松果菊苷对db/db糖尿病小鼠心肌的保护作用

糖尿病心肌病(diabetic cardiomyopathy, DCM)是指发生于糖尿病患者,不能用冠心病、高血压性心脏病及其他心脏病变来解释的心肌疾病。目前,DCM的病因和发病机制尚未完全阐明,且缺乏特异性治疗手段。中药管花肉苁蓉提取物松果菊苷(echinacoside, ECH)对心肌细胞具有保护作用。以db/m小鼠为正常对照组(db/m组),db/db小鼠分为模型组(db/db组)和ECH干预组(db/db+ECH组),探讨了ECH对糖尿病db/db小鼠心肌的影响及机制。db/db+ECH组小鼠给予松果菊苷灌胃,db/m组和db/db组小鼠给予0.9%氯化钠溶液灌胃。心脏超声观察心脏功能,Masson染色观察组织胶原纤维含量,逆转录聚合酶链式反应检测Ⅰ型胶原和Ⅲ型胶原mRNA的表达,蛋白质免疫印迹技术检测转化生长因子-β1(transforming growth factor-β1, TGF-β1)、phospho-Smad2(p-Smad2)和phospho-Smad3(p-Smad3)的表达。结果显示,ECH能够改善db/db小鼠左心室肥大和心脏功能,降低胶原沉积(P<...     

松果菊苷对多柔比星心脏毒性保护作用及机制研究

目的:观察松果菊苷(ECH)能否减轻多柔比星(DOX)心脏毒性并初步阐明其作用机制。方法:通过单次腹腔注射大剂量多柔比星(15 mg/kg)建立急性心脏毒性小鼠模型,DOX处理后每日通过腹腔注射ECH(50 mg/kg/day)。实验分组如下:正常组(Control组);单纯松果菊苷处理组(ECH组);多柔比星处理组(DOX组);多柔比星+松果菊苷处理组(DOX+ECH组)。给药5天后检测左心室功能、心肌组织病理改变、氧化应激和心肌凋亡情况。结果:与Control组相比,DOX组小鼠心脏收缩和舒张功能明显减弱,心肌细胞出现空泡变性,心肌MDA含量、凋亡率以及促凋亡蛋白Bax和cleaved Caspase-3表达明显增加,而抑制凋亡蛋白Bcl-2表达量、SOD与GSH-Px活性明显下降。与DOX组相比,松果菊苷能明显改善心脏功能,缓解心肌空泡变性,降低MDA含量、凋亡率以及Bax和cleaved Caspase-3表达量,而提高Bcl-2表达量、SOD与GSH-Px活性(均P 0.05)。结论:松果菊苷可以通过抑制心肌组织氧化应激损伤和凋亡缓解多柔比星诱导的急性心脏毒性。     

小檗碱联合松果菊苷抗人脑胶质细胞衰老的实验研究

摘要 目的：探究小檗碱联合松果菊苷抗人脑胶质细胞衰老的作用及其分子机制。方法：采用依托泊苷诱导人脑胶质细胞衰老,使用小檗碱与松果菊苷联合干预,采用β-半乳糖苷酶染色法色观察衰老阳性细胞比例,采用CCK-8法检测细胞活力,采用流式细胞术检测细胞周期,采用Western blot法检测细胞中衰老相关蛋白FoxO1、CAT、SOD2、 Bcl-2的表达水平。结果：小檗碱联合松果菊苷可显著减少依托泊苷诱导的衰老阳性细胞比例,显著增强细胞活力,显著降低G2/M期细胞比例,显著提高FoxO1、CAT、SOD2、Bcl-2的蛋白水平。结论：小檗碱联合松果菊苷可显著抑制依托泊苷诱导的人脑胶质细胞衰老,可能与增强细胞活力、推进细胞周期进程、降低胞内氧化应激水平、抗凋亡等途径有关。     

肉苁蓉中松果菊苷和毛蕊花糖苷的植物雌激素活性研究

研究肉苁蓉中松果菊苷和毛蕊花糖苷的雌激素活性。采用荧光素酶报告质粒法检测受试药物松果菊苷和毛蕊花糖苷的雌激素活性;利用雌激素受体竞争性结合实验和荧光素酶报告质粒法,检测松果菊苷和毛蕊花糖苷与雌激素的竞争性作用。松果菊苷和毛蕊花糖苷有上调雌激素应答元件(ERE)活性,和雌激素共同作用可以拮抗雌激素对ERE的上调作用。松果菊苷和毛蕊花糖苷通过上调ERE荧光素酶活性而表现出植物雌激素活性,可作为候选SERMs。     

前体物及诱导剂对肉苁蓉松果菊苷含量的影响

目的:通过在寄主梭梭根部添加松果菊苷前体物质及其合成诱导剂,研究它们对肉苁蓉中松果菊苷积累的影响.方法:以高效液相色谱法测定不同处理的样品中松果菊苷的含量,采用DiamoNsil Dilcma C18(5μm,250×4.6mm)色谱柱;流动相:A相为1.5％醋酸溶液,B相为甲醇;流速0.5mL/min,检测波长335nm,室温.结果:松果菊苷在0.86 ～4.3μg的范围内线性关系良好,r=0.9996,平均地加样回收率为98.93％,RSD =4.36％.对寄主梭梭以不同种类和浓度的前体物质及诱导剂处理,均可促进肉苁蓉中松果菊苷的积累.结论:酪氨酸加诱导剂处理对松果菊苷积累的效果更为显著.     

藏药短管兔耳草中松果菊苷和麦角甾苷的RP-HPLC分析

建立了藏药短管兔耳草中松果菊苷和麦角甾苷含量的高效液相色谱分析法.采用Waters XTerra RP18色谱柱(150mm×4.6 mm,5μm),以甲醇-1%冰醋酸溶液(28:72,V:V)为流动相,流速1.0 mL/min,检测波长330 nm,柱温30℃,在20 min内分离检测了该两种化合物.松果菊苷和麦角甾苷进样量分别在0.077～4.950μg(r=0.999 9)和0.085～5.450μg(r=0.999 9)内呈良好线性,平均加样回收率分别为98.35%和92.50%,RSD分别为2.35%和2.86%.所建立的方法简便、快捷、结果准确可靠,重现性好,可用于藏药短管兔耳草的质量控制,并为兔耳草属植物中苯丙素苷类化合物的分离分析提供一定的参考.     

电子顺磁共振对五种中草药抗氧化活性的研究

采用电子顺磁共振(EPR)技术,通过大黄、香青兰、香茅草、懈寄生和骆驼蓬子五种中草药对1,1-二苯基-2-苦基肼自由基(DPPH)、羟基自由基(·OH)和超氧阴离子自由基(O-·2)3种自由基清除能力大小的比较,研究了大黄等五种中草药抗氧化活性能力。这五种中草药对3种自由基均有一定的清除作用,其中大黄清除DPPH和超氧阴离子自由基的IC50小于0.5 mg/mL,清除羟基自由基的IC50=1.892 mg/mL。结果表明五种中草药中大黄的抗氧化活性能力最强,为中草药用于生物体的抗氧化应激研究提供依据。     

顶羽菊抗氧化活性研究

目的:探讨顶羽菊提取物的抗氧化活性。方法:采用Folin-Ciocaheu法测定顶羽菊水提物和醇提物中的多酚含量,并以芦丁为标准品测定其黄酮含量;通过总还原力测定法、Fenton法、改良的邻苯三酚自氧化法、过氧化脂质测定、亚硝酸盐清除率测定和亚硝胺合成阻断率测定,分别对顶羽菊提取物的总还原力、超氧阴离子自由基和羟自由基清除能力、脂质过氧化抑制作用、清除亚硝酸盐自由基和亚硝胺阻断率进行测定。结果:顶羽菊水提物和醇提物中含有以黄酮类为主要成分的多酚类物质;具有较强的还原性和清除超氧阴离子自由基、羟自由基的活性,且醇提物的作用高于水提物;二者对脂质过氧化的抑制率达47%以上;顶羽菊提取物具有较强的清除亚硝酸钠和阻断亚硝胺合成的能力,水提物对亚硝酸盐的最大清除率为60.4%,醇提物对亚硝胺合成的阻断率为86.6%。结论:顶羽菊醇提物可作为抗氧化剂和防癌剂,用于清除机体内自由基、抗脂质氧化、延缓机体衰老、预防心血管系统疾病和癌症的发生。     

用顺磁共振研究家蝇衰老过程蝇头自由基特性的改变

用顺磁共振（ＥＳＲ）方法直接测量家蝇头中自由基浓度和性质及ＳＯＤ活性随龄变化情况。结果蝇头内自由基浓度随龄显著增加,且自由基升高的同时,对应ＳＯＤ活性下降。两种主要自由基成份的浓度比也随龄发生改变,其中一宽谱信号组份与衰老的关系可能更为密切。提示除自由基浓度外,自由基组份的比例改变,在衰老中也有重要作用。     

电子顺磁共振法测定清栓酶在沙鼠脑缺血再灌流损伤中的抗自由基作用

本文设计了沙鼠脑缺血再灌流实验模型,以清拴酶作脑缺血后静脉注射再灌流模型和非药物再灌流模型组对照,用电子顺磁共振法(ESR)测定脑组织自由基波谱,结果清栓酶组出现自由基信号很弱,接近正常组,显著区别于未用药脑缺血再灌流30分钟和60分钟组(P<0.01),证明清栓酶有抗自由基和再灌注损伤的作用.     

辣椒叶多糖抗氧化作用研究

目的:从辣椒叶中分离纯化活性多糖并考察其抗氧化活性。方法:采用水提醇沉法提取多糖,Sevag法脱蛋白,得辣椒叶粗多糖;分别使用超纯水、0.06 mol/L NaCl溶液、0.18 mol/L NaCl溶液作为洗脱液,通过DEAE-52离子交换柱色谱纯化得到三种辣椒叶多糖LD-0、LD-0.06、LD-0.18,测定多糖含量。DPPH、ABTS法检测多糖体外抗氧化作用。以小鼠血清、肝组织中总超氧化物歧化酶活性、过氧化氢酶活性及丙二醛含量为指标,考察小鼠灌胃LD-0.06多糖对脂质过氧化模型的影响。结果:辣椒叶粗多糖、LD-0、LD-0.06、LD-0.18多糖含量分别为9.92%、43.14%、82.97%、37.63%,其中LD-0.06多糖含量最高。体外抗氧化实验结果显示,三种结果均具备较好的清除能力,其中LD-0.06对ABTS+、DPPH·的清除效果最好,IC50值分别为0.58 mg/m L和0.60 mg/m L,结果与对照组在0.05水平具有显著性差异,说明辣椒叶多糖提取物是一种有效的天然抗氧化剂。在脂质过氧化模型小鼠体内,与模型组比较,LD-0.06多糖能显著增强小鼠血清和肝组织中的T-SOD与CAT活性,降低MDA的含量,且剂量越高,体内抗氧化能力越强。结论:辣椒叶多糖提取物具有一定的抗氧化作用,为进一步开发利用辣椒资源提供了理论依据。     

Selenoprotein W serves as an antioxidant in chicken myoblasts

Background

Selenoprotein W (SelW) was thought to play an antioxidant role in mammals. Because chicken SelW has no cysteine (Cys) at the residue 37 (Cys37) that is required for the presumed antioxidant function in mammals, this study was conducted to determine whether chicken SelW possessed the same function.

Methods

Small interfering RNAs (siRNAs) technology was applied to suppress the SelW expression in chicken embryonic myoblasts. Thereafter, these myoblasts were treated with different concentrations of H₂O₂ and assayed for cell viability, apoptosis rate, reactive oxygen species (ROS) status, and expression levels of apoptosis-related genes and proteins (Bax, Bcl-2, and caspase-3).

Results

Silencing of the myoblast SelW gene decreased their cell viability, and increased their apoptosis rate and susceptibility to H₂O₂. While the knockout down of SelW up-regulated Bax and caspase-3 and down-regulated Bcl-2, the induced oxidative injuries were alleviated by treatment with a ROS scavenger, N-acetyl-l-cysteine (NAC).

Conclusion

Chicken SelW protected embryonic myoblasts against cell apoptosis mediated by endogenous and exogenous H₂O₂.

General significance

Chicken SelW possesses antioxidant function similar to the mammalian homologues despite the lack of Cys37 in the peptide.     

SIRT5 desuccinylates and activates SOD1 to eliminate ROS

Cu/Zn superoxide dismutase (SOD1) is a key antioxidant enzyme. Deficiency of SOD1 is associated with various human diseases, including cancer. Here, we report that SOD1 is succinylated and that succinylation decreases its activity. SIRT5 binds to, desuccinylates and activates SOD1. SOD1-mediated ROS reduction is increased when SIRT5 is co-expressed. Furthermore, mutation of the SOD1 succinylation site inhibits the growth of lung tumor cells. These results reveal a novel post-translational regulation of SOD1 by means of succinylation and SIRT5-dependent desuccinylation, which is important for the growth of lung tumor cells.     

Cellular aging of mitochondrial DNA-depleted cells

We have reported that mitochondrial DNA-depleted rho(0) cells are resistant to cell death. Because aged cells have frequent mitochondrial DNA mutations, the resistance of rho(0) cells against cell death might be related to the apoptosis resistance of aged cells and frequent development of cancers in aged individuals. We studied if rho(0) cells have features simulating aged cells. SK-Hep1 hepatoma rho(0) cells showed typical morphology associated with aging such as increased size and elongated appearance. They had increased senescence-associated beta-Gal activity, lipofuscin pigment, and plasminogen activator inhibitor-1 expression. Consistent with their decreased proliferation, the expression of mitotic cyclins was decreased and that of cdk inhibitors was increased. Rb hypophosphorylation and decreased telomerase activity were also noted. Features simulating aged cells were also observed in MDA-MB-435 rho(0) cells. These results support the mitochondrial theory of aging, and suggest that rho(0) cells could serve as an in vitro model for aged cells.     

Nitric oxide availability is increased in contracting skeletal muscle from aged mice,but does not differentially decrease muscle superoxide

Reactive oxygen and nitrogen species have been implicated in the loss of skeletal muscle mass and function that occurs during aging. Nitric oxide (NO) and superoxide are generated by skeletal muscle and where these are generated in proximity their chemical reaction to form peroxynitrite can compete with the superoxide dismutation to hydrogen peroxide. Changes in NO availability may therefore theoretically modify superoxide and peroxynitrite activities in tissues, but published data are contradictory regarding aging effects on muscle NO availability. We hypothesised that an age-related increase in NO generation might increase peroxynitrite generation in muscles from old mice, leading to an increased nitration of muscle proteins and decreased superoxide availability. This was examined using fluorescent probes and an isolated fiber preparation to examine NO content and superoxide in the cytosol and mitochondria of muscle fibers from adult and old mice both at rest and following contractile activity. We also examined the 3-nitrotyrosine (3-NT) and peroxiredoxin 5 (Prx5) content of muscles from mice as markers of peroxynitrite activity. Data indicate that a substantial age-related increase in NO levels occurred in muscle fibers during contractile activity and this was associated with an increase in muscle eNOS. Muscle proteins from old mice also showed an increased 3-NT content. Inhibition of NOS indicated that NO decreased superoxide bioavailability in muscle mitochondria, although this effect was not age related. Thus increased NO in muscles of old mice was associated with an increased 3-NT content that may potentially contribute to age-related degenerative changes in skeletal muscle.     

Increase of reactive oxygen species in different tissues during lipopolysaccharide-induced fever and antipyresis: an electron paramagnetic resonance study

Abstract

Fever is a regulated increase in body temperature and a component of the acute-phase response, triggered mainly after the invasion of pathogens in the body. Reactive oxygen species (ROS) are generated during the physiological and pathological processes, and can act as both signalling molecules as well as promoters of oxidative stress. Male Wistar rats, pretreated with oral doses of acetaminophen, celecoxib, dipyrone, or ibuprofen 30?min before an intravenous lipopolysaccharide (LPS) or sterile saline injection, showed a reduced febrile response in all animals tested. The formation of ROS in the fresh blood, liver, brown adipose tissue (BAT), and hypothalamus of febrile and antipyretic-treated animals was assessed by electron paramagnetic resonance using the spin probe 1-hydroxy-3-methoxycarbonyl-2,2,5,5-tetramethylpyrrolidine (CMH). While the CM^? concentrations remained unaltered in the blood samples examined 5?h after the induction of fever, we found increased CM^? levels in the liver (in µM, saline: 290?±?42; LPS: 512?±?34), BAT (in µM, saline: 509?±?79, LPS: 855?±?79), and hypothalamus (in µM, saline: 292?±?35; LPS: 467?±?8) at the same time point. Importantly, none of the antipyretics were seen to alter the CM^? accumulation profile. Data from this study suggest that there is an increased formation of ROS in the different tissues during fever, which may cause oxidative stress, and that the antipyretics tested do not interfere with ROS production.     

Triarylmethyl-based biradical as a superoxide probe

Abstract

Superoxide radical represents one of the most biologically relevant reactive oxygen species involved in numerous physiological and pathophysiological processes. Superoxide measurement through the decay of an electron paramagnetic resonance (EPR) signal of a triarylmethyl (TAM) radical possesses the advantage of a high selectivity and relatively high rate constant of TAM reaction with the superoxide. Hereby we report a straightforward synthesis and characterization of a TAM–TAM biradical showing a high reactivity with superoxide (second-order rate constant, (6.7?±?0.2)?×?10³ M^?1 s^?1) enabling the measurement of superoxide radical by following the increase of a sharp EPR signal associated with the formation of a TAM-quinone-methide monoradical product.