21—氨基类固醇U—75412E对石英细胞毒性抑制作用的研究

观察了２１－氨基类固醇类药物Ｕ－７５４１２Ｅ对石英致肺伤的抑制作用，结果表明，Ｕ－７５４１２Ｅ具有很强的清除活性氧基团稳定细胞膜作用，显著降低了过氧化氢，乳酸脱氢酶和超氧化物歧化酶的释放，阻断了石英对肺泡巨噬细胞的损伤。     

21─氨基类固醇U─75412E对石英细胞毒性抑制作用的研究

观察了２１一氨基类固醇类药物Ｕ一７５４１２Ｅ对石英致肺巨噬细胞损伤的抑制作用。结果表明，Ｕ一７５４１２Ｅ具有很强的清除活性氧基团稳定细胞膜作用，显著降低了过氧化氢，乳酸脱氢酶和超氧化物歧化酶的释放。阻断了石英对肺泡巨噬细胞的损伤。     

21-氨基类固醇对大鼠实验性矽肺治疗的病理观察

我国矽肺的发病率仍很高 ,对矽肺的治疗自然是当前研究的热门课题之一。为了寻找治疗矽肺的理想药物 ,我们采用了 2 1 氨基类固醇 (Ｌａｚａｒｏｉｄ ,ｕ 75 412Ｅ)试验性治疗大鼠矽肺 ,观察治疗后大鼠矽肺的病理形态学改变 ,旨在探讨 2 1 氨基类固醇对矽肺纤维化的疗效作用机理 ,为尘肺治疗提供实验依据。1　材料与方法1 1　大鼠矽肺模型制备健康雄性大鼠 30只 ,体重 2 0 0～ 2 5 0ｇ ,经吸入麻醉后非暴露式气管注入石英粉尘 5 0ｍｇ(由中国预防医学科学院劳动卫生研究所提供 )。1 2　大鼠分组　　将染尘大鼠按体重排序后随机分为矽肺治疗…     

石英对大鼠肺上皮细胞和成纤维细胞的增殖抑制及致hprt基因突变的研究

目的探讨石英对大鼠肺泡II型上皮细胞和成纤维细胞的增殖抑制及致hprt基因突变的差异。方法采用(MTT噻唑蓝)比色法检测大鼠肺成纤维细胞和肺泡II型上皮细胞的增殖抑制毒性。以含6-巯基鸟嘌呤(6-TG)的培养基筛选突变细胞克隆,检测hprt基因突变频率。结果在相同的染毒条件下,肺泡II型上皮细胞对石英刺激比成纤维细胞更易受损伤,上皮细胞半数增殖抑制浓度(IC50)约为140μg/cm2,成纤维细胞的IC50约为282μg/cm2。在致hprt基因突变方面,石英粉尘对两种细胞都有致突变作用。在同样剂量染毒条件下,肺泡Ⅱ型上皮细胞的hprt突变频率为84.2×10-6～156.6×10-6,较成纤维细胞(67.6×10-6～114.3×10-6)更容易发生hprt基因突变,差异有显著性(P<0.05)。结论石英对大鼠肺成纤维细胞和肺泡II型上皮细胞的细胞毒性及对hprt基因致突变作用强度存在明显差异。肺泡II型上皮细胞对石英刺激的反应敏感性高于成纤维细胞。     

矽肺患者肺泡灌洗液的肿瘤坏死因子检测和促成纤维细胞生长能力的研究

对５６例矽肺中尉得支气管肺泡灌洗液（ＢＡＬＦ）及ＢＡＬＦ中肺巨噬细胞（ＡＭ）无血清培养上清液中ＴＮＦ含量进行了检测，同时探讨了它们对人胚肺成纤维细胞（ＦＢ）增殖活性的影响，结果表明：ＢＡＬＦ中可疑矽肺上ＴＮＦ含量高于其它各种期矽肺，随着期别增加而减少，ＡＭ上清液中ＴＮＦ含量ＩＩ期高于Ｉ期，ＢＡＬＦ和ＡＭ上清液促ＦＢ增殖活性与ＴＮＦ含量高低有一定关系，随着ＴＮＦ浓度增高而增高，但不成平行关系，这可能     

p53/p21信号转导通路在石英诱导人胚肺成纤维细胞恶性转化中的作用

目的观察石英诱导恶性转化的人胚肺成纤维细胞(T-HELF)中p53蛋白的表达量,并探讨p53蛋白对p21、细胞周期蛋白D1和细胞周期蛋白依赖激酶4(CDK4)蛋白表达量及蛋白间相互作用的影响。方法利用胞浆胞核分离技术,分别提取人胚肺成纤维细胞(HELF)、T-HELF胞浆和胞核蛋白,运用Western blot检测p53、磷酸化p53及p21蛋白在细胞中的表达量及分布。利用RNA干扰技术,在T-HELF中转染2μg p53 siRNA,同时设立转染CMV-neo空白载体质粒的对照组,观察p53、磷酸化p53、p21、细胞周期蛋白D1和CDK4的蛋白表达量及改变。用免疫沉淀方法检测HELF和T-HELF中p21、细胞周期蛋白D1及CDK4蛋白结合物水平的变化,并在T-HELF中分别加入20μmol/L p53化学抑制剂pifithrin-α(PFT-α)和2μg p53转染质粒,观察其对p21、细胞周期蛋白D1及CDK4蛋白间相互作用的影响。结果石英刺激HELF可引起胞核中p53及磷酸化p53蛋白表达量显著增高(P<0.05),T-HELF胞核中p53的蛋白表达量较HELF显著降低(P<0.05)。转染p53 siRNA后,p53蛋白与对照组相比表达下降,p21及细胞周期蛋白D1蛋白表达量增加,差异均有统计学意义(P<0.05),尚未观察到CDK4蛋白表达量的变化(P>0.05)。免疫沉淀结果显示抑制p53的表达可下调p21与细胞周期蛋白D1蛋白复合物的表达量(P<0.05),但尚未观察到其对p21、细胞周期蛋白D1与CDK4蛋白结合的影响(P>0.05)。结论 p53可通过调控p21、细胞周期蛋白D1的蛋白表达和蛋白间相互作用参与石英诱导的恶性转化过程。     

二氧化硅影响人肺成纤维细胞α-平滑肌肌动蛋白表达的实验研究

目的 探讨二氧化硅（SiO2）体内体外影响人肺成纤维细胞α-平滑肌肌动蛋白（α-SMA）的表达情况.方法 体内实验以SiO2灌注的大鼠矽肺模型为研究对象,实验组32例（7、14、21和28d各8例）,对照组32例.免疫组化法检测肌成纤维细胞标志物α-SMA的表达;体内实验以人肺成纤维细胞（HLF-02）为研究对象,分别用SiO2刺激的体外小鼠腹腔巨噬细胞系（RAW264.7细胞）上清液、SiO2未刺激的RAW264.7细胞上清液、SiO2悬液以及转化生长因子β1（TGF-β1）作用24 h,免疫印迹法检测α-SMA的表达变化情况.结果 （1）染尘28 d大鼠肺组织有表达α-SMA阳性的肌成纤维细胞出现.（2）RAW264.7细胞上清液（SiO2）可诱导HLF-02细胞α-SMA的表达,而TGF-β1可明显上调α-SMA表达.（3）单纯SiO2悬液对HLF-02细胞α-SMA的表达没有影响.结论 肌成纤维细胞与矽肺纤维化进展有关;体外条件下肌成纤维细胞的出现不是SiO2直接作用的结果,而与SiO2活化巨噬细胞分泌的介质TGF-β1有关.     

沙尘暴颗粒物对人肺成纤维细胞的细胞毒性研究

目的 探讨沙尘暴颗粒物(PM10、PM25)对人肺成纤维细胞的细胞毒性。方法 分别用50、100、150、200ug／ml的PM10和PM25对人肺成纤维细胞进行染毒,24h后测定细胞线粒体琥珀酸脱氢酶活力、细胞外乳酸脱氢酶和酸性磷酸酶的漏出量。结果 50ug／ml以上浓度的沙尘暴颗粒物可剂量依赖性地抑制人肺成纤维细胞的线粒体琥珀酸脱氢酶活力。在更高染毒浓度,沙尘暴颗粒物可引起细胞外乳酸脱氢酶和酸性磷酸酶的漏出增加。结论 沙尘暴颗粒物对人肺成纤维细胞可产生明显的毒性作用。线粒体可能是沙尘暴颗粒物毒作用的敏感部位。     

细胞外信号调节激酶/c-Jun氨基末端激酶在炭黑诱导的人胚肺成纤维细胞毒性中对激活蛋白-1信号通路的作用

目的 探讨细胞外信号调节激酶(extracellular signal-regulated kinases,ERK)/c-Jun氨基末端激酶(c-Jun N-terminal kinases,JNK)在炭黑诱导的人胚肺成纤维细胞(human embryonic lung fibroblasts,HELF)毒性中对激活蛋...     

硒和维生素E对紫外线引起DNA损伤的保护作用

目的 研究硒和维生素E对由紫外线诱导的DNA损伤的保护作用。方法 体外培养人肺成纤维细胞。加硒和维生素E处理2h后，紫外线分别照射7，15，30min，然后用单细胞凝胶电泳技术检测细胞DNA的损伤情况。结果 经紫外线直接照射的细胞DNA损伤严重，而在照射过程中加入中浓度的硒或维生素E后细胞DNA损伤明显减轻。结论 紫外线照射细胞可使DNA受到损伤，硒和维生素E具有拮抗这种损伤的作用，可能与其抗氧化等功能有关。     

Protective effects of vitamins C and E against hepatotoxicity induced by methyl parathion in rats

Male rats were given vitamins C+E, methyl parathion, or both daily via gavage for seven weeks. Body weight was decreased while liver weight increased significantly at the end of fourth and seventh weeks in the methyl parathion- and methyl parathion plus vitamin-treated groups. Serum total protein, albumin, triglyceride, low density lipoprotein-cholesterol (VLDL-cholesterol) levels decreased, and serum alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), γ-glutamyl-transferase (GGT), lactate dehydrogenase (LDH), and total cholesterol levels increased significantly in the methyl parathion- and the methyl parathion plus vitamin-treated rats. There was a statistically significant difference for all biochemical parameters when the methyl parathion plus vitamin-treated group was compared with methyl parathion-treated group. In electron microscopic investigation, cytopathological alterations were observed in hepatocytes of the methyl parathion- and the methyl parathion plus vitamin-treated rats. As a result, methyl parathion-induced hepatotoxicity is reduced by vitamins C+E, but vitamins C+E did not provide complete protection.     

Comparative analysis of the effects of flavonoids on proliferation, cytotoxicity, and apoptosis in human colon cancer cell lines

Summary Flavonoids are polyphenolic compounds that occur ubiquitously in foods of plant origin. Their proposed protective role in tumor development may prevail especially in the intestinal tract due to direct exposure of intestinal epithelia to these dietary ingredients. We have screened more than 30 flavonoids for their effects on cell proliferation and potential cytotoxicity in the human colon cancer cell lines Caco-2, displaying features of small intestinal epithelial cells, and HT-29, resembling colonic crypt cells. In addition, for selected compounds we assessed whether they induce apoptosis by determining caspase-3 activation. Studies on the dose dependent effects of the flavonoids showed antiproliferative activity of all compounds with EC₅₀ values ranging between 39.7 ± 2.3 μM (baicalein) and 203.6 ± 15.5 μM (diosmin). In almost all cases, growth inhibition by the flavonoids occured in the absence of cytotoxicity. There was no obvious structure-activity relationship in the antiproliferative effects either on basis of the subclasses (i.e., isoflavones, flavones, flavonols, flavanones) or with respect to kind or position of substituents within a class. In a subset of experiments we examined the antiproliferative activities of the most potent compound of each flavonoid subgroup in addition in LLC-PK₁, a renal tubular cell line, and the human breast cancer cell line MCF-7. Out of four flavonols tested, three displayed almost equal antiproliferative activities in all cell lines but fisetin was less potent in MCF-7 cells. The flavanones bavachinin and flavanone inhibited growth of Caco-2 and HT-29 cells with lower EC₅₀ values than that obtained in LLC-PK₁ and MCF-7 cells. The lower susceptibility of LLC-PK₁ and MCF-7 cells towards growth arrest was even more pronounced in the case of the flavone baicalein. Half maximal growth-inhibition in LLC-PK₁ and MCF-7 required 2.5 and 6.6 fold higher concentrations than that needed in the intestinal cell lines. The flavonoids failed to affect apoptosis in LLC-PK₁ and MCF-7, whereas baicalein and myricetin were able to induce apoptosis in HT-29 and Caco-2 cells. In conclusion, flavonoids of the flavone, flavonol, flavanone, and isoflavone classes possess antiproliferative effects in different cancer cell lines. The capability of flavonoids for growth inhibition and induction of apoptosis can not be predicted on the basis of their chemical composition and structure. Received: 28 December 1998, Accepted: 18 March 1999     

Protective effects of broccoli (Brassica oleracea) and its active components against radical-induced oxidative damage

The radical scavenging effect and protective potential from oxidative damage by radical generator, 2,2'-azobis (2-amidinopropane) dihydrochloride (AAPH), in renal epithelial LLC-PK1 cell of broccoli (Brassica oleracea) were investigated and identified the active components under the bioassay-linked fractionation method. The MeOH extract, and fractions of CH2Cl2, BuOH and H2O from broccoli showed the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging effect in a dose-dependent manner. In addition, they exerted the protective effect against LLC-PK1 cellular damage induced by AAPH dose-dependently. In particular, the BuOH fraction was evaluated as the most active fraction, indicating that the BuOH fraction contains the active components with antioxidative capacity. Employing a bioassay-linked fractionation method, the active principles were isolated and characterized as 1,2-disinapoylgentiobiose and 1-sinapoyl-2-feruloylgentiobiose from the BuOH fraction. These two compounds from broccoli displayed potent antioxidant effects against the DPPH radical, showing the IC50 values of 5.18 and 7.52 microg/mL, respectively. Moreover, the compounds significantly and dose-dependently recovered cell viability lowered by AAPH treatment, suggesting the protective roles from cellular oxidative damage. The present study suggests that broccoli has excellent antioxidative potential and the hydroxycinamic acid esters from broccoli, 1,2-disinapoylgentiobiose and 1-sinapoyl-2-feruloylgentiobiose, are considered as the active components with antioxidative effect.     

Protective effects of broccoli (Brassica oleracea) against oxidative damage in vitro and in vivo

The antioxidative effect and protective potential against diabetes of the broccoli flower were investigated both in vitro and in a diabetic rat model. Among fractions of MeOH, CH2Cl2, BuOH, and H2O, the BuOH fraction exerted the strongest inhibitory activities on 1,1-diphenyl-2-picrylhydrazyl radical, radical-induced protein oxidation, and nitric oxide generation by sodium nitroprusside. The in vitro results suggest that the BuOH fraction from the broccoli flower has a protective potential against oxidative stress. The rat model with diabetes induced by streptozotocin was employed to evaluate the protective effect of the BuOH fraction in vivo. Diabetic rats showed reduced body weight gain and heavier kidney and liver weights than normal rats, while oral administration of the BuOH fraction at an oral dose of 100 or 200 mg/kg body weight/d for 20 d attenuated the physiological changes induced by diabetes. In addition, oral administration of the BuOH fraction to diabetic rats led to significant decreases in serum glucose and glycosylated protein, while it resulted in the increase of serum albumin, implying that the BuOH fraction improves the abnormal metabolism of glucose and protein that leads to oxidative stress. Moreover, it significantly reduced thiobarbituric acid-reactive substance levels in serum, hepatic and renal mitochondria. This suggests that the BuOH fraction would alleviate the oxidative stress associated with diabetes through the inhibition of lipid peroxidation. The present study demonstrates that the BuOH fraction has an antioxidative effect in vitro and it protects against oxidative stress induced by diabetes in an in vivo model.     

Protective effects of vitamin E against 3,3',4,4',5-pentachlorobiphenyl (PCB126) induced toxicity in zebrafish embryos

3,3',4,4',5-Pentachlorinated biphenyls 126 (PCB126) is a global environmental contaminant that can induce cellular oxidative stress. We investigated whether vitamin E can protect against toxicity from PCB126 during zebrafish (Danio rerio) development. Zebrafish embryos were exposed to 100nM PCB126 and compared with a second group that was co-exposed with 100muM vitamin E until 5 days post fertilization. PCB126 induced pericardial sac edema, yolk sac edema, and growth retardation in zebrafish embyos. In contrast, vitamin E co-exposure group did not show any gross changes. Real-time PCR results showed that vitamin E co-exposure group were restored to control group for the expression levels of heat shock protein 70 Cognate, aryl hydrocarbon receptor type-2, cytochrome P450 1A, and superoxide dismutase-1. These data give insights into the use of vitamin E to reduce PCB126-mediated toxicity and into the use of zebrafish embryos for exploring mechanisms underlying the oxidative potential of AHR agonists.     

Role of antibody dependent cell mediated cytotoxicity (ADCC) in Sm-p80-mediated protection against Schistosoma mansoni

Schistosomiasis is a major health problem in the developing world and for international travelers to the endemic countries. Existing strategies to control schistosomiasis have had limited successes so far. The addition of an effective vaccine in existing control measures would be greatly beneficial in reducing the impact of the disease. In this regard, Sm-p80 mediated protection against intestinal schistosomiasis caused by Schistosoma mansoni has been observed to be promising in two animal models of infection and disease. In this study, the role of antibody dependent cell mediated cytotoxcity (ADCC) was deciphered in Sm-p80-mediated protection especially in the elimination of lung stage schistosomula. This was achieved using lung lavage cells and lung cells that were isolated from mice immunized with and without Sm-p80 formulated in a recombinant vaccine formulation. Significant differences were observed in cytotoxicity assays using immune sera with the lung lavage cells which showed 51% more killing of schistosomula and elevated levels of nitric oxide in the supernatants were detected compared to controls.     

Protective effect of enzymatic hydrolysates from highbush blueberry (Vaccinium corymbosum L.) against hydrogen peroxide-induced oxidative damage in Chinese hamster lung fibroblast cell line

Blueberry was enzymatically hydrolyzed using selected commercial food grade carbohydrases (AMG, Celluclast, Termamyl, Ultraflo and Viscozyme) and proteases (Alcalase, Flavourzyme, Kojizyme, Neutrase and Protamex) to obtain water soluble compounds, and their protective effect was investigated against H₂O₂-induced damage in Chinese hamster lung fibroblast cell line (V79-4) via various published methods. Both AMG and Alcalase hydrolysates showed higher total phenolic content as well as higher cell viability and ROS scavenging activities, and hence, selected for further antioxidant assays. Both AMG and Alcalase hydrolysates also showed higher protective effects against lipid peroxidation, DNA damage and apoptotic body formation in a dose-dependent fashion. Thus, the results indicated that water soluble compounds obtained by enzymatic hydrolysis of blueberry possess good antioxidant activity against H₂O₂-induced cell damage in vitro.     

Protective effects of green and white tea against benzo(a)pyrene induced oxidative stress and DNA damage in murine model

In the current investigation, the ameliorative effect of green tea (GT) and white tea (WT) against benzo(a)pyrene (BaP) induced oxidative stress and DNA damage has been studied in the livers and lungs of Balb/c mice. A single dose of BaP (125 mg/kg, b.w. orally) increased the levels of lipid peroxidation (LPO) and decreased endogenous antioxidants such as superoxide dismutase (SOD), glutahione reductase (GR), catalase (CAT), and glutathione (GSH) significantly. Pretreatment with GT and WT for 35 days before a single dose of BaP elevated the decreased activity of GR, SOD, and CAT in liver tissue and also tended to normalize the levels of GSH and LPO in both hepatic and pulmonary tissues. The percentage of DNA in comet tail and 8-hydroxy-2'-deoxyguanosine levels reflected the decreasing pattern of DNA damage from the BaP-treated group to the groups that received pretreatment with GT and WT. Our study concludes that both GT and WT are effective in combating BaP induced oxidative insult and DNA damage. However, WT was found to be more protective than GT with respect to CAT (only in the liver), percentage of DNA in comet tail (only in the lungs), GST activity, and GSH content in both the tissues.     

Protective effect of raisin (currant) against spatial memory impairment and oxidative stress in Alzheimer disease model

Objectives: Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by progressive pathological changes of the brain. A number of studies demonstrated compelling evidence of the importance of oxidative processes in AD pathogenesis. Raisin contains polyphenol, phenolic acid, and tannin compounds, which have antioxidant and anti-inflammatory properties. The present study was aimed to evaluate the protective effect of raisin on neurobehavioral and histological changes in rats with Alzheimer.

Methods: Animal model of AD was induced by intraperitoneal injection of aluminium chloride for 60 days (100?mg/kg body weight). During these 60 days both Alzheimer’s and control rats were given 6?g of raisin per rat. At the end of the treatment, blood was collected for biochemical assessment. We used a Morris water task and passive avoidance test to assess spatial memory.

Results: Our results showed that aluminium exposure significantly decreased the memory in the MWT and passive avoidance test, but in the raisin?+?AlCl₃ group, it significantly increased spatial memory in both tests. Also, Aluminium exposure significantly increased malondialdehyde (MDA) and decreased ferric reducing ability of plasma (ferric reducing/antioxidant power (FRAP)), while treatment with raisin significantly decreased MDA and increased FRAP in plasma of blood.

Discussion: Our findings showed that raisin has a neuroprotective effect and improves the spatial memory in AD animal models.