岩藻聚糖硫酸酯降血脂及抗氧化作用的研究

目的：　观察低分子量岩藻聚糖硫酸酯（ｌｏｗ ｍｏｌｅｃｕｌａｒ ｓｕｌｆａｔｅｄ ｆｕｃａｎ , Ｌ Ｍ Ｓ Ｆ） 对实验性高脂血症大鼠的血脂水平及血清和组织中脂质过氧化物（ Ｌ Ｐ Ｏ） 含量和 Ｓ Ｏ Ｄ 活力的影响,探讨其降血脂、抗氧化作用与抗动脉粥样硬化（ Ａ Ｓ） 的关系。方法：　利用实验性高脂血症大鼠模型观察 Ｌ Ｍ Ｓ Ｆ 的降脂作用及对血清和组织中 Ｌ Ｐ Ｏ 和 Ｓ Ｏ Ｄ 的影响。结果：　３０ 天实验结束后,高脂血症大鼠在血脂升高的同时,血清和组织中 Ｌ Ｐ Ｏ 含量上升, Ｓ Ｏ Ｄ 活力下降。 Ｌ Ｍ Ｓ Ｆ 能显著降低高脂血症大鼠血清中 Ｔ Ｇ（ Ｐ＜ ０ ．０５） 和 Ｔ Ｃ（ Ｐ＜ ０ ．０１） 含量,提高 Ｈ Ｄ Ｌ Ｃ 含量（ Ｐ＜ ０ ．０５） ; Ｌ Ｍ Ｓ Ｆ 对高脂血症大鼠具有较强的抗氧化作用,能显著降低血清和组织中 Ｌ Ｐ Ｏ 含量（ Ｐ＜ ０ ．０１） ,同时升高 Ｓ Ｏ Ｄ 活力（ Ｐ＜ ０ ．０１） 。结论：　 Ｌ Ｍ Ｓ Ｆ 显著的降血脂及抗氧化作用使其在抗动脉粥样硬化（ Ａ Ｓ） 方面有较大的应用价值。     

乙醇慢性摄入染毒对大鼠肝脏ADH和GST活性,GSH含量的影响

给实验动物慢性摄入乙醇平均每只每天量为８．０ｇ／ｋｇ体重，历时９０天。结果显示：（１）大鼠肝细胞浆中醇脱氢酶（ＡＤＨ）和谷胱甘肽硫转移酶（ＧＳＴ）活性，染毒组较对照组均明显减低（Ｐ＜０．０１）；（２）大鼠肝细胞浆内谷胱甘肽（ＧＳＨ）含量染毒组较对照组也明显减低（Ｐ＜０．０１）。提示ＡＤＨ和ＧＳＴ活性及ＧＳＨ含量在酒精性肝病发病中起着重要作用。     

硒和维生素E对糖尿病大鼠红细胞[Ca~(2+)]i水平的影响

目的：　观察链脲佐菌素（ＳＴＺ）糖尿病大鼠补充硒（Ｓｅ）和／或维生素Ｅ（ＶＥ）后红细胞内游离钙浓度［Ｃａ２＋ ］ｉ的变化。方法：　用ＳＴＺ制成糖尿病（ＤＭ）大鼠,分为四组：（１）ＤＭ 对照组;（２）Ｓｅ 治疗组;（３）ＶＥ治疗组;（４）Ｓｅ 和ＶＥ治疗组;另有正常对照组,每天以同体积的生理盐水灌胃。实验期为３０ 天,分析血Ｓｅ、ＶＥ及红细胞［Ｃａ２＋ ］ｉ。　结果：　补充Ｓｅ 和／或ＶＥ后,红细胞［Ｃａ２＋ ］ｉ显著下降,与ＤＭ 对照组比较,差异有显著意义（Ｐ＜ ０．０５,Ｐ＜ ０．０１）,以联合用药组降幅较大。血硒水平联合用药组高于其他各组（Ｐ＜ ０．０１）,补Ｓｅ组高于补ＶＥ组和ＤＭ 对照组（Ｐ＜ ０．０１）;血清ＶＥ浓度联合用药组高于ＤＭ 对照组和补Ｓｅ 组（Ｐ＜ ０．０１,Ｐ＜ ０．０５）,而补ＶＥ组血清ＶＥ浓度已恢复至正常水平。　结论：　Ｓｅ和ＶＥ对ＤＭ 大鼠红细胞［Ｃａ２＋ ］ｉ异常升高有明显的抑制作用。     

七城市居民体重指数变动趋势及与血压的关系

目的：对北京、上海等七城市３５岁以上居民１４６６６人的ＢＭＩ变化情况、ＢＭＩ对血压的影响进行随访研究。将基线ＢＭＩ按＜２０、２０～２５、＞２５ｋｇ／ｍ２分为低体重、正常体重和肥胖进行分析。结果：男、女性肥胖患病率分别是１８．３８％与２４．５３％，女性明显高于男性（Ｐ＜０．０５）；ＳＢＰ、ＤＢＰ水平和高血压患病率与ＢＭＩ呈正相关关系。３年随访期间，男女队列分别有４５．３０％和４５．４８％的人ＢＭＩ升高，男性ＢＭＩ升高了０．２１ｋｇ／ｍ２，女性升高了０．３１ｋｇ／ｍ２，人群平均ＳＢＰ、ＤＢＰ和高血压患病率也明显上升，ＢＭＩ增高人群的平均ＳＢＰ、ＤＢＰ与高血压患病率的升高幅度明显大于ＢＭＩ恒定和ＢＭＩ下降人群（Ｐ＜０．０１）。     

膳食钙对高血压大鼠血压的影响及其机理研究

方法：雄性ＳＤ大鼠经外科摘除左肾，按血压并参考体重随机分为三组：Ａ、Ｂ组饲料含钙（Ｃａ）０．７８％，Ｃ组含Ｃａ２．０％，Ｂ、Ｃ组每周皮下注射去氧皮质酮（ＤＯＣ）２５ｍｇ／ｋｇｂｗ，实验共持续７周。结果：Ｂ组血压从第４周开始显著高于Ａ、Ｂ组：Ｂ、Ｃ组血清亚硝酸根离子（ＮＯ－２）的浓度均显著高于Ａ组（Ｐ＜０．０１），Ｃ组亦显著高于Ｂ组（Ｐ＜０．０１）。依赖还原性辅酶Ⅱ－黄递酶（ＮＡＤＰＨ－ｄ）组织化学染色显示；Ｂ、Ｃ组主动脉内膜一氧化氮合成酶（ＮＯＳ）阳性反应较Ａ组增强，且中膜亦呈阳性反应；Ｃ组较Ｂ组阳性反应增强，其中膜亦呈阳性反应。结论：高钙膳食可能通过促进ＤＯＣ－ＮａＣｌ型高血压大鼠一氧化氮（ＮＯ）的合成或释放而降低血压     

海藻硫酸多糖抗氧化与抗肿瘤作用的实验研究

目的：观察海藻硫酸多糖（ＳＰ）对正常及荷瘤小鼠肝匀浆及红细胞中ＳＯＤ，ＧＳＨ－Ｐｘ活性及脂质过氧化产物ＭＤＡ含量的影响，探讨其抗氧化与抗肿瘤之间的关系。结果：移植肿瘤Ｓ１８０使肝组织中ＳＯＤ，ＧＳＨ－Ｐｘ活性分别由１１３．７３±８．１７降至７１．４１±１０．９８ｍｇ／Ｌ（Ｐ＜０．０５），３２．３４±０．０５降至２９．９６±０．１６Ｕ（Ｐ＜０．０１），ＭＤＡ含量由０．２３４±０．００１增至０．２８０±０．０１２（Ｐ＜０．０５），腹腔注射或口服ＳＰ则使ＳＯＤ，ＧＳＨ－Ｐｘ活性增至１１８．７７±１８．９２ｍｇ／Ｌ（Ｐ＜０．０５），３６．５８±１．０６Ｕ（Ｐ＜０．０１），ＭＤＡ含量降至０．１０４±０．０３９（Ｐ＜０．０１）。且腹腔注射ＳＰ１００ｍｇｋｇ－１ｄ－１×１０ｄ可使肿瘤抑制率达３９．１３％，口服ＳＰ２００ｍｇｋｇ－１ｄ－１×１０ｄ也能使肿瘤抑制率达２８．０４％。结论：ＳＰ抑瘤作用的机理可能与抗氧化有关。     

脂质过氧化物及超氧化物歧化酶在肾小球疾病中的临床观察

本研究测定了２５例原发性肾病综合征（ＰＮＳ）、１５例急性肾小球肾炎（ＡＧＮ）患者和３０例健康人血清脂质过氧化物（ＬＰＯ）及全血超氧化物歧化酶（ＳＯＤ）的含量。结果：ＰＮＳ组和ＡＧＮ组血清ＬＰＯ均显著高于对照组（Ｐ＜０．０１）：ＰＮＳ组和ＡＧＮ组全血ＳＯＤ均显著低于对照组（Ｐ＜０．０５）。表明ＰＮＳ和ＡＧＮ患者脂质过氧化作用增强，抗氧化机能下降，提示ＰＮＳ和ＡＧＮ的发生与脂质过氧化和抗氧化失衡有关。     

二硫化碳对大鼠肝脏脂质过氧化作用的研究

观察了二硫化碳（ＣＳ２）腹腔注射染毒对大鼠肝脏脂质过氧化物（ＬＰＯ）含量超氧化物歧化酶（ＳＯＤ）和谷胱甘肽过氧化物酶（ＧＳＨ－ＰＸ）活力的影响，急性染毒实验结果显示，大鼠肝ＬＰＯ含量随ＣＳ２染毒剂量增加而明显升高（ｒ＝０．８１０８，Ｐ＜０．０１），ＳＯＤ活性随剂量增加有降低趋势，ＧＳＨ－ＰＸ活性未见显著变化。亚急性实验结果显示，染毒２１ｄ染毒组ＧＳＨ－ＰＸ活力，染毒４５ｄ染毒组ＳＯＤ及ＧＳＨ－ＰＸ活力与对照组比较均显著降低（Ｐ＜０．０５），这表明，ＣＳ２是一个重要的致脂质过氧化物。     

石油加工作业人员染色体畸变和微核形成的观察

对某石油化工厂沥青岗位工人４３人、催化常减压岗位工人１６６人和对照组１３４人，进行了外周血淋巴细胞染色体、淋巴细胞微核、口腔粘膜微核观察。其结果为：沥青组外周血淋巴细胞染色体畸变细胞率（为０．５３％），染色体畸变率（为０．７７％），均高于对照组（０．０７％，０．０７％）（Ｐ均＜０．０１）和催化常减压组（０．０８％，０．１１％）（Ｐ均＜０．０１）；沥青组外周血淋巴细胞微核人员出现率（７０．４５％）和平均微核细胞率（１．２‰）高于对照组（４．５％，０．０４‰）（Ｐ均＜０．０１）和催化常减压组（２５．７０％，０．３２‰）（Ｐ均＜０．０１），且催化常减压组亦显著高于对照组（Ｐ＜０．０１）；沥青组口腔粘膜细胞微核人员出现率（２９．５４％）和平均微核细胞率（０．２７‰）显著高于对照组（５．２％，０．０４‰）（Ｐ均＜０．０１）和催化常减压组（１０．２４％，０．０７％）（Ｐ均＜０．０１）。可见，从事石油加工作业人员，无论是沥青还是催化常减压组，其细胞遗传物质在不同程度上均受到损伤。     

甲基汞诱发大鼠肾脏脂质过氧化作用的探讨

采用ＴＢＡ及ＤＴＮＢ比色法，测定不同染毒时间和染毒剂量，甲基汞对大鼠肾脏丙二醛（ＭＤＡ）含量及谷胱甘肽过氧化物酶（ＧＳＨ—ＰＸ）活性的影响。结果发现染毒组ＭＤＡ含量均显著高于对照组（Ｐ＜０．０２～Ｐ＜０．０１），染毒后２４ｈ处死动物，除５．０ｍｇ／ｋｇ·ｗｔ组ＭＤＡ含量显著低于对照组外（Ｐ＜０．００１），其余各剂量组ＭＤＡ含量均分别高于各自的对照组（Ｐ＜０．０１～Ｐ＜０．０５）。另外，雌性大鼠肾脏ＧＳＨ－Ｐｘ活性于染毒后２４ｈ、７２ｈ显著低于对照组（Ｐ＜０．００１，Ｐ＜０．０１）。     

Extract of green tea leaves partially attenuates streptozotocin-induced changes in antioxidant status and gastrointestinal functioning in rats

Rats with severe streptozotocin (STZ)-induced diabetes were subjected to dietary green tea extract supplementation at 2 doses (0.01% and 0.2%; GTL and GTH groups, respectively) to evaluate their effects on antioxidant, gastrointestinal, and renal parameters of experimental animals. The lower dietary supplementation reflects daily consumption of 3 cups of green tea for an average adult weighing 70 kg. Supplementation of a diet with green tea extract had no influence on elevated food intake, body weight loss, increased glucose concentration, or declined antioxidant capacity of water-soluble substances in plasma in the diabetic rats. In cases of intestinal maltase activity, attenuation of liver and kidney hypertrophy, triacylglycerol concentration, and aspartate aminotransferase activity in the serum, both dietary treatments normalized metabolic disorders caused by STZ injection to a similar extent. Unlike the GTL group, the GTH treatment significantly ameliorated development of diabetes-induced abnormal values for small intestinal saccharase and lactase activities, renal microalbuminuria, thiobarbituric acid-reactive substance content in kidney tissue, as well as total antioxidant status in the serum of rats. The GTH group was also characterized by higher antioxidant capacity of lipid-soluble substances in plasma and superoxide dismutase activity in the serum. Although the higher dose of green tea extract did not completely protect against STZ-induced hyperglycemia and oxidative stress in experimental rats, this study suggests that green tea extract ingested at high amounts may prove to be a useful therapeutic option in the reversal of diabetic dysfunction.     

饮茶与脑卒中关系的研究

目的 探讨饮茶与脑卒中的关系。方法 利用1998年秋季所获得的全国12个省、市、自治区15组人群心血管病及危险因素的横断面调查资料,以各项资料均完整者共14212人作为分析对象。结果 调整其他脑卒中危险因素后,饮茶者与不饮茶者相比,脑卒中的OR值是0.60(95％CI:0.42～0.85)。饮茶剂量与脑卒中危险呈一定的剂量反应关系,与不饮茶者相比,每月饮茶>150g,脑卒中的OR值是0.56(95％CI:0.36～0.89),每月饮茶量<150g者与脑卒中的关联不具有统计学意义。结论 饮茶与脑卒中患病间存在独立的负相关关系,多饮茶可能具有预防脑卒中的作用。     

The efficacy of black tea in ameliorating endothelial function is equivalent to that of green tea

Consumption of tea has been shown to improve endothelial function. It is assumed that catechins are the tea components responsible for these beneficial effects. In black tea, catechin concentrations are significantly lower than in green tea. The present study was designed to compare green and black tea with regard to amelioration of endothelial function. Endothelial function in response to both teas was assessed in bovine aortic endothelial cells (BAEC) and rat aortic rings. To elucidate whether these findings are also applicable to humans, flow-mediated dilation (FMD) and nitro-mediated dilation (NMD) were assessed by ultrasound in twenty-one healthy women before and 2 h after consumption of green and black tea (2 h of FMD and NMD), in comparison with water (control). In BAEC, green and black tea significantly increased endothelial NO synthase activity to the same extent. Similarly, both teas induced comparable endothelial-dependent vasodilation in rat aortic rings. In human subjects, ingestion of green and black tea led to significant increases in FMD: from 5.4 (sd 2.3) to 10.2 (sd 3) % (baseline-adjusted difference (BAD) for 2 h of FMD, green tea v. water: 5.0 (95 % CI 3.0, 7.0) %; P < 0.001) and from 5 (sd 2.6) to 9.1 (sd 3.6) % (BAD for 2 h of FMD, black tea v. water: 4.4 (95 % CI 2.3, 6.5) %; P < 0.001), respectively. The increase in FMD was not significantly different between the two tea preparations (BAD for 2 h of FMD, green tea v. black tea: 0.66 (95 % CI - 0.76, 2.09) %; P = 0.36). NMD did not vary between any of the groups. In conclusion, green and black tea are equally effective in improving endothelial function.     

Acute effect of black and green tea on aortic stiffness and wave reflections

OBJECTIVE: While most studies have shown an inverse relation between tea consumption and cardiovascular risk, other studies have shown opposite results. Aortic stiffness and wave reflections are markers of cardiovascular disease and prognosticators of cardiovascular risk. METHODS: The acute effect of black and green tea on aortic stiffness and wave reflections was assessed in 29 healthy volunteers in a randomized, single-blind, sham-procedure controlled, cross-over design. In the black tea sub-study, 16 subjects received 6 gm of tea, caffeine (175 mg), or hot water in 3 different sessions. In the green tea sub-study, 13 subjects received 6 gm of tea, caffeine (125 mg), or hot water. Carotid-femoral pulse wave velocity and wave reflection indices were measured at baseline and for 3 hours after consumption. RESULTS: Black tea increased pulse wave velocity during the first 90 min (increase by 0.49 m/sec, P < 0.05), showing a rapid return towards baseline values thereafter (P = 0.07 for the whole study period); in contrast, green tea had no effect. Both black and green tea increased augmentation index (by 5.0% and by 6.6%, P < 0.01 and P < 0.001, respectively) throughout the study. These changes were less than the respective changes produced by caffeine. Both black and green tea had a significant pressor effect. No change in oxidant status was found with both types of tea. CONCLUSIONS: Both black and green tea increases acutely wave reflections and only black tea increases aortic stiffness. Tea flavonoids may play a role in the attenuation of the effects of caffeine contained in tea.     

Black and green tea polyphenols attenuate blood pressure increases in stroke-prone spontaneously hypertensive rats

Oxidative stress was reported to be involved not only in cardiovascular diseases, but also in hypertension. Epidemiologic studies indicated that tea consumption slightly reduces blood pressure. We conducted two studies to determine whether black and green tea can lower blood pressure (BP) in stroke-prone spontaneously hypertensive rats (SHRSP). Male SHRSP (n=15) were allowed to recover for 2 wk after a transmitter for measuring BP was implanted in the peritoneal cavity. The rats were divided into three groups: the control group consumed tap water (30 mL/d); the black tea polyphenol group (BTP) consumed water containing 3.5 g/L thearubigins, 0.6 g/L theaflavins, 0.5 g/L flavonols and 0.4 g/L catechins; and the green tea polyphenol group (GTP) consumed water containing 3.5 g/L catechins, 0.5 g/L flavonols and 1 g/L polymetric flavonoids. The telemetry system was used to measure BP, which were recorded continuously every 5 min for 24 h. During the daytime, systolic and diastolic BP were significantly lower in the BTP and GTP groups than in the controls. Protein expressions of catalase and phosphorylated myosin light chain (MLC-p) were measured in the aorta by Western blotting. GTP significantly increased catalase expression, and BTP and GTP significantly decreased MLC-p expression in the aorta. These data demonstrate that both black and green tea polyphenols attenuate blood pressure increases through their antioxidant properties in SHRSP. Furthermore, because the amounts of polyphenols used in this experiment correspond to those in approximately 1 L of tea, the regular consumption of black and green tea may also provide some protection against hypertension in humans.     

饮绿茶预防中年人高脂血症和肥胖症的现况研究

目的:研究绿茶对中年人高脂血症和肥胖症的预防作用。方法:对平顶山市3317例参加常规体检的在职工作人员进行体格检查、调查表调查和血脂测定,统计分析饮绿茶对高脂血症和肥胖症的影响。结果:饮绿茶可降低中年人血清总胆固醇(TC)、低密度脂蛋白胆固醇(LDL-C,均P<0.01)和甘油三酯(TG)水平(P<0.05);而且,饮绿茶降低了中年人肥胖症患病率(P<0.05)。经年龄、性别、吸烟量、饮酒量和锻炼时间校正后上述关系依然存在。结论:饮绿茶可预防中年人高脂血症和肥胖症。     

Effect of increased tea consumption on oxidative DNA damage among smokers: a randomized controlled study

Tea drinking has been associated with decreased occurrence of cancer and heart disease. One potential mechanism for these findings is the strong antioxidant effect of tea polyphenols. A phase II randomized controlled tea intervention trial was designed to study the effect of high consumption (4 cups/d) of decaffeinated green or black tea on oxidative DNA damage as measured by urinary 8-hydroxydeoxyguanosine (8-OHdG) among smokers over a 4-mo period. A total of 143 heavy smokers, aged 18-79 y, were randomized to drink either green or black tea or water. Levels of plasma and urinary catechins and urinary 8-OHdG were measured monthly. A total of 133 of 143 smokers completed the 4-mo intervention. Multiple linear regression models were used to estimate the main effects and interaction effect of green and black tea consumption on creatinine-adjusted urinary 8-OHdG, with or without adjustment for potential confounders. Plasma and urinary levels of catechins rose significantly in the green tea group compared with the other two groups. Assessment of urinary 8-OHdG after adjustment for baseline measurements and other potential confounders revealed a highly significant decrease in urinary 8-OHdG (-31%) after 4 mo of drinking decaffeinated green tea (P = 0.002). No change in urinary 8-OHdG was seen among smokers assigned to the black tea group. These data suggest that regular green tea drinking might protect smokers from oxidative damages and could reduce cancer risk or other diseases caused by free radicals associated with smoking.     

Jasmine green tea epicatechins are hypolipidemic in hamsters (Mesocricetus auratus) fed a high fat diet.

These studies were designed to test the hypolipidemic activity of green tea epicatechins (GTE) isolated from jasmine green tea. In Experiment 1, three groups of hamsters were given a semisynthetic diet containing 200 g lard/kg and 1 g cholesterol/kg for 4 wk. The control group received distilled water, and the other two groups received either 15 g/L green tea water extract (GTWE) or 5.0 g/L GTE solution. Both the GTWE and GTE groups had lower concentrations of serum total cholesterol (TC) and triacylglycerols (TG) than the controls (P < 0.05). In Experiment 2, four groups of hamsters received tap water as the drinking fluid, but they were given the same high fat and cholesterol diet supplemented with 0 (control), 1.1, 3.4 or 5.7 g GTE/kg diet. The hypolipidemic effect of jasmine GTE was dose dependent. In Experiment 3, the time-course of changes in serum TC and TG was monitored in hamsters given the high fat diet supplemented with 5.7 g GTE/kg in comparison with that of controls. The hypolipidemic effects of dietary GTE were evident after feeding for 2 wk. Dietary supplementation of GTE did not affect liver fatty acid synthase. However, GTE-supplemented hamsters had higher fecal excretions of total fatty acids, neutral sterols and acidic sterols compared with the control group. In Experiment 4, hamsters were fed nonpurified diet; the control group drank distilled water, and the GTE group drank distilled water containing 5.0 g GTE/L. No differences in activities of 3-hydroxy-3-methyl glutaryl coenzyme A reductase and intestinal acyl CoA:cholesterol acyltransferase were observed. This study suggests that the hypolipidemic activity of GTE is not due to inhibition of synthesis of cholesterol or fatty acid but is most likely mediated by its influence on absorption of dietary fat and cholesterol.     

饮茶对大鼠大肠变性隐窝病灶及大肠肿瘤的影响

以二甲基肼诱发Wistar大鼠大肠癌为模型,研究了绿茶和茶色素(红茶的主要成分)大肠癌的化学预防作用和对大肠肿瘤的影响。结果表明,在第16周2个饮茶组动物的变性隐窝病灶(ACF)形成数比阳性对照组显著减少(P< 0.01);在第32周时阳性对照组100% 发生了肿瘤(平均瘤数为2.6个/只,平均瘤体积为294.7m m 3/瘤)。绿茶组和茶色素组的平均瘤数抑制率分别为47.1% 和43.1% ,平均瘤体积抑制率分别为77.1% 和68.1% 。表明绿茶和茶色素对实验性大肠肿瘤具有预防作用,ACF作为一个有用的中间终点可代替癌发生率进行大肠癌化学预防剂研究