Takagaki Akiko, Nanjo Fumio
Food Research Laboratories, Mitsui Norin Company, Ltd. , 223-1 Miyabara, Fujieda-shi, Shizuoka 426-0133, Japan.
J Agric Food Chem. 2015 Sep 23;63(37):8262-6. doi: 10.1021/acs.jafc.5b03676. Epub 2015 Sep 11.
Inhibitory activity of angiotensin I-converting enzyme (ACE) was examined with (-)-epigallocatechin gallate (EGCG) metabolites produced by intestinal bacteria, together with tea catechins. All of the metabolites showed ACE inhibitory activities and the order of IC50 was hydroxyphenyl valeric acids > 5-(3,4,5-trihydroxyphenyl)-γ-valerolactone (1) > trihydroxyphenyl 4-hydroxyvaleric acid ≫ dihydroxyphenyl 4-hydroxyvaleric acid ≫ 5-(3,5-dihydroxyphenyl)-γ-valerolactone (2). Among the catechins, galloylated catechins exhibited stronger ACE inhibitory activity than nongalloylated catechins. Furthermore, the effects of a single oral intake of metabolites 1 and 2 on systolic blood pressure (SBP) were examined with spontaneously hypertensive rats (SHR). Significant decreases in SBP were observed between 2 h after oral administration of 1 (150 mg/kg in SHR) and the control group (p = 0.002) and between 4 h after administration of 2 (200 mg/kg in SHR) and the control group (p = 0.044). These results suggest that the two metabolites have hypotensive effects in vivo.
研究了肠道细菌产生的（-）-表没食子儿茶素没食子酸酯（EGCG）代谢产物以及茶儿茶素对血管紧张素I转换酶（ACE）的抑制活性。所有代谢产物均表现出ACE抑制活性，IC50的顺序为羟基苯基戊酸>5-（3,4,5-三羟基苯基）-γ-戊内酯（1）>三羟基苯基4-羟基戊酸≫二羟基苯基4-羟基戊酸≫5-（3,5-二羟基苯基）-γ-戊内酯（2）。在儿茶素中，没食子酰化儿茶素比未没食子酰化儿茶素表现出更强的ACE抑制活性。此外，用自发性高血压大鼠（SHR）研究了单次口服代谢产物1和2对收缩压（SBP）的影响。在口服1（SHR中150mg/kg）后2小时与对照组之间（p = 0.002）以及口服2（SHR中200mg/kg）后4小时与对照组之间（p = 0.044）观察到SBP显著降低。这些结果表明这两种代谢产物在体内具有降压作用。
