Antihypertensive activity of AMC3, an engineered 11S amaranth globulin expressed in Escherichia coli, in spontaneously hypertensive rats

• The in vivo effect of AMC3 enzymatic hydrolysates in SHR rats.
• AMC3 protein have been modified with Val–Tyr and Ile–Pro–Pro antihypertensive peptide.
• AMC3 had significant antihypertensive action by oral administration.

The acidic-subunit of 11S seed storage globulin of Amaranthus hypochondriacus was recently modified by the incorporation of antihypertensive biopeptides: four units of Val–Tyr dipeptides (VY) in tandem and one of Ile–Pro–Pro tripeptide (IPP), was named AMC3. The in vivo effect of AMC3 enzymatic hydrolysates (AEH) produced in Escherichia coli, was evaluated in spontaneously hypertensive rats (SHR) by once-oral administration experiments. As positive control a SHR group received a dose of captopril (50 mg/kg) (an angiotensin-converting enzyme (ACE) inhibitor used for the treatment of hypertension). Mean arterial pressure (MAP) was measured for 6 h after AEH or captopril administration. AEH administration at maximal dose (100 mg/kg) significantly reduced MAP similar to the group treated with captopril. The maximal reduction in MAP was observed after 3.5 h after AEH oral administration. The present study showed that enzymatic hydrolysates of AMC3 containing ACE inhibitory peptides (4xVY and IPP) sequences had significant antihypertensive action by oral administration in spontaneously hypertensive rats (SHR).