矢车菊素上调CYP7A1表达促进脂肪变性L02细胞内胆固醇降解

为了研究矢车菊素对肝细胞胆固醇代谢的影响,以人肝细胞系L02为研究对象,采用软脂酸建立肝细胞脂肪变性模型并通过不同浓度矢车菊素处理,采用ELISA检测细胞内胆固醇及胆汁酸浓度,RT—PCR和Westernblot检测胆固醇降解限速酶CYP7A11i3．RNA及蛋白表达水平。结果显示：与空白组相比,10g／L和30g／L软脂酸组L02细胞内胆固醇水平随软脂酸浓度增加而升高（P〈0．05）,而胆汁酸水平没有明显变化,此过程伴随cYP7A1蛋白表达上调（P〈0．05）。舍有30g／L软脂酸的模型细胞组内添加5mg／L以上矢车菊素可显著降低细胞内胆固醇水平并同时增加胆汁酸浓度（P〈0．05）,此过程伴随CYP7A1mRNA及蛋白的显著上调（P〈0．05）;当矢车菊素添加剂量为20mg／L时,与模型组相比CYP7A1蛋白极显著上调（P〈0．01）。结果提示,矢车菊素能够通过促进L02细胞CYP7A1蛋白表达,实现促进脂肪变性肝细胞胆固醇代谢的调节作用。     

JNK抑制剂对仔猪肝细胞药物性损伤的缓解作用及其机理

【目的】研究c-Jun氨基末端激酶(JNK)抑制剂SP600125对仔猪原代肝细胞药物性损伤的缓解作用及机理。【方法】通过二步灌流法获得仔猪原代肝细胞,将肝细胞分为对照组(C)、JNK抑制剂组(SP)、模型组(M)和治疗组(T),每组6个重复。对照组细胞不添加药物,SP组用2μmol/L SP600125处理细胞,M组用80μg/mL脂多糖(LPS)+20μg/mL恩诺沙星(ENR)处理细胞,T组用80μg/mL LPS+20μg/mL ENR+2μmol/L SP600125处理细胞,处理12 h后,收集上清测定谷丙转氨酶(ALT)和谷草转氨酶(AST)活性,收集细胞测定谷胱甘肽过氧化物酶(glutathione peroxidase, GSH-Px)、超氧化物歧化酶(superoxide dismutase, SOD)活性、丙二醛(malondialdehyde, MDA)含量及肝细胞核因子-1(hepatocyte nuclear factor 1,HNF-1)和谷胱甘肽-S-转移酶A1(glutathione S-transferase alpha 1,GSTA1)mRNA的相...     

矢车菊素-3-葡萄糖苷的吸收、代谢及生理功能研究进展

矢车菊素-3-葡萄糖苷是自然界中分布最为广泛的一种花青素,因其强抗氧化、抗炎等生理功能而具有潜在促生长、抗腹泻等作用,但其在体内可被迅速代谢,进入血液循环的大部分为其代谢产物。因此,矢车菊素-3-葡萄糖苷的生理功能在很大程度上基于其代谢产物的生理活性。本文就矢车菊素-3-葡萄糖苷在体内的吸收率、吸收部位、主要代谢途径及代谢产物的生理功能进行综述,为其在新型无抗饲料添加剂中的应用提供理论依据。     

脂联素对犊牛肝细胞脂氧化关键酶表达的影响

体外原代培养犊牛肝细胞,添加0、16、64和128μg/L脂联素（adiponectin,ADPN）,分别培养4、8h后,提取细胞总RNA。应用实时荧光定量PCR方法,检测脂氧化关键酶脂酰辅酶A氧化酶（ACO）、肝脏脂肪酸结合蛋白（L-FABP）、肉碱脂酰转移酶-Ⅰ（CPTⅠ）、肉碱脂酰转移酶-Ⅱ（CPTⅡ）mRNA表达变化。结果显示,在ADPN作用4h后,ACO、L-FABP、CPTⅠ、CPTⅡ基因mRNA水平均随ADPN浓度的增加而增加,且均显著高于对照组,呈剂量依赖关系;作用8h时,ACO表达也增加,但差异不显著,L-FABP在中高剂量组显著高于对照组,CPTⅠ和CPTⅡ在各ADPN处理组均显著高于对照组。结果表明,ADPN可显著促进脂氧化关键酶的表达,增强肝脏脂氧化作用,减少肝脂储存。     

软脂酸在体外激活Caspase9和Caspase3引起L02细胞凋亡

以人肝细胞系L02为试验材料,采用Western blot和流式细胞术检测软脂酸对L02细胞凋亡及Caspase3、Caspase9信号的影响,为解决动物摄人高能量日粮时肝损伤状况提供理论依据.试验结果显示,软脂酸可以通过激活Caspase3和Caspase9引起L02细胞凋亡,发生凋亡的L02细胞多处于凋亡早期,L02细胞凋亡率与软脂酸的剂量呈正相关.当软脂酸浓度超过30 mg/mL,处理24 h后可显著升高L02细胞凋亡率(P＜0.05).上述结果表明,软脂酸在体外激活Caspase9和Caspase3信号从而诱导L02细胞进入早期凋亡阶段.     

桑椹矢车菊素-3-芸香糖苷抵抗链脲佐菌素诱导胰岛β细胞凋亡的作用

矢车菊素-3-芸香糖苷(C3R)是桑椹花青素的主要成分,研究从成熟桑椹中提取C3R对链脲佐菌素(STZ)诱导人源性胰岛β细胞凋亡的抑制作用及可能的调控机制。采用MTT法及流式细胞计数检测发现:桑椹C3R对正常胰岛β细胞株INS-1具有极显著的促增殖作用(P0.01);50μg/m L桑椹C3R液处理STZ诱导凋亡模型胰岛β细胞株INS-1 48 h后,其早期凋亡、晚期凋亡和坏死的细胞数量极显著下降(P0.01)。以经桑椹C3R液处理的STZ诱导凋亡模型胰岛β细胞的c DNA为模板,通过qRT-PCR检测细胞中的几个凋亡相关蛋白基因的转录水平变化,其中抗凋亡蛋白基因Bcl-x L的mRNA转录水平极显著上调(P0.01),促凋亡蛋白基因Bad、Bax及Caspase 8、Caspase 6基因的mRNA转录水平极显著下调(P0.01)。研究结果表明,桑椹C3R对STZ诱导的胰岛β细胞凋亡具有明显的抵抗作用,由此也证实了桑椹花青素的药用开发价值。     

镉对大鼠原代肝细胞的毒性损伤

用两步灌流法获得大鼠肝细胞,肝细胞暴露于浓度为2.5、5、10μmol/L的醋酸镉24 h.测定了细胞活力、培养上清液中乳酸脱氢酶(LDH)、天冬氨酸转氨酶(AST)和丙氨酸转氨酶(ALT)活性及细胞内谷胱甘肽过氧化物酶(GSH-PX)活性、还原型谷胱甘肽(GSH)和丙二醛(MDA)含量的变化.结果表明,细胞相对存活率显著下降(P<0.01),LDH、AST和ALT的释放量增加,5μmol/L和10 μmol/L剂量组与对照组相比差异均显著(P<0.01),细胞内GSH-PX活性降低,各剂量染毒组与对照组相比,差异均极显著(P<0.01);细胞内GSH含量升高,5 μmol/L和10μmol/L剂量组与对照组差异均显著(P<0.05),细胞内MDA含量升高,10μmol/L剂量组与对照组相比差异显著(P<0.05).表明镉可致肝细胞损伤,并且氧化应激起了重要作用.     

橙皮素对铅致大鼠脑组织氧化损伤的保护效应

为研究铅暴露所致大鼠脑组织氧化损伤和橙皮素的保护作用机制,大鼠用醋酸铅(500mg Pb/L)和橙皮素(50mg/kg)处理。处理结束后测定大鼠脑组织中丙二醛(MDA)、还原型谷胱甘肽(GSH)、超氧化物歧化酶(SOD)和过氧化氢酶(CAT)含量。结果表明,铅可显著提高大鼠脑组织中MDA含量(P<0.05),极显著降低GSH含量(P<0.01)和显著降低SOD和CAT活性(P<0.05);与铅处理组相比,橙皮素却能显著降低铅处理脑组织MDA含量(P<0.05),极显著提高GSH含量(P<0.01)和显著提高SOD和CAT活性(P<0.05)。说明铅可导致大鼠脑组织脂质过氧化损伤,橙皮素对铅致脑损伤具有一定保护作用。     

丹参对奶牛脂肪变性肝细胞NF-κB和CYP450表达的影响

为探讨丹参对脂肪变性奶牛肝细胞的作用机制,采用胶原酶两步灌流法分离培养奶牛肝细胞,不同浓度DL-乙硫氨酸处理,油红染色观察其脂滴数量,MTT法测定肝细胞的活性,生化法检测TG含量。用不同浓度的丹参处理变性肝细胞后,生化法检测ALT、AST、TG、SOD、MDA的含量或活性,ELISA法测定TNF-α的含量,Western blot法检测NF-κB和CYP450的蛋白表达水平。结果显示,筛选出2 mmol/L的DL-乙硫氨酸作用24 h作为体外造模的最佳条件。用丹参处理后,能降低ALT、AST、TG和MDA的活性或含量,抑制TNF-α的释放,增加SOD活性。随丹参浓度增加和处理时间的延长,CYP450的表达呈逐渐降低的趋势。24 h时,丹参对NF-κB的表达无明显影响;48 h时,随丹参浓度的增加,NF-κB的表达呈逐渐降低的趋势。这表明丹参对奶牛脂肪肝有一定的治疗作用,其作用机制与促进脂质代谢、抑制肿瘤细胞坏死因子、抗脂质过氧化及降低NF-κB和CYP450的表达密切相关。     

内毒素脂多糖及氨基胍对体外培养山羊肝细胞脂质过氧化损伤的影响

本试验探讨了内毒素脂多糖(LPS)诱导体外培养肝细胞脂质过氧化损伤机制及氨基胍(AG)对体外培养的肝细胞脂质过氧化的保护作用。随机分为两组:LPS处理组(不同LPS浓度处理);LPS+AG处理组(1mg/L LPS处理的同时加入不同浓度AG),分析了不同处理的山羊肝细胞中丙二醛(MDA)和超氧化物歧化酶(SOD)的变化。结果发现LPS处理导致山羊肝细胞MDA含量明显增加和SOD活性降低;LPS处理的同时加入AG能明显降低LPS导致的MDA含量的增加和SOD活性的降低。说明内毒素明显引起肝组织脂质过氧化作用,而合并应用AG则可以明显减轻肝组织脂质过氧化作用,提示AG可拮抗LPS对肝细胞造成的过氧化损伤,对内毒素血症有治疗价值。     

六氟双酚A对斑马鱼肝脏细胞氧化应激的影响

为研究六氟双酚A(BPAF)对斑马鱼肝脏细胞的毒性机制。试验以斑马鱼肝脏细胞为研究模型,选择不同浓度的BPAF(0、10、20、30μmol/L)作用于斑马鱼肝脏细胞系ZFL细胞,检测BPAF对ZFL细胞的细胞毒性以及细胞的抗氧化酶活性。结果表明,10、20、30μmol/L BPAF均可极显著抑制ZFL细胞的细胞活性(P<0.01);与对照组相比,10μmol/L BPAF组细胞丙二醛(MDA)含量显著提高(P<0.05),20、30μmol/L BPAF组细胞MDA含量极显著提高(P<0.01);20、30μmol/L BPAF组细胞谷胱甘肽过氧化物酶(GSH-Px)活性极显著降低(P<0.01);10、20、30μmol/L BPAF组细胞过氧化氢酶(CAT)活性极显著降低(P<0.01);20、30μmol/L BPAF组ZFL细胞超氧化物歧化酶(SOD)活性极显著降低(P<0.01)。研究表明,BPAF可通过干扰细胞的氧化应激,对ZFL细胞产生细胞毒性。     

Quercetin protects spermatogonial cells from 2,4-d-induced oxidative damage in embryonic chickens

Quercetin, an antioxidant flavonoid, is considered beneficial to human and animal health. In this study, the protective effects of quercetin in relation to oxidative damage of testicular cells were studied by analysis of the intracellular antioxidant system after treatment of embryonic chickens with hypoxanthine-xanthine oxidase (HX-XO) or 2,4-dichlorophenoxyacetic acid (2,4-D). Testicular cells from Day 18 embryos were challenged with quercetin alone or in combinations with HX-XO or 2,4-D for 48 h in culture. The results showed that quercetin manifested no deleterious effects on spermatogonial cells at concentrations up to 1.0 microg/ml. Exposure to HX-XO or 2,4-D (50 microg/ml) induced condensed nuclei and vacuolated cytoplasm and a decrease in testicular cell viability and spermatogonial cell number. Membrane integrity was damaged by elevated lactate dehydrogenase leakage. Exposure to HX-XO or 2,4-D also elicited lipid peroxidation by elevation of thiobarbituric acid reactive substances and decreased glutathione content and superoxide dismutase activity. However, simultaneous supplementation with quercetin restored these parameters to the levels in the controls. Consequently, HX-XO and 2,4-D induced oxidative stress in spermatogonial cells; however, dietary quercetin may attenuate the negative effects of environmental toxicants and restore the antioxidant system in testicular cells.     

Stanniocalcin-1 protects bovine intestinal epithelial cells from oxidative stress-induced damage

Chronic enteritis can produce an excess of reactive oxygen species resulting in cellular damage. Stanniocalcin-1(STC-1) reportedly possesses anti-oxidative activity, the aim of this study was to define more clearly the direct contribution of STC-1 to anti-oxidative stress in cattle. In this study, primary intestinal epithelial cells (IECs) were exposed to hydrogen peroxide (H₂O₂) for different time intervals to mimic chronic enteritis-induced cellular damage. Prior to treatment with 200 µM H₂O₂, the cells were transfected with a recombinant plasmid for 48 h to over-express STC-1. Acridine orange/ethidium bromide (AO/EB) double staining and trypan blue exclusion assays were then performed to measure cell viability and apoptosis of the cells, respectively. The expression of STC-1 and apoptosis-related proteins in the cells was monitored by real-time PCR and Western blotting. The results indicated that both STC-1 mRNA and protein expression levels positively correlated with the duration of H₂O₂ treatment. H₂O₂ damaged the bovine IECs in a time-dependent manner, and this effect was attenuated by STC-1 over-expression. Furthermore, over-expression of STC-1 up-regulated Bcl-2 protein expression and slightly down-regulated caspase-3 production in the damaged cells. Findings from this study suggested that STC-1 plays a protective role in intestinal cells through an antioxidant mechanism.     

Maternal supply of cysteamine alleviates oxidative stress and enhances angiogenesis in porcine placentaOA

Background: Oxidative stress in placenta is associated with the occurrence of adverse pregnancy outcomes in sow,but there are few satisfactory treatment strategies for these conditions. This study investigated the potential of cysteamine(CS) as an antioxidant protectant for regulating the reproductive performance, redox status, and placental angiogenesis of sows.Methods: The placental oxidative stress status and vascular density of piglets with different birth weights: < 1.0 kg(low birth weig...     

H2O2诱导BRL-3A细胞模拟大鼠肝脏氧化应激损伤的研究

动物冷暴露过程中,肝脏因发生氧化应激而受损.利用不同浓度过氧化氢(H2O2)作用BRL-3A细胞,根据细胞存活率确定500 μmol/L H2O2作用细胞3h为施加条件,然后通过检测蛋白质羰基含量、超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)和过氧化氢酶(CAT)活性,探讨在细胞水平上建立冷暴露大鼠肝脏损伤模型.结果显示,H2O2处理组细胞存活率下降,蛋白质羰基含量升高,SOD、GSH-Px和CAT活性均降低.与对照组相比,其存活率、细胞内蛋白质羰基含量和CAT活性,均差异极显著(P＜0.01),细胞内SOD和GSH-Px活性,差异显著(P＜0.05).结果表明,500 μmol/L H2O2作用于BRL-3A细胞可导致氧化应激的发生,其相关指标与大鼠冷暴露后肝脏受损指标改变趋势类似,利用BRL-3A细胞建立冷暴露引起的肝脏氧化损伤模型,为进一步探讨冷应激对肝脏损伤的机制奠定基础.     

Effects of dietary antioxidant supplementation on oxidative damage and resistance to oxidative damage during prolonged exercise in sled dogs

OBJECTIVES: To determine effects of dietary antioxidant supplementation on plasma concentrations of antioxidants, exercise-induced oxidative damage, and resistance to oxidative damage during exercise in Alaskan sled dogs. ANIMALS: 62 Alaskan sled dogs. PROCEDURE: Dogs were matched for age, sex, and ability and assigned to 1 of 3 groups: sedentary and nonsupplemented (control [C]; n = 21), exercised and supplemented (S; 22), and exercised and nonsupplemented (N; 19). Dogs in group S were given 400 units of alpha-tocopherol acetate, 3 mg of beta-carotene, and 20 mg of lutein orally per day for 1 month, then dogs in groups S and N completed 3 days of exercise. Blood samples were collected before and after 1 and 3 days of exercise and after 3 days of rest. Plasma antioxidant concentrations were determined, and oxidative damage to DNA (plasma 7,8 dihydro-8-oxo-2'deoxyguanosine [8-oxodG] concentration) and membrane lipids (plasma hydroperoxide concentration) and resistance of plasma lipoproteins to oxidation were assessed. RESULTS: Supplementation increased plasma concentrations of alpha-tocopherol, beta-carotene, and lutein. Plasma concentration of alpha-tocopherol increased and concentration of lutein decreased in group S with exercise. Concentration of 8-oxodG decreased in group S but increased in group N during and after exercise. Lag time of in vitro oxidation of lipoprotein particles increased with exercise in group S only. CONCLUSIONS AND CLINICAL RELEVANCE: Dietary supplementation with antioxidants resulted in increased plasma concentrations of antioxidants. Moreover, supplementation decreased DNA oxidation and increased resistance of lipoprotein particles to in vitro oxidation. Antioxidant supplementation of sled dogs may attenuate exercise-induced oxidative damage.