茶多酚的药理作用研究进展

综述了茶多酚作为茶叶中具有重要生理活性的多种有效成分混合物,具有抗动脉粥样硬化、抗氧化等药理作用,对动脉粥样硬化、心血管等疾病有一定的预防和治疗作用。     

不同茶叶及茶多酚对高脂饲料致大鼠脂肪肝的影响

目的:考察不同产地绿茶、红茶以及绿茶多酚对高脂饲料致大鼠脂肪肝的影响.方法:大鼠喂饲高脂饲料制备大鼠脂肪肝模型,喂饲含不同茶叶或茶多酚的高脂饲料,观察体重变化、睾丸脂肪垫重量、血清TG和TC、肝脏脂肪性变、肝匀浆甘油三酯和胆固醇含量.结果:各受试物组睾丸脂肪垫重量均较模型对照组减轻,云南绿茶组和四川绿茶组肝匀浆甘油三酯和胆固醇均明显低于模型对照;茶多酚组肝匀浆甘油三酯也明显低于模型对照组,但高于云南绿茶组和四川绿茶,茶多酚组肝匀浆胆固醇低于模型对照组,但明显高于云南绿茶组和四川绿茶组;云南红茶组肝匀浆甘油三酯和胆固醇与模型对照组相当.结论:云南绿茶和四川绿茶均对高脂饲料致大鼠脂肪肝的形成有明显抑制作用;茶多酚也有一定作用;但云南红茶作用不明显.     

茶多酚对大鼠糖耐量的影响

目的：探讨茶多酚对大鼠糖耐量的影响。方法：测定大鼠口服葡萄糖,蔗糖和淀粉后0、1和2小时的血糖.结果：茶多酚能抑制大鼠口服蔗糖和淀粉后1和2小时的血糖的升高。结论：茶多酚能改善大鼠的糖耐量。     

茶多酚早期干预对N-甲基亚硝基脲诱发膀胱肿瘤影响的实验研究

目的研究茶多酚早期干预是否能够抑制或拮抗N-甲基亚硝基脲诱发膀胱肿瘤的发生。方法将72只雌性Wistar大鼠随机分为对照组、实验组各36只,两组采用膀胱灌注法给予N-甲基亚硝基脲,对照组同时给予0.9%NaCl溶液灌胃,实验组予茶多酚灌胃;分别于实验后第3、5、7、9、11、13周处死6只大鼠获取膀胱标本,观察两组急慢性炎症、不典型增生和癌肿的发生率。结果对照组从第3周起发生膀胱黏膜不典型增生,第9周逐步出现膀胱癌,第13周癌变率100%;实验组未见膀胱癌发生;组间病理学分类情况比较,第13周癌变情况差异有统计学意义(P<0.05)。两组病理计分情况同期比较,除第3周外,其余观察时点差异均有统计学意义(P<0.05)。结论茶多酚可有效拮抗、抑制N-甲基亚硝基脲诱发膀胱肿瘤的发生。     

Protective effect of green tea polyphenol (-)-epigallocatechin gallate and other antioxidants on lipid peroxidation in gerbil brain homogenates

The aim of this study was to compare the protective effects of green tea polyphenol (-)-epigallocatechin gallate (EGCG) and other well-known antioxidants on the lipid peroxidation in gerbil brain homogenates. Oxidative stress was induced by H2O2 (10 mM) or ferrous ammonium sulfate (5 microM) and lipid peroxidation was studied. Hydrogen peroxide and ferrous ions are capable of oxidizing a wide range of substrates and causing biological damage. The reaction, referred to as the Fenton process, is complex and can generate both hydroxyl radicals and higher oxidation states of the iron. Thiobarbituric acid-reactive substances (TBA-RS) were used as a marker of lipid peroxidation. EGCG, trolox, lipoic acid, and melatonin reduced H2O2- or ferrous ion-induced lipid peroxidation in a concentration-dependent manner. In reducing the H2O2-induced lipid peroxidation, IC50 values of antioxidants were as follows: EGCG (0.66 microM), trolox (37.08 microM), lipoic acid (7.88 mM), and melatonin (19.11 mM). In reducing the ferrous ion-induced lipid peroxidation, IC50 values of antioxidants were as follows: EGCG (3.32 microM), trolox (75.65 microM), lipoic acid (7.63 mM), and melatonin (15.48 mM). Under the in vitro conditions of this experiment, EGCG was the most potent antioxidant in inhibiting H2O2 or ferrous ion-induced lipid peroxidation in the gerbil brain homogenates.     

茶多酚对链脲佐链菌素诱发糖尿病大鼠降糖作用的实验研究

目的：探讨茶多酚对糖尿病大鼠的降糖作用。方法：大鼠尾静脉注射链脲佐链菌素形成糖尿病大鼠,测定茶多酚对糖尿病大鼠口服葡萄糖、蔗糖和淀粉后0、1和2小时血糖的影响;并同时测定大鼠血胰岛素、C肽、糖化血红蛋白、一氧化氮及内皮素。结果：茶多酚能抑制糖尿病大鼠口服蔗糖和淀粉后1和2小时的血糖的升高,稳定糖尿病大鼠的糖化血红蛋白,升高其一氧化氮而降低其内皮素。结论：茶多酚能改善糖尿病大鼠的糖耐量,稳定其血糖,机理可能为茶多酚能抑制淀汾酶所致。     

绿茶对五倍子发酵品的影响

目的比较百药煎(五倍子发酵品)中鞣质和没食子酸含有量来选择何种绿茶(茶叶,茶渣和茶汁)作为发酵基质。方法制备茶叶、茶渣和茶汁与五倍子混合发酵产物后,采用紫外分光光度法测定鞣质含有量,高效液相法测定没食子酸含有量。结果五倍子、酒曲与煎煮后的茶渣、茶汁混合发酵的鞣质含有量为11.59%,没食子酸含有量为10.43%;五倍子、酒曲、茶叶直接混合发酵的鞣质含有量为15.25%,没食子酸含有量为6.21%;五倍子、酒曲与煎煮后的茶汁混合发酵的鞣质含有量为16.41%,没食子酸含有量为7.63%;五倍子、酒曲混合发酵的鞣质含有量为21.39%,没食子酸含有量为5.34%。结论茶叶煎煮后茶渣和茶汁一起加入五倍子酒曲中发酵,鞣质转化率最高,发酵效果最好。     

绿茶提取物EGCG对舌癌Tca8113细胞凋亡的影响

目的探讨绿茶提取物EGCG对人舌癌细胞株Tca8113体外凋亡的影响。方法体外培养人舌癌Tca8113细胞,采用不同浓度的EGCG对其进行干预,用AO/EB荧光染色法和DNA琼脂糖凝胶电泳法检测其对舌癌细胞凋亡的影响。结果在EGCG的作用下,舌癌Tca8113细胞的凋亡具有浓度依赖性。结论 EGCG可能通过增加细胞凋亡达到抗癌作用。     

绿茶中茶多酚的复合酶-微波法提取工艺研究

目的 采用复合酶-微波法从绿茶中提取茶多酚.方法 通过单因素试验法和正交试验法确定复合酶-微波法提取茶多酚的最佳工艺,同时比较复合酶-微波法、复合酶法、索氏法和微波法对提取效果的影响.结果 优化得到提取茶多酚的最佳工艺为:在50℃条件下用纤维素酶和果胶酶前处理40 min,微波辐射8 min,微波功率500 W,料液比1∶30,25%乙醇溶液作为萃取剂.结论 验证试验表明,最佳工艺可行;从提取时间和提取效率来看,复合酶-微波法提取茶多酚比复合酶法、索氏法和微波法耗时少、提取效率高.     

In vitro anti‐adhesive activity of green tea extract against pathogen adhesion

Camellia sinensis polysaccharide has been reported to possess anti‐adhesive activity against pathogens. The present study was designed to investigate whether hot water extracts obtained from green tea leaves might inhibit pathogen adhesion to human or mouse cell lines. Green tea extract‐4 (CSI‐4) with the maximum yield of 4% (w/v) is composed of a major proportion of carbohydrates containing 40% uronic acids, but lack of catechins. It showed strong inhibitory activities against hemagglutination mediated by pathogens Helicobacter pylori, Propionibacterium acnes and Staphylococcus aureus with the minimum inhibitory concentrations of 0.01‐0.5 mg/mL. CSI‐4 further demonstrated an inhibitory effect on the adhesion of these pathogens to host cell lines with the IC₅₀ values (50% inhibition of adhesion) of 0.14–2.3 mg/mL. It exhibited the highest activity against P. acnes, but no inhibitory effects were observed against Lactobacillus acidophilus, Bifidobacterium bifidum, Escherichia coli, or Staphylococcus epidermidis. Our results suggest that CSI‐4 may exert a selective anti‐adhesive effect against certain pathogenic bacteria with no adverse effects against beneficial or commensal bacteria. Copyright © 2008 John Wiley & Sons, Ltd.     

饮用绿茶对血管性认知功能障碍的影响

目的探讨饮用绿茶的习惯对血管性认知功能障碍(VCI)及其影像学表现的影响。方法选择VCI患者77例,根据饮用的绿茶量分为A组(0杯或小于1杯/d)、B组(1～2杯/d)、C组(3～5杯/d及以上),对所有患者进行MMSE及MoCA评分,并依据脑MRI表现对脑白质损害程度及是否存在关键部位缺血进行评分。结果 VCI患者之间的血管危险因素无显著性差异(P>0.05),C组患者认知功能评分明显好于A组及B组(P均<0.05),各组患者之间的室周高信号(PVH)评分无显著性差异,而B组及C组患者的白质高信号(WM-HS)评分明显低于A组(P均<0.05),各组患者之间的关键部位病变无显著性差异。结论长期饮用绿茶的VCI患者,脑白质损害程度及认知功能障碍较轻。     

普洱茶、红茶、绿茶中真菌毒素的检测

检测茶叶中黄曲霉毒素(B_1,B_2,G_1和G_2)、伏马霉素(FB_1,FB_2,FB_3)和脱氧雪腐镰刀菌烯醇,明确茶叶中的真菌毒素含量范围并为茶叶监管提供依据。采用有机溶剂(0.1%甲酸乙腈溶液)以及80℃热水2种方法提取茶叶中的真菌毒素,利用超高效液相色谱串联质谱(UPLC-MS/MS)法进行分析测定。黄曲霉毒素B1,G1的线性范围为39.1~5 000 ng·L~(-1),黄曲霉毒素B2,G2的线性范围为117~15 000 ng·L~(-1);伏马霉素(FB1,FB2,FB3)的线性范围为2.44~313 ng·L~(-1);脱氧雪腐镰刀菌烯醇的线性范围为3 125~5 000 ng·L~(-1)。所得8种真菌毒素的回归方程均有良好的线性关系(r≥0.999 0),回收率为85.7%~99.6%,相对标准偏差10%。对20种国际市售茶叶中的8种真菌毒素进行测定,结果显示采用有机溶剂提取法,包括普洱茶、红茶、绿茶在内的多种茶叶产品都不同程度含有微量的真菌毒素,其中黄曲霉毒素B2在6种茶叶产品中被检测到,黄曲霉毒素G_1在3种茶叶中被检测到,伏马霉素FB_1在2种茶叶中被检测到,伏马霉素FB2在一种茶叶中被检测到。而采用热水提取方法,只有一种茶叶产品的茶汤中检测到微量的伏马霉素B_1,B_2,其他各种茶叶的茶汤中均未检出毒素。以上2种方法检出的真菌毒素含量在0.15~7.31μg·kg~(-1),均未超过国际食品安全规定的真菌毒素限量。80℃热水提取模拟实际的饮茶方法,更能准确地检测茶叶中进入茶汤的真菌毒素,适用于茶叶(采用热水冲泡的)饮用产品,而有机溶剂萃取法适用于食用产品中霉菌毒素绝对含量的检测。     

Quantitative analysis of the active constituents in green tea

Since green tea has been reported to exhibit the effects of promoting antitumour activity, antimutagenicty and antioxidation, we have analyzed its active components by high performance thin layer chromatography (HPTLC). It is suggested that drinking green tea at normal levels daily is not sufficient to produce pharmacological actions.     

茶多酚抗大鼠酒精性肝损伤的细胞因子基因表达谱研究

目的:观察茶多酚抗大鼠酒精性肝损伤的细胞因子基因表达谱变化并探讨其作用机制。方法:大鼠随机分成3组,分别为酒精致模组(A组)、茶多酚治疗组(B组)和对照组(C组),在12周时观察各组肝脏标本组织损伤情况,并进行定量和半定量统计分析,同时用cDNA芯片测定肝脏组织的细胞因子表达水平。结果:与C组比较,A组和B组肝脏均出现不同程度的肝损伤表现。B组肝脏以脂肪变为主,其他肝损害较A组轻,表现在肝细胞肿胀程度较轻且面积较小,点、灶状坏死较少,未出现桥接坏死,脂变相对较轻,大泡性脂变相对较少,肝脏胶原沉积量少于A组。B组与A组比较:表达上调基因有IL-3,IL-4,IL-1R2,IL-6R,IL-7R2,表达下调基因有IL-3Ra,IL-1R1。A组与C组比较:表达上调基因有IL-13,IL-1R1,IL-7R2,EPO-R,LIFR,表达下调基因有IL-1R2,IL-5R2,CSF1,CD27,IL-6R。结论:茶多酚有抗大鼠酒精性肝损伤的作用,其作用机制可能与调节细胞因子的基因表达水平有关。     

重叠率在绿茶和茶多酚指纹谱研究中的应用

目的:探讨重叠率在植物以及植物提取物指纹谱研究中的地位和应用。方法:以绿茶和茶多酚的HPLC指纹谱为例来进行说明。结果:重叠率可为绿茶和茶多酚的特征指纹谱选择有代表性的样品,并可依之推断茶多酚样品的提取原料、工艺以及生产厂家等。结论:重叠率可作为建立特征指纹谱样品筛选的有力依据,并可为产品与原料、工艺间相互关系的探究提供参考。     

基于"谱-效"相关和网络药理学方法研究杜仲黑茶的抗氧化活性

目的:构建20批杜仲黑茶指纹图谱,联合其抗氧化活性建立"谱-效"相关模型,结合网络药理学方法,预测其潜在抗氧化活性成分及生物通路和机制.方法:采用高效液相色谱(HPLC)法测定杜仲黑茶中主要成分含量;以化学计量学方法建立主要成分与抗氧化活性的相关性;通过TCMSP、Swiss Target Prediction、BATMAN-TCM等数据库获得杜仲黑茶高"谱-效"相关成分及靶点,通过PPI和KEGG分析对杜仲黑茶抗氧化活性成分及其作用机制进行靶向预测,进一步筛选潜在活性标志物.结果:基于杜仲黑茶指纹图谱对其9种主要成分采用Person相关性分析,筛选出7种潜在活性标志物,包括表没食子儿茶素没食子酸酯、芦丁、新绿原酸、绿原酸、原儿茶酸、没食子酸和槲皮素-3-0-桑布双糖苷.利用网络药理学方法构建了杜仲黑茶-特征成分-靶点网络,其中MAPK3、TNF、IL-6、CXCL8、VEGFA、JUN等为关键靶点,而杜仲黑茶抗氧化活性主要涉及氮代谢、TNF信号通路、HIF-1信号通路、VEGF信号通路、Rap1信号通路等.结论:采用"谱-效"相关和网络药理学方法进行杜仲黑茶抗氧化活性研究,为其质量控制提供了新的思路.     

Anti-diabetic activity of green tea polyphenols and their role in reducing oxidative stress in experimental diabetes

An aqueous solution of green tea polyphenols (GTP) was found to inhibit lipid peroxidation (LP), scavenge hydroxyl and superoxide radicals in vitro. Concentration needed for 50% inhibition of superoxide, hydroxyl and LP radicals were 10, 52.5 and 136 micro g/ml, respectively. Administration of GTP (500 mg/kg b.wt.) to normal rats increased glucose tolerance significantly (P<0.005) at 60 min. GTP was also found to reduce serum glucose level in alloxan diabetic rats significantly at a dose level of 100 mg/kg b.wt. Continued daily administration (15 days) of the extract 50, 100 mg/kg b.wt. produced 29 and 44% reduction in the elevated serum glucose level produced by alloxan administration. Elevated hepatic and renal enzymes produced by alloxan were found to be reduced (P<0.001) by GTP. The serum LP levels which was increased by alloxan and was reduced by significantly (P<0.001) by the administration of 100 mg/kg b.wt. of GTP. Decreased liver glycogen, after alloxan administration showed a significant (P<0.001) increase after GTP treatment. GTP treated group showed increased antioxidant potential as seen from improvements in superoxide dismutase and glutathione levels. However catalase, LP and glutathione peroxidase levels were unchanged. These results indicate that alterations in the glucose utilizing system and oxidation status in rats increased by alloxan were partially reversed by the administration of the glutamate pyruvate transaminase.     

Vitamin C is one of the lipolytic substances in green tea

We have studied the influence of vitamin C contained in green tea on the lipolysis of well-differentiated 3T3-L1 cells. When mature adipocytes were exposed to vitamin C the triglyceride concentration was decreased (p < 0.05) and the activity of glycerophosphate dehydrogenase, a marker of adipose conversion, was significantly inhibited (p < 0.01). These data suggest that green tea may have a lipolytic activity due to the mechanism by which the vitamin C contained in it inhibits triglyceride accumulation.     

Superoxide dismutase activity enhanced by green tea inhibits lipid accumulation in 3T3-L1 cells

We studied the effect of powdered green tea on intracellular superoxide dismutase activity in the adipose conversion of 3T3-L1 cells. By the 14 days of culture with insulin, the triglyceride concentration was increased. When powdered green tea and insulin were added simultaneously, the increased triglyceride content was decreased (p < 0.05), and the superoxide dismutase activities were significantly enhanced (p < 0.05). These data suggest that green tea may have an antilipogenic activity due to its radical scavenging activity mechanism.