含血管紧张素转化酶抑制肽的酪蛋白水解物与紫薯提取物联用对原发性高血压大鼠血压的影响

以富含血管紧张素转化酶（angiotensin converting enzyme，ACE）抑制肽的酪蛋白水解物和富含花青素的紫薯提取物为原料，灌胃12 周龄雄性原发性高血压大鼠（spontaneously hypertensive rats，SHR）和正常雄性Wistar大鼠，研究富含ACE抑制肽的酪蛋白水解物和紫薯提取物对SHR血压的影响。用不同剂量的酪蛋白水解物（10、20、30、40 mg/kg，以体质量计，下同）和紫薯提取物（5.4、10.8、21.6、32.4 mg/kg，花青素含量为9.25%）分别灌胃SHR和Wistar大鼠。然后选用酪蛋白水解物的2 个剂量组分别与紫薯提取物的3 个剂量组联合灌胃SHR。用智能无创血压计测量SHR血压变化。结果表明：富含ACE抑制肽的酪蛋白水解物和富含花青素的紫薯提取物，在实验灌胃剂量范围内均具有较好的降压效果，而且两者联用进行单次灌胃后降压效果显著提高（P＜0.05）。其中酪蛋白水解物（10 mg/kg）分别与紫薯提取物3 个剂量（5.4、10.8、21.6 mg/kg）联合灌胃SHR后4 h或者5 h，血压分别降低了（24.67±4.46）、（28.47±3.96）、（41.51±4.89） mmHg。用酪蛋白水解物（20 mg/kg）分别与紫薯提取物的3 个剂量（5.4、10.8、21.6 mg/kg）联合灌胃SHR后5 h或者6 h，SHR血压分别降低了（38.03±3.46）、（43.92±2.92）、（47.20±4.31） mmHg。两者联用灌胃后对Wistar正常大鼠的血压无影响。另外，酪蛋白水解物2 个剂量（10、20 mg/kg）和紫薯提取物（10.8 mg/kg）分别联合使用，间隔4 h灌胃1 次，每天灌胃2 次，SHR大鼠血压较灌胃前分别降低了（28.20±3.02）、（43.54±2.55） mmHg，而且能较长时间维持在较低血压水平。因此，富含ACE抑制肽的酪蛋白水解物和富含花青素的紫薯提取物联合食用对SHR的降压具有显著效果。

Effect of Oral Administration of Casein Hydrolysate Containing ACE Inhibitory Peptides and Purple Sweet Potato Extract on the Systolic Blood Pressure (SBP) of Spontaneously Hypertensive Rats (SHR)

In order to investigate the effect of casein hydrolysates containing ACE inhibitory peptides and purple sweet
potato extract containing anthocyanins on the systolic blood pressure (SBP) of spontaneously hypertensive rats (SHR) and
Wistar rats, 12-week-old male SHR and Wistar rats were orally administered with different doses of casein hydrolysates (10,
20, 30, and 40 mg/kg mb) and purple sweet potato extract (5.4, 10.8, 21.6 and 32.4 mg/kg mb) as well as combinations of
casein hydrolysates at two hypotensive doses identified and purple sweet potato extract at three hypotensive doses selected,
respectively. The blood pressure of SHR was tested by non-invasive automated sphygmomanometer. The results showed
that both casein hydrolysates and purple sweet potato extracts had a significant hypotensive effect on SHR rats. Moreover,
their effect was significantly enhanced when they were applied in combination at a single dose (P < 0.05). The SBP of SHR
rats was reduced by (24.67 ± 4.46), (28.47 ± 3.96), and (41.51 ± 4.89) mmHg, respectively, at 4 or 5 h after administration
of 10 mg/kg mb casein hydrolysates in combination with purple sweet potato extract at three doses of 5.4, 10.8 and
21.6 mg/kg mb, while it was reduced by (38.03 ± 3.46), (43.92 ± 2.92), and (47.20 ± 4.31) mmHg, respectively, at 5 or 6 h
post-administration of casein hydrolysates at 20 mg/kg mb in combination with purple sweet potato extract at 5.4, 10.8
and 21.6 mg/kg mb. Nevertheless, no effect on the SBP of Wistar rats was observed when they were used in combination.
Combined administration of casein hydrolysates at 10 and 20 mg/kg mb with purple sweet potato extract at 10.8 mg/kg mb
twice daily at 4 h intervals resulted in a decrease in the SBP of SHR rats of (28.20 ± 3.02) and (43.54 ± 2.55) mmHg as
compared with that before administration, respectively. Furthermore, the lower levels of SBP could be maintained for a
long period. Therefore, casein hydrolysate containing ACE inhibitory peptides and purple sweet potato extract containing
anthocyanins, when orally administered in combination, can significantly reduce the SBP of SHR.