Search for food constituents having ability to induce or inhibit liver enzymes and their safety assessment

寻找具有诱导或抑制肝酶能力的食品成分及其安全性评价

• 批准号: 07672405
• 负责人: YOSHIMURA Hidetoshi
• 金额: $ 1.41万
• 依托单位: Nakamura Gakuen University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07672405/
• 关键词: caffeine; epicatechins; rat liver microsomes; cytochrome P450; enzyme induction; enzyme inhibition; ラット肝ミクロゾーム; シトクロムP-450; 酵素誘導と阻害

(1) Commercial canned beverages (coffee, green tea, oolong tea, black tea and tochu tea) were given ad libitum to male Wistar rats for 20 and 10 days and killed at the next day. Using liver microsomes prepared from these rats, effects of the beverages on cytochrome P450 isozymes were studied.(2) Caffeine contents (mg/100 ml) in the beverages were estimated to be 34.0 (coffee), 14.1 (green tea), 19.4 (oolong tea), 14.3 (black tea) and 0.0 (tochu tea). Taking into account the ingested volumes of the beverages (about 25 ml/day/body), daily intake of caffeine per body in the coffee-group was calculated to be about 8 mg.(3) Contents of (-) epicatechin, (-) epicatechin gallate, (-) epigallocatechin and (-) epigallocatechin gallate in each of the canned beverages (green tea, oolong tea and black tea) varied considerably with the lot, but the total amounts were estimated to be 13 to 26 mg/100 ml.(4) Amount of daily intake of each beverage was almost same as that of control, but the body weight … More gain of the coffee-and tochu tea-groups were suppressed significantly after 20 days experiment as compared with that of control.(5) In the coffee-groups of 20 and 10 days experiments, activities of 7-ethoxy-resorufin O-deethylation, acetanilide hydroxylation and testosterone 6beta-hydroxylation were significantly increased in parallel with increase of cytochrome P450, suggesting a probable induction of P4501A and 3A subfamilies. significant decrease of benzphetamine N-demethylation sctivity in the coffee-groups suggested also a probable decrease of content of the constitutive P4502C11, considering a tendency to decrease activities of testosterone 2alpha-and 16alpha-hydroxylations.(6) These changes of liver enzyme activities mediated by cytochrome P450 are consideaed to be induced mainly by caffeine, but the caffeine-free beverages also showed some inductive effect. This suggests that the epicatechins may have caffeine-like inducing ability, but the conclusive evidence supporting this assumption has not yet been obtained. Less

(1)给雄性Wistar大鼠自由饮用商业罐装饮料(咖啡、绿茶、乌龙茶、红茶、藤茶)20天和10天，次日处死。(2)饮料中咖啡因含量(mg/100ml)分别为34.0(咖啡)、14.1(绿茶)、19.4(乌龙茶)、14.3(红茶)和0.0(托州茶)。考虑到饮料的摄入量(约25毫升/天/体)，咖啡组每人每天的咖啡因摄入量约为8毫克。(3)每种罐装饮料(绿茶、乌龙茶和红茶)中(-)表儿茶素、(-)表儿茶素没食子酸酯、(-)表儿茶素和(-)表儿茶素没食子酸酯的含量随批次的不同而变化很大，但总摄入量估计为13-26毫克/100毫升。(4)每种饮料的每日摄入量与对照组几乎相同，但体重…实验20天后，咖啡组和藤茶组的增重显著低于对照组。(5)在实验20天和10天的咖啡组中，7-乙氧基间苯二酚O-脱乙基、乙酰苯胺羟化和睾酮6β-羟化活性显著增加，同时细胞色素P450活性增加，提示可能诱导了P4501A和3A亚家族的产生。考虑到睾酮2α和16α羟化活性有降低的趋势，咖啡组苯非他明N-去甲基化活性的显著降低也可能导致构成成分P4502C11含量的减少。(6)细胞色素P450介导的这些肝酶活性的变化被认为主要是由咖啡因诱导的，但不含咖啡因的饮料也显示出一定的诱导作用。这表明表儿茶素可能具有类似咖啡因的诱导能力，但支持这一假设的确凿证据尚未获得。较少