzheimer’s disease, is increasingly recognized. Until few years ago, microglial activation in pathological conditions was considered dangerous to neurons due to its causing inflammation. Today we know that these glial cells also play a crucial physiological and neuroprotective role, which is altered in neurodegenerative conditions.

Areas covered: The neuroinflammatory hypothesis for neurodegenerative diseases has led to the trial of anti-inflammatory agents as therapeutics with largely disappointing results. New information about the physiopathological role of microglia has highlighted the importance of immunomodulation as a potential new therapeutic approach. This review summarizes knowledge on microglia as a potential therapeutic target in the most common neurodegenerative diseases, with focus on compounds directed toward the modulation of microglial immune response through specific molecular pathways.

Expert opinion: Here we support the innovative concept of targeting microglial cells by modulating their activity, rather than simply trying to counteract their inflammatory neurotoxicity, as a potential therapeutic approach for neurodegenerative diseases. The advantage of this therapeutic approach could be to reduce neuroinflammation and toxicity, while at the same time strengthening intrinsic neuroprotective properties of microglia and promoting neuroregeneration.     

Fasudil alleviates brain damage in rats after carbon monoxide poisoning through regulating neurite outgrowth inhibitor/oligodendrocytemyelin glycoprotein signalling pathway

Carbon monoxide (CO) poisoning can lead to many serious neurological symptoms. Currently, there are no effective therapies for CO poisoning. In this study, rats exposed to CO received hyperbaric oxygen therapy, and those in the Fasudil group were given additional Fasudil injection once daily. We found that the escape latency in CO poisoning group (CO group) was significantly prolonged, the T₁/T_total was obviously decreased, and the mean escape time and the active escape latency were notably extended compared with those in normal control group (NC group, P < 0.05). After administration of Fasudil, the escape latency was significantly shortened, T₁/T_total was gradually increased as compared with CO group (>1 week, P < 0.05). Ultrastructural damage of neurons and blood‐brain barrier of rats was serious in CO group, while the structural and functional integrity of neuron and mitochondria maintained relatively well in Fasudil group. Moreover, we also noted that the expressions of neurite outgrowth inhibitor (Nogo), oligodendrocyte‐myelin glycoprotein (OMgp) and Rock in brain tissue were significantly increased in CO group, and the elevated levels of the three proteins were still observed at 2 months after CO poisoning. Fasudil markedly reduced their expressions compared with those of CO group (P < 0.05). In summary, the activation of Nogo‐OMgp/Rho signalling pathway is associated with brain injury in rats with CO poisoning. Fasudil can efficiently down‐regulate the expressions of Nogo, OMgp and Rock proteins, paving a way for the treatment of acute brain damage after CO poisoning.     

Enhancement of oligodendrocyte autophagy alleviates white matter injury and cognitive impairment induced by chronic cerebral hypoperfusion in rats

Cognitive impairment caused by chronic cerebral hypoperfusion(CCH) is associated with white matter injury(WMI), possibly through the alteration of autophagy. Here, the autophagy—lysosomal pathway(ALP) dysfunction in white matter(WM) and its relationship with cognitive impairment were investigated in rats subjected to two vessel occlusion(2VO). The results showed that cognitive impairment occurred by the 28th day after 2VO. Injury and autophagy activation of mature oligodendrocytes and neuronal a...     

补阳还五汤通过AMPK/mTOR/ULK1信号通路调控自噬减轻大鼠脑缺血/再灌注损伤

目的探讨补阳还五汤抗大鼠脑缺血/再灌注损伤的AMPK/mTOR/ULK1自噬信号通路机制。方法用改良线栓法建造大鼠左侧脑缺血模型,各组大鼠每24 h给药1次,共3次。再灌注72 h后观察大鼠神经损伤情况和脑梗死体积改变;尼氏染色法和TUNEL染色法观察神经细胞形态、数量以及凋亡情况;Western blot检测自噬蛋白和AMPK/mTOR/ULK1自噬信号通路相关蛋白表达情况。结果补阳还五汤改善大鼠神经功能缺陷,减少脑梗死体积和神经细胞凋亡,减轻脑组织病理损伤;抑制AMPK磷酸化活化,解除AMPK对下游mTOR和ULK1的抑制,促进二者磷酸化激活,抑制细胞自噬。AMPK激动剂Metformin提高细胞自噬水平,同时逆转了补阳还五汤抗大鼠脑缺血/再灌注损伤作用。结论补阳还五汤介导AMPK/mTOR/ULK1自噬信号通路对脑缺血/再灌注损伤大鼠发挥神经保护作用。     

右美托咪定通过调节CX3CL1-CX3CR1信号通路对老年大鼠肝部分切除术后认知功能障碍的改善作用研究

目的 观察右美托咪定通过调节CX3CL1-CX3CR1信号通路对老年大鼠肝部分切除术术后认知功能障碍(POCD)的改善作用.方法 60只SPF级老年SD大鼠随机分为假手术组、模型组、阳性对照组、右美托咪定组和CX3CL1抗体+右美托咪定组.阳性对照组大鼠于术前3 d给予布洛芬混悬液35 mg/kg,ig给药,8 h/次...     

奥卡西平和卡马西平对致(痫)大鼠认知功能的影响

目的 观察卡马西平、奥卡西平对癫(痫)认知功能的影响.方法 采用随机数字表方法将实验大鼠分为对照组、致(痫)组、奥卡西平组及卡马西平组,每组各20只.对照组用0.9％氯化钠注射液造模;致(痫)组用氯化锂-匹罗卡品造模,不服用药物;奥卡西平组用氯化锂-匹罗卡品造模,并用奥卡西平200 mg/d灌胃;卡马西平组用氯化锂-匹罗卡品造模,并用卡马西平200 mg/d灌胃,通过Morris水迷宫实验测试并记录逃避潜伏期和平台象限游泳时间.实时聚合酶链反应(RT-PCR)法检测ERK-2 mRNA、NCAM-1 mRNA表达,免疫组织化学化法检测细胞外调节蛋白激酶2 (ERK-2)蛋白、神经细胞黏附分子1(NCAM-1)蛋白表达(阳性神经元计数).结果 训练初期,卡马西平组、奥卡西平组、致(痫)组、对照组逃逸潜伏期平均时间、平台象限游泳时间分别为(81±9)和(27±9)s,(72 ±9)s和(32±14)s,(67 ±7)s和(37±13),(36±5)s和(51 ±11)s,卡马西平组、奥卡西平组、致(痫)组和对照组比较,差异均有统计学意义(均P＜0.01).卡马西平组、奥卡西平组、致(痫)组、对照组NCAM/β3-actin和ERK-2 /β3-actin分别为0.60±0.12和0.43 ±0.11、0.66 ±0.03和0.51±0.17、0.95 ±0.21和0.59±0.24、0.48±0.04和0.75 ±0.23,卡马西平组、奥卡西平组的大鼠海马组织NCAM-1 mRNA表达水平明显低于致(痫)组(P＜0.01).致(痫)组中ERK-2的mRNA表达水平明显低于对照组(P＜0.01).卡马西平组、奥卡西平组的大鼠海马组织中ERK-2表达水平明显低于致(痫)组(P＜0.01).结论 ERK-2在癫(痫)发作1个月时在海马的表达水平下降,NCAM-1则相反.二者均参与了癫(痫)认知功能障碍的发病,卡马西平能加重癫(痫)认知功能障碍,奥卡西平对癫(痫)认知功能障碍影响轻微.     

Thyroid hormone disruption and cognitive impairment in rats exposed to PBDE during postnatal development

Polybrominated diphenyl ether flame-retardants (PBDEs) are thyroid-disrupting environmental chemicals. We investigated the effects of postnatal exposure to DE-71 (a mixture of tetra- and penta-brominated congeners), n-propylthiouracil (PTU) and thyroxine (T4) replacement on open-field (OF) and radial maze (RAM) tests. Wistar rats (5 males/5 females per litter, 32 litters) were treated orally (PND 5–22) with PTU (4 mg/kg bw/d), DE-71 (30 mg/kg bw/d), with and without co-administration of T4 (15 μg/kg bw/d, sc). PTU depressed T4 serum levels and body weight gain and enlarged thyroid gland. Although decreasing T4 levels, DE-71 did not change thyroid and body weights. PTU-treated rats showed hyperactivity (PND 42 and 70), and working and reference memory learning deficits (RAM, PND 100). Although not altering motor activity and working memory, DE-71 caused a reference memory deficit (females only). T4 co-administration averted hypothyroxinemia and long-term cognitive deficits caused by PTU and DE-71.     

七氟烷短时吸入对新生大鼠海马caspase-3活性和认知功能发育的影响

目的探讨七氟烷短时吸入对新生大鼠海马caspase-3活性和认知功能发育的影响。方法 7日龄新生SD大鼠64只,随机分为A、B、C、D 4组(n=16):A组吸入40%氧气1 h,B、C、D组分别吸入1.0%、2.0%、4.0%七氟烷1 h。各组随机取8只大鼠,于吸入七氟烷后24 h采用流式细胞仪定量分析海马caspase-3的活性,观察海马神经细胞凋亡情况;各组余8只大鼠于7 wk采用Morris水迷宫测试其认知功能。结果 B、C、D组Morris水迷宫测试成绩低于A组,而且随着吸入七氟烷浓度的增加,逃避潜伏期和探索时间逐渐延长,差异有统计学意义(均P<0.01);吸入1.0%、2.0%、4.0%七氟烷大鼠海马神经细胞凋亡率分别为(31.0±2.7)%、(52.8±4.9)%、(71.4±3.2)%,均高于A组(1.9±0.8)%,而且随着吸入七氟烷浓度的增加,神经细胞凋亡率逐渐增加,差异有统计学意义(均P<0.01)。结论七氟烷短时吸入导致海马神经细胞凋亡,并阻抑新生大鼠认知功能发育。     

冰片对长时连续作业大鼠觉醒能力及认知功能的影响

目的:探讨冰片对长时连续作业大鼠觉醒能力和认知功能损害的干预作用。方法:首先采取跑台作业方法建立大鼠长时连续作业模型,将模型大鼠分为跑台冰片组和跑台对照组,另设未跑台对照组。随后观察冰片对长时连续作业大鼠活动-静止行为、觉醒时间以及穿梭箱主动回避反应的影响。结果:3组纳入测试的大鼠各为6只。结果显示给予0.4g/kg冰片(经胃灌饲)可增加大鼠长时连续作业后的自主活动量(每分钟活动次数未跑台对照组为54.1±5.4,跑台对照组为15.5±8.3,跑台冰片组为26.8±7.8,3组之间两两比较,P均<0.05)和觉醒时间(未跑台对照组为639min±46min,跑台对照组为411min±36min,跑台冰片组为501min±52min,3组之间两两比较,P均<0.05),同时还可改善长时连续作业大鼠的认知功能(穿梭箱主动回避作为测试反应时间,未跑台对照组为5.63s±1.01s,跑台对照组为6.85s±1.24s,跑台冰片组为6.26s±0.96s,3组之间两两比较,P均<0.05)。结论:冰片可在一定程度上逆转长时连续作业对大鼠觉醒能力和认知功能的损害作用。     

电针调控Nrf2/HO-1通路对缺血缺氧性脑损伤大鼠小胶质细胞活化的影响

目的 探究电针调控核因子E2相关因子2(Nrf2)/血红素加氧酶1(HO-1)通路对缺血缺氧性脑损伤（HIBD）大鼠小胶质细胞活化的影响。方法 随机将40只SD大鼠均分为假手术组、模型组、电针组、电针+全反式维甲酸组。除假手术组外其余组均通过颈总动脉结扎及缺氧建立HIBD大鼠模型,假手术组大鼠仅暴露左侧颈总动脉及迷走神经,不进行结扎及缺氧处理。造模结束后,电针组于百会穴进行电针刺激;电针+全反式维甲酸组大鼠经电针刺激后腹腔注射全反式维甲酸（7 mg/kg）。通过Longa评分进行大鼠神经行为学评分;旷场及水迷宫实验检测大鼠自主活动能力和认知功能;TUNEL法检测大鼠神经细胞凋亡情况;免疫组化法检测大鼠脑组织中小胶质细胞标志蛋白离子钙结合衔接分子1(Iba1)表达;试剂盒检测大鼠脑组织中白细胞介素10(IL-10)、IL-1β、活性氧（ROS）及丙二醛（MDA）水平;Western blot检测脑组织CD68、诱导型一氧化氮合酶（iNOS）和精氨酸酶（Arginase）及Nrf2/HO-1通路相关蛋白表达。结果 与假手术组比较,模型组大鼠神经行为学评分、逃避潜伏期、大脑皮质神经细胞凋亡率...     

Cannabinoid CB(2) receptors modulate ERK-1/2 kinase signalling and NO release in microglial cells stimulated with bacterial lipopolysaccharide

BACKGROUND AND PURPOSE

Cannabinoid (CB) receptor agonists have potential utility as anti-inflammatory drugs in chronic immune inflammatory diseases. In the present study, we characterized the signal transduction pathways affected by CB₂ receptors in quiescent and lipopolysaccharide (LPS)-stimulated murine microglia.

EXPERIMENTAL APPROACH

We examined the effects of the synthetic CB₂ receptor ligand, JWH-015, on phosphorylation of MAPKs and NO production.

KEY RESULTS

Stimulation of CB₂ receptors by JWH-015 activated JNK-1/2 and ERK-1/2 in quiescent murine microglial cells. Furthermore, CB₂ receptor activation increased p-ERK-1/2 at 15 min in LPS-stimulated microglia. Surprisingly, this was reduced after 30 min in the presence of both LPS and JWH-015. The NOS inhibitor l-NAME blocked the ability of JWH-015 to down-regulate the LPS-induced p-ERK increase, indicating that activation of CB₂ receptors reduced effects of LPS on ERK-1/2 phosphorylation through NO. JWH-015 increased LPS-induced NO release at 30 min, while at 4 h CB₂ receptor stimulation had an inhibitory effect. All the effects of JWH-015 were significantly blocked by the CB₂ receptor antagonist AM 630 and, as the inhibition of CB₂ receptor expression by siRNA abolished the effects of JWH-015, were shown to be mediated specifically by activation of CB₂ receptors.

CONCLUSIONS AND IMPLICATIONS

Our results demonstrate that CB₂ receptor stimulation activated the MAPK pathway, but the presence of a second stimulus blocked MAPK signal transduction, inhibiting pro-inflammatory LPS-induced production of NO. Therefore, CB₂ receptor agonists may promote anti-inflammatory therapeutic responses in activated microglia.     

西洋参总皂苷对大鼠肝微粒体CYP1A2活性的影响

目的考察西洋参总皂苷对大鼠肝微粒体CYP1A2活性的影响。方法将大鼠随机分为空白对照组(空白组)、西洋参总皂苷低剂量组[低剂量组,50 mg/(kg·d)]、西洋参总皂苷中剂量组[中剂量组,100 mg/(kg·d)]、西洋参总皂苷高剂量组[高剂量组,200 mg/(kg·d)]和β-萘黄酮阳性药对照组[阳性药组,80 mg/(kg·d)],预处理11 d后,观察大鼠肝微粒体CYP1A2酶活性、CYP1A2 mRNA表达和CYP1A2酶蛋白表达情况,研究CYP1A2特异性探针底物非那西丁在预处理大鼠体内的药动学变化。结果预处理后,大鼠肝微粒体CYP1A2活性、mRNA和蛋白表达随西洋参总皂苷剂量升高有增加趋势,非那西丁在预处理大鼠体内代谢速率加快。结论西洋参总皂苷对大鼠肝微粒体CYP1A2活性有一定诱导作用。     

涤痰汤对老年轻度认知功能障碍大鼠海马NGFβ、BDNF含量的影响

目的:观察涤痰汤对老年轻度认知功能障碍大鼠学习记忆能力及海马组织神经生长因子(NGFβ)、脑源性神经营养因子(BDNF)含量的影响。方法:采用中年大鼠颈部皮下注射D-半乳糖结合半高脂饮食建立老年轻度认知功能障碍大鼠模型。将60只大鼠随机分为正常组、模型组、西药组、涤痰汤高剂量组(以下简称"涤高组")、涤痰汤低剂量组(简称"涤低组"),另设12只3月龄青年大鼠作为青年对照组。采用Morris水迷宫检测大鼠学习记忆能力,免疫比色法检测大鼠血清、大脑皮质超氧化物歧化酶(SOD)、丙二醛(MDA)水平;通过酶联免疫吸附法(ELISA)检测大鼠NGFβ、BDNF的含量。结果:与模型组相比,涤高组、涤低组潜伏期均明显缩短(P<0.05),血清、皮质SOD水平显著升高(P<0.05),MDA水平均显著下降(P<0.05)。涤高组海马NGFβ、BDNF含量均增加(P<0.05),涤低组海马组织BDNF含量明显升高(P<0.05)。结论:涤痰汤可能通过增加大鼠海马NGF、BDNF蛋白表达,改善老年认知功能障碍大鼠的学习记忆能力。