Antihypertensive activities of the plasteins derived from casein hydrolysates in spontaneously hypertensive rats

Abstract

Two casein plasteins were prepared from the Neutrase-catalyzed plastein reaction of casein hydrolysates in the presence of proline and phenylalanine, respectively, and assessed for their antihypertensive activities at 300 mg/kg body using rat model. After being oral administered, the two plasteins at initial time of 2–6 h resulted in the rats decreased systolic and diastolic blood pressures of 10–23 and 8–19 mmHg, respectively; however, the measured antihypertensive activities showed decreasing trends as oral administrating time prolonged. The two plasteins also decreased serum levels of angiotensin II, angiotensin I converting enzyme, and aldosterone, but had unclear effect on serum angiotensinogen level. The two plasteins showed same antihypertensive activities without statistical difference (p > 0.05), and were more efficient than casein hydrolysates but less effective than captopril (p < 0.05) to exert antihypertensive effect. It is concluded that the plastein reaction can confer casein hydrolysates with enhanced in vivo antihypertensive activities.

Keywords

• Casein hydrolysates
• Neutrase
• plastein reaction
• antihypertensive activity
• spontaneously hypertensive rat