Abstract
The effect of γ-aminobutyric acid (GABA)-enriched Agaricus blazei (AG-GABA) and mycelia of Agaricus blazei (AG-M) on blood pressure of spontaneously hypertensive rats (SHR) was studied. Powdered AG-GABA or AG-M was fed on SHR at the levels of 5% (Experiment-A) or 2% (Experiment-B) in a 1% NaCl (control) diet for 21 or 28 days and that systolic and diastolic blood pressure were measured by tail cuff. Animals of AG-GABA and AG-M groups showed significantly lower blood pressure compared to the control group. AG-GABA had stronger hypotensive effect than AG-M. The serum levels of total cholesterol (TC) and triglyceride of groups fed AG-GABA and AG-M were lower than those of the control group, and atherogenic index [(TC-HDL-C)/HDL-C] was improved in 21 or 28 days. The inhibitory activity of the angiotensin I-converting enzyme (ACE) was compared among of AG-GABA, AG-M and GABA. The IC50 of AG-GABA and AG-M for ACE were 1.9 and 1.7 mg/ml, respectively. However, GABA showed no inhibitory activity against the ACE. These phenomena suggested that AG-GABA has concomitant hypotensive effects by GABA and ACE inhibitory substance (unknown).
