脂多糖预处理改善脂多糖诱导的中脑脑片神经元损伤

目的探讨脂多糖（lipopolysaccharide,LPS）预处理对脂多糖所致中脑脑片多巴胺能神经元炎性损伤的影响及其可能的机制。方法建立大鼠中脑脑片体外培养体系,于体外培养14d后以不同剂量脂多糖（0、1、3、6及10ng／mL）预处理24h,然后用大剂量脂多糖（100ng／mL）作用72h,观察脂多糖预处理对脑片乳酸脱氢酶（lactic acid dehydrogenase,LDH）活性的影响。通过免疫组化检测酪氨酸羟化酶（Tyrosine hydroxylase,TH）和OX-42的阳性细胞数变化,应用酶联免疫吸附法测定培养液上清肿瘤坏死因子-α（tumor necrosis factor-α,TNF-α）水平。结果100ng／mL多糖作用72h后引起脑片TH阳性细胞数从对照组的191±12减少到46±4,LDH活性明显升高（P〈0．01）,小胶质细胞大量激活,TNF-α水平显著增高（P〈0．01）。脂多糖预处理能减少神经细胞的丢失（3ng／mL和6ng／mL的LPS处理后TH阳性细胞数分别为126±12和180±13）,降低脑片LDH活性（P〈0．05）,并有效地抑制小胶质细胞的激活,明显减少TNF-α的生成（P〈0．05）。结论小剂量脂多糖预处理可改善脂多糖对大鼠中脑脑片多巴胺能神经元的损伤,其作用机制可能是通过抑制小胶质细胞的激活,减少TNF-α的释放,减轻炎症反应对神经元的损伤。这种保护作用可为帕金森氏病的治疗提供新思路。     

Efficacy of suspended moxibustion in stroke rats is associated with a change in tail temperature

Suspended moxibustion-produced heat can transfer from the acupoint to other sites of the body. The suspended moxibustion should be terminated when clinical propagated sensation disappears, because this implies that the quantity of moxibustion is sufficient. We wanted to investigate if this phenomenon also occurs in experimental animals. In the present study, a rat model of stroke was established and treated with suspended moxibustion at Dazhui (DU14) for 60 minutes. Results showed that the increase in tail temperature began at 15 minutes after suspended moxibustion and decreased gradually at 40 minutes. In addition, neurological function was significantly improved in stroke rats with tail temperature increase following suspended moxibustion, and this effect was associated with significantly reduced tumor necrosis factor α and interleukin 1β mRNA. However, there was no significant difference between 40-and 60-minute suspended moxibustion. The findings indicate that elevated tail temperature began to decrease at 40 minutes after suspended moxibustion, and further suspended moxibustion was not useful in the recovery of stroke rats.     

Amentolfavone protects hippocampal neurons:anti-inlfammatory,antioxidative, and antiapoptotic effects

Amentoflavone is a natural biflavone compound with many biological properties, including anti-inlfammatory, antioxidative, and neuroprotective effects. We presumed that amentolfavone exerts a neuroprot...     

Buyang Huanwu Decoction fraction protects against cerebral ischemia/reperfusion injury by attenuating the inflammatory response and cellular apoptosis

Buyang Huanwu Decoction fraction extracted from Buyang Huanwu Decoction contains saponins of Astragalus, total paeony glycoside and safflower flavones. The aim of this study was to demonstrate the neuroprotective effect and mechanism of Buyang Huanwu Decoction fraction on ischemic injury both in vivo and in vitro. In vivo experiments showed that 50-200 mg/kg Buyang Huanwu Decoction fraction reduced infarct volume and pathological injury in ischemia/reperfusion rats, markedly inhibited expression of nuclear factor-κB and tumor necrosis factor-α and promoted nestin protein expression in brain tissue. Buyang Huanwu Decoction fraction (200 mg/kg) exhibited significant effects, which were similar to those of 100 mg/kg Ginkgo biloba extract. In vitro experimental results demonstrated that 10-100 mg/L Buyang Huanwu Decoction fraction significantly improved cell viability, decreased the release of lactate dehydrogenase and malondialdehyde levels, and inhibited the rate of apoptosis in HT22 cells following oxygen-glucose deprivation. Buyang Huanwu Decoction fraction (100 mg/L) exhibited significant effects, which were similar to those of 100 mg/L Ginkgo biloba extract. These findings suggest that Buyang Huanwu Decoction fraction may represent a novel, protective strategy against cerebral ischemia/reperfusion injury in rats and oxygen-glucose deprivation-induced damage in HT22 cells in vitro by attenuating the inflammatory response and cellular apoptosis.     

Fermented Chinese formula Shuan-Tong-Ling attenuates ischemic stroke by inhibiting inflammation and apoptosis

The fermented Chinese formula Shuan-Tong-Ling is composed of radix puerariae(Gegen),salvia miltiorrhiza(Danshen),radix curcuma(Jianghuang),hawthorn(Shanzha),salvia chinensis(Shijianchuan),sinapis alba(Baijiezi),astragalus(Huangqi),panax japonicas(Zhujieshen),atractylodes macrocephala koidz(Baizhu),radix paeoniae alba(Baishao),bupleurum(Chaihu),chrysanthemum(Juhua),rhizoma cyperi(Xiangfu) and gastrodin(Tianma),whose aqueous extract was fermented with lactobacillus,bacillus aceticus and saccharomycetes.ShuanTong-Ling is a formula used to treat brain diseases including ischemic stroke,migraine,and vascular dementia.Shuan-Tong-Ling attenuated H_2O_2-induced oxidative stress in rat microvascular endothelial cells.However,the potential mechanism involved in these effects is poorly understood.Rats were intragastrically treated with 5.7 or 17.2 m L/kg Shuan-Tong-Ling for 7 days before middle cerebral artery occlusion was induced.The results indicated Shuan-Tong-Ling had a cerebral protective effect by reducing infarct volume and increasing neurological scores.Shuan-Tong-Ling also decreased tumor necrosis factor-α and interleukin-1β levels in the hippocampus on the ischemic side.In addition,Shuan-Tong-Ling upregulated the expression of SIRT1 and Bcl-2 and downregulated the expression of acetylated-protein 53 and Bax.Injection of 5 mg/kg silent information regulator 1(SIRT1) inhibitor EX527 into the subarachnoid space once every 2 days,four times,reversed the above changes.These results demonstrate that Shuan-Tong-Ling might benefit cerebral ischemia/reperfusion injury by reducing inflammation and apoptosis through activation of the SIRT1 signaling pathway.     

Estrogen down-regulates glial activation in male mice following 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine intoxication

Emerging evidence suggests beneficial effect of estrogen for Parkinson's disease (PD), yet the exact mechanisms implicated remain obscured. Activated glia observed in MPTP mouse model and in PD may participate in the cascade of deleterious events that ultimately leads to dopaminergic nigral neuronal death. In vitro studies demonstrate that estrogen can modify the microglial and astroglial expression of inflammatory mediator, such as cytokines and chemokines implicated in neuroinflammation and neurodegeneration. To determine whether estrogen-elicited neuroprotection in PD is mediated through glia, adult male C57Bl/6 mice were treated with 17beta-estradiol (E2) for a total of 11 days. Following 5 days of pretreatment with E2, they were injected with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) on the sixth day. The brains were collected on day 11. Immunohistochemistry and quantitative study were used to assess the number of tyrosine hydroxylase-immunoreactive (TH-IR) neurons in the substantia nigra pars compacta (SNpc) and that of activated astrocytes and activated microglia in the SNpc and the striatum. Pretreatment with E2 decreased the loss of TH-IR nigral neurons and diminished the deficit of TH-IR striatal fibers triggered by MPTP. The neuroprotective effect of E2 was coincident with an attenuation of a glial response within the nigra and the striatum. These findings suggest that the neuroprotective effects of E2 evidenced in MPTP mouse model might mediate through an inhibition of reactive glia. However, direct neuroprotective effects of E2 upon TH-IR neurons cannot be excluded.