锌对铅诱发大鼠脂质过氧化时间毒性的拮抗作用研究

采用时间毒理学方法，研究锌对铅诱发大鼠脂质过氧化昼夜节律的影响。结果显示：正常大鼠体内脂质过氧化物（ＬＰＯ）含量具有近似昼夜节律，以１４∶１４为峰值，０２∶１４为谷值。经不同剂量醋酸铅染毒后，３个剂量组大鼠体内ＬＰＯ含量均比对照增高，呈明显的剂量效应关系；且昼夜节律消失。经硫酸锌联合处理后，３个剂量组大鼠体内ＬＰＯ含量均比单独铅染毒的相应剂量组低；且低剂量铅组ＬＰＯ含量的昼夜节律重新出现，但峰值相位提前５小时。提示铅对机体的脂质过氧化作用具有时间毒性，锌对低剂量铅所诱发的脂质过氧化时间毒性具有一定的拮抗作用     

硒对氟致大鼠脂质过氧化拮抗作用的研究

给SD大鼠饮用含氟、硒及氟和硒的去离子水溶液8周,现察氟与脂质过氧化作用的关系以及硒对氟致脂质过氧化的拮抗作用。结果表明,氟可明显抑制大鼠全血谷胱甘肽过氧化物酶(GSH-Px)活性,使血清、肾、肝、心、睾丸等组织中的脂质过氧化物(LPO)含量明显升高。饮水中加硒能促进体内氟的排泄,增强机体的抗氧化能力,提高血中GSH-Px活性,降低体内的LPO含量。结果提示,硒对氟引起的脂质过氧化作用的拮抗机理可能与机体的排氟能力提高及体内抗氧化酶(如GSG-Px)活性明显增强有关。     

牛磺酸对铅脂质过氧化损伤的拮抗作用

目的探讨牛磺酸(Tau)对铅致细胞脂质过氧化损伤的拮抗作用.方法 40只Wistar大鼠分为5组,即:空白对照组,染铅组,Tau的100、400、800组:为染铅4周后分别以100、400、800 mg@kg-1@d-1 Tau灌胃4周.第8周末处死动物,测定血铅、血清丙二醛(MDA)、超氧化物歧化酶(SOD)和肝、肾组织MDA、SOD、谷胱甘肽(GSH)、谷胱甘肽过氧化物酶(GSH-Px)等指标水平.结果①Tau 100、Tau 400组大鼠血铅水平明显降低,与染铅组相比,差异有显著性(P＜0.05).②Tau 100、Tau 400组大鼠血清MDA含量降低,SOD活力升高,与染铅组相比,差异有显著性(P＜0.05).③各染铅组大鼠肝、肾组织MDA和GSH含量显著升高,SOD、GSH-Px活力明显降低,而Tau可拮抗铅的上述作用.其中,与染铅组相比,Tau 400、Tau 800组大鼠肝、肾MDA和GSH含量显著降低,SOD和GSH-Px活力明显恢复(P＜0.01或P＜0.05).结论 Tau可拮抗铅致大鼠血、肝、肾脂质过氧化损伤,对染铅大鼠有保护作用.     

有机硒对铅中毒的拮抗作用试验研究

将９０只大鼠用醋酸铅溶液灌胃，当尿铅＞（０．８１±０．２６）ｍｇ／Ｌ，血铅＞（４．８±０．３３）ｍｇ／Ｌ时，随机分为３组，测定血清中氧化损伤的指标发现超氧化物歧化酶（ＳＯＤ）活性降低和丙二醛（ＭＤＡ）升高。用一种有机硒化合物（ＦＣＱＹ）灌胃后，ＳＯＤ活性明显升高，并有效地抑制脂质过氧化（ＭＤＡ降至正常范围）。将动物处死后，测定骨铅、肾铅和肝铅含量，发现该有机硒能干扰铅的吸收和蓄积。为铅中毒的防治提供了探讨药物治疗的信息     

硒对氟致大鼠脂质过氧化拮抗作用

目的 研究氟与脂质过氧化的关系，硒对氟引起的脂质过氧化的影响。方法 将40只SD大鼠随机分为4组。按对照、氟、硒、硒氟不同饮水饲养8周，观察硒对氟引起大鼠血清、肝、肾、心、睾丸脂质过氧化的影响。结果 与对照组相比．加氟组全血谷胱甘肽过氧化物酶(GSH-Px)显著下降，血清、肝、肾、心、睾丸的脂质过氧化(LPO)含量水平明显升高；加硒组增强机体抗氧化功能，提高全血GSH-Px活性，降低机体LPO含量。结论 可通过补硒来拮抗氟引起的脂质过氧化。     

茶多酚抗染尘大鼠体内脂质过氧化的实验研究

观察了染尘后大鼠体内ＬＰＯ的变化以及茶酚对这种变化的影响。实验分为对照组、矿尘４０ｍｇ组、矿尘８０ｍｇ组和矿尘８０ｍｇ茶多酚组。结果表明染尘３个月时各级染尘大鼠体内ＬＰＯ多酚对矿尘所诱致的体内脂质过经反应增强具有一定的抑制作用。     

牛磺酸对铅所致大鼠贫血的拮抗作用

铅是一种古老的毒物，许多研究认为铅不仅具有神经毒性、肾毒性，而且对造血系统有一定的影响，铅可以影响卟啉代谢，抑制血红素合成酶的生成，从而引起铅性贫血。本实验对牛磺酸对铅中毒大鼠部分血液指标的影响进行了探讨，以期找到一种拮抗铅中毒的药物。     

正己烷致大鼠脂质过氧化损伤的研究

目的　探讨正己烷毒性的作用机制。方法　采用静式染毒方式连续 8h给 SD大鼠吸入正己烷 15 g/ m3。结果　大鼠全血 GSH含量明显降低 ,t- test P<0 .0 1;大鼠血清中 MDA含量虽有增多的趋势 ,但无统计学意义 (t- test P>0 .0 5 ;大鼠肝组织中 SOD和 GSH- Px活性明显降低 ,t- test P<0 .0 1。结论　正己烷可引起或增强机体氧自由基反应 ,导致脂质过氧化损伤 ,这可能是烷烃类物质对机体毒性作用机制之一。     

牛磺酸锌对铅暴露大鼠脂质过氧化损伤的拮抗作用

目的探讨牛磺酸锌(taurine-zinc,TZC)对铅暴露大鼠脂质过氧化损伤的拮抗作用。方法将40只3周龄健康雄性SD大鼠随机分成5组,分别为对照组、染铅组和10、50、100 mg/kg TZC拮抗组,每组8只。除对照组外,其余4组大鼠灌胃乙酸铅溶液(30 mg/kg)染毒;之前1 h,各剂量TZC拮抗组灌胃相应剂量的TZC溶液,每天1次,连续45 d。实验结束后测定各组大鼠血铅含量及血清中总抗氧化能力(T-AOC)、丙二醛(MDA)含量、超氧化物歧化酶(SOD)活力及抑制羟自由基能力。结果染铅组大鼠血铅含量和血清中MDA含量高于对照组,血清中T-AOC、SOD活力、抑制羟自由基能力低于对照组,差异有统计学意义(P<0.05)。各剂量TZC拮抗组SOD活力、T-AOC和抑制羟自由基能力均介于对照组和染铅组之间;且随着TZC剂量的升高,染铅大鼠血清中MDA含量呈先下降后升高的趋势,血清中T-AOC、SOD活力及抑制羟自由基能力均呈先升高后下降的趋势,并均以50 mg/kg TZC拮抗组最接近对照组。结论牛磺酸锌可拮抗铅导致的大鼠脂质过氧化损伤。     

白藜芦醇对铅诱导小鼠脂质过氧化的拮抗作用

目的探讨白藜芦醇对铅暴露引起的氧化损伤的拮抗作用。方法铅染毒动物模型用含铅(醋酸铅0.5%)饮用水构建。60只健康雄性昆明种小鼠随机分为6组,每组10只:正常对照组,铅染毒组,铅染毒+白藜芦醇低、中、高剂量干预组,白藜芦醇组。检测小鼠血铅和组织铅含量及肝、肾组织中超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)、过氧化氢酶(CAT)活性和丙二醛(MDA)的含量和抗氧化能力指数。结果与铅染毒组相比,白藜芦醇处理组肝、肾组织中SOD、CAT和GSH-Px活性均上升(P<0.01),MDA含量降低(P<0.01)。白藜芦醇使用剂量在800～1 200mg/kg时能够显著地提高机体抗氧化酶的活力,增强机体的抗氧化能力。铅染毒小鼠血浆、肝组织及肾组织中ORAC值均有一定程度的减小,给予白藜芦醇可以拮抗铅毒性引起的ORAC值的下降。结论白藜芦醇通过提高抗氧化酶活性,以减轻铅毒引起的脂质过氧化损伤,提高小鼠机体的抗氧化能力,而实现保护肝、肾组织的作用。     

铅对怀孕大鼠及其胎鼠肝脏脂质过氧化的影响

目的 探讨铅对母鼠及胎鼠肝脏损伤的机制。方法 雌性大鼠于怀孕前经饮水染铅1个月,受孕后仍持续染铅,于孕第20天处死,取母鼠及胎鼠的血和肝脏,测定血铅、肝组织脂质过氧化（LPO）水平及相关抗氧化指标。结果 （1）随着饮水中铅含量的增加,母鼠及胎鼠血铅含量均增加,胎鼠血铅负荷达到母鼠水平;（2）肝组织LPO水平在母鼠0.2%组及胎鼠0.05%、0.2%组显著高于对照组;（3）还原型谷胱甘肽（GSH）含量在母鼠与胎鼠0.05%、0.2%组显著增高,谷胱甘肽过氧化物酶（GSH-Px)含量则显著降低。结论 铅可使孕鼠及其胎鼠肝脏脂质过氧化作用增强,并可能通过脂质过氧化作用而影响胚胎发育,胎鼠对铅的毒性更敏感。     

锌硒对铅致小鼠学习记忆功能障碍及脑脂质过氧化的保护作用

研究了单独给铅和联合给铅锌、铅锌硒对小鼠神经行为功能和脑组织、红细胞脂质过氧化（ＬＰＯ）水平及全血谷胱甘肽过氧化物酶（ＧＳＨ－Ｐｘ）活性的相互关系。结果表明单独给铅组小鼠学习记忆能力下降，脑组织和红细胞丙二醛（ＭＤＡ）含量升高，全血ＧＳＨ－Ｐｘ活性降低，与对照组比较具有显著性差异。联合给予铅锌和铅锌硒组水迷宫无误率升高，到达安全台时间缩短，脑组织和红细胞ＭＤＡ含量减少，全血ＧＳＨ－Ｐｘ活性升高，与单独给铅组比较具有统计学意义     

茶多酚对急性百草枯中毒大鼠治疗作用的实验研究

目的 探讨茶多酚（ｔｅａ ｐｏｌｙｐｈｅｎｏｌｓ,ＴＰ）对急性百草枯中毒的治疗作用方法 大鼠用百草枯（ｐａｒａｑｕａｔ,ＰＱ）灌胃（２５０ｍｇ／ｋｇ）染毒后３ｈ再经口灌注ＴＰ,分别测定染毒后８、２４、４８、７２ｈ大鼠血浆和支气管肺泡灌洗液（ＢＡＬＦ）中丙二醛（ＭＤＡ）含量及超氧化物歧化酶（ＳＯＤ）、谷胶基肽过氧化物酶（ＧＳＨ－Ｐｘ）的活力,并观察肺组织结构改变。结果 ＰＱ染毒后血浆及ＢＡＬＦ中ＭＤ     

Acute effect of nut consumption on plasma total polyphenols, antioxidant capacity and lipid peroxidation

Background:  Nuts have been shown to have beneficial effects on human health due to the healthy fat content; however, the effect of antioxidants (i.e. polyphenols) in nuts have not been fully investigated. The present study aimed to assess the immediate effect of a polyphenol-rich meal (75% of energy from nuts: walnuts or almonds) and a polyphenol-free meal on plasma polyphenol content, antioxidant capacity and lipid peroxidation in healthy volunteers.
Methods:  Thirteen subjects participated in a randomized, crossover, intervention study. After an overnight fast, walnuts, almonds or a control meal in the form of smoothies were consumed by study subjects. Each subject participated on three occasions, 1 week apart, consuming one of the smoothies each time. Blood samples were obtained at fasting and then at intervals up to 3.5 h after consumption of the smoothies.
Results:  There was a significant increase in plasma polyphenol concentration following both nut meals, with peak concentrations being achieved at 90 min, and with a walnut meal having a more sustained higher concentration than an almond meal. The plasma total antioxidant capacity reached its highest point at 150 min postconsumption of the nut meals, and was higher after the almond compared to walnut meal. A gradual significant ( P  < 0.05) reduction in the susceptibility of plasma to lipid peroxidation was observed 90 min after ingestion of the nut meals. No changes were observed following consumption of control meal.
Conclusions:  Consumption of both nuts increased plasma polyphenol concentrations, increased the total antioxidant capacity and reduced plasma lipid peroxidation.     

Optimization of the microwave-assisted extraction conditions of tea polyphenols from green tea

Green tea, a popular drink with beneficial health properties, is a rich source of polyphenols that have a wealth of physiological activities. The purpose of the present study was to develop a microwave-assisted extraction (MAE) of green tea polyphenols. MAE of tea phenols from green tea was investigated through orthogonal array design. The content of total phenols in tea infusions was determined using UV/vis spectrophotometric methods. Four factors (microwave intensity, microwave irradiate time, microwave irradiate number of times and tea/water ratio) have a substantial impact on the extraction. The extraction conditions of tea polyphenols are optimized, and the order of importance that influenced the extraction rate was found to be: microwave radiate time>microwave intensity>tea/water ratio>radiate number of times, and the optimal performance of extraction was obtained under microwave intensity 600 W, microwave radiate time 3 min and microwave radiate number of times once with tea/water ratio 1:20.MAE offers important advantages over conventional methods, such as shorter extraction times, substantial savings of energy and a reduced environmental burden.     

Prenatal malnutrition and lead intake produce increased brain lipid peroxidation levels in newborn rats

Objectives: Prenatal malnutrition (M) and lead intoxication (Pb) have adverse effects on neuronal development; one of the cellular mechanisms involved is a disruption of the pro- and anti-oxidant balance. In the developing brain, the vulnerability of neuronal membrane phospholipids is variable across the different brain areas. This study assesses the susceptibility of different brain regions to damage by quitar tissue oxidative stress and lead quitar concentrations to determine whether the combined effect of prenatal malnutrition (M) and lead (Pb) intoxication is worse than the effect of either of them individually.

Methods: M was induced with an isocaloric and hypoproteinic (6% casein) diet 4 weeks before pregnancy. Intoxication was produced with lead acetate in drinking water, from the first gestational day. Both the M and Pb models were continued until the day of birth. Four brain regions (hippocampus, cortex, striatum, and cerebellum) were dissected out to analyze the lipid peroxidation (LP) levels in four groups: normally nourished (C); normally nourished but intoxicated with lead (CPb); malnourished (M); and M intoxicated with lead (MPb).

Results: Dam body and brain weights were significantly reduced in the fourth gestational week in the MPb group. Their pups had significantly lower body weights than those in the C and CPb groups. The PbM group exhibited significant increases of lead concentration and LP in all areas evaluated. A potentiation effect of Pb and M on LP was found in the cerebellum.

Discussion: This study provides information on how environmental conditions (intoxication and malnutrition) during the intrauterine period could differentially affect the development of neuronal plasticity and, in consequence, alter adult brain functions such as learning and memory.     

茶多酚对顺铂所致肾损伤的作用及其可能机制探讨

目的 研究茶多酚（TP）对顺铂（DDP）所致肾毒性作用的保护作用及其可能机制。方法 小鼠随机分为4组：对照组、DDP组、DDP＋高剂量TP组、DDP＋低剂量TP组,分别给药处理后,观察血清中尿素氮（BUN）、肌酐（Cr)变化情况,测定肾组织均浆中超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH－Px)的活性。结果 DDP组的血清中BUN及Cr值上升与对照组比较差异有显著性（P＜0．05）,加入高剂量TP以后血清中BUN及Cr值低于DDP组（P＜0．05）。给予DDP后SOD、GSH－Px活性降低与对照组比较差异有显著性;DDP＋高剂量TP组SOD及GSH－Px值高于DDP组（P＜0．05）。结论 TP在一定程度上缓解DDP所致的肾损伤,其可能机制可能与抗氧化功能有关。     

砷中毒病区腐植酸对脂质过氧化反应的影响

目的探讨台湾乌脚病的病因。方法在体外进行了砷、腐植酸引发脂质过氧化反应的实验。用ＭＤＡ－ＴＢＡ比色法测定了从中国内蒙砷中毒地区和台湾乌脚病区井水以及贵州高砷煤中提取的腐植酸样品。结果试管内实验发现腐植酸能引起不饱和脂肪酸钠盐产生脂质过氧化反应,但作用较弱且不稳定。０．０５ｍｍｏｌ／Ｌ的Ｆｅ２＋能促进这一反应,而１ｍｍｏｌ／Ｌ的Ａｓ２Ｏ３却不能。各地腐植酸样品因来源、成分和结构不同,引起脂质过氧化反应的程度也不同,发现内蒙腐植酸引起脂质过氧化反应能力最强,其次是贵州样品、台湾样品,最后是商品腐植酸（购自美国Ａｌｄｒｉｃｈ公司）。实验还发现微量铁存在时,商品腐植酸引起的脂质过氧化反应是一个动力学过程,它同时具有分解脂质过氧化产物的能力。结论这一实验结果提示流行病学调查者关注乌脚病病区和高砷、高腐植酸地区环境中铁及其他过渡元素与腐植酸和砷的关系。