添加紫薯提取物和酪蛋白水解物酸奶降血压和护肝功能评价

在普通酸奶的基础上，添加富含花青素的紫薯提取物（purple sweet potato extract，PSPE）-A和富含血管 紧张素转换酶（angiotensin converting enzyme，ACE）抑制肽的酪蛋白水解物（CH-A），制备发酵酸奶，采用动 物实验模型评价其降血压和护肝功能。将1 kg中含有3.0 g CH-A＋1.5 g PSPE-A的酸奶和1 kg中含有3.0 g CH-A＋ 3.0 g PSPE-A的酸奶，每天以3.33 g/kg（以体质量计，下同）的剂量，分别灌胃原发性高血压大鼠（spontaneously hypertensive rats，SHR）。结果显示：在灌胃后4 h，SHR尾动脉收缩压（systolic blood pressure，SBP）分别下降 了（23.13±2.41）、（26.23±1.44）mm Hg。将两种酸奶以3.33 kg/kg的剂量连续灌胃30 d，通过酒精性肝损伤模 型评价护肝作用。结果显示：两种酸奶对SHR血清及肝脏的5 个指标：谷草转氨酶（aspartate aminotransferase， AST）、谷丙转氨酶（alanine aminotransferase，ALT）、甘油三酯、丙二醛（malondialdehyde，MDA）、还原型谷 胱甘肽中至少3 个指标（AST、ALT、MDA）水平有显著改善作用（P＜0.05）；通过肝组织病理切片观察，两种 酸奶对肝细胞和脂肪代谢均有改善作用。因此，添加富含花青素紫薯提取物和富含ACE抑制肽的酪蛋白水解物的酸 奶，在实验的剂量范围内具有降血压和保护肝脏的作用。

Antihypertensive and Hepatoprotective Effects of Yogurt Containing Purple Sweet Potato Extract and Casein Hydrolysate

The objective of this paper is to produce a new yogurt containing purple sweet potato extract (PSPE) rich in anthocyanins (PSPE-A) and casein hydrolysate rich in angiotensin converting enzyme (ACE) inhibitory peptides (CH-A) based on ordinary yoghurt processing, and to evaluate its anti-hypertensive and hepatoprotective effects using animal model. Spontaneously hypertensive rats (SHR) were orally administered with yogurts containing 3.0 g of CH-A and 1.5 g of PSPE-A (treatment 1) or 3.0 g of CH-A and 3.0 g of PSPE-A (treatment 2) at a dosage of 3.33 g/kg. Results showed that at 4 h after administration, systolic blood pressure (SBP) of SHR in treatments 1 and 2 was decreased by (23.13 ± 2.41) and (26.23 ± 1.44) mm Hg, respectively. The SHR were orally administered with the yoghurts at a dose of 3.33 g/kg for 30 days to evaluate their hepatoprotective effect against alcoholic liver damage. Results showed that among five tested indexes, namely aspartate transaminase (AST), alanine transaminase (ALT), triglyceride (TG), malondialdehyde (MDA) and reduced glutathione (GSH), at least three indexes such as AST, ALT and MDA were improved significantly (P < 0.05). Both yogurts improved the hepatic cells and fat metabolism as evidenced by histopathological examination. Therefore, yoghurt containing purple sweet potato extract rich in anthocyanins and casein hydrolysate rich in ACE exerts antihypertensive and hepatoprotective effects in the experimental dosage range.