茶多酚有效成分对淋巴细胞增殖的抑制和抗氧化作用

研究表明,茶多酚具有很强的消除有害自由基、抗衰老等多种药理作用[1],茶多酚临床治疗白癜风具有较明显的效果,但其各类组分在临床治疗白癜风所发挥的作用还未见报道。1材料与方法1.1动物C57BL/6(B6)小鼠,体质量(20±2)g,由浙江中医药大学实验动物中心提供。1.2主要药品与试剂H2O2、EGCG均购自美国Sigma公     

不同提取工艺对鄂产绿茶多糖体外降糖活性的影响

目的 探讨不同提取方法对鄂产绿茶多糖降糖活性的影响.方法 分别采用酶法、热水提取法、冷水提取法提取鄂产绿茶的茶多糖.通过体外实验观察不同提取方法所得绿茶多糖对α-葡萄糖苷酶、α-淀粉酶、蔗糖酶活性影响,选出对酶抑制作用最强的多糖.结果 3种提取方法所得绿茶多糖对α-葡萄糖苷酶的抑制作用无明显差别;酶法所提绿茶多糖对α-淀粉酶、蔗糖酶活性强于热水提取法、冷水提取法所得的绿茶多糖.结论 酶法提取的绿茶多糖具有较好的体外降血糖活性.     

红茶菌发酵液抑菌作用研究

目的 研究不同pH值下红茶菌发酵液及其蛋白提取液的抗菌作用,为探寻新的抗菌物质奠定基础. 方法 采用K-B纸片扩散法检测不同pH值下红茶菌发酵液及不同量的蛋白提取液分别对大肠埃希菌、金黄色葡萄球菌和白色念珠菌的抑菌作用. 结果 红茶菌发酵液在酸性条件下对金黄色葡萄球菌和大肠埃希菌的生长具有明显的抑制作用,而在碱性条件下均未表现出抑制作用;红茶菌蛋白提取液对金黄色葡萄球菌和大肠埃希菌有抑菌活性,红茶菌发酵液及蛋白提取液对白色念珠菌无明显抑菌作用. 结论 红茶菌发酵液具有明显的抑制金黄色葡萄球菌和大肠埃希菌生长的作用.红茶菌发酵产生的蛋白质类物质是红茶菌液中的抑菌活性成分之一,具有用作食品抑菌剂的潜在价值.     

三种不同方法测定砖茶中氟含量的比较

目的　研究砖茶氟含量的测定方法。方法　分别用砖茶氟卫生标准 (讨论意见稿 )中的粉碎沸水浴、食品中氟的测定方法粉碎盐酸浸泡、四川农大的全叶熬煮 3种不同方法对 10份砖茶样品进行离子选择电极法测定。结果　 3种不同缓冲液对同一茶汤氟的检出没有差别 ,而不同前处理方法氟的浸出率差异较大 ,其中粉碎盐酸浸泡只占粉碎沸水浴的 49.5 %～ 61.0 % ,平均 5 5 .1% ,全叶熬煮占粉碎沸水浴的 62 .4%～ 80 .9% ,平均70 .6%。结论　 3种不同的测定方法测定结果有较大差异 ,不同的缓冲液对测同一茶汤氟没有明显的差异 ,不同的前处理方法都只浸出了部分氟。砖茶氟测定方法 ,尤其是前处理应以少数民族的生活习惯结合起来综合考虑     

Selective phytochemicals targeting pancreatic stellate cells as new anti-fibrotic agents for chronic pancreatitis and pancreatic cancer

Activated pancreatic stellate cells (PSCs) have been widely accepted as a key precursor of excessive pancreatic fibrosis, which is a crucial hallmark of chronic pancreatitis (CP) and its formidable associated disease, pancreatic cancer (PC). Hence, anti-fibrotic therapy has been identified as a novel therapeutic strategy for treating CP and PC by targeting PSCs. Most of the anti-fibrotic agents have been limited to phase I/II clinical trials involving vitamin analogs, which are abundant in medicinal plants and have proved to be promising for clinical application. The use of phytomedicines, as new anti-fibrotic agents, has been applied to a variety of complementary and alternative approaches. The aim of this review was to present a focused update on the selective new potential anti-fibrotic agents, including curcumin, resveratrol, rhein, emodin, green tea catechin derivatives, metformin, eruberin A, and ellagic acid, in combating PSC in CP and PC models. It aimed to describe the mechanism(s) of the phytochemicals used, either alone or in combination, and the associated molecular targets. Most of them were tested in PC models with similar mechanism of actions, and curcumin was tested intensively. Future research may explore the issues of bioavailability, drug design, and nano-formulation, in order to achieve successful clinical outcomes with promising activity and tolerability.     

余苣降酸茶的HPLC指纹图谱研究

目的:建立余苣降酸茶HPLC指纹图谱,以控制该中药复方茶剂的质量。方法:采用HPLC梯度洗脱法测定余苣降酸茶的指纹图谱,色谱柱为Waters Sun Fire C18色谱柱(250 mm×4.6 mm,5μm);流动相为0.2%磷酸水溶液-乙腈,柱温:30℃,检测波长:308 nm,进样量:10μl,流速:1.0 ml·min^-1。结果:测得10批余苣降酸茶供试品HPLC色谱图,并标示出20个共有峰,确定其中2个已知峰分别为没食子酸和葛根素;并明确了20个共有峰的原药材归属。结论:该方法建立的余苣降酸茶HPLC指纹图谱重复性好,色谱峰信息量大,为全面控制该制剂的质量提供了可靠的方法。     

Tea polyphenols alleviate tri‐ortho‐cresyl phosphate‐induced autophagy of mouse ovarian granulosa cells

Tri‐ortho‐cresyl phosphate (TOCP), a widely used plasticizer in industry, can cause female reproductive damage. Tea polyphenols (TPs) have multiple health effects via inhibiting oxidative stress. However, the reproductive protection of TPs in TOCP‐induced female reproductive system damage is yet to be elucidated. In the study, TOCP inhibited cell viability and induced autophagy of mouse ovarian granulosa cells; while TPs could rescue the inhibition of viability and induction of autophagy. 3‐MA, an autophagy inhibitor, could also rescue the inhibition of cell viability. These results indicated that TPs played a protective role in TOCP‐induced autophagy. Furthermore, TPs could inhibit the induction of oxidative stress of the cells by TOCP, which implying that TPs might alleviate TOCP‐induced autophagy via inhibiting oxidative stress. Furthermore, TPs could rescue TOCP‐induced autophagy and oxidative stress in the mouse ovarian tissues. Taken together, these results indicated that TPs could protect TOCP‐induced ovarian damage via inhibiting oxidative stress.     

都匀毛尖对小鼠肝脏CYP3A酶活性及其mRNA水平的影响

目的:研究绿茶对细胞色素P450 3A(CYP3A)酶活性及其mRNA水平的影响,推测绿茶对药物代谢的作用.方法:绿茶选用都匀毛尖,120只昆明种雄性小鼠随机分为4组,对照组正常饮食饮水,低、中、高剂量绿茶组分别予0.25 g/(kg·d)、0.5 g/(kg·d)、1.0g/(kg·d)都匀毛尖茶汤灌胃,分别在1周、2周、3周时处死小鼠,测定小鼠肝脏微粒体CYP3A的活性,并用RT-PCR技术检测小鼠肝脏中CYP3A11 mRNA水平.结果:都匀毛尖能抑制CYP3A酶活性,呈时间-剂量依赖性;都匀毛尖可抑制CYP3A11 mRNA表达,且呈时间-剂量依赖性.结论:都匀毛尖对CYP3A的酶活性及mRNA水平均呈时间-剂量依赖性抑制作用,提示都匀毛尖可能通过影响CYP3A酶活性对药物的代谢发挥作用.     

Inhibitory effects of polyphenol-enriched extract from Ziyang tea against human breast cancer MCF-7 cells through reactive oxygen species-dependent mitochondria molecular mechanism

A polyphenol-enriched extract from selenium-enriched Ziyang green tea (ZTP) was selected to evaluate its antitumor effects against human breast cancer MCF-7 cells. In ZTP, (−)-epigallocatechin gallate (28.2%) was identified as the major catechin, followed by (−)-epigallocatechin (5.7%) and (−)-epicatechin gallate (12.6%). ZTP was shown to inhibit MCF-7 cell proliferation (half maximal inhibitory concentration, IC₅₀ = 172.2 μg/mL) by blocking cell-cycle progression at the G0/G1 phase and inducing apoptotic death. Western blotting assay indicated that ZTP induced cell-cycle arrest by upregulation of p53 and reduced the expression of CDK2 in MCF-7 cells. ZTP-caused cell apoptosis was associated with an increase in Bax/Bcl-2 ratio, and activation of caspase-3 and -9. MCF-7 cells treated with ZTP also showed an overproduction of reactive oxygen species, suggesting that reactive oxygen species played an important role in the induction of apoptosis in MCF-7 cells. This is the first report showing that ZTP is a potential novel dietary agent for cancer chemoprevention or chemotherapy.