DTF降茶氟剂降茶氟初步研究

目的探讨DTF制剂降茶氟效果。方法在不同制茶方法程序中加入DTF制剂观察其降氟效果。结果在冲泡或煮沸(1.0g茶叶,200ml水量)沏茶中,0.2gDTF可使茶氟降低约60%,使茶水氟浓度由2.0～4.0mg/L降到1.0mg/L左右,茶液色、味、pH值无改变。结论DTF是1种有效的降茶氟剂。     

绿茶对小鼠Lewis肺癌生长的抑制及免疫调节

为了研究茶叶防癌作用，以接种Ｌｅｗｉｓ肺癌细胞的Ｃ５７／ＢＬ６Ｊ小鼠为实验模型，研究绿茶对带瘤小鼠肿瘤生长的抑制及免疫调节作用。结果表明，接种Ｌｅｗｉｓ肺癌细胞后，Ｃ５７／ＢＬ６Ｊ小鼠胸腺重量及其指数减轻，Ｔ淋巴细胞ＣＤ４亚群阳性百分数及ＣＤ＋４／ＣＤ＋８比值下降，外周血白细胞本底化学发光降低，受酵母多糖刺激产生的化学发光增高以及脾ＩｇＭ抗体生成细胞数减少。绿茶对小鼠体内Ｌｅｗｉｓ肺癌的生长有明显抑制作用，并对上述各项指标的不良改变有不同程度的保护效果     

茶水中锌含量分析方法研究

目的:建立测定茶水中锌含量的方法。方法:采用锌试剂吸光光度法测定茶水中锌含量。结果:在一定条件下,锌含量在0~80μg/25 ml范围内遵守朗伯比耳定律,方法的精密度(RSD)在1.38%~3.27%之间,回收率在94%~107%之内,检测限为5.2μg/L,表观摩尔吸光系数为2.2×104L/mol.cm。结论:本方法经用于茶水样品分析,结果符合要求。     

原子吸收法测定茶叶中的微量元素和溶出率

用火焰原子吸收法测定了3种云南茶叶中的铜、锌、锰、铁和铬的含量及溶出率。其中铜、锌、锰、和铁的溶出率均是红茶和绿茶大于沱茶,铬的溶出率则相近。     

复方山绿茶缓释袋泡剂的研究

用网状多孔性纤维包念材料制备的复方山绿茶缓袋泡剂，具有速释和缓释作用，在１－８ｈ内按埝级方式释药。Ｔ０．５为１．３ｈ，Ｔｄ为３．２ｈ，１－８ｈ的平均释药速率７２．３５ｍｇ／ｈ。与传统的半生药型袋泡剂比较，具有栽药量高，使用方便，性质稳定，疗效确切的优点。     

茶多酚口含片中总儿茶素的含量测定

在酸性介质中对香英兰素与儿茶素的显色反应进行了研究，改进了反应条件，以５０６ｎｍ为测定波长，测定ＴＰ口含片中儿茶素的含量，线性范围７．５８μｇ～５３．０５μｇ（ｒ＝０．９９９８），回收率９７．９７％，ＲＳＤ１．８５％，认为改良法简便，灵敏，口含片辅料无干扰，可用于原料的药和制剂的含量分析。     

The effects of a low dose of caffeine on cognitive performance

There is little evidence concerning the effects of caffeine in doses typical of one cup of tea. The present study investigated the effect of 60 mg caffeine, consumed in either tea or hot water, on performance on a subset of the CANTAB test battery. Eight males participated in a practice session and four test sessions. In each test session, the participant consumed a different hot beverage and then, over approximately 90 min, completed nine tests from the CANTAB battery. The four beverages were created by crossing beverage identity (tea or hot water) and caffeine dose (0 or 60 mg). Significant speeding of reaction time by caffeine consumption was found in pattern recognition, delayed match to sample, and match to sample visual search. The effect on reaction time of 60 mg caffeine can be detected, and may be evident within minutes of consumption. Received: 16 March 1998/Final version: 27 July 1998     

Reduction of nickel-induced contact hypersensitivity reactions by topical tea tree oil in humans

Objective and Design: Whilst the anti-microbial properties of tea tree oil (TTO) are established, the anti-inflammatory effects of TTO in human skin remain largely anecdotal and require evaluation. This study examined the effect of topically applied TTO on nickel-induced contact hypersensitivity reactions in human dorsal skin.Treatment: TTO (100%), a 5% TTO lotion, a placebo lotion (no TTO), or 100% macadamia oil were applied at days 3 and 5 after nickel exposure.Methods: The flare area and erythema index were measured on days 3, 5 and 7. The regulatory effects of TTO were also investigated on the proliferative response to nickel or polyclonal mitogens by peripheral blood mononuclear cells from nickel-sensitive and control subjects.Results: TTO (100%) significantly reduced the flare area and erythema index when compared to the nickel-only sites. With respect to the erythema index, the anti-inflammatory effects were predominantly, but not exclusively, seen in a subgroup of nickel-sensitive subjects with a prolonged development phase of nickel-induced contact hypersensitivity response. The 5% TTO lotion, the placebo lotion and the 100% macadamia oil were all without significant effect. TTO significantly inhibited proliferation to nickel but not to non-specific polyclonal mitogens by peripheral blood mononuclear cells from nickel-sensitive subjects.Conclusions: Topical application of 100% TTO may have therapeutic benefit in nickel-induced contact hypersensitivity in human skin. The mode of action of TTO requires further investigation, but may be an effect on the antigen presenting cells or the antigen presenting process in nickel-induced contact hypersensitivity, as well as vascular changes associated with this response.Received 14 February 2004; returned for revision 30 June 2004; accepted by J. S. Skotnicki 13 September 2004     

The effect of drinking tea at high altitude on hydration status and mood

The effect of drinking tea on hydration status and mood was studied in nine male and four female members of expeditions based at Mt. Everest base camp at an altitude of 5,345 m. Whilst exposed to altitude-cold diuresis, participants were subjected to a crossover experimental design comprising two 24-h dietary interventions. In the tea condition, hot brewed tea formed a major part of fluid intake, whereas in the no-tea condition tea was excluded from the diet. Subjects were prohibited in both cases from consuming other caffeinated beverages, caffeinated foods, and alcoholic drinks. Mean fluids ingested [mean (SE); tea=3,193 (259) ml versus no tea=3,108 (269) ml] and urine volume (tea=2,686 (276) ml versus no tea=2,625 (342) ml] were similar under both conditions. Statistical analysis found no difference in urine stimulated as a result of the tea intervention (P=0.81). Several markers of hydration status were also taken immediately pre and post each condition, including measures of urine specific gravity, urine electrolyte balance (K⁺, Na⁺), and urine colour. None of these measures indicated a difference in hydration status as a result of the dietary intervention in either the control or tea condition. A difference was, however, found in mood, with subjects reporting reduced fatigue when tea was included in the diet (P=0.005). The study shows therefore that even when drunk at high altitude where fluid balance is stressed, there is no evidence that tea acts as a diuretic when consumed through natural routes of ingestion by regular tea drinkers, but that it does have a positive effect on mood.