Antihypertensive effect of corn peptides, produced by a continuous production in enzymatic membrane reactor, in spontaneously hypertensive rats

The aim of this study was to produce corn peptides (CP) with potent angiotensin converting enzyme (ACE)-inhibitory activity and to investigate antihypertensive effects in spontaneously hypertensive rats (SHRs). Results showed that the hydrolysate yield and quality were stable during continuous CP production using an enzymatic membrane reactor (EMR). The hydrolysate was then filtered through a 3 kDa cut-off membrane and the IC50 value of permeate was decreased fourfold (IC50 = 0.29 mg protein/ml). Gastric-intubation CP (Mw < 3 kDa) at a dose of 100 mg/kg bw revealed the best antihypertensive effects in both acute and long-term animal studies using SHRs’ models, the reductions in maximal systolic blood pressure (SBP) were 26.57 mm Hg and 34.45 mm Hg, respectively. Long-term antihypertensive effect of CP administration at a dose of 100 mg/kg bw was comparable to Captopril at 2 mg/kg bw dose. The CP significantly inhibited the ACE activities in SHRs’ lungs and testes (p < 0.01 ∼ p < 0.05) suggesting that these were CP’s target sites.