Phytochemicals from berries and grapes inhibited the formation of advanced glycation end‐products by scavenging reactive carbonyls

Phenolic phytochemicals were extracted from blueberries, blackberries, strawberries, raspberries, cranberries, and Noble muscadine grapes. These extracts were purified to remove free sugars. Blueberry extract was separated into five fractions using a Sephadex LH‐20 column. Berry extracts and fractions significantly inhibited AGEs generation in (bovine serum albumin) BSA‐fructose, BSA‐methylglyoxal, and arginine‐methylglyoxal models, respectively. Their capacity to scavenge methylglyoxal suggested carbonyl scavenging as a major mechanism of protein glycation inhibition. Procyanidins were detected in all berry extracts and blueberry subfractions and were deduced to be one class of active compounds. (+)‐Catechin, constituent unit of procyanidins, was used as a model compound to react with glyoxal and methylglyoxal. Five catechin‐carbonyl adducts were detected and their structures were tentatively identified using HPLC‐ESI‐MSⁿ. Results in this study suggested that sugar‐free phytochemicals extracted from berries were effective carbonyl scavengers and protein glycation inhibitors. These phytochemicals could be beneficial to prevent AGE‐related chronic diseases.     

红糖色源物的探讨

红糖(又称为黑糖)的深红褐色源主要是甘蔗本身所具有的多种生理活性的多酚化合物与人体需要的微量元素,部分来自制糖过程各种化学变化形成的深色素物。本文对这些色素物试图进行剖析探讨,论述天然色素物的保健价值,讨论在制糖过程如何使美拉德反应既增加红糖的色、香风味的正面作用,又不会产生微量的不良产物-丙烯酰胺的负面作用。     

焙炒对米茶中丙烯酰胺和晚期糖基化终产物的影响

研究焙炒温度、时间、加水量和浸润时间对米茶加工过程中丙烯酰胺(Acrylamide,AA)和晚期糖基化终产物(Advanced glycation end products,AGEs)的影响。结果表明,随着焙炒温度升高和时间的增加,AA和AGEs含量增加,但是当温度高于200℃时AA含量会呈现降低趋势;随加水量增加和浸润时间延长,AGEs含量显著性减少(p<0.05),米茶中的AA含量先降低,在加水量超过10%,浸润时间超过10 min之后升高。在190℃,加水量10%(w/w),浸润10 min,焙炒35 min最适加工条件下AA和AGEs含量分别为141μg/kg和360 AU/g,低于同类产品,正常食用对人体安全。      

Advanced Glycation End Products,Inflammation, and Chronic Metabolic Diseases: Links in a Chain?

Advanced glycation end products (AGEs) are a diverse group of compounds produced when reducing sugars react with proteins or other compounds to form glycosylated molecules. AGEs may form endogenously, and glycation of molecules may negatively affect their function. AGEs may also be consumed in food form with dietary AGEs reported to be particularly high in foods treated with high heat: baked, broiled, grilled, and fried foods. Whether dietary AGEs are absorbed in significant quantities and whether they are harmful if absorbed is a question under current debate. The American Diabetes Association makes no recommendation regarding avoidance of these foods, but many researchers are concerned that they may be pro-inflammatory and way worsen cardiac function, kidney function, diabetes and its complications and may even contribute to obesity.     

褐藻多酚对晚期糖基化终产物的抑制作用研究

目的 研究褐藻多酚对晚期糖基化终产物(advanced glycation end products,AGEs)生成的抑制作用及其机制.方法 建立牛血清蛋白与葡萄糖体外模拟体系及食品热加工鱼肉肠模型,以不同浓度褐藻多酚为抑制剂,研究其对AGEs生成的抑制作用;通过分析模拟体系中赖氨酸和葡萄糖含量、蛋白质巯基水平及葡萄糖...     

Inhibitory effects of guava (Psidium guajava L.) leaf extracts and its active compounds on the glycation process of protein

Hyperglycaemia causes increased protein glycation and the formation of early glycation products and advanced glycation end products (AGEs) which are major factors responsible for the complications of diabetes. This study investigated the ability of guava leaf and compounds to inhibit glycation process in an albumin/glucose model system and compared the potency of these extracts with Polyphenon 60 which is a commercial polyphenol product extracted from green tea and with the standard antiglycation agent, aminoguanidine. The results showed that the inhibitory effects of guava leaf extracts on the formation of α-dicarbonyl compounds were over 95% at 50 μg/ml. Phenolic compounds present, namely gallic acid, catechin and quercetin exhibited over 80% inhibitory effects, but ferulic acid showed no activity. The guava leaf extracts also showed strong inhibitory effects on the production of Amadori products and AGEs from albumin in the presence of glucose. The phenolic compounds also showed strong inhibitory effects on the glycation of albumin, especially quercetin exhibited over 95% inhibitory effects at 100 μg/ml. According to the results obtained, guava leaf extracts are potent antiglycation agents, which can be of great value in the preventive glycation-associated complications in diabetes.     

茶多酚对蛋白质糖基化作用的影响

采用葡萄糖与谷氨酸在90℃下反应以及葡萄糖与牛血清白蛋白37℃反应模拟体外糖基化作用,通过在激发波长350nm,发射波长440nm测定荧光强度,探讨了不同浓度茶多酚对糖基化反应产物的影响。另外,腹腔注射链脲菌素（STZ）建立小鼠糖尿病模型,每天灌胃200mg/kg体重的茶多酚溶液,通过测定小鼠血清中糖化血红蛋白及糖基化终产物荧光强度的变化观察茶多酚对高糖机体内蛋白质糖基化的影响。结果表明：茶多酚对体外糖基化反应有抑制作用,而且存在剂量-效应关系;同时能降低糖尿病小鼠机体内糖化血红蛋白的含量,缓解由糖基化引起的糖尿病肾脏损伤。     

食品中晚期糖基化终产物的研究进展

晚期糖基化终产物(advanced glycation end products,AGEs)被认为和氧化应激、多种慢性疾病以及人体衰老等具有密切关系,近年来成为医药和健康领域的研究热点,但在食品领域研究相对较少。事实上,食物由于不同的加工处理方法和存放条件,可能会产生AGEs;若长期摄入AGEs可能增加体内的AGEs水平从而对人体造成危害,对食品中AGEs的研究已引起食品领域科学家的关注。文中主要对食品中AGEs的生成机理、主要种类、检测方法、对人体的影响,以及控制方法等几方面进行综述。     

桑椹花色苷对晚期糖基化末端产物抑制作用及其机制分析

晚期糖基化末端产物(Advanced Glycation End Products,AGEs)是蛋白质游离氨基与还原糖羰基反应形成的一类复杂物质的总称,是诱发糖尿病等多种慢性病的重要因素之一,而多酚类化合物能够抑制AGEs的形成。为了探讨桑椹花色苷对AGEs的抑制机制,建立牛血清蛋白(BSA)/葡萄糖(Glucose)生成AGEs模拟反应体系,以0.5%酸性乙醇提取、AB-8型大孔树脂纯化的桑椹花色苷为抑制剂,测定反应体系中蛋白质羰基、巯基含量变化、羟基自由基(·OH)对AGEs形成的影响,利用SDS-PAGE凝胶电泳技术分析BSA的分子量变化。研究结果表明,随着桑椹花色苷浓度的增加,反应体系中的AGEs含量显著降低(P0.05)。桑椹花色苷可显著抑制·OH诱导的AGEs的形成(P0.05)。桑椹花色苷通过保护巯基和抑制蛋白质形成羰基而抑制AGEs生成;SDS-PAGE图谱显示,桑椹花色苷可阻断糖基化反应导致的蛋白质交联物的形成。     

食品中晚期糖基化末端产物的研究进展

晚期糖基化末端产物(advanced glycation end products, AGEs)是还原糖与氨基酸发生非酶褐变反应的产物之一。医学研究结果表明,AGEs与人类诸多疾病的发生有密切关系,而膳食摄入是体内AGEs的重要来源。但是由于AGEs种类较多,对于食品中的AGEs含量的检测尚缺乏标准的方法,食品加工工艺对食品中AGEs形成的影响报道较少。因此,本文从食品中AGEs形成、结构、检测方法及AGEs在体内代谢、对人体健康影响和预防措施等方面对AGEs进行了较系统的阐述,为进一步研究AGEs奠定基础。