Green coffee bean extract and its metabolites have a hypotensive effect in spontaneously hypertensive rats.
The effects of a water-soluble green coffee bean extract (GCE) on blood pressure were investigated using spontaneously hypertensive rats (SHR). There was a dose-dependent reduction in blood pressure after a single ingestion (180 to 720 mg/kg, p.o.) or long-term ingestion (0.25 to 1% diet for 6 weeks) of GCE. A single oral ingestion (50 to 200 mg/kg) of 5-caffeoylquinic acid (5-CQA), the major component of GCE, dose-dependently decreased blood pressure, suggesting that 5-CQA is involved in the hypotensive effect of GCE in SHR. Because significant increases in caffeic acid (CA) or ferulic acid (FA) were detected in plasma after oral ingestion of 5-CQA in SHR, these acids (2.5, 5,10 micromol/kg) were intravenously injected into SHR under anesthesia and the carotid arterial pressure was measured. Of the two components, FA had a stronger depressor effect than CA. The depressor effect of FA (50 mg/kg, p.o.) was attenuated by the concurrent injection of atropine sulfate (5 mg/kg, s.c.), suggesting that the hypotensive effect of FA in SHR might be mediated via the muscarinic acetylcholine receptors. These findings indicate that oral ingestion of GCE or 5-CQA decreases blood pressure in SHR, and that FA, which is a metabolite of 5-CQA, is a candidate hypotensive component.
Suzuki
Atsushi
A
Biological Science Laboratories, Kao Corp., Tochigi, Japan.
Kagawa
Daiji
D
Ochiai
Ryuji
R
Tokimitsu
Ichiro
I
Saito
Ikuo
I
D000284:Administration, Oral; D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology*; D001285:Atropine / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects; D002109:Caffeic Acids / Q000494:pharmacology*; D002339:Carotid Arteries / Q000187:drug effects / Q000502:physiology; D003069:Coffee / Q000737:chemistry*; D003373:Coumaric Acids / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D006973:Hypertension / Q000503:physiopathology*; D007275:Injections, Intravenous; D007279:Injections, Subcutaneous; D008297:Male; D018727:Muscarinic Antagonists / Q000494:pharmacology; D010936:Plant Extracts / Q000494:pharmacology*; D011801:Quinic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology*; D051381:Rats; D011918:Rats, Inbred SHR / Q000502:physiology*; D011921:Rats, Inbred WKY; D013997:Time Factors
D000959:Antihypertensive Agents; D002109:Caffeic Acids; D003069:Coffee; D003373:Coumaric Acids; D018727:Muscarinic Antagonists; D010936:Plant Extracts; D011801:Quinic Acid; D001285:Atropine; C004999:ferulic acid