刺五加提取物在自由基模型中的活性作用

背景与目的： 研究刺五加醇提物和水提物在几种自由基体外模型中的抗氧化作用。 材料与方法： 建立DPPH体系,观察刺五加不同浓度的醇提物和水提取物对DPPH自由基的抑制作用;建立·OH和O2 两种化学发光体系观察刺五加不同浓度的两种提取物对发光强度的抑制作用;采用CHP、VC／Fe2＋和CC14／NADP作为激发剂,建立微粒体脂质过氧化(LPO)损伤模型,观察不同浓度的刺五加两种提取物对MDA生成的抑制作用。 结果：在DPPH体系中,刺五加两种提取物对DPPH的抑制率均显著高于对照组 (P<0.01),呈明显剂量-效应关系,刺五加醇提物和水提物对DPPH的IC50分别为0.18 mg/ml和0.09 mg/ml;在两种化学发光的体系中,除了0.625 mg/ml的刺五加醇提物与对照组的差异无统计学意义(P=0.102),其它浓度的两种提取物对O2 和·OH的抑制率均显著高于对照组(P<0.01),呈明显剂量-效应关系,刺五加醇提物的IC50分别为0.488 mg/ml和1.29 mg/ml;水提物为 0.24 mg/ml和0.37 mg/ml;在CHP模型中,1.25 mg/ml的刺五加水提物表现出了一定的促氧化作用,但差异无统计学意义 (P>0.05)。3种LPO损伤模型中刺五加两种提取物各浓度组的MDA含量均显著低于对照组(P<0.05),且有一定的剂量-效应关系。 结论： 刺五加在几种体外模型中均具有较强的抗氧化作用,在DPPH和两种化学发光体系中,刺五加水提物的抗氧化活性强于醇提物;而在3种LPO模型中,刺五加醇提物的抗氧化活性强于水提物。     

二硫化碳女（雌）性性腺毒性与致脂质过氧化作用研究

二硫化碳女（雌）性性腺毒性与致脂质过氧化作用研究张文昌１连祥霖１杨乃富１王彪２王德彤３王韵华３１福建医学院劳动卫生教研室２福建南平地区职业病防治院３福建南平化纤厂职工医院二硫化碳（ＣａｒｂｏｎＤｉｓｕｌｆｉｄｅ，ＣＳ２）是应用广泛的工业用有机溶剂。既...     

川芎提取物的多模型体系抗氧化活性测定

目的：研究川芎醇提物和水提物在几种自由基体外模型中的抗氧化作用位点与活性强度,以及此两种提取物在小鼠氧化损伤模型中的综合抗氧化作用。方法：建立DPPH体系,观察川芎醇提物和水提物对DPPH自由基的清除率;建立OH和O_2~-化学发光体系观察川芎的两种提取物对发光强度的抑制作用;采用CHP、Vc/Fe~（2＋）和CCl_4/NADP~＋作为激发剂,建立微粒体脂质过氧化（LPO）损伤模型,观察川芎两种提取物对MDA生成的抑制作用。建立小鼠氧化损伤模型,观察川芎两种提取物对SOD和CAT蛋白表达水平的影响,以及对MDA生成的抑制作用。结果：在DPPH体系中,川芎的醇和水两种提取物对DPPH的清除率均显著高于对照组（P〈0.01）,且呈明显剂量-效应关系,川芎醇提物和水提物对DPPH的IC_（50）分别为3.47和6.19 mg/ml;在两种化学发光体系中,川芎的醇提物和水提物对O_2~-和OH的清除率均显著高于对照组（P〈0.01）,且呈明显剂量-效应关系,川芎醇提物对O_2~-和OH的IC_（50）分别为2.56和4.21mg/ml,水提物对O_2~-和OH为2.34和2.80mg/ml;3种LPO损伤模型中川芎两种提取物各浓度组的MDA含量均显著低于对照组（P〈0.05）;在体内实验中,与对照组相比,川芎水提物和醇提物组均明显降低肝组织和血清内MDA的含量（P〈0.05）;川芎水提物和醇提物能明显提高肝组织内SOD蛋白表达水平;川芎醇提物可以提高肝组织内CAT蛋白表达水平。结论：川芎提取物在几种体外模型和体内模型中均具有较好的抗氧化作用。     

脂质过氧化与食管癌发病关系的研究

本文用硫代巴比妥酸荧光法测定了122例食管癌前各期人群及食管癌宿主血清中的过氧化脂质(Lipoperoxide,Lpo)含量。结果显示,随食管上皮细胞病变的进展,机体Lpo水平明显升高。癌症组与癌前增生组和正常组比较,差异非常显著,但癌前增生组与正常组间差异无显著性,提示脂质过氧化水平的升高可能是食管癌发生后的伴行改变,其机制尚待探讨。     

DHA在人乳腺癌中对阿霉素细胞毒活性的影响与脂质过氧化作用的关系

目的　探讨廿二碳六烯酸 (DHA)影响阿霉素 (ADM)对人乳腺癌DMA MB 435s细胞毒活性的机理是否通过DHA的脂质过氧化作用。方法　在培养的人乳腺癌DMA MB 435s细胞株中加入不同配伍的细胞毒药物、多不饱和脂肪酸 (PUFAs)、前氧化剂VitC和VitK3混合物及抗氧化剂VitE等 ,在细胞的抽提物中以TBA法每 2 4小时测定脂质过氧化产物丙二醛 (MDA)及用亚硝酸盐分光光度法测定一氧化氮 (NO)的含量 ,并作出MDA、NO含量与细胞毒性间的剂量 -效应相关直线。结果　从细胞培养的第三天开始 ,出现明显的细胞活力变化 ,同时伴有脂质过氧化物 (MDA)水平的增加及NO含量的降低。细胞抽提物中MDA及NO含量与细胞毒性之间存在直线相关关系。结论　DHA能明显增加ADM对MDA MB 435s细胞株的细胞毒活性 ,机理之一是DHA增强了瘤细胞内的脂质过氧化作用。     

食管癌及癌前各期人群血清SOD同功酶状态及脂质过氧化水平研究

以食管癌高发区河南鹤壁农村作为研究现场,选择经食管细胞学诊断的食管上皮细胞正常、轻度增生、重度增生人群及未经任何治疗的食管癌初诊病例作为研究对象,进行了血清过氧化脂质水平、超氧化物歧化酶同功酶活力和含量的综合测定。结果显示,随食管上皮细胞从正常到癌变病变级别的增高,宿主血清脂质过氧化水平显著增高(P<0.01),超氧化物歧化酶总活力显著下降,且主要表现为 CuZnSOD 活性的显著降低(P<0.01),而 CuZnSOD 含量却随病变级别增高而显著增加,呈现与 CuZnSOD 活性相反的变化趋势,表明食管癌发生发展与自由基代谢失衡有关。结果还提示食管癌宿主体内可能存在无活性的 CuZnSOD。     

煤焦油烟对作业工人血中超氧化物歧化酶活性及脂质过氧化产物含量影响的研究

本文通过对武钢焦比厂４０名炼焦作业工人和４０名健康人血中ＳＯＤ和ＬＰＯ水平进行研究，结果表明炼焦工人血中ＳＯＤ活性明显低于对照组．差异非常显著（Ｐ＜０．０ｌ）．血清中ＬＰＯ含量明显高于对照组，差异极显著（Ｐ＜０．０ｌ）。同时分析了作业工人的工龄和烟酒嗜好与ＳＯＤ及ＬＰＯ之间的关系．结果都未见有明显差异。     

红景天提取物对微粒体LPO模型的影响

背景与目的： 探讨红景天醇提物和水提物的抗氧化作用及其剂量反应关系。 材料与方法： 回流法和煎煮法分别制备红景天醇提物和水提物。钙沉淀法提取雄性SD大鼠肝微粒体。采用四种激发剂Vc/Fe2＋、过氧基异丙苯(Cumine hydroperoxide,CHP)、 CCl4/辅酶Ⅱ(Nicotinamide-adenine dinucleotide phosphate, NADP)和还原型辅酶Ⅱ(Reduced form of nicotinamide-adenine dinucleotide phosphate,NADPH)-腺苷二磷酸(Adenosine diphosphate,ADP)／Fe2＋建立微粒体脂质过氧化(Lipid peroxidation,LPO)模型,加入浓度为 25 mg/ml、12.5 mg/ml、6.25 mg/ml、3.13 mg/ml、1.56 mg/ml的红景天醇提物和水提物,观察在4 种模型系统中抗氧化作用。在VC/Fe2＋、CHP、 CCl4/NADP模型中通过比色法测定对丙二醛(Malondialdehyde,MDA)的抑制作用,NADPH-ADP／Fe2＋模型通过氧电极法测定对耗氧量的抑制作用。 结果： 红景天水提物在浓度为6.25～25.00 mg/ml范围内,其CHP模型中的MDA含量显著低于阳性模型对照组。在 Vc/Fe2＋、CHP和CCl4/NADP 模型中,红景天醇提物和水提物各浓度组MDA含量均非常显著低于对照组,并且在一定终反应浓度内有剂量-反应关系。在NADPH-ADP／Fe2＋模型中,最高浓度的醇提物和水提物的抑制率分别达到76％和43％。 结论： 红景天的两种提取物都具有较强的抗氧化作用,并存在一定的剂量效应关系。其中红景天醇提物对酶参与性反应的作用强于水提物。该研究初步探讨了红景天抗氧化作用的机制,其结果为红景天在自由基损伤中的保护作用提供了实验依据。     

淮河蚌埠段水中有机物对小鼠遗传毒性和脂质过氧化作用的影响

目的 :探讨淮河水蚌埠段有机污染物对小鼠遗传毒性和脂质过氧化作用的影响。方法 :用淮河蚌埠段上、下游水、出厂水及末梢水的有机提取物分别做小鼠微核试验、精子畸形试验 ,并进行脂质过氧化物 (LPO)、超氧化物歧化酶 (SOD)及谷胱甘肽过氧化物酶 (GSH Px)检测。结果 :淮河不同区段水质有机提取物均有不同程度的致突变性 ;与对照组相比 ,血清、肝、脑组织LPO水平增加 (P <0 .0 5～ 0 .0 1) ,SOD和GSH Px活性降低 (P <0 .0 5～ 0 .0 1) 结论 :淮河N段水有机污染物有潜在的遗传毒性 ,并能影响小鼠的脂质过氧化作用     

"调肝颗粒剂"阻断肝癌前病变过程中的抗氧化和清除自由基作用

目的探讨氧自由基与肝细胞癌变的关系,以及调肝颗粒剂的抗氧化作用.方法:用二乙基亚硝胺(DEN)建立SoltFarber二步肝癌前病变短期动物模型,用调肝颗粒剂进行干预,电子自旋共振(ESR)技术测定羟自由基清除率,改良的硫代巴比土酸(TBA)法测定过氧化脂质(LPO),用双硫代硝基苯(DTNB)直接显色法测定谷胱甘肽过氧化物酶(GSH-Px),用黄嘌呤-黄嘌呤氧化酶法测定超氧化物歧化酶(SOD).结果:调肝颗粒剂能明显抑制肝癌前病变过程中产生的丙二醛(MDA),并对羟自由基具有良好的清除作用.与此同时提高肝组织及血浆中的SOD、GSH-Px活力.结论:调肝颗粒剂可以通过抗氧化来干预、阻断肝癌前病变.     

Free Radical Scavenging Properties of Annona squamosa

Annona squamosa has extensively been used in the traditional and folkloric medicine and found to possess many biological activities. Different solvents, petroleum ether, chloroform, ethyl acetate and methanol extracts of Annona squamosa seeds (ASPE, ASCH, ASEA, ASME) have been used to prepare plant extracts. The present investigations dealt with the free radical scavenging activity of four extracts using various techniques such as total reducing power estimation, total phenolic count, 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging effect, evaluation of ABTS cation decolorisation capacity, FRAP assay, hdroxyl radical scavenging assay, super oxide assay and Nitric oxide radical scavenging assay of the extracts. The results showed that the four extracts of Annona squamosa showed significant reducing power in four extracts. The total phenolic contents in petroleum ether, chloroform, ethyl acetate, methanol extracts and positive control were 0.64±0.17, 0.54±0.27, 0.49±0.24, 0.57±0.22 and 0.66±0.33. The antioxidant capacity by ABTS assay of ASPE, ASCH, ASEA, ASME and positive control, trolox showed 77.75±0.5,73.25±1.7,78.5± 1.2 , 80 ± 0.8 μg/ml and 94.2 ± 0.9 respectively. The (50 % scavenging activity) SA50 of ASPE and ASCH, ASEA and ASME was found to be 34.4 μg/ml, 43.8 μg/ml 34.7 μg/m and 28.8 μg/ml respectively by DPPH assay. The percentage of hydroxyl radical scavenging increased with the increasing concentration of the extracts. ASPE, ASCH, ASEA and ASME showed superoxide radical scavenging activity, as indicated by their values 66 ± 0.5, 68 ± 1 ,63 ± 1 and 70 ± 0.5 μg/ml respectively compared to gallic acid which was 97 ± 0.5 μg/ml. The values for scavenging of nitric oxide for ASPE, ASCH, ASEA and ASME were 91.0 ± 1.0, 66.75 ± 0.5, 71.75 ± 1.1 and 75.75 ± 1.15 μg/ml while value for standard ascorbic acid was 91.0 ± 1.0 μg/ml. The results revealed strong antioxidants in four extracts may lead to the development of potent antioxidant agents from Annona squamosa seeds.     

Irradiation After Surgically Induced Brain Injury in the Rat: Timing in Relation to Severity of Radiation Damage

The aim of this study was to evaluate how timing of irradiation after brain surgery in rats relates to overall extent of brain radiation damage. Extent of injury was determined according to lipid peroxidation (malondialdehyde; MDA) levels in brain tissue. Thirty female rats were randomly assigned to five equal groups (Groups A-E). Four groups underwent trephination and scalpel hemisection of right frontal lobe. Rats in Groups B and D received 25 Gy cranial irradiation in a LINAC system at 10 and 20 days after surgery, respectively. Twenty-four hours later they were killed and their right frontal lobes were removed for lipid peroxidation determination. Groups A and C were not irradiated; these groups were killed and had their frontal lobes removed on day 11 and day 21 post-surgery, respectively. The remaining six animals (Group E, sham surgery) underwent trephination only, and were killed and had their frontal lobes removed 24 h later. There was a significant difference between the mean MDA levels in the control group and Group D, and between the levels in Group B and Group D (P < 0.05 for both). The difference between the mean for Group A and the mean for Group B was even more significant (P < 0.01). The most striking differences were between the control group and Group B, and between Group B and Group C (P < 0.001 for both). The data from this rat model suggest that, in humans, starting radiotherapy early (1-2 weeks) after debulking of a brain tumor may result in significantly higher levels of tissue damage than if the radiation is started 3 weeks or more postoperatively. Further experimental research is needed to project these findings in rats to human subjects.     

Chemoprevention of rat mammary carcinogenesis by black tea polyphenols: modulation of xenobiotic-metabolizing enzymes, oxidative stress, cell proliferation, apoptosis, and angiogenesis

Chemoprevention of dietary constituents has emerged as a cost-effective approach to control the incidence of breast cancer. The present study was therefore designed to evaluate the chemopreventive efficacy of black tea polyphenols (Polyphenon-B) during the preinitiation phase of 7,12-dimethylbenz[a]anthracene (DMBA) induced mammary carcinogenesis using xenobiotic-metabolizing enzymes, cellular redox status, cell proliferation, apoptosis, and angiogenesis as biomarkers of chemoprevention. Intragastric administration of DMBA induced adenocarcinomas that showed enhanced activities of phase I carcinogen activation and phase II detoxification enzymes with increased lipid and protein oxidation and decrease in antioxidant status. This was associated with increased cell proliferation, angiogenesis, and evasion of apoptosis as revealed by upregulation of proliferating cell nuclear antigen (PCNA), Bcl-2, and vascular endothelial growth factor (VEGF), and downregulation of Bax, caspase 3, and poly(ADP-ribose) polymerase (PARP). Dietary administration of Polyphenon-B effectively suppressed the incidence of mammary tumors as evidenced by modulation of xenobiotic-metabolizing enzymes and oxidant-antioxidant status, inhibition of cell proliferation and angiogenesis, and induction of apoptosis. The present study provides evidence that Polyphenon-B exerts multifunctional inhibitory effects on DMBA-induced mammary carcinogenesis and suggests that it can be developed as a potential chemopreventive agent.     

Suppressive Effects of Okinawan Food Items on Free Radical Generation from Stimulated Leukocytes and Identification of Some Active Constituents: Implications for the Prevention of Inflammation-associated Carcinogenesis

Okinawa prefecture in Japan is a distinct area characterized by unique traditional food habits and longevity. ‍Prolonged exposure to activated leukocytes, playing pivotal roles in chronic inflammation-associated carcinogenesis, ‍is known to lead to oxidative and nitrosative damage to macromolecules in the body since they are primary sources ‍of free radicals, such as superoxide anion (O2 ‍-) and nitric oxide (NO). In this study, we estimated anti-oxidative and ‍anti-nitrosative activities of Okinawan food items by employing two cellular experimental systems: (1) phorbol ‍ester-induced O2 ‍- generation from differentiated HL-60 human promyelocytic leukemia cells; and (2) ‍lipopolysaccharide (LPS)-induced NO generation in RAW264.7 murine macrophages. A total of 138 food items, ‍consisting of 42 samples unique to Okinawa and 96 common in the Japanese main island, were purchased at local ‍markets in Okinawa and extracted with chloroform. When tested at a concentration of 100 ìg/ml, 38% (16/42) of ‍the former showed 70% or more inhibition of O2 ‍- generation while 21% (20/96) of the latter did so. In parallel, 64% ‍(27/42) of the former showed significant NO generation suppression in contrast to 48% (46/96) of the latter . Twentyone ‍active species were further tested at a concentration of 20 ìg/ml, and eleven species, including sugar cane, wild ‍turmeric, and zedoary, were indicated to be most promising items with anti-oxidative and anti-nitrosative properties. ‍In addition, some of the active constituents (chebulagic acid, a resveratrol derivative, and sesquiterpenoids) were ‍identified. Our results suggest that food items typical in the Okinawa area have higher cancer preventive potential ‍than those common in Japan.     

吸烟引起人体氧化损伤的可能机制

背景与目的： 通过多项生物标志物研究吸烟对DNA氧化损伤、脂质过氧化和氧化防御机制的影响。 材料与方法： 选取年龄在18～25岁的男性吸烟志愿者60名和非吸烟者30名,分为吸烟组和非吸烟组。分别通过高效液相色谱-电化学检测法(HPLC-ECD)测定24 h尿样中8-羟基脱氧鸟苷(8-OHdG)水平;应用彗星实验测定外周血淋巴细胞DNA链的断裂情况;采用高效液相色谱-紫外线检测法(HPLC-UV)测定24 h尿样中丙二醛(MDA)、丙酮(ACON)和戊醛(PP)水平;采静脉血测定血浆超氧化物歧化酶(SOD)、谷胱苷肽过氧化氢酶(GPX)和过氧化氢酶含量。 结果： 吸烟组尿8-OHdG和外周血淋巴细胞DNA的断裂分别比非吸烟组高185％和97 ％(P均<0.01),尿MDA、ACON和PP较非吸烟组显著增高(P均<0.01),SOD、GPX和过氧化氢酶分别较非吸烟组低15％,10％和9％(P≤0.01)。 结论： 吸烟可以引起机体的氧负荷,造成DNA氧化损伤、脂质过氧化和抗氧化酶的改变。     

过氧基异丙苯对雄性小鼠的自由基毒性与遗传毒性的研究

背景与目的： 过氧基异丙苯是实验室常用的自由基激发剂,本实验旨在了解过氧基异丙苯(Cumene hydroperoxide,CHP)的自由基毒性和遗传毒性,为制造氧化损伤疾病相关动物模型提供参考剂量。 材料与方法： 36只健康昆明种成年雄性小鼠,体重(38.3±7.8) g , 随机分为4 组。灌胃染毒,染毒剂量分别为2 000、500、125和0 μg/kg。每天1 次,每周5 d,共计40 d。实验结束后处死小鼠,观察小鼠骨髓微核、精子畸变率,测定睾丸组织匀浆中丙二醛(Malondialdehyde,MDA)、 总超氧化物歧化酶(Total superoxide dismutase,T-SOD)、还原型谷胱甘肽(Glutathion,GSH)的水平。 结果： CHP染毒各组小鼠体重有程度不同的减轻,随染毒剂量的增加,睾丸组织匀浆中MDA含量逐渐增加,T-SOD活力、 GSH含量逐渐降低,其中2 000 μg/kg体重染毒组睾丸组织匀浆中MDA含量与对照组比较差异有统计学意义(P<0.01),500 μg/kg染毒组GSH含量、SOD活力与对照组比较差异有统计学意义(P<0.05);骨髓嗜多染红细胞微核及精子畸变率增高,2 000 μg/kg染毒组与对照组比较差异有统计学意义(P<0.01)。 结论： CHP对昆明种小鼠具有很强的自由基毒性和遗传毒性,CHP的自由基毒性引发的氧化损伤可能是其遗传毒性的重要机制。     

单肺通气方式对食管癌患者围手术期炎性细胞因子和氧自由基的影响

目的： 探讨单肺通气（OLV）方式对食管癌患者围手术期炎性细胞因子和氧自由基的影响。方法：拟行食管癌根治术患者40例,随机分为长时间组(Ⅰ组)和间断双肺通气组(Ⅱ组),每组20例。两组患者分别在麻醉诱导后(T₁)、OLV 45min(T₂)、90min(T₃)及术后2 h(T₄)采取外周静脉血,分别测定血清肿瘤坏死因子-α（TNF-α）、白细胞介素（IL）-6、IL-8、丙二醛（MDA）浓度及超氧化物歧化酶（SOD）活性。结果：两组患者的TNF-α、IL-6和IL-8于T2时均明显上升（P<0.05）,Ⅱ组T₃、T₄时TNF-α、IL-6和IL-8均明显低于Ⅰ组（P<0.05）。两组患者的MDA于T₃、T₄时显著升高（P<0.05）,且Ⅱ组在T₃、T₄时显著低于Ⅰ组（P<0.05）;两组患者的SOD于T₃、T₄时显著降低（P<0.05）,且Ⅱ组在T₃、T₄时显著高于Ⅰ组（P<0.05）。结论：单肺通气期间间断双肺通气可减轻对肺组织的损伤。