加拿大一枝黄花总黄酮对急性肝损伤小鼠的保护作用

为了研究加拿大一枝黄花总黄酮(FSC)对CCl4致小鼠急性肝损伤的保护作用,试验将SPF级昆明种小鼠随机分为6组,分别为对照组、模型组、水飞蓟素组[水飞蓟素给药量为150 mg/(kg·d)]和FSC低、中、高剂量组[FSC给药量分别为75,150,300 mg/(kg·d)],连用10 d,末次灌胃2 h后,对照组小鼠腹腔注射花生油(按体重10 mL/kg),其余各组小鼠腹腔注射0.01%CCl4花生油溶液,小鼠禁水不禁食18 h后眼球采血并测定血清中碱性磷酸酶(ALP)、天门冬氨酸氨基转移酶(AST)、丙氨酸氨基转移酶(ALT)、总超氧化物歧化酶(T-SOD)和谷胱甘肽过氧化物酶(GSH-Px)活性,以及丙二醛(MDA)和总胆红素(TBIL)含量,同时采集肝脏组织测定肿瘤坏死因子α(TNF-α)和白细胞介素-6(IL-6)含量。结果表明:FSC能有效缓解CCl4诱导的急性肝损伤,与对照组比,模型组小鼠血清AST、ALT、ALP活性及TBIL含量显著升高(P<0.05),表明肝损伤模型构建成功;FSC各剂量组小鼠血清AST、ALT、ALP活性及TBIL含量随着FSC剂量的升高而下降,且在不同剂量条件下均与模型组呈显著差异(P<0.05);FSC各剂量组小鼠血清MDA含量随着FSC剂量的增加而下降,而T-SOD、GSH-Px活性随着FSC剂量的增加均升高,不同剂量条件下的MDA含量和T-SOD活性,以及中、高剂量条件下的GSH-Px活性较模型组均差异显著(P<0.05);FSC各剂量组血清中TNF-α、IL-6含量随着FSC剂量的增加而下降,且在不同剂量条件下较模型组差异显著(P<0.05)。说明一定剂量的FSC对CCL4诱导的急性肝损伤具有保护作用,其作用机制可能与提高清除自由基酶的活性,抑制肝脏组织中自由基脂质过氧化反应,抑制炎性细胞因子的释放有关。

桑拿脱水和低氧刺激后运动对白细胞热休克蛋白70表达及有氧能力的影响

目的:通过观察桑拿高温脱水和低氧恢复期运动时的白细胞热休克蛋白70(HSP70)、最大吸氧量(VO2max)、血乳酸(BLa)的变化,并与常温条件下相同运动负荷时相比较,探讨桑拿高温脱水和低氧刺激后恢复期运动对热休克蛋白表达和有氧能力的影响。方法:10名身体健康的体育系男性大学生,在三种不同环境下进行递增负荷运动:(1)桑拿前(常温条件,25℃,相对湿度65%);(2)桑拿后(进行桑拿浴之后,常温条件,25℃,相对湿度65%);(3)低氧后(低氧实施期之后,常温条件,25℃,相对湿度65%),分别测试递增负荷运动前安静时、运动后即刻、运动后3小时受试者白细胞HSP70表达、血液SOD活性和MDA含量及VO2max、血乳酸(BLa)和HR等生理机能指标。结果:(1)桑拿前安静时的HSP70(13701.87±5367.17)水平明显高于桑拿后(7517.57±1980.01,P<0.05)和低氧后(2850.79±2233.81,P<0.05);(2)桑拿后和低氧后运动后恢复期除MDA外,HSP70水平、SOD浓度低于桑拿前。(3)桑拿后和低氧后的VO2max及运动时间都较桑拿前略有增加。同时HRmax和BLa浓度有所下降,但无显著性差异(P>0.05)。以上结果表明,运动负荷可增加热休克蛋白70表达量,在桑拿后恢复期有可能具有“应激保护”作用。桑拿和低氧刺激后运动负荷的刺激,增加有氧能力,可能与热休克蛋白合成变化有关。

桑拿浴后渐增负荷运动对有氧能力的影响

观察10名身体健康的体育系男子大学生在桑拿高温脱水恢复期,运动时的最大吸氧量(VO2max)、血乳酸浓度(HLa)、通气阈值(VT)的变化,并与常温条件相同运动负荷时相比较,探讨桑拿高温脱水恢复期时的运动对有氧能力的影响。其结果发现在桑拿浴后,恢复期常温条件运动时,VO2max、VT及运动时间都比常温条件增加,同时HR和HLa浓度有所下降,表明桑拿后恢复期可能具有"应激保护"作用。

热休克蛋白90在预热适应成纤维细胞中作用

目的建立小鼠成纤维细胞株NIHF-3T3应激适应细胞模型,探讨热休克蛋白90(HSP90)在应激适应中的作用及机制。方法通过预热适应(42℃,20min)建立应激适应细胞模型,并通过再次热应激时(44℃,40min)细胞膜损伤指标、DNA损伤指标、细胞形态学改变综合评价适应效果。以免疫细胞化学检测应激适应对细胞内HSP90合成和细胞内定位的影响。结果结合预适应后再次热应激所致的损害情况,初步确定预适应后6h为最佳应激保护时间。再次热应激时,细胞膜损伤指标、DNA损伤指标、细胞形态改变均表明预适应后预处理(42℃,20min)6h后,再次热应激时,培养液中乳酸脱氢酶(LDH)漏出变化率、细胞DNA受损较直接热应激组为轻,细胞损伤状态减轻。热应激40min后细胞内HSP90含量均呈现下降趋势,并伴有细胞内的重新分布。结论通过对NIH-3T3细胞进行预适应处理,通过观测细胞膜损伤、DNA损伤、细胞形态变化情况,确定应激保护的时间点,建立了细胞应激适应模型,初步确认HSP90在该模型中的保护作用。

HSP90高表达细胞系的建立及其对底物蛋白结合能力的影响

目的建立HSP90稳定高表达细胞系,探讨HSP90在应激适应中的作用及其机制。方法含人类HSP90β全长基因的质粒pSmycHSP经酶切鉴定、大肠杆菌转化、质粒提取纯化后,以电穿孔转染,G418筛选建立HSP90稳定高表达的小鼠成纤维细胞系。通过免疫共沉淀方法,观察HSP90表达与底物蛋白HSP70、Raf-1的结合情况。结果经G418筛选的阳性克隆HSP90clone细胞HSP90胞膜、胞核强染。免疫共沉淀结果表明,细胞内HSP90含量、HSP90结合的Raf-1量、HSP90结合的HSP70量变化趋势为外源性HSP90转染细胞>对照。结论HSP90高表达导致HSP90蛋白与部分底物蛋白的结合性改变。提示细胞可通过HSP90分子伴侣功能,抗衡应激反应中蛋白质变性引起的细胞损伤。

高温条件下在蛋鸡日粮中添加柠檬酸的效果

高温条件下 ,对315只黄金褐蛋鸡在日粮中添加柠檬酸的效果进行了试验 ,设0 %、0.1 %、0.2 %、0.3 %、0.4 %、0.5 %6个柠檬酸水平和0.3 %菌宝共7个处理组。28d试验结果表明 ,柠檬酸可以减缓蛋鸡热应激 ,提高产蛋率和饲料报酬 ;0.1 %～0.4 %的柠檬酸组与0.3 %的菌宝组效果相当 ;各处理对粪便水分无显著影响。与对照组相比 ,柠檬酸添加组和菌宝组平均产蛋率分别提高9.69 %、8.08 %、8.67 %、8.81 %、2.97 %和8.69 %;饲料报酬分别提高7.60 %,6.46 %、7 98 %、7.98 %、1.90 %和6.84 %;每只鸡每天多收入0.017元、0.011元、0.015元、0.010元、0.00元和0.

四氢小檗碱改善血管内皮细胞损伤的研究

目的:采用四氢小檗碱(tetrahydroberberine,THB)作用于模拟脑缺血再灌注损伤的糖氧剥夺模型(oxygen glucose deprivation,OGD)和脂多糖(lipopolysaccharides,LPS)诱导血管内皮细胞损伤模型,探讨其对血管内皮细胞损伤的干预作用。方法:采用MTT比色法检测THB终浓度分别为0、2.5、5、10、20、40μg/mL对EA.hy926细胞存活率的影响。实验第I小组分组:正常对照组、OGD组、OGD+THB-10μg/mL组、OGD+THB-20μg/mL组、OGD+THB-40μg/mL组;实验第Ⅱ小组分组:正常对照组、LPS组、OGD+LPS组以及OGD+LPS+THB-20μg/mL组。通过荧光定量PCR检测实验I、Ⅱ处理小组的炎症相关因子如Caspase-1、ASC、IL-1β、IL-6等基因的相对表达量,同时Western Blot分析检测IL-1β、HO-1蛋白表达量。结果:MTT法结果表明四氢小檗碱对EA.hy926细胞存活无影响即不存在细胞毒性。实验I、Ⅱ处理小组的qPCR结果显示,OGD模型能明显通过下调Caspase-1、ASC、IL-1β与IL-6基因的表达发挥抗炎的应激保护作用;THB对于OGD模型的抗炎效果一般,但通过OGD+LPS组与OGD+LPS+THB-20μg/mL组对比发现THB也是通过下调炎症基因表达发挥抗炎效果的。Western Blot分析检测IL-1β蛋白表达量与qPCR结果一致,HO-1蛋白作为保护因子表达量与炎症因子荧光定量结果相反。结论:OGD模型可以提高细胞应激保护作用,四氢小檗碱通过下调Caspase-1、ASC、IL-1β与IL-6基因的表达,上调HO-1蛋白表达,抑制NLRP3炎症小体的活化发挥抗炎的作用。

大鼠保护性热应激模型中肿瘤坏死因子及一氧化氮的研究

目的 通过研究保护性热应激模型建立过程中肿瘤坏死因子 (tumornecrosisfactor,TNF)及一氧化氮 (nitricoxide,NO)的动态变化规律及其作用 ,为该模型的建立提供进一步的理论依据。方法 给予大鼠适量热应激处理 ,然后分离血清 ,分别用放射免疫均相竞争法和硝酸还原酶法测定热应激后 0～ 2 4h不同时相TNF、NO的浓度。结果 热应激后 2、4、8、12h ,TNF浓度升高 ,与对照组比较 ,差异有显著性 (P <0 .0 5、P <0 .0 1) ,0h、2 4h与对照组的差异无显著性 (P >0 .0 5 )。热应激后 4h ,血清TNF浓度达到峰值 [(3.35± 0 .2 0 )ng/ml],较 0h和 2h明显升高 ,差异有显著性 (P <0 .0 1) ,8、12、2 4h较 4h明显降低 ,差异有显著性 (P <0 .0 5、P <0 .0 1) ,2 4h恢复到正常水平。热应激后 2、4、8、12、2 4h ,大鼠血清NO浓度较对照组升高 ,差异有显著性 (P <0 .0 5 )。热应激后 8h ,NO浓度达到峰值 [(10 8.2 1± 2 7.89) μmol/L],与 0、2、4h比较 ,差异有显著性 (P <0 .0 1) ,12h开始下降 ,与 8h比 ,差异有显著性 (P <0 .0 5 ) ,2 4h进一步降低 ,但仍然高于对照组。结论 保护性热应激模型建立过程中TNF、NO起了很重要的作用。

Preparation of Purified and Inactivated HP-PRRS Vaccine

[Objective] The aim of this study was to improve the purification and protective potency of HP-PRRS inactivated vaccine. [Method] HP-PRRS virus that had been multiplied inside Marc-145 cells was collected and concentrated 50 times and then inactivated. Complete virions were separated and collected by chromatography with Sepharose 4 Fast Flow. Oil adjuvant was added to prepare purified inactivated vaccine. [Result] Viral protein was separated from other proteins by purification and the viral protein contents ranged from 76.7% to 82.4%, and 96% of the expected serum proteins were removed. Protective potency of purified vaccine was above 4/5 and positive conversion rate of antibody was over 86%, both higher than that of unpurified vaccine. The differences were significant. [Conclusion] The experiment il-lustrated that the immune efficacy of vaccine can be enhanced through concentrat- ing and purifying, while the non-viral protein can be removed, so that allergic reaction and stress response cadsed by vaccine inoculation can be avoided.

Association of high expression in rat gastric mucosal heat shock protein 70 induced by moxibustion pretreatment with protection against stress injury

AIM:To study the effect of moxibustion on Zusanli or Liangmeng point on gastric mucosa injury in stress-induced ulcer rats and its correlation with the expression of heat shock protein 70 (HSP70). METHODS:Sixty healthy SD rats (30 males,30 females) were divided into control group,injury model group,Zushanli point group,Liangmeng point group. Stress gastric ulcer model was induced by binding cold stress method. Gastric mucosa ulcer injury (UI) index was calculated by Guth method. Gastric mucosa blood flow (GMBF) was recorded with a biological signal analyzer. Protein content and gene expression in gastric mucosal HSP70 were detected by immunohistochemistry (IHC) and reverse transcription polymerase chain reaction (RT-PCR). Thiobarbital method was used to determine malondialdehyde (MDA) content. Gastric mucosal endothelin (ET) and prostaglandin E2 (PGE2) were analyzed by radioimmunoassay. RESULTS:High gastric mucosal UI index,high HSP70 expression,low GMBF and PGF2,elevated MDA and ET were observed in gastric mucosa of rats subjected to cold stress. Moxibustion on Zusanli or Liangmeng point decreased rat gastric mucosal UI index,MDA and ET. Conversely,the expression of HSP70,GMBF,and PGE2 was elevated in gastric mucosa after pretreatment with moxibustion on Zusanli or Liangmeng point. The observed parameters were significantly different between Zusanli and Liangmeng points. CONCLUSION:Pretreatment with moxibustion on Zusanli or Liangmeng point protects gastric mucosa against stress injury. This protection is associated with the higher expression of HSP70 mRNA and protein,leading to release of PGE2 and inhibition of MDA and ET,impairment of gastric mucosal index.

Protective effect of melatonin against multistress condition induced lipid peroxidation via measurement of gastric mucosal lesion and plasma malondialdehyde levels in rats

AIM： To study the protective effect of a natural antioxidant, melatonin, against multistress condition induced lipid peroxidation v/a determination of gastric damage and plasma malondialdehyde （MDA） level by high performance liquid chromatography in rats. METHODS： We compared indomethacin-induced gastric damage and MDA plasma level in three groups of rats： unoperated, bile duct ligated and sham-operated and evaluated the role of the melatonin on gastric damage and plasma MDA level. Indomethacin and melatonin were injected intraperitoneally in doses of 50 mg/kg and 20 mg/kg, respectively. Animals were killed 4 h after indomethacin injection. RESULTS： Indomethacin induced more severe gastric damage and plasma MDA level in bile duct ligated animals was significantly higher （3.1±0.04 μmol/L） than sham （2.8±0.04 μmol/L） and unoperated animals （1.4±0.08 μmol/L）. Pretreatment with melatonin reduced indomethacin-induced gastric damage and plasma MDA level. CONCLUSION： Considering the results of this study, we suggest that in multistress conditions the intensity of gastric damage and the plasma MDA level are great and melatonin reduces the negative effect of lipid peroxidation and cell damage by oxidative stress in multistress conditions due to its antioxidizing activity.

Protective Effects of Vitamin E on Diabetes-induced Oxidative Stress Status and Homocysteine in the Rat Heart

Objective： We aimed to investigate protective effects ofvit E on oxidative stress status and homocysteine （Hey） in cardiac tissue of diabetic rats. Methods： Sixteen Wistar male rats were treated with STZ （streptozotocin） （60 mg/kg） to induce diabetes. Diabetic rats were divided into two groups： NTD （non-treated diabetic） and VETD （vit E-treated diabetic） rats. The VETD group received 300 mg/kg vit E with daily feeding. Eight normal rats of the same age were used as the control group. After 6 weeks, the rats were anesthetized, their cardiac tissue was removed, and homogenated supernatant was separated. Samples were assayed for TAC （total antioxidant capacity）, LPO （lipid peroxidation）, nitrite （NO2）, nitrate （NO3）, and Hcy. Key Findings： The contents of LPO, NO3 and Hcy in NTD compared to control group indicate a significant increase, but the levels of these parameters decreased in VETD （p 〈 0.05）. There was a significant decrease in the amount of TAC in the NTD group but in VETD group, that significantly increased （p 〈 0.05）. The amount of NO2 in NTD and VETD groups, compared to the control group, did not show any significant changes （p 〉 0.05）. Conclusions： Significant decrease of oxidative stress and Hey in the cardiac tissue caused by vit E supplementation strongly indicated that this radical scavenger may promote a protective effect on diabetic cardiomyopathy through the attenuation of oxidative stress and increase antioxidant defense mechanism.

肺热咳嗽服良药

咳嗽．是机体受到伤害时的一种保护性应激反应．是将可能对机体产生进一步伤害的异物或病理产物“痰”．驱除体外的一种病理反应方式。治咳选药。绝不可见咳止咳．以单纯止咳为治疗目的。如果是由外感邪气导致的咳嗽，早用、滥用镇咳收敛药，会造成邪滞，反使病情变得复杂难治．甚至可能并发肺炎等严重疾病。因此。

冬季风寒咳嗽良药

咳嗽是肺系疾病的主要症状之一,也是机体受到伤害时的一种保护性应激反应。选药治咳,绝不可见咳止咳,以单纯止咳为治疗目的。如果是由外感邪气导致的咳嗽,早用、滥用镇咳收敛药,会造成邪滞,使病情变得复杂难治,甚至可能并发肺炎等严重疾病。中医强调辨证论治,着眼于造成肺气不得宣畅的原因来治疗。

内质网应激

内质网应激(ER stress)是真核细胞的一种保护性应激反应,通过ER stress细胞降低胞内未折叠蛋白的浓度,阻碍未折叠蛋白发生凝集,哺乳动物细胞ER stress过程比原生动物和酵母细胞要复杂,但都具有一些共同的特点。

银屑病表皮热休克蛋白27、70、60的表达

目的探讨热休克蛋白(HSP)在银屑病发病中的作用。方法通过免疫组化和图像分析检测了25例银屑病患者治疗前后皮损、非皮损区表皮组织中HSP27、HSP70和HSP60的表达,并与6例正常人作对照。结果HSP27、HSP70在非皮损、正常人表皮中呈基础表达,在银屑病患者皮损中的表达很弱,治愈后表皮中HSP27、HSP70的表达又恢复;HSP60的表达在银屑病皮损组表皮中均为阳性,而银屑病非皮损组、治愈后组表皮中及正常人对照表皮组织中HSP60的表达均阴性。结论热休克蛋白在银屑病应激保护机制中可能发挥一定的作用。

The mechanisms of brain ischemic insult and potential protective interventions

The mechanisms of brain ischemic insult include glutamate excitoxicity, calcium toxicity, free radicals, nitric oxide, inflammatory reactions, as well as dysfunctions of endoplasmic reticulum and mitochondrion. These injury cascades are interconnected in complex ways, thus it is hard to compare their pathogenic importances in ischemia models. And the research in cellular and molecular pathways has spurred the studies in potential neuroprotections mainly in pharmacological fields, such as anti-excitotoxic treatment, calcium-channel antagonism, approaches for inhibition of oxidation, inflammation and apoptosis, etc. Besides, other protective interventions including thrombolysis, arteriogenesis, regeneration therapy, and ischemia preconditioning or postconditioning, are also under investigations. Despite the present difficulties, we are quite optimistic towards future clinical applications of neuroprotective agents, by optimizing experimental approaches and clinical trials.

Salusins protect myocardium against ischemic injury by alleviating endoplasmic reticulum stress

Salusins are regulatory peptides that affect cardiovascular function. We previously reported that salusin-a and -β protected cultured cardiomyocytes from serum deprivation-induced cell death through upregulating glucose-regulated protein 78 （GRP78）, an endoplasmic reticulum （ER） resident protein whose overexpression acts as a marker and suppressor of ER stress. The present study examined whether salusin-α and -β inhibit ER stress in ischemic myocardium. In a rat model of myocardial infarction created by ligating the left anterior descending coronary artery （LAD）, salusin-α or -β was intravenously injected at 5 or 15 nmol kg-1 15 min prior to 2 h of LAD occlusion. The high dose of salusin-α and -β3 significantly improved heart function and hemodynamics in LAD-occluded rats, but had no effects in sham-operated rats. The arrhythmias caused by LAD oc- clusion were markedly attenuated by salusin-α and -β. The apoptotic rate in ischemic myocardium was reduced from 31.5%±3.7% to 19.8%±2.2% and 12.3%±2.2%, and the infarct size was reduced from 53.4%±4.0% of the risk area to 26.5%±9.7% and 23.7%±8.9% by 15 nmol kg-1 salusin-α and -β, respectively. Furthermore, salusin-α and -β prevented the ac- tivation of GRP78 and ER stress-specific apoptotic effectors caspase-12 and CHOP （C/EBP homologous protein）, and attenu- ated the reduction of an ER stress-associated antiapoptotic protein Bcl-2 in ischemic cardiac tissue. The salusins also inhibited the ER stress induced by tunicamycin in cultured rat H9c2 cardiomyocytes. These results indicate that salusins protect myo- cardium against ischemic injury by inhibiting ER stress and ER stress-associated apoptosis.

Protective effects of β-dihydroagarofuran-type sesquiterpene against Aβ_(25-35)-induced neuronal apoptosis and oxidative damage

Excessive beta-amyloid （Aβ） plays a detrimental role in the pathogenesis of Alzheimer＇s disease （AD）, which is closely associated with apoptosis and oxidative stress in neurons. Therefore, identification of active small molecules with potent effects on neutralizing Aβ-induced neurotoxicity would be a promising strategy for delaying or preventing AD progression. In the present study, we discovered that pretreatment with CF-1 （（1R,2S,4R,5S,7R,9S, IOS）-1,15-diacetoxy-2-benzoyloxy-9-cinnamoyloxy- β-di-hydroagarofuran）, a sesquiterpene isolated from the seeds of Celastrus flagellaris, attenuated Aβ25_35-induced reduction in cell viability in a concentration-dependent manner, as evaluated by the 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide （MTT） assay. Above neuroprotective effect of CF-1 was associated with a significant decrease of apoptotic cells as measured by 4,6-diamidino-2-phenylindole （DAPI） staining, which concurrently happened with marked inhibition in the level of cleaved Caspase-3, an apoptotic executive protein. CF-1 pretreatment also markedly reduced the intracellular accumulation of reactive oxygen species （ROS） following Aβ exposure in SH-SY5Y neuroblastoma cells, but such pretreatment had no notable influence on 2,2-diphenyl-l-picrylhydrazyl （DPPH） scavenging. In conclusion, we demonstrated that a novel natural product, CF-1, possessed promising effects against Aβ-induced neuronal apoptosis and oxidative stress, which could be a potential drug lead or candidate for the treatment of Aβ-associated neurotoxicity.