Green asparagus (Asparagus officinalis) prevented hypertension by an inhibitory effect on angiotensin-converting enzyme activity in the kidney of spontaneously hypertensive rats

J Agric Food Chem. 2013 Jun 12;61(23):5520-5. doi: 10.1021/jf3041066. Epub 2013 May 30.

Abstract

Green asparagus (Asparagus officinalis) is known to be rich in functional components. In the present study, spontaneously hypertensive rats (SHR) were used to clarify whether green asparagus prevents hypertension by inhibition of angiotensin-converting enzyme (ACE) activity. Six-week-old male SHR were fed a diet with (AD group) or without (ND group) 5% asparagus for 10 weeks. Systolic blood pressure (SBP) (AD: 159 ± 4.8 mmHg, ND: 192 ± 14.7 mmHg), urinary protein excretion/creatinine excretion, and ACE activity in the kidney were significantly lower in the AD group compared with the ND group. Creatinine clearance was significantly higher in the AD group compared with the ND group. In addition, ACE inhibitory activity was observed in a boiling water extract of asparagus. The ACE inhibitor purified and isolated from asparagus was identified as 2″-hydroxynicotianamine. In conclusion, 2″-hydroxynicotianamine in asparagus may be one of the factors inhibiting ACE activity in the kidney, thus preventing hypertension and preserving renal function.

MeSH terms

  • Angiotensin-Converting Enzyme Inhibitors / chemistry
  • Angiotensin-Converting Enzyme Inhibitors / metabolism*
  • Animals
  • Antihypertensive Agents / metabolism*
  • Asparagus Plant / chemistry
  • Asparagus Plant / metabolism*
  • Azetidinecarboxylic Acid / analogs & derivatives
  • Azetidinecarboxylic Acid / chemistry
  • Azetidinecarboxylic Acid / metabolism
  • Blood Pressure
  • Humans
  • Hypertension / diet therapy*
  • Hypertension / enzymology
  • Hypertension / physiopathology
  • Hypertension / prevention & control*
  • Kidney / enzymology*
  • Male
  • Peptidyl-Dipeptidase A / metabolism
  • Plant Preparations / chemistry
  • Plant Preparations / metabolism*
  • Rats
  • Rats, Inbred SHR

Substances

  • Angiotensin-Converting Enzyme Inhibitors
  • Antihypertensive Agents
  • Plant Preparations
  • nicotianamine
  • Azetidinecarboxylic Acid
  • Peptidyl-Dipeptidase A