番茄红素对CHL细胞DNA氧化损伤的影响

目的研究番茄红素对CHL细胞氧化损伤的影响。方法在CHL细胞培养液中分别加入0.5、1、5及10μmol/L番茄红素,给予H2O2作用30min,用单细胞凝胶电泳方法测定细胞DNA损伤情况。结果加入不同剂量番茄红素的CHL细胞经过24h培养后自发性DNA损伤(拖尾率和DNA迁移长度)与溶剂对照组相比没有明显差异。而加入0.5、1、5μmol/L番茄红素后H2O2诱导的CHL细胞DNA损伤率明显低于H2O2组(P<0.05);但10μmol/L番茄红素对H2O2诱导的DNA损伤的保护作用丧失。结论0.5、1、5μmol/L番茄红素对H2O2诱导的细胞DNA损伤有保护作用,10μmol/L番茄红素的抗氧化能力丧失。     

Absorption and DNA protective effects of flavonoid glycosides from an onion meal

Summary Background. It is widely believed that antioxidant micronutrients obtained from fruit and vegetables afford significant protection against cancer and heart disease, as well as ageing. Flavonoids are potential antioxidants found in food such as onions; information on their effectiveness in vivo is so far lacking. Aims. To determine uptake as well as in vivo antioxidant effects of flavonoids from foods. Methods. Six healthy non-obese normocholesterolaemic female volunteers in the age range 20–44 years participated in a randomised two-phase crossover supplementation trial to compare the antioxidant effects associated with (a) a meal of fried onions and (b) a meal of fried onions and fresh cherry tomatoes. Plasma flavonoids, lymphocyte DNA damage, plasma ascorbic acid, tocopherols and carotenoids, urinary malondialdehyde and 8-hydroxy-2’-deoxyguanosine were determined to assess flavonoid absorption and antioxidant efficacy. Results. Flavonoid glucosides (quercetin-3-glucoside and isorhamnetin-4-glucoside) were significantly elevated in plasma following ingestion of the onion meal and the increases were associated with an increased resistance of lymphocyte DNA to DNA strand breakage. A significant decrease in the level of urinary 8-hydroxy-2’-deoxyguanosine was evident at 4 h following ingestion of the onion meal. After the combined tomato and onion meal, only quercetin was detected in plasma. Endogenous base oxidation was decreased but resistance to strand breakage was unchanged. There was no significant change in the excretion of urinary malondialdehyde following either meal. Conclusion. Both meals – onions, and onions together with tomatoes – led to transient decreases in biomarkers of oxidative stress, although the particular biomarkers affected differ. It is possible that the differences in patterns of response reflect the different uptakes of flavonoids but the underlying mechanism is not understood. Received: 1 April 2000, Accepted: 1 August 2000     

Paraoxonase 1 Q192R (PON1-192) polymorphism is associated with reduced lipid peroxidation in R-allele-carrier but not in QQ homozygous elderly subjects on a tomato-rich diet

Summary. Background: The oxidative modification of LDL is considered to play a central role in the pathogenesis of atherosclerosis and coronary heart disease (CHD). Paraoxonase (PON1) protects LDL from oxidation and may therefore retard the developement of atherosclerosis. The PON1–192 polymorphism is associated with diminished PON1 concentrations and an increased risk for CHD in RR-allele subjects. Aim of the study: To investigate the effect of tomato juice consumption on PON1 activity and other parameters related to oxidative stress in healthy elderly subjects. Furthermore, the PON1–192 genotype has been determined in the volunteers in order to see whether possible treatment effects are related to the PON1–192 polymorphism. Methods: Fifty elderly subjects were randomly assigned to control (mineral water) or intervention group (tomato juice). Subjects of the tomato juice group consumed daily 330 mL tomato juice for 8 weeks. Antioxidant status was measured as LDL oxidation, plasma malondialdehyde, ferric reducing ability of plasma (FRAP) and PON1 activity. The PON1–192 polymorphism was determined by restriction fragment length polymorphism polymerase chain reaction (RFLP-PCR). Plasma carotenoids were analyzed by HPLC. Results: Tomato juice consumption reduced LDL-oxidation and improved antioxidant status in R-allele carriers, but not in the QQ genotype group. PON1 activity increased irrespective of the genotype in both, control and intervention group. Conclusions: The changes in antioxidant status after tomato juice consumption seem to depend on the PON1–192 genotype. Healthy elderly, carrying the R-allele, could specificly reduce their higher cardiovascular risk by changing dietary habits. Received: 9 October 2002, Accepted: 28 October 2002 Correspondence to: Achim Bub     

番茄红素对高脂兔血管脂质过氧化损伤的影响及机制探讨

目的：观察番茄红素对高脂喂饲所致家免主动脉脂质过氧化损伤的影响。方法：采用高脂喂饲模型，将30只新西兰家兔随机分为3组：对照组、高脂模型组和番茄红素组，分别给予普通饲料和高脂饲料喂养，番茄红素组另加用番茄红素；于实验开始前1d和开始后第2、4、6、8周末取空腹血测定血清总胆固醇、甘油三酯、高密度脂蛋白胆固醇、血清超氧化物歧化酶活性、丙二醛含量、血清一氧化氮含量和一氧化氮合酶活性。实验结束后，苏丹Ⅳ染色和HE染色观察主动脉血管病理变化。结果：与高脂模型组相比，番茄红素组血清甘油三酯含量减低；血清超氧化物歧化酶活性明显增加；血清丙二醛的含量减少；一氧化氮含量增加；主动脉脂质斑块面积减少。结论：番茄红素对兔主动脉脂质过氧化损伤具有较好的保护作用，能减轻高脂兔动脉粥样硬化病变形成。降甘油三酯，抗脂质过氧化损伤及保护血管内皮功能可能是番茄红素产生抗动脉粥样硬化作用的重要机制。     

Does pizza protect against cancer?

We analyzed the potential role of pizza on cancer risk, using data from an integrated network of case-control studies conducted in Italy between 1991 and 2000. Cancer sites were: oral cavity and pharynx (598 cases), esophagus (304 cases), larynx (460 cases), colon (1,225 cases) and rectum (728 cases). Controls were 4,999 patients admitted for acute, non-neoplastic conditions to the same hospital network as cases. Odds ratios for regular pizza consumers were 0.66 (95% confidence interval, CI = 0.47-0.93) for oral and pharyngeal cancer, 0.41 (95% CI = 0.25-0.69) for oesophageal, 0.82 (95% CI = 0.56-1.19) for laryngeal, 0.74 (95% CI = 0.61-0.89) for colon and 0.93 (95% CI = 0.75-1.17) for rectal cancer. Pizza appears therefore to be a favorable indicator of risk for digestive tract neoplasms in this population.     

番茄红素对急性肺损伤大鼠肺泡巨噬细胞影响

目的观察番茄红素对急性肺损伤大鼠肺泡巨噬细胞吞噬功能的影响。方法以0．5，1．0，3．0mg／（kg·bw）的番茄红素连续给雄性Wistar大鼠灌胃30d，用脂多糖制造大鼠急性肺损伤模型，分别在1，4，6h后支气管肺泡灌洗，检测肺泡巨噬细胞吞噬功能、细胞计数以及肺相对重等指标。结果在各剂量番茄红素作用下，肺泡巨噬细胞吞噬功能明显增强，与模型组相比，注射脂多糖1h后，喂饲番茄红素组吞噬功能增强，增强率分别为11．2％，27．9％，38．1％；4h后，增强率分别为5．9％，4．4％，17．0％；6h后，增强率分别为16．6％，15．2％和21．9％。番茄红素3个剂量组之间呈剂量-反应关系（P〈0．05）。结论番茄红素在0．5，1．0，3．0mg／（kg·bw）剂量下能增强肺泡巨噬细胞的吞噬功能。     

番茄红素对环孢素所致大鼠肾毒性的保护作用

目的:研究番茄红素(lycopene,LP)对环孢素(cyclosporine,CsA)所致肾功能衰竭的保护作用及机制。方法:雄性SD大鼠po给予溶媒或LP(10mg/kg)6d后,再联合给予0.9%氯化钠注射液或CsA(50mg/kg)14d,观察大鼠肾功能与肾脏组织的结构改变。结果:连续14d给予CsA可致大鼠体重下降,血清肌酐(creatinine,Crea)和尿素氮(blood urea nitrogen,BUN)水平显著升高、肌酐清除率(creatinine clearance,Ccr)和肾脏抗氧化活性下降,肾脏组织出现大量细胞排列紊乱和小管萎缩。提前给予LP可以有效增加肾脏抗氧化能力,逆转CsA所致的大鼠体重下降和肾功能衰竭,降低大鼠血清Crea和BUN而提高体内Ccr;组织病理学检测也证实LP可有效的拮抗CsA引起的肾小管变性萎缩。结论:LP能有效拮抗CsA所致的大鼠肾功能衰竭,其作用与LP可以增强CsA大鼠抗氧化能力有关。     

Olive oil enriched in lycopene from tomato by-product through a co-milling process

Abstract

The aim of this investigation was to produce an olive oil (OO) naturally enriched with antioxidants, recovering carotenoids, in particular lycopene, using an industrial by-product of tomato seeds and skin. For this purpose, a technological process in a low-scale industrial plant to co-mill olives and tomato by-product in de-frosted or freeze-dried forms was applied and studied with respect to control samples. Preliminary results obtained from two different experiments were carried out by 40?kg of cultivar Correggiolo olives and 60?kg of olive blends from different cultivars. In both the experiments, the co-milling showed significant enrichment in carotenoids, especially in lycopene (mean values of 5.4 and 7.2?mg/kg oil from defrosted and freeze-dried by-products, respectively). The experimental results demonstrated the possibility to obtain a new functional food naturally enriched in antioxidant compounds, which might be marketed as “OO dressing enriched in lycopene” or “condiment produced using olives and tomato by-product”.     

Iron availability: An updated review

Iron is an essential trace element in human nutrition and its deficiency is a world nutritional problem. Due to the high prevalence of anaemia in developing and industrialized countries, it is necessary to maintain a suitable iron intake through diet in order to achieve an appropriate status of this element in the body. For this reason, accurate knowledge of iron availability of foods is essential in order to plan intervention strategies that improve deficient situations of this nutrient. Regarding to the two forms of iron present in foods, heme iron has greater availability than non-heme iron. Beside this, non-heme iron availability is conditioned by several dietary factors, such as classic factors (meat, ascorbic acid, fibre, phytic acid, polyphenols) and new factors (caseinophosphopeptides and fructo-oligosaccharides with prebiotic characteristics).

For that reason, the aim of this paper is to accurately review all investigations reported in the past decade related to dietetic factors that influence the bioavailability of different iron forms.     

番茄红素对糖尿病模型大鼠肾损伤的治疗及血管紧张素转换酶的作用

目的观察番茄红素对糖尿病性肾病的治疗作用及其可能的作用机制。方法采用高糖高脂饮食加链脲佐菌素法制备2型糖尿病大鼠模型。2型糖尿病大鼠分别ig给予番茄红素5,10和20 mg.kg-1每天1次,连续8周。8周后取尾尖血用罗氏血糖仪测定空腹血糖(FBG)含量,腹主动脉采血后分离血清和血浆,用全自动生化分析仪测定血清肌酐(Scr)、尿素氮(BUN)和24 h尿蛋白(UP)含量,放免法检测血浆胰岛素(Ins)、血管紧张素Ⅱ(AngⅡ)和肾组织AngⅡ含量。HE染色观察肾组织病理形态的变化,RT-PCR法检测肾组织血管紧张素转换酶(ACE)和ACE2 mRNA的表达,Western印迹法检测肾组织ACE2蛋白的表达。结果与正常对照组相比,模型对照组FBG,Ins,Scr,BUN,AngⅡ和24 h UP含量均明显升高(P<0.05);与模型对照组相比,番茄红素10和20 mg.kg-1组Scr,BUN,AngⅡ和24 h UP含量均显著降低,Scr由(54.2±4.3)μmol.L-1分别降低到40.3±2.0和(34.4±3.8)μmol.L-1,BUN由(17.7±2.3)mmol.L-1分别降低到15.5±1.2和(13.1±0.5)mmol.L-1,血浆中AngⅡ由(858±56)ng.L-1分别降低到680±62和(623±64)ng.L-1,肾组织AngⅡ由(19.8±2.9)ng.g-1分别降低到16.7±2.6和(13.6±2.4)ng.g-1蛋白,24 h UP由(16.4±3.5)mg分别降低到13.7±1.9和(9.9±2.3)mg(P<0.05)。与正常对照组相比,模型对照组ACE2,ACE mRNA和ACE2蛋白表达水平显著降低(P<0.01),与模型对照组相比,番茄红素5,10和20 mg.kg-1组ACE2 mRNA和蛋白表达水平则显著升高(P<0.05),其中番茄红素20 mg.kg-1组效果更为明显(P<0.01);ACE mRNA表达水平与模型对照组无明显差异。结论番茄红素能降低糖尿病模型大鼠蛋白尿,改善肾功能,减轻肾组织病理变化,增强肾组织ACE2 mRNA和蛋白的表达,提示番茄红素对糖尿病性肾病的治疗作用可能与抑制肾局部肾素-血管紧张素系统的途径有关。