eNOS gene polymorphisms modify the association of PM10 with oxidative stress

Previous studies have suggested that air pollution increases various health outcomes through oxidative stress and oxidative stress-related genes modify the relationship between air pollution and health outcomes. Therefore, we evaluated the effect of PM₁₀ on the levels of malondialdehyde (MDA), oxidative stress biomarker, and the effect modification by genetic polymorphisms of eNOS, oxidative stress-related gene, in the 560 Korean elderly. We obtained urine samples repeatedly from participants during five medical examinations between 2008 and 2010 and all ambient air pollutant concentration data from the Korea National Institute of Environmental Research air quality monitoring system. We measured urinary levels of MDA to assess oxidative stress and genotyped eNOS (rs1799983, rs2853796, and rs7830). Mixed-effect model was used to estimate the effect of PM₁₀ on the level of oxidative stress biomarker and their modification by genotypes. PM₁₀ showed apparent positive effect on MDA level after adjusting for age, sex, BMI, cotinine level, temperature, dew point, levels of SO₂, O₃, NO₂, and CO, and season (p = 0.0133). Moreover, the association of PM₁₀ with MDA was found only in participants with eNOS GG genotype for rs1799983 (p = 0.0107), TT genotype for rs2853796 (p = 0.0289), or GT genotype for rs7830 (p = 0.0158) and in participants with a set of risky haplotypes (GTT, GTG, GGT, and TGT) (p = 0.0093). Our results suggest that PM₁₀ affect oxidative stress in the elderly and eNOS genotype affect the oxidative stress level in regard of exposure to PM₁₀.     

Aflatoxin B1 and fumonisin B1 affect the oxidative status of bovine peripheral blood mononuclear cells

Mycotoxins are secondary metabolites having a high cytotoxic potential. They are produced by molds and released in food and feed. To date, the mechanisms underlying the mycotoxin-induced cytotoxicity have not been fully clarified. The induction of oxidative stress, as a possible mechanism, has been postulated. This in vitro study was focused on the effect of two widely occurring mycotoxins, aflatoxin B₁ (AFB₁) and fumonisin B₁ (FB₁), on the oxidative status of bovine peripheral blood mononuclear cells (PBMC) incubated for 2 and 7 days at different levels of AFB₁ (0, 5 and 20 μg/ml) and FB₁ (0, 35 and 70 μg/ml). Reactive oxygen metabolites (ROM), intracellular thiols (SH), malondialdehyde (MDA) and gene expression of cytoplasmic superoxide dismutase (SOD) and glutathione peroxidase (GSHPX-1) were measured on PBMC after incubation. The highest concentration of AFB₁ and all concentrations of FB₁ caused an increase (p < 0.05) of intracellular ROM without any time dependent effect. Intracellular SH decreased with 20 μgAFB₁/ml (p < 0.05) and the effect was particularly marked after 7 days of exposure. Intracellular SH were not affected by FB₁ even though a lower (p < 0.05) SH level after 2 days exposure than after 7 days was observed. MDA increased (p < 0.05) in AFB₁ or FB₁ treated PBMC. The exposure to FB₁ for 7 days increased MDA (p < 0.05) only in cells treated with 70 μg/ml. Exposure of PBMC to AFB₁ reduced SOD mRNA while FB₁ decreased both SOD and GSHPX-1 mRNA abundance. These results demonstrate that, even though by different mechanisms, AFB₁ and FB₁ may induce cytotoxicity through an impairment of the oxidative status of PBMC.     

DJ-1保护多巴胺能神经元抵抗过氧化氢氧化应激损伤的研究

目的 探讨DJ-1保护多巴胺能神经元免受过氧化氢(H₂O₂)损伤的机制。 方法 使用神经生长因子(NGF)将大鼠嗜铬细胞瘤细胞(PC12细胞)诱导为多巴胺能神经元模型。H₂O₂处理引起细胞氧化应激损伤模型,CCK-8试剂盒检测细胞活性,DHE染色检测细胞内ROS水平。PI / Hoechst染色检测细胞凋亡,蛋白质免疫印迹法(Western blot)检测DJ-1和TH蛋白的表达。构建DJ-1过表达载体,检测DJ-1对H₂O₂中PC12细胞的保护作用及对细胞内活性氧(ROS)的影响。RT-qPCR检测α-synuclein,p53,Bax,Bcl-2的表达变化。 结果 H₂O₂处理可显着降低PC12细胞的活性,H₂O₂处理24 h以上可引起细胞凋亡。H₂O₂处理下调DJ-1蛋白和TH蛋白的表达,并且在RNA水平上α-突触核蛋白的表达增加。另外 p53, Bax和 caspase-3表达增加, Bcl-2表达减少。DJ-1的过表达可以抑制H₂O₂引起的ROS增加,DJ-1可以维持细胞活性,减少H₂O₂的凋亡。在RNA水平抑制α-突触核蛋白,p53,bax,bcl-2的凋亡和抗凋亡基因表达变化。 结论 DJ-1能够抑制H₂O₂引起的 ROS水平升高,减少α-synuclein积累,抑制 p53,凋亡基因如 bax的表达减弱了多巴胺能神经元中H₂O₂诱导的氧化应激损伤。     

Paraquat induces oxidative stress and neuronal cell death; neuroprotection by water-soluble Coenzyme Q10

Neuronal cell death induced by oxidative stress is correlated with numerous neurodegenerative diseases, including Alzheimer's disease (AD), Parkinson's disease (PD), and stroke. The causes of sporadic forms of age-related neurodegenerative diseases are still unknown. Recently, a correlation between paraquat exposure and neurodegenerative diseases has been observed. Paraquat, a nonselective herbicide, was once widely used in North America and is still routinely used in Taiwan. We have used differentiated Human Neuroblastoma (SHSY-5Y) cells as an in vitro model to study the mechanism of cell death induced by paraquat. We observed that paraquat-induced oxidative stress in differentiated SHSY-5Y cells as indicated by an increase in the production of cellular reactive oxygen species (ROS). Furthermore, apoptosis was evident as indicated by cellular and nuclear morphology and DNA fragmentation. Interestingly, pretreatment of SHSY-5Y cells with water-soluble Coenzyme Q10 (CoQ10) before paraquat exposure inhibited ROS generation. Pretreatment with CoQ10 also significantly reduced the number of apoptotic cells and DNA fragmentation. We also analyzed the effect of paraquat and CoQ10 on isolated mitochondria. Our results indicated that treatment with paraquat induced the generation of ROS from isolated mitochondria and depolarization of the inner mitochondrial membrane. Pretreatment with CoQ10 was able to inhibit ROS generation from isolated mitochondria as well as the collapse of mitochondrial membrane potential. Our results indicate that water-soluble CoQ10 can prevent oxidative stress and neuronal damage induced by paraquat and therefore, can be used for the prevention and therapy of neurodegenerative diseases caused by environmental toxins.     

人参皂苷Rg1对H2O2诱导的HaCaT细胞氧化损伤保护作用研究

目的 观察人参皂苷Rg₁对H₂O₂诱导的HaCaT细胞氧化损伤保护作用,并探讨其机制。方法 体外培养HaCaT细胞, H₂O₂诱导细胞建立氧化应激损伤模型,分为空白组、H₂O₂损伤组、人参皂苷Rg₁保护组。细胞增殖与毒性检测试剂盒(CCK-8)检测细胞存活率,Hochest染色法检测细胞凋亡情况,活性氧检测试剂盒测定细胞活性氧(ROS)水平,Western blot检测细胞中caspase-3、caspase-6、caspase-8、GAPDH蛋白表达。结果 H₂O₂诱导HaCaT细胞半数抑制浓度为100 μg?mL^-1;与H₂O₂损伤组比较,5、10和15mg?L^-1人参皂苷Rg₁预处理后,HaCaT细胞存活率明显升高(P<0.05),细胞核皱缩损伤状态明显改善,细胞凋亡数量显著减少。同时,人参皂苷Rg₁预处理可显著降低HaCaT细胞ROS水平,下调凋亡相关标志蛋白-活化型caspase-3、caspase-6、caspase-8蛋白表达水平。结论 人参皂苷Rg₁对H₂O₂诱导的HaCaT细胞氧化应激损伤具有一定的保护作用,其机制可能与增强细胞清除自由基能力及抑制凋亡相关。     

Cytoplasmic p21, ERK1/2 activation,and cytoskeletal remodeling are associated with the senescence-like phenotype after airborne particulate matter (PM10) exposure in lung cells

The exposure to particulate matter with a mean aerodynamic diameter ≤10 μm (PM₁₀) from urban zones is considered to be a risk factor in the development of cancer. The aim of this work was to determine if PM₁₀ exposure induces factors related to the acquisition of a neoplastic phenotype, such as cytoskeletal remodeling, changes in the subcellular localization of p21^CIP1/WAF1, an increase in β-galactosidase activity and changes in cell cycle. To test our hypothesis, PM₁₀ from an industrial zone (IZ) and a commercial zone (CZ) were collected, and human adenocarcinoma lung cell cultures (A549) were exposed to a sublethal PM₁₀ concentration (10 μg/cm²) for 24 h and 48 h. The results showed that PM₁₀ exposure induced an increase in F-actin stress fibers and caused the cytoplasmic stabilization of p21^CIP1/WAF1 via phosphorylation at Thr¹⁴⁵ and Ser¹⁴⁶ and the phosphorylation of ERK1/2 on Thr²⁰². Changes in the cell cycle or apoptosis were not observed, but an increase in β-galactosidase activity was detected. The PM₁₀ from CZ caused more dramatic effects in lung cells. We conclude that PM₁₀ exposure induced cytoplasmic p21^CIP1/WAF1 retention, ERK1/2 activation, cytoskeleton remodeling and the acquisition of a senescence-like phenotype in lung cells. These alterations could have mechanistic implications regarding the carcinogenic potential of PM₁₀.     

大气细颗粒物PM2.5诱导肺上皮MLE-12细胞的氧化应激和自噬

目的 研究大气细颗粒物PM_2.5对小鼠肺泡Ⅱ型上皮细胞MLE-12细胞的氧化应激和自噬的影响。方法 用采集和处理的2009年北京市细颗粒物PM_2.5 25,50,100和200 mg·L^-1暴露处理MLE-12细胞24和48 h,用MTT比色法测定细胞存活率,双乙酰基二氯荧光素(DCFH-DA)荧光探针检测细胞内活性氧类(ROS)自由基生成,Western蛋白质印迹法检测微管相关蛋白1轻链3 Ⅰ蛋白(LC3Ⅰ)和LC3Ⅱ表达,激光共聚焦显微镜观察细胞自噬体的形成。结果 与细胞对照组比较,PM_2.5 100和200 mg·L^-1处理24 h组细胞存活率明显降低,分别降低28%和33%(P<0.01);暴露处理48 h,PM_2.5 25~200 mg·L^-1组细胞存活率均明显下降(P<0.01),并呈浓度效应关系(R²=0.4940,P<0.01)。PM_2.5 100和200 mg·L^-1处理MLE-12细胞3 h,胞内ROS水平较细胞对照组显著升高,分别升高27.6%和60.7%(P<0.01)。此外,PM_2.5 100 mg·L^-1处理细胞12,24和48 h及PM_2.5 50,100和200 mg·L^-1处理细胞24 h细胞自噬标志物LC3Ⅱ蛋白表达均明显增强,呈现明显的时间效应(R²=0.9150,P<0.01)和浓度效应(R²=0.6338,P<0.01)关系。PM_2.5 100 mg·L^-1处理24 h细胞内自噬体荧光强度明显升高(P<0.05),细胞核周边有明显的自噬泡环绕。结论 PM_2.5诱导肺泡Ⅱ型上皮MLE-12细胞的氧化应激,并引发细胞自噬。     

人参皂苷Rg3对H2O2诱导人肾小球系膜细胞氧化应激损伤的保护作用及其机制研究

目的探究人参皂苷Rg_3对H_2O_2诱导人肾小球系膜细胞氧化应激损伤的保护作用及其作用机制。方法采用H_2O_2诱导建立人肾小球系膜细胞氧化应激损伤模型。以不同浓度的人参皂苷Rg_3对人肾小球系膜细胞预处理24 h,采用CCK-8试验、乳酸脱氢酶(LDH)试剂盒以及丙二醛(MDA)测定试剂盒分别检测细胞凋亡数量、细胞培养液中LDH水平和MDA含量。通过流式细胞术、q RT-PCR以及Western blotting检测细胞周期、CDK4的m RNA水平和蛋白表达。结果 400μmol/L H_2O_2培养细胞4 h能够建立稳定有效的人肾小球系膜细胞氧化应激损伤模型。随着人参皂苷Rg_3浓度的增加,被H_2O_2损伤的细胞的凋亡数量、细胞外LDH活性、细胞产生的MDA的含量均明显下降。40μmol/L人参皂苷Rg_3可以把人肾小球系膜细胞的细胞周期阻滞在G1期,下调CDK4的m RNA水平和蛋白表达水平。结论人参皂苷Rg_3可以通过抑制CDK4而对人肾小球系膜细胞氧化应激损伤发挥保护作用。     

水飞蓟宾对H2O2诱导大鼠H9C2心肌细胞氧化应激损伤的保护作用

目的探讨水飞蓟宾对H2O2诱导状态下H9C2心肌细胞氧化应激损伤的保护作用.方法将大鼠H9C2心肌细胞分为对照组、H2O2(200μmol/L)干预组以及水飞蓟宾(100、200μmol/L)+H2O2(200μmol/L)干预组,每组设6个复孔.各组经过药物干预6 h后,通过Giemsa染色法观察细胞形态学,通过MTT法测定细胞存活率、流式细胞术测定细胞凋亡率;测定细胞培养液中乳酸脱氢酶(LDH)、磷酸激酶(CK)、谷草转氨酶(AST)活性和丙二醛(MDA)含量;测定细胞中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和谷胱甘肽过氧化物酶(GSH-Px)活性.结果 与对照组比较,H2O2干预组H9C2心肌细胞形态明显异常、存活率显著降低且凋亡率显著升高,培养液中LDH、CK、AST活性和MDA含量均显著升高,细胞中SOD、CAT、GSH-Px活性显著降低,差异均具有统计学意义(P<0.05).与H2O2干预组比较,水飞蓟宾(100、200μmol/L)+H2O2(200μmol/L)干预组培养液中AST、CK活性和MDA含量均显著降低,差异具有统计学意义(P<0.05);水飞蓟宾(200μmol/L)+H2O2(200μmol/L)干预组H9C2心肌细胞形态明显改善、存活率显著升高、凋亡率显著降低,培养液中LDH活性显著降低,细胞中SOD、CAT、GSH-Px活性显著升高,差异均具有统计学意义(P<0.05).结论 水飞蓟宾能够有效改善H2O2诱导状态下H9C2心肌细胞形态,提高其存活率并降低凋亡率,改善细胞中抗氧化酶活性、降低细胞损伤,提示水飞蓟宾对H2O2诱导H9C2心肌细胞氧化应激损伤具有剂量相关性的保护作用.     

On the antioxidant properties of kynurenic acid: Free radical scavenging activity and inhibition of oxidative stress

Kynurenic acid (KYNA) is an endogenous metabolite of the kynurenine pathway for tryptophan degradation and an antagonist of both N-methyl-d-aspartate (NMDA) and alpha-7 nicotinic acetylcholine (α7nACh) receptors. KYNA has also been shown to scavenge hydroxyl radicals (OH) under controlled conditions of free radical production. In this work we evaluated the ability of KYNA to scavenge superoxide anion (O₂⁻) and peroxynitrite (ONOO⁻). The scavenging ability of KYNA (expressed as IC₅₀ values) was as follows: OH = O₂⁻ > ONOO⁻. In parallel, the antiperoxidative and scavenging capacities of KYNA (0-150 μM) were tested in cerebellum and forebrain homogenates exposed to 5 μM FeSO₄ and 2.5 mM 3-nitropropionic acid (3-NPA). Both FeSO₄ and 3-NPA increased lipid peroxidation (LP) and ROS formation in a significant manner in these preparations, whereas KYNA significantly reduced these markers. Reactive oxygen species (ROS) formation were determined in the presence of FeSO₄ and/or KYNA (0-100 μM), both at intra and extracellular levels. An increase in ROS formation was induced by FeSO₄ in forebrain and cerebellum in a time-dependent manner, and KYNA reduced this effect in a concentration-dependent manner. To further know whether the effect of KYNA on oxidative stress is independent of NMDA and nicotinic receptors, we also tested KYNA (0-100 μM) in a biological preparation free of these receptors - defolliculated Xenopus laevis oocytes - incubated with FeSO₄ for 1 h. A 3-fold increase in LP and a 2-fold increase in ROS formation were seen after exposure to FeSO₄, whereas KYNA attenuated these effects in a concentration-dependent manner. In addition, the in vivo formation of OH evoked by an acute infusion of FeSO₄ (100 μM) in the rat striatum was estimated by microdialysis and challenged by a topic infusion of KYNA (1 μM). FeSO₄ increased the striatal OH production, while KYNA mitigated this effect. Altogether, these data strongly suggest that KYNA, in addition to be a well-known antagonist acting on nicotinic and NMDA receptors, can be considered as a potential endogenous antioxidant.     

高效液相色谱-光化学衍生法测定湖南产莲子中黄曲霉毒素G1、G2、B1、B2

目的对不同来源的湖南产莲子中黄曲霉毒素G_1、G_2、B_2、B_1进行高效液相色谱-光化学衍生法测定。方法采用高效液相色谱–光化学衍生法,采用岛津GL Inertsil ODS-3色谱柱(250 mm×4.6 mm,5μm),流动相为甲醇–乙腈–水(35∶13∶52),柱温35℃;光化学衍生器(254 nm)激发波长λ_(ex)=360 nm,发射波长λ_(ex)=450 nm。结果黄曲霉毒素G_1、G_2、B_2、B_1分别在6.7～33.3、11.4～56.8、10.3～51.5、4.1～20.3 pg线性关系良好;平均回收率分别为98.07%、97.72%、96.11%、99.52%,RSD值分别为1.69%、1.40%、2.72%、1.34%(n=6)。9批莲子样品中,有6批未检出黄曲霉毒素,来自于农贸市场农户自存的2批次检出黄曲霉毒素B_1,实验室塑料袋包装储存1年的1批检出黄曲霉毒素B_1、B_2,但质量分数均低于法定标准限量。结论不同来源湖南产莲子中黄曲霉毒素质量分数均低于《中国药典》2020年版规定限量。该法测定结果准确、重复性良好,可为完善莲子安全性控制和质量标准提升提供实验依据。     

高效液相色谱-荧光检测法测定沉香中黄曲霉毒素B1、B2、G1、G2

目的建立高效液相色谱–光化学衍生–荧光检测法测定沉香药材中黄曲霉毒素B1、B2、G1、G2。方法采用高效液相色谱法,通过免疫亲和柱提取和净化,荧光检测器检测。Agilent Zorbax Ecilpse Plus C18色谱柱(250 mm×4.6 mm,5μm);流动相:甲醇–水(45∶55);体积流量:0.8 m L/min;柱温:30℃;进样盘温度:4℃;荧光激发波长为360 nm,发射波长为450 nm。结果黄曲霉毒素B1、B2、G1、G2分别在9.3~74.4、3.0~24.0、9.3~74.4、3.5~28.0 pg线性关系良好,r均大于0.998 0;检测限分别为1.86、0.60、1.86、0.70 pg,定量限分别为7.44、2.40、7.44、2.80 pg。平均回收率分别为78%、92%、82%、99%,RSD值分别为4.4%、3.0%、4.3%、2.8%。结论所建立的方法结果准确、重复性、稳定性均良好,可用于沉香药材中黄曲霉毒素的质量控制。     

Nordihydroguaiaretic acid attenuates potassium dichromate-induced oxidative stress and nephrotoxicity.

Larrea tridentata also known as Creosote bush, Larrea, chaparral, greasewood or gobernadora has been used in the folk medicine for the treatment of several illnesses. The primary product that is present at high concentrations in the leaves from this plant is nordihydroguaiaretic acid (NDGA) which is a powerful antioxidant. On the other hand, potassium dichromate (K(2)Cr(2)O(7))-induced nephrotoxicity is associated with oxidative stress. The aim of this work was to study the effect of NDGA on K(2)Cr(2)O(7)-induced nephrotoxicity and oxidative stress. Nephrotoxicity was induced by a single injection of K(2)Cr(2)O(7) (15 mg/Kg). A group of K(2)Cr(2)O(7)-treated rats was administered NDGA by mini osmotic pumps (17 mg/Kg/day). The results show that NDGA was able to ameliorate the structural and functional renal damage evaluated by histopathological analysis and by measuring proteinuria, urinary excretion of N-acetyl-beta-d-glucosaminidase, serum creatinine, and serum glutathione peroxidase activity. In addition, immunostaining of 4-hydroxy-2-nonenal and 3-nitrotyrosine, markers of oxidative and nitrosative stress, respectively, was ameliorated by the NDGA treatment. These data strongly suggest that the antioxidant properties of NDGA are involved in its renoprotective effect in K(2)Cr(2)O(7)-treated rats.     

辅酶Q10注射液正交函数——分光光度测定法

本文报告了用正交函数法直接测定辅酶Q₁₀注射液含量的方法。以无水乙醇为溶剂,选择波长范围为268～292nm,间隔为12nm,用3点求二次正交多项式的P₂值,可消除吐温-80的干扰。辅酶Q₁₀回收率为98.60±0.66%。本法操作简单,准确度和精密度均较满意。     

HPLC-ELSD同时测定跌打丸中三七皂苷R1、人参皂苷Rg1和人参皂苷Rb1的含量

目的 建立同时测定跌打丸中三七皂苷R₁、人参皂苷Rg₁和人参皂苷Rb1含量的HPLC-ELSD检测方法。方法 采用Phenomenex Kinetex C₁₈色谱柱(100 mm×4.6 mm,2.6 μm),柱温30 ℃,流速0.5 mL·min^-1,流动相为乙腈-水,梯度洗脱,ELSD检测器,漂移管温度110 ℃,载气(空气)体积流量3.0 L·min^-1。结果 三七皂苷R₁、人参皂苷Rg₁、人参皂苷Rb1分别在0.158~3.16 μg(r=0.999 8),0.407~8.14 μg(r=0.999 5),0.446~8.92 μg(r=0.999 9)内呈良好的线性关系,平均加样回收率分别为97.55%(RSD=1.04%),98.09%(RSD=1.03%),97.34%(RSD=0.81%)。结论 该方法简便、快速、准确,可用于跌打丸的质量控制。     

The anti-inflammatory prostaglandin 15d-PGJ<Subscript>2</Subscript> decreases oxidative/nitrosative mediators in brain after acute stress in rats

Rationale Immobilisation stress is followed by accumulation of oxidative/nitrosative mediators in brain after the release of tumour necrosis factor-alpha (TNF) and other cytokines, nuclear factor kappa B (NFB) activation, nitric oxide synthase-2 (NOS-2) and cyclooxygenase-2 (COX-2) expression in the brain.Objectives This study was conducted to assess if some of the anti-inflammatory products of COX can modify the accumulation of oxidative/nitrosative species seen in brain after stress and to study the mechanisms by which this effect is achieved.Methods Young-adult male Wistar rats were subjected to a single session of immobilisation during 6 h.Results In stressed animals, brain levels of the anti-inflammatory 15d-PGJ₂ increases concomitantly with COX-2 expression. Inhibition of COX-2 with NS-398 prevents stress-induced 15d-PGJ₂ increase. Injection of supraphysiological doses of 15d-PGJ₂ (80–120 g/kg) decreases stress-induced increase in NOS-2 activity as well as the stress-induced increase in NO metabolites. On the other hand, 15d-PGJ₂ decreases stress-induced malondialdehyde (an indicator of lipid peroxidation) accumulation in cortex and prevents oxidation of the main anti-oxidant glutathione. The mechanisms involved in the anti-oxidative properties of 15d-PGJ₂ in stress involve NFB blockade (by preventing stress-induced IB decrease) as well as inhibition of TNF release in stressed animals. At the doses tested, 15d-PGJ₂ decreases COX-2 expression and PGE₂ release during stress, suggesting an alternative mechanism for this endogenous compound.Conclusions These findings demonstrate a role for this anti-inflammatory pathway in the brain response to stress and open the possibility for preventing accumulation of oxidative/nitrosative species and subsequent brain damage.     

Prenatal methylmercury exposure hampers glutathione antioxidant system ontogenesis and causes long-lasting oxidative stress in the mouse brain

During the perinatal period, the central nervous system (CNS) is extremely sensitive to metals, including methylmercury (MeHg). Although the mechanism(s) associated with MeHg-induced developmental neurotoxicity remains obscure, several studies point to the glutathione (GSH) antioxidant system as an important molecular target for this toxicant. To extend our recent findings of MeHg-induced GSH dyshomeostasis, the present study was designed to assess the developmental profile of the GSH antioxidant system in the mouse brain during the early postnatal period after in utero exposure to MeHg. Pregnant mice were exposed to different doses of MeHg (1, 3 and 10 mg/l, diluted in drinking water, ad libitum) during the gestational period. After delivery, pups were killed at different time points - postnatal days (PND) 1, 11 and 21 - and the whole brain was used for determining biochemical parameters related to the antioxidant GSH system, as well as mercury content and the levels of F(2)-isoprostane. In control animals, cerebral GSH levels significantly increased over time during the early postnatal period; gestational exposure to MeHg caused a dose-dependent inhibition of this developmental event. Cerebral glutathione peroxidase (GPx) and glutathione reductase (GR) activities significantly increased over time during the early postnatal period in control animals; gestational MeHg exposure induced a dose-dependent inhibitory effect on both developmental phenomena. These adverse effects of prenatal MeHg exposure were corroborated by marked increases in cerebral F(2)-isoprostanes levels at all time points. Significant negative correlations were found between F(2)-isoprostanes and GSH, as well as between F(2)-isoprostanes and GPx activity, suggesting that MeHg-induced disruption of the GSH system maturation is related to MeHg-induced increased lipid peroxidation in the pup brain. In utero MeHg exposure also caused a dose-dependent increase in the cerebral levels of mercury at birth. Even though the cerebral mercury concentration decreased to nearly basal levels at postnatal day 21, GSH levels, GPx and GR activities remained decreased in MeHg-exposed mice, indicating that prenatal exposure to MeHg affects the cerebral GSH antioxidant systems by inducing biochemical alterations that endure even when mercury tissue levels decrease and become indistinguishable from those noted in pups born to control dams. This study is the first to show that prenatal exposure to MeHg disrupts the postnatal development of the glutathione antioxidant system in the mouse brain, pointing to an additional molecular mechanism by which MeHg induces pro-oxidative damage in the developing CNS. Moreover, our experimental observation corroborates previous reports on the permanent functional deficits observed after prenatal MeHg exposure.     

辅酶Q10乳剂的处方工艺改进与质量评价

目的 对处方工艺改进的辅酶Q₁₀乳剂进行质量评价,并建立其含量测定方法。方法 制备高油量辅酶Q₁₀乳剂,利用HPLC建立其含量测定与有关分析方法,并进行理化性质表征,测定包封率,考察灭菌、冻融和稀释稳定性,进行强光降解试验以及影响因素、加速和长期试验。结果 辅酶Q₁₀乳剂粒径、Zeta电位、pH值、含量和包封率分别为(239.5±0.8)nm、(-32.28±2.04)mV、(5.86±0.02)、(100.59±1.24)%和(98.5±1.1)%,灭菌、冻融和稀释稳定性均良好。乳剂光解速率与稀释倍数呈正比,与载药量呈反比。辅酶Q₁₀乳剂需避光制备、低温储存;(40±2)℃避光放置10天,pH值下降0.61;加速和长期试验稳定性良好。结论 高油量辅酶Q₁₀乳剂符合静脉注射液的质量要求,稳定性良好。     

Oxidized casein impairs antioxidant defense system and induces hepatic and renal injury in mice

ScopeOxidized protein products (OPPs) can be easily found in meat and milk during processing and storage. Evidence supports that accumulation of endogenous OPPs plays a negative role in physiological metabolism. However, the impacts of dietary OPPs and the mechanisms have not been elucidated yet. The present study evaluated whether oral oxidized casein would destruct the antioxidant defense system and cause potential oxidized injury in mice liver and kidney.Methods and resultsWe performed oxidized casein (modified respectively by H₂O₂–Cu and HClO) feeding experiments using KM mice (20–22 g). A 10-weeks feeding of oxidized casein as basal protein caused oxidative stress by increasing protein carbonylation (PC), advanced oxidation protein products (AOPPs), dityrosine (Dityr), lipid peroxidation and ROS levels in mice liver, kidney and blood (P < 0.05). In mice liver and kidney, the mRNA expression of Nrf2, γ-GCS, HO-1, GPX-3, and GPX-4 up-regulated, the protein level of Nrf2 in nucleus increased. However, activities of anti-oxidant enzymes (CAT, SOD, and GPX) decreased (P < 0.05). Moreover, histopathological examination displayed the formation of fibrous septa in mice liver and kidney after oxidized casein feeding.ConclusionOxidized casein impairs antioxidant defense system and induces hepatic and renal fibrosis.     

Amelioration of oxidative stress in bio-membranes and macromolecules by non-toxic dye from Morinda tinctoria (Roxb.) roots

Plant dyes have been in use for coloring and varied purposes since prehistoric times. A red dye found in the roots of plants belonging to genus Morinda is a well recognized coloring ingredient. The dye fraction obtained from the methanolic extract of the roots of Morinda tinctoria was explored for its role in attenuating damages caused by H₂O₂-induced oxidative stress. The antioxidant potential of the dye fraction was assessed through DPPH radical scavenging, deoxyribose degradation and inhibition of lipid peroxidation in mice liver. It was subsequently screened for its efficiency in extenuating damage incurred to biomembrane (using erythrocytes and their ghost membranes) and macromolecules (pBR322 DNA, lipids and proteins) from exposure to hydrogen peroxide. In addition, the non-toxic nature of the dye was supported by the histological evaluation conducted on the tissue sections from the major organs of Swiss Albino mice as well as effect on Hep3B cell line (human hepatic carcinoma). The LC–MS confirms the dye fraction to be morindone. Our study strongly suggests that morindone present in the root extracts of M. tinctoria, in addition to being a colorant, definitely holds promise in the pharmaceutical industry.