Effects of Metabolites Produced from (-)-Epigallocatechin Gallate by Rat Intestinal Bacteria on Angiotensin I-Converting Enzyme Activity and Blood Pressure in Spontaneously Hypertensive Rats.
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.
Food Research Laboratories, Mitsui Norin Company, Ltd. , 223-1 Miyabara, Fujieda-shi, Shizuoka 426-0133, Japan.
Akiko
A
Takagaki
Food Research Laboratories, Mitsui Norin Company, Ltd. , 223-1 Miyabara, Fujieda-shi, Shizuoka 426-0133, Japan.
Fumio
F
Nanjo
D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology*; D000818:Animals; D000959:Antihypertensive Agents / Q000378:metabolism / Q000494:pharmacology* / Q000652:urine; D001419:Bacteria / Q000378:metabolism*; D001794:Blood Pressure / Q000187:drug effects; D002392:Catechin / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology / Q000652:urine; D006973:Hypertension / Q000188:drug therapy*; D007422:Intestines / Q000382:microbiology*; D007783:Lactones / Q000378:metabolism / Q000494:pharmacology; D008297:Male; D051381:Rats; D011918:Rats, Inbred SHR; D013662:Tea / Q000737:chemistry; D014631:Valerates / Q000378:metabolism / Q000494:pharmacology
D000806:Angiotensin-Converting Enzyme Inhibitors; D000959:Antihypertensive Agents; D007783:Lactones; D013662:Tea; D014631:Valerates; D002392:Catechin; C045651:epigallocatechin gallate; C057580:gallocatechol
angiotensin I-converting enzyme; blood pressure; epigallocatechin gallate; intestinal bacteria; metabolite; spontaneously hypertensive rat; valerolactone