Isolation of an Antihypertensive Peptide from Alcalase Digest of Spirulina platensis

摘要

An angiotensin I-converting enzyme (ACE) inhibitory peptide Ile-Gln-Pro with an IC_(50) value of 5.77 ± 0.09 μM was purified from the alcalase digests of Spirulina platensis by gel filtration chromatography and two steps of reverse-phase high-performance liquid chromatography (RP-HPLC). The peptide was synthesized and showed resistance to in vitro digestion by gastrointestinal proteases. Kinetics studies indicated that the peptide was a noncompetitive inhibitor and that the K_i value was 7.61 ± 0.16 μM. Oral administration of Ile-Gln-Pro at a dosage of 10 mg/kg showed significant decreases of the weighted systolic blood pressure (SBP) and diastolic blood pressure (DBP) in spontaneously hypertensive rats (SHR) at 4, 6, and 8 h after treatment. The results showed that the ACE inhibitory peptide from Spirulina platensis may have potential for use in the prevention and treatment of hypertension.