Photoprotective effects of topical formulations containing a combination of Ginkgo biloba and green tea extracts

The beneficial photoprotective effects of topical formulations containing combined extracts of Ginkgo biloba (GB) and green tea (GT) have not been investigated. The present study aims to assess the photoprotective effects of topical formulations containing GB and GT combined or not by applications on the dorsal skin of hairless mice prior to UVA/B irradiation. After 20 h, skin barrier damage (TEWL), erythema, histological alterations and sunburn cell formation were evaluated. The results showed that only extract supplemented formulations protected the skin against the UV‐induced damage. Formulations containing GB provided total protection of the skin barrier function avoiding UV radiation damage such as TEWL and erythema and were more effective than those containing GT. However, it is suggested that formulations containing combined GB and GT may provide substantial photoprotective effects since different aspects of skin damage were influenced by each extract. Copyright © 2011 John Wiley & Sons, Ltd.     

石榴皮多酚凝胶的制备及质量控制

目的:制备石榴皮多酚凝胶,建立其质量控制方法并考察其经皮渗透性。方法:以卡波姆-940为基质,甘油为润湿剂,氮酮为透皮吸收促进剂,山梨酸钾为防腐剂,三乙醇胺为中和剂,制备凝胶剂;采用紫外分光光度法测定石榴皮多酚凝胶中总多酚含量,并做小鼠离体皮肤经皮渗透试验。结果:凝胶制备工艺可行;没食子酸在0.024 5～0.245 0 g·L-1线性关系良好(r=0.999 6);平均回收率99.56%,RSD 0.58%。没食子酸24 h皮肤透过率为36.95%。结论:石榴皮多酚凝胶的制备方法简单,质量控制方法可靠,且有良好的渗透性。     

Improvements of mean body mass index and body weight in preobese and overweight Japanese adults with black Chinese tea (Pu-Erh) water extract

Water-soluble black Chinese (Pu-Erh) tea extract (BTE), which contains high gallic acid content, has been demonstrated to elicit antiobese effects in animals. Because gallic acid is related with the reduction of visceral fat and cholesterol contents and improvement of obesity in animals, we investigated the effects of BTE intake on 36 preobese Japanese adults (body mass index [BMI], >25- <30 kg/m²) in a 12-week double-blind, randomized, placebo-controlled group comparison study using powdered barley tea with or without (placebo) BTE. A follow-up 4-week period after BTE intake termination was monitored to observe the withdrawal effect. All subjects ingested barley tea with or without BTE (333 mg) before each of the 3 daily meals. In the BTE-treated group, the mean pretreament values of body weight and BMI significantly decreased after intake and after BTE withdrawal. However, the corresponding values scored significant differences only from 8 weeks after intake (vs the placebo-treated group). The mean values of the waist circumference indicated a similar tendency. Furthermore, coronal navel section (same anatomical position) images of computed tomography of all BTE- and non-BTE-treated subjects revealed that the visceral fat areas (cm²) were significantly (P < .05) less in the former 12 weeks after BTE ingestion. Measured biochemical parameters did not indicate significant differences, and BTE-treated subjects did not complain of any adverse effects (abdominal distension, etc). Ingestion of BTE exhibited significant effects in reducing the mean waist circumference, BMI, and visceral fat values and might be useful for weight control and prevention of obesity development (or metabolic syndrome) in humans.     

绿茶多酚对高糖高脂饮食大鼠肾纤溶酶原激活物抑制剂表达的影响

目的研究绿茶多酚(GTPs)对高糖高脂饮食大鼠肾纤溶酶原激活物抑制剂-1(PAI-1)表达的影响及机制。方法健康雄性Wistar大鼠随机分为五组:正常对照组(CON)、高糖高脂组(HG)、GTPs干预组(低、中、高剂量绿茶多酚组,G1、G2、G3)。CON组大鼠给予普通饲料,HG组及GTPs干预组给予高糖高脂饲料。喂养100d后处死所有大鼠,测定血清胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白(LDL)、肾组织匀浆液总抗氧化能力(T-AOC)、超氧化物歧化酶(SOD)及谷胱甘肽过氧化物酶(GSH-Px)活性和丙二醛(MDA)含量。分别采用荧光实时定量PCR法、免疫印记法测定肾皮质PAI-1mRNA和蛋白表达水平。结果 HG组大鼠血清TC、TG、LDL-C水平和肾皮质MDA含量比CON组明显升高(P<0.05)。与HG组相比GTPs干预组血清TC、TG及LDL-C水平和肾皮质MDA含量均明显降低(P<0.05),T-AOC、SOD、GSH-Px水平升高(P<0.05)。高糖高脂饮食大鼠肾皮质PAI-1mRNA及蛋白表达水平升高,GTPs可以逆转高糖高脂饮食所导致的大鼠肾皮质PAI-1mRNA及蛋白表达水平升高,但三个剂量GTPs干预组之间未见显著性差别。结论绿茶多酚可能通过调节血脂、抗氧化作用、以及降低PAI-1基因及蛋白表达水平从而保护肾脏。     

茶多酚对奥氮平诱导肥胖大鼠的减肥作用研究

目的建立抗精神病药奥氮平(olanzapine)诱导的肥胖大鼠模型,探讨茶多酚(TP)的减肥作用及机制。方法健康雌性SD大鼠70只,按体重随机分为正常对照组10只,其余60只灌胃给予奥氮平(1.2 mg/kg)2 w。将造模成功的40只肥胖大鼠随机分为模型组、盐酸西布曲明组(2.5 mg/kg)、茶多酚低(150 mg/kg)、高(300 mg/kg)剂量组,每组10只。动物继续给予奥氮平处理,同时灌胃给予上述药物处理5 w。在处理过程中,测定大鼠的体重、摄食和摄水量。第5 w末时,利用SMART video-tracking system测定大鼠白昼和黑暗时相的自主活动,然后处理大鼠,采用高效液相色谱-电化学检测(HPLC-ECD)法测定下丘脑中去甲肾上腺素(norepinephrine,NE)、多巴胺(dopamine,DA)、5-羟色胺(5-HT)、3,4-二羟基苯乙酸(DOPAC)、5-羟吲哚乙酸(5-HIAA)的含量。结果 TP处理肥胖大鼠5 w后,饮食量、饮水量和体重明显低于模型大鼠(P<0.05,P<0.01);对动物白昼时相活动与模型组比较无明显影响(P>0.05),但对黑暗时相的平均活动速度和活动距离明显强于模型组(P<0.01);与模型组比较,对下丘脑5-HT含量无明显影响(P>0.05),但明显增加5-HT代谢产物5-HIAA的含量(P<0.01),明显降低DA和DOPAC含量(P<0.01),同时明显增加NE的含量。结论 TP对奥氮平诱导的肥胖大鼠具有抑制饮食量和饮水量、增加活动、降低体重的作用,此作用与其对下丘脑单胺类神经递质的调节有关。     

Folin-Ciocalteu比色法应用于蔬菜和水果总多酚含量测定的研究

目的优化Folin-Ciocalteu比色法测定总多酚含量的条件,应用该法在最适反应条件下测定22种蔬菜和4种水果中的总多酚含量。方法以吸光度为评价指标,分别对样品中总多酚的浸提方法、测定波长、呈色反应体系中主要反应液的用量、显色温度、反应时间进行优化并逐一考察Folin-Ciocalteu比色法的重复性、精密度、稳定性和加标回收率后,以没食子酸为标准品,在最适反应条件下对22种蔬菜和4种水果中的总多酚含量进行测定。结果经过一系列优化试验,确定Folin-Ciocalteu比色法的最佳反应条件为:以50%丙酮溶液为总多酚提取溶剂,Folin-Ciocalteu显色剂用量2ml,10%碳酸钠溶液用量10ml,显色温度50℃,反应时间1h,测定波长765nm。没食子酸标准品在质量浓度0～0.20 mg/ml范围内与其吸光度呈良好线性关系(R2=0.9987),Folin-Ciocalteu比色法重复性试验RSD为3.89%,精密度试验RSD为1.89%,稳定性试验RSD为0.40%,平均回收率为102.12%,RSD为1.27%。22种蔬菜中豇豆总多酚含量最高(143.20mg/100g),西葫芦最低(10.54...     

Influence of storage and in vitro gastrointestinal digestion on total antioxidant capacity of fruit beverages

Eight fruit beverages containing grape, orange and apricot, with/without iron and/or zinc and with/without milk added were analyzed for total antioxidant capacity (ORAC and TEAC methods), ascorbic acid content, and total polyphenols. The influence of cold storage (2-4 °C) during the product shelf-life (135 days) and antioxidant capacity after an in vitro gastrointestinal digestion were evaluated. Antioxidant capacity for all beverages together increased significantly (p < 0.05) at the end of storage (16.4% and 12.8% for ORAC and TEAC, respectively), whereas ascorbic acid remained stable. Regarding in vitro digestion, antioxidant values of bioaccessible fractions of fruit beverages increased (p < 0.05) 59% and 20% for ORAC and TEAC, respectively, while ascorbic acid and polyphenol content fell 36% and 16%, respectively (p < 0.05). Supplementation of fruit beverages with milk and/or Fe/Zn did not modify total antioxidant capacity of samples during either cold storage or during in vitro digestion.     

Prevention of diet-induced obesity by dietary black tea polyphenols extract in vitro and in vivo

Objective

The effects of certain tea components on the prevention of obesity in humans have recently been reported, although it is still unclear whether black tea consumption is beneficial. We obtained black tea extract (BTPE) consisting of polyphenols specific to black tea, and from it, prepared a polymerized polyphenol fraction (BTP). The effectiveness of oral administration of the BTPE was examined in in vitro and in vivo experiments.

Methods

Effects of BTPE or BTP on pancreatic lipase activity were investigated in vitro. Male Wistar rats were administered an oral lipid emulsion containing BTPE at a concentration of 500 or 1000 mg/kg body weight and sequential plasma lipid levels were measured. Female C57BL/6N mice were fed a standard or high-fat diet supplemented with 1% or 5% (w/w) BTPE for 8 wk and changes in body weight were examined.

Results

BTP and BTPE inhibited pancreatic lipase activity with an IC₅₀ of 15.5 and 36.4 μg/mL in vitro, respectively. BTPE suppressed increases in rat plasma triglyceride levels in a dose-dependent manner after oral administration of a lipid emulsion. Furthermore, administration of the 5% BTPE suppressed increases in body weight (P < 0.05), parametrial adipose tissue mass, and liver lipid content (reduced to 56.9% and 81.7% of control mice, respectively, P < 0.05) in mice fed a high-fat diet.

Conclusion

The BTPE may prevent diet-induced obesity by inhibiting intestinal lipid absorption. It was suggested that the major active component in the BTPE was BTP.     

茶多酚对高蛋氨酸饮食大鼠GSH-Px、NOS活性及MDA、NO含量的影响

目的探讨茶多酚(TP)对高蛋氨酸饮食大鼠谷胱甘肽过氧化物酶(GSH-Px)、一氧化氮合酶(NOS)活性及丙二醛(MDA)、一氧化氮(NO)含量的影响。方法将大鼠随机分为对照组,模型组,TP低、中和高剂量组;对照组喂饲正常基础饲料,模型组及TP组均喂饲3%高蛋氨酸饲料,TP低、中、高剂量组每天经灌胃分别给予50、100和200mg/kg TP,对照组和模型组经灌胃给予等容量的蒸馏水。8周后断头处死大鼠,苏木素-伊红(HE)染色观察主动脉弓结构改变;试剂盒测定血清GSH-Px及NOS活性、MDA及NO含量。结果各组GSH-Px活性均无统计学差异;与模型组相比,TP低剂量组MDA含量下降27.1%(P<0.01),TP各剂量组NOS活性分别上升18.7%、15.1%、18.0%(P<0.01),TP低高剂量组NO含量分别增高113.4%和73.4%(P<0.01)。HE染色显示模型组动脉壁增厚,平滑肌增生,TP中高剂量组可抑制平滑肌增生。结论 TP可降低高蛋氨酸饮食引起的脂质过氧化水平,并通过提高NOS活性和NO含量维持内皮细胞的正常功能。     

茶的健康效益和人群干预研究

在癌症预防方面,饮茶可抑制多种化学致癌物对动物的致癌作用,包括DMBA诱发的金黄色地鼠口腔肿瘤;阻断NMBzA前体在大鼠体内的合成,抑制食道肿瘤的发生;NMBzA诱发的大鼠食道癌;DENA诱发的大鼠肝癌癌前病灶;DMH诱发的大鼠大肠癌前病变及大肠肿瘤的发生;NNK诱发小鼠肺腺瘤.茶防癌作用的有效成分主要为茶多酚和茶色素.其防癌的主要机制是抗氧化、预防DNA损伤以及免疫调节.饮茶对吸烟引起的人体氧化损伤和DNA损伤有明显的保护作用;饮混合茶可阻断口腔粘膜白斑患者病损的发展,从而对口腔癌有预防作用.茶对心血管系统有保护作用,体外实验发现茶色素可抑制铜、铁离子诱导的LDL氧化修饰;动物试验表明,茶对Ox-LDL所致的内皮细胞损伤具有保护作用并有降低试验性动脉粥样硬化的作用.绿茶、茶色素能有效预防肾性高血压所引起的心肌肥大.临床研究也证明茶及茶叶提取物具有抗动脉硬化,活血化淤之功能.饮茶对糖尿病有一定保护作用,从动物试验和人体试验两个方面证实白茶具有一定辅助降血糖功能.