Influence of diet enriched with green tea on innate humoral and cellular immune response of kelp grouper (Epinephelus bruneus) to Vibrio carchariae infection

Effect of diet enriched with green tea at 0, 0.01, 0.1 or 1.0% levels on immune responses such as non-specific humoral (lysozyme, antiprotease and complement) and cellular (myeloperoxidase content, production of reactive oxygen, and nitrogen species) and disease resistance on week 1, 2 or 4 in kelp grouper Epinephelus bruneus challenged with Vibrio carchariae (2.47 × 10(8) CFU ml(-1)) was quantified. At all doses green tea supplementation significantly enhanced the serum lysozyme activity from weeks 1 to 4. On the other hand, after week 2 the serum hemolytic complement activity, leucocyte myeloperoxidase content and reactive nitrogen species protection significantly increased in groups fed with 0.01 and 0.1% green tea supplementation diets. The serum antiprotease activity significantly increased in group fed with at 1.0% green tea from week 1 to 4. However, all diets except at 0.01% level resulted in a significant decrease in reactive oxygen species protection during the experimental period. Challenged groups fed with green tea enriched diet at 0.01 and 0.1% level had a higher relative percent survival than with 1.0% diet on week 1, 2 or 4. The results suggest that dietary administration of green tea supplementation at a concentration of 0.01 and 0.1% level positively enhances the non-specific humoral and cellular immune responses and disease resistance of kelp grouper E. bruneus to V. carchariae.     

Attractiveness of host volatiles combined with background visual cues to the tea leafhopper,Empoasca vitis

The tea green leafhopper, Empoasca vitis (Göthe) (Hemiptera: Cicadellidae), is a serious pest of tea plants. We examined the behavioral responses of E. vitis adults to odors from the shoots of three host plants in a Y‐tube olfactometer with background visual cues. The host plants were tea [Camellia sinensis (L.) Kuntze (Theaceae)], peach [Prunus persica (L.) Siebold & Zucc. (Rosaceae)], and grapevine [Vitis vinifera L. (Vitaceae)]. Volatiles from the shoots were analyzed. Both yellow‐green and gold backgrounds enhanced the olfactory responses of E. vitis adults to tea plant odors, and this enhancement was stronger under a high light intensity. On the yellow‐green background, E. vitis adults significantly preferred the odors from shoots of the three host plants compared with clean air. Moreover, E. vitis adults preferred grapevine odor over the tea plant odor. The volatile blends of the three plant species were distinctly different. Peach plant shoots emitted the greatest amount of volatiles, whereas grapevine shoots released the greatest diversity of compounds. These results provide evidence that background visual cues could enhance the response of E. vitis adults to host‐plant volatiles. The leafhoppers can discern different host odors, suggesting the possibility of using peach plant and grapevine odors to monitor and manage this pest in tea plantations.     

Productivity and biochemical properties of green tea in response to full-length and functional fragments of HpaG Xooc, a harpin protein from the bacterial rice leaf streak pathogen Xanthomonas oryzae pv. oryzicola

Harpin proteins from plant pathogenic bacteria can stimulate hypersensitive cell death (HCD), drought tolerance, defence responses against pathogens and insects in plants, as well as enhance plant growth. Recently, we identified nine functional fragments of HpaG;Xooc, a harpin protein from Xanthomonas oryzae pv.oryzicola, the pathogen that causes bacterial leaf streak in rice. Fragments HpaG;1-94'HpaG;10-42, and HpaG;62-138, which contain the HpaG;Xooc regions of the amino acid sequence as indicated by the number spans, exceed the parent protein in promoting growth, pathogen defence and HCD in plants. Here we report improved productivity and biochemical properties of green tea (Camellia sinensis) in response to the fragments tested in comparison with HpaG;Xooc and an inactive protein control. Field tests suggested that the four proteins markedly increased the growth and yield of green tea, and increased the leaf content of tea catechols, a group of compounds that have relevance in the prevention and treatment of human diseases. In particular, HpaG;1-94 was more active than HpaG;Xooc in expediting the growth of juvenile buds and leaves used as green tea material and increased the catechol content of processed teas. When tea shrubs were treated with HpaH;Xooc and HpaG;1-94 compared with a control, green tea yields were over 55% and 39% greater, and leaf catechols were increased by more than 64% and 72%, respectively. The expression of three homologues of the expansin genes, which regulate plant cell growth, and the CsCHS gene encoding a tea chalcone synthase, which critically regulates the biosynthesis of catechols, were induced in germinal leaves of tea plants following treatment with HpaG;1-94 or HpaG;Xooc. Higher levels of gene expression were induced by the application of HpaG;1-94 than HpaG;Xooc. Our results suggest that the harpin protein, especially the functional fragment HpaG;1-94, can be used to effectively increase the yield and improve the biochemical properties of green tea, a drink with medicinal properties.     

Theanine is a candidate amino acid for pharmacological stabilization of mast cells

The increasing occurrences of allergic disorders may be attributed to exposure to environmental factors that contribute to the pathogenesis of allergy. The health benefits of green tea have been widely reported but are largely unsubstantiated. Theanine is the major amino acid present in green tea. In this study, we investigated the role of theanine in both IgE- and non- IgE-induced allergic response. Theanine inhibited compound 48/80-induced systemic anaphylactic shock and ear swelling responses. IgE-mediated passive cutaneous anaphylaxis was inhibited by the oral administration or pharmaceutical acupuncture of theanine. Histamine release from mast cells was decreased with the treatment of theanine. Theanine also repressed phorbol 12-myristate 13-acetate and calcium ionophore A23187-induced TNF-α, IL-1β, IL-6, and IL-8 secretion by suppressing NF-κB activation. Furthermore, theanine suppressed the activation of caspase-1 and the expression of receptor interacting protein-2. The current study demonstrates for the first time that theanine might possess mast cell-stabilizing capabilities.     

响应面法优化超声提取绿茶茶多酚工艺

利用响应面法对超声提取绿茶荼多酚的工艺条件进行优化,在单因素试验的基础上,根据中心组合设计原理采用三因素三水平的响应面分析法,依据回归分析确定最优提取工艺条件。结果表明,其最佳工艺条件为：液料比为40．2mL／g,超声功率为476W,提取时间为15．1min,采用该工艺条件,茶多酚的提取得率达到10．312％,通过响应面法得到一个能较好预测试验结果的模型方程。     

Effects of green tea and physical exercise on memory impairments associated with aging

We investigated the effects of physical exercise and green tea supplementation (associated or not) on biochemical and behavioral parameters in the time course of normal aging. Male Wistar rats aged 9 months were divided into groups: control, physical exercise (treadmill running), and supplemented with green tea while either performing physical exercise or not. A young control group was also studied. Physical exercise and green tea supplementation lasted 3 months. Afterwards, behavioral and biochemical tests were performed. Biochemical measurements revealed differences in antioxidant and oxidant responses in hippocampus, prefrontal cortex and striatum. Behavioral testing showed age-related memory impairments reversed by physical exercise. The association of green tea supplementation and physical exercise did not provide aged rats with additional improvements in memory or brain oxidative markers. Green tea per se significantly decreased reactive oxygen species levels and improved antioxidant defenses although it did not reverse memory deficits associated with normal aging.     

茶假眼小绿叶蝉对不同茶香精和寄主植物的趋性反应

利用"T"形室观察了茶假眼小绿叶蝉Empoasca vitis Gthe对4种茶香精和3种寄主植物的趋性反应。结果表明,假眼小绿叶蝉对不同茶香精粉和寄主植物的趋性反应不同。叶蝉对绿茶和乌龙茶A香精有明显的趋向反应,而对乌龙茶B香精即铁观音茶香精则有明显的忌避反应,对红茶香精则无反应。假眼小绿叶蝉对茶梢和青菜的趋性反应无显著差异,而对茶梢和大豆的趋性反应有差异,表现出更喜好趋向茶梢。     

Green tea polyphenol extract attenuates lung injury in experimental model of carrageenan-induced pleurisy in mice

Here we investigate the effects of the green tea extract in an animal model of acute inflammation, carrageenan-induced pleurisy. We report here that green tea extract (given at 25 mg/kg i.p. bolus 1 h prior to carrageenan), exerts potent anti-inflammatory effects in an animal model of acute inflammation in vivo.Injection of carrageenan (2%) into the pleural cavity of mice elicited an acute inflammatory response characterized by fluid accumulation in the pleural cavity that contained many neutrophils (PMNs), an infiltration of PMNs in lung tissues and increased production of nitrite/nitrate, tumour necrosis factor alpha. All parameters of inflammation were attenuated by green tea extract treatment. Furthermore, carrageenan induced an up-regulation of the adhesion molecule ICAM-1, as well as nitrotyrosine and poly (ADP-ribose) synthetase (PARS) formation, as determined by immunohistochemical analysis of lung tissues. Staining for the ICAM-1, nitrotyrosine, and PARS was reduced by green tea extract.Our results clearly demonstrate that treatment with green tea extract exerts a protective effect and offers a novel therapeutic approach for the management of lung injury.     

假眼小绿叶蝉对茶梢挥发物的行为反应

【目的】研究假眼小绿叶蝉Empoasca vitis G?the对健康茶梢和蝉害茶梢挥发物的行为反应,筛选出可引诱假眼小绿叶蝉的茶梢挥发物。【方法】以动态吸附法收集健康茶梢和蝉害茶梢挥发物,用气相色谱–质谱联用仪(GC-MS)进行定性定量分析,借助于Y形嗅觉仪检测多种挥发物引诱假眼小绿叶蝉成虫的活性。【结果】从健康茶梢和蝉害茶梢中共鉴定出30种挥发物组分,其中烯烃类含量较大。健康茶梢和蝉害茶梢挥发物中共有组分有13种,蝉害之后其含量皆上升,其中Z-b-罗勒烯和乙酸叶醇酯的含量分别是健康茶梢中的142.27倍、12.90倍。蝉害茶梢中新出现的组分有12种,其中紫苏烯含量较高。在10-2、10~(-4)、10-6 g/mL浓度下,乙酸叶醇酯表现出极显著的引诱水平(P<0.01);紫苏烯在10~(-2)和10~(-4) g/mL浓度下表现出极显著引诱水平(P<0.01);10~(-4) g/mL浓度下,Z-b-罗勒烯和D-柠檬烯极显著引诱假眼小绿叶蝉(P<0.01);10~(-4) g/mL芳樟醇、10~(-6) g/mL乙酸正丁酯和10~(-6) g/mL D-柠檬烯呈现出显著引诱水平(P<0.05);混合物组分Blend1和Blend2分别表现出极显著和显著引诱水平;而10~(-6) g/mLa-法尼烯显著排斥假眼小绿叶蝉(P<0.05)。【结论】假眼小绿叶蝉成虫对健康茶梢和蝉害茶梢挥发物多种组分具有不同的行为反应,引诱效果较强的单组分或混合组分的选定可为田间引诱效果试验提供参考。     

Targeting oxidative stress response by green tea polyphenols: clinical implications

Abstract

Green tea polyphenols, the most interesting constituent of green tea leaves, have been shown to have both pro-oxidant and antioxidant properties. Both pro-oxidant and antioxidant properties are expected to contribute to modulation of oxidative stress response under ideal optimal dosage regimens. Exposure to a low concentration of a pro-oxidant prior to exposure to oxidative stress induces the expression of genes that code for proteins that induce adaptation in a subsequent oxidative stress. On the other hand, exposure to an antioxidant concurrently with exposure to the oxidative stress affords protection through free radical scavenging or through other indirect antioxidant mechanisms. In any case, the optimal conditions that afford protection from oxidative stress should be defined for any substance with redox properties. Green tea polyphenols, being naturally occurring substances, seem to be an ideal option for the modulation of oxidative stress response. This paper reviews available data on the pro-oxidant and antioxidant properties of green tea polyphenols focusing on their potential on the modulation of oxidative stress response.     

白化和黄化茶树品种绿茶游离氨基酸、儿茶素类及咖啡碱差异分析

为探究以白化和黄化茶树品种鲜叶为原料制成的绿茶滋味品质和代谢物差异,对广德市6个白化品种绿茶(奶白茶)和14个黄化品种绿茶(黄金芽茶)进行感官审评和代谢物分析。结果表明,奶白茶滋味鲜爽而收敛性略弱;黄金芽茶滋味收敛性强而鲜度低于奶白茶。游离氨基酸总量以及呈现鲜味、甜味的游离氨基酸在奶白茶中的含量显著高于黄金芽茶,而贡献收敛性的儿茶素类化合物和没食子酸含量以及呈现苦味的咖啡碱含量在奶白茶中显著低于黄金芽茶。偏最小二乘法判别分析(PLS-DA)表明导致两种绿茶滋味差异的标志性化合物有7种,分别是茶氨酸、精氨酸、谷氨酸、天冬氨酸、表没食子儿茶素没食子酸酯(EGCG)、表儿茶素没食子酸酯和咖啡碱。味觉活性值(Dot)最高的EGCG在黄金芽茶中的呈味贡献显著高于奶白茶。因此,游离氨基酸、儿茶素类化合物、没食子酸和咖啡碱含量差异导致白化和黄化茶树品种绿茶滋味不同。     

Antimutagenic activity of selenium-enriched green tea toward the heterocyclic amine 2-amino-3-methylimidazo[4,5-f]quinoline

Both selenium and green tea have been reported to exhibit antigenotoxic and cancer chemopreventive properties. We compared the antimutagenic activities of regular green tea and selenium-enriched green tea obtained from Hubei Province, China, toward the heterocyclic amine, 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) in the Salmonella assay. Selenium-enriched green tea obtained by foliar application of selenite exhibited concentration-dependent inhibition of IQ-induced mutagenesis in the presence of rat liver S9 and was significantly more effective than regular green tea tested under the same conditions. Analytical studies revealed no major differences in the polyphenol or caffeine content between regular green tea and selenium-enriched green tea, but the latter tea contained approximately 60-fold higher concentrations of selenium compared with regular green tea. The only soluble form of selenium was identified as selenite. The antimutagenic effects of certain individual tea constituents, such as epicatechin gallate and catechin, were enhanced by the addition of selenite to the Salmonella assay. Sodium selenite, sodium selenate, seleno-dl-cysteine, seleno-l-methionine, and l-Se-methylselenocysteine were not antimutagenic toward IQ when tested alone, but augmented significantly the inhibitory potency of green tea. The results suggested an enhancing (“coantimutagenic”) effect of selenium in combination with green tea in vitro, but in vivo studies are needed to assess whether there is a synergistic effect of tea and selenium to protect against heterocyclic amine-induced mutagenesis and carcinogenesis.     

Stimulatory effect of oral administration of green tea and caffeine on locomotor activity in SKH-1 mice

Administration of green tea or caffeine was shown previously to inhibit ultraviolet B light-induced carcinogenesis in SKH-1 mice, and this effect was associated with a reduction in dermal fat. In the present study, oral administration of 0.6% green tea (6 mg tea solids/ml) or 0.04% caffeine (0.4 mg/ml; equivalent to the amount of caffeine in 0.6% green tea) as the sole source of drinking fluid to SKH-1 mice for 15 weeks increased total 24 hr locomotor activity by 47 and 24%, respectively (p<0.0001). Oral administration of 0.6% decaffeinated green tea (6 mg tea solids/ml) for 15 weeks increased locomotor activity by 9% (p<0.05). The small increase in locomotor activity observed in mice treated with decaffeinated green tea may have resulted from the small amounts of caffeine still remaining in decaffeinated green tea solutions (0.047 mg/ml). The stimulatory effects of orally administered green tea and caffeine on locomotor activity were paralleled by a 38 and 23% increase, respectively, in the dermal muscle layer thickness. In addition, treatment of the mice with 0.6% green tea or 0.04% caffeine for 15 weeks decreased the weight of the parametrial fat pad by 29 and 43%, respectively, and the thickness of the dermal fat layer was decreased by 51 and 47%, respectively. These results indicate that oral administration of green tea or caffeine to SKH-1 mice increases locomotor activity and muscle mass and decreases fat stores. The stimulatory effect of green tea and caffeine administration on locomotor activity described here may contribute to the effects of green tea and caffeine to decrease fat stores and to inhibit carcinogenesis induced by UVB in SKH-1 mice.     

Green, oolong and black tea extracts modulate lipid metabolism in hyperlipidemia rats fed high-sucrose diet

The main goal of this study was to compare effects of ethanol-soluble fractions prepared from various types of teas on sucrose-induced hyperlipidemia in 5-week old male Sprague-Dawley rats. Rats (n = 6-8 per group) weighed approximately 200 g were randomly divided into control diet, sucrose-rich diet, green tea, oolong tea and black tea groups. Control-diet group was provided with modified AIN-93 diet while the others consumed sucrose-rich diet. Tea extracts (1% w/v) were supplied in the drink for green tea, oolong tea and black tea groups. Results indicated sucrose-rich diet induced hypertriglyceridemia and hypercholesterolemia. Food intake was reduced by oolong tea extract. Consuming oolong and black tea extracts also significantly decreased body weight gains and food efficiency. Hypertriglyceridemia was normalized by green and black tea drink on day 18 and by oolong tea extract on day 25, respectively. Hypercholesterolemia was normalized by green tea on day 18 and by oolong tea and black tea on day 25, respectively. Plasma HDL-cholesterol concentrations were not affected by any tea extract. The triglyeride content in the liver as well as the cholesterol content in the heart of rats fed sucrose-rich diet were elevated and were normalized by all types of tea drink tested. Although green and oolong tea extracts contained similar composition of catechin, our findings suggest green tea exerted greater antihyperlipidemic effect than oolong tea. Apparent fat absorption may be one of the mechanisms by which green tea reduced hyperlipidemia as well as fat storage in the liver and heart of rats consumed sucrose-rich diet.     

Green tea as inhibitor of the intestinal absorption of lipids: potential mechanism for its lipid-lowering effect

Animal and epidemiological studies suggest that green tea catechins may reduce the risk of cardiovascular diseases [e.g., coronary heart disease (CHD)]. The health benefit of green tea has been attributed to its antioxidant and anti-inflammatory properties; however, considerable evidence suggests that green tea and its catechins may reduce the risk of CHD by lowering the plasma levels of cholesterol and triglyceride. Although the mechanism underlying such effect of green tea is yet to be determined, it is evident from in vitro and in vivo studies that green tea or catechins inhibit the intestinal absorption of dietary lipids. Studies in vitro indicate that green tea catechins, particularly (-)-epigallocatechin gallate, interfere with the emulsification, digestion, and micellar solubilization of lipids, critical steps involved in the intestinal absorption of dietary fat, cholesterol, and other lipids. Based on the observations, it is likely that green tea or its catechins lower the absorption and tissue accumulation of other lipophilic organic compounds. The available information strongly suggests that green tea or its catechins may be used as safe and effective lipid-lowering therapeutic agents.     

Green tea aroma fraction reduces β-amyloid peptide-induced toxicity in Caenorhabditis elegans transfected with human β-amyloid minigene

Green tea is a popular world-wide beverage with health benefits that include preventive effects on cancer as well as cardiovascular, liver and Alzheimer’s diseases (AD). This study will examine the preventive effects on AD of a unique aroma of Japanese green tea. First, a transgenic Caenorhabditis elegans (C. elegans) CL4176 expressing human β-amyloid peptide (Aβ) was used as a model of AD. A hexane extract of processed green tea was further fractionated into volatile and non-volatile fractions, named roasty aroma and green tea aroma fractions depending on their aroma, by microscale distillation. Both hexane extract and green tea aroma fraction were found to inhibit Aβ-induced paralysis, while only green tea aroma fraction extended lifespan in CL4176. We also found that green tea aroma fraction has antioxidant activity. This paper indicates that the green tea aroma fraction is an additional component for prevention of AD.     

茶蚜对不同SPAD值绿色的趋性

以茶蚜(Toxoptera aurantii)为研究对象,研究其对模拟SPAD值(叶色值)绿色和不同施氮量处理茶梢的趋性。结果表明:不同虫态茶蚜对不同SPAD值绿色的趋性存在显著差异,茶树叶片含氮量与其SPAD值之间存在显著的线性关系,茶蚜各虫态对模拟绿色趋性最强的SPAD值的相应含氮量分别为:低龄若蚜在2.83%左右,高龄若蚜在2.83%~3.14%,有翅和无翅成虫在3.14%左右;而各虫态表现出最大趋性的茶树叶片相应含氮量分别为:低龄若蚜在2.64%~3.13%,高龄若蚜在2.68%~2.83%,无翅成虫在2.42%~2.84%,有翅成虫在2.63%~3.13%。表明不同虫态茶蚜对茶树叶片含氮量的需要存在差异,其结果可为茶园合理施肥以及控制蚜虫危害提供依据。