乳清蛋白酶解ACE抑制肽分离纯化技术的研究

采用6000 u的超滤膜对乳清蛋白水解物中的ACE抑制肽进行了初步分离,确定了超滤的条件,并测定超滤前后水解物的ACE抑制率,结果表明通过超滤可以富积乳清蛋白水解物中的ACE抑制肽.采用阳离子交换树脂对水解物进行脱盐,通过测定水解物的氮回收率、脱盐率以及ACE抑制率,表明采用阳离子交换树脂脱盐率可以达到80%以上,氮的回收率达到90%以上,而水解物经过阳离子交换树脂基本上对其ACE抑制率没有影响.     

抑制血管紧张素转化酶的中药及活性成分的研究

比较32味中药对血管紧张素转化酶（angiotensin converting enzyme,ACE）的抑制作用,并对枸杞的活性成分进行鉴别。高效液相色谱法（HPLC）评价药物对ACE活力的抑制作用,柱层析法对具有最强抑制作用的中药进行分离,确定活性最高的部位。32味中药提取物对ACE有不同程度的抑制作用,其中抑制作用最强的是枸杞,抑制率高达92.30%。枸杞提取物用D-101大孔树脂粗分,50%乙醇洗脱部位对ACE的抑制活性最强,此部位通过硅胶柱进一步纯化得到纯度更高的ACE抑制部位及活性成分。枸杞提取物对ACE酶有很强的抑制效果,大孔树脂和硅胶能很好的分离枸杞中对ACE有抑制作用的化合物。      

抑制血管紧张素转化酶的中药及活性成分的研究

比较32味中药对血管紧张素转化酶(angiotensin converting enzyme,ACE)的抑制作用,并对枸杞的活性成分进行鉴别.高效液相色谱法(HPLC)评价药物对ACE活力的抑制作用,柱层析法对具有最强抑制作用的中药进行分离,确定活性最高的部位.32味中药提取物对ACE有不同程度的抑制作用,其中抑制作用最强的是枸杞,抑制率高达92.30％.枸杞提取物用D-101大孔树脂粗分,50％乙醇洗脱部位对ACE的抑制活性最强,此部位通过硅胶柱进一步纯化得到纯度更高的ACE抑制部位及活性成分.枸杞提取物对ACE酶有很强的抑制效果,大孔树脂和硅胶能很好的分离枸杞中对ACE有抑制作用的化合物.     

Antioxidant capacity and angiotensin I converting enzyme inhibitory activity of a melon concentrate rich in superoxide dismutase

Antioxidant capacity and angiotensin 1-converting enzyme (ACE) inhibitory activity of a melon concentrate rich in superoxide dismutase (SOD-MC) were investigated in vitro. The total antioxidant capacity (TAC) was measured by the Trolox equivalent antioxidant capacity assay (TEAC), the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical assay, and the ferric reducing antioxidant power assay (FRAP). The ability of the extract to scavenge three specific reactive oxygen species (superoxide radical anion (O(2)(-)), hydroxyl radical (HO()) and hydrogen peroxide (H(2)O(2))) was also investigated in order to better evaluate its antioxidant properties. Even if the measures of TAC were relatively low, results clearly established an antioxidant potential of SOD-MC that exhibited the highest radical-scavenging activity towards O(2)(-), with a IC(50) 12-fold lower than that of H(2)O(2) or HO(). This lets hypothesis that the antioxidant potential of SOD-MC could be mainly due to its high level of SOD. Moreover, for the first time, an ACE inhibitory activity of SOD-MC (IC(50)=2.4±0.1mg/mL) was demonstrated, showing that its use as a functional food ingredient with potential preventive benefits in the context of hypertension may have important public health implications and should be carefully considered.     

佛手提取物及活性部位抑制血管紧张素转化酶活性的研究

目的：筛选不同溶剂佛手提取物对血管紧张素转化酶（angiotensin converting enzyme,ACE）的抑制作用及活性部位。方法：用HPLC法比较不同溶剂佛手提取物对ACE的抑制作用,并提取纯化抑制ACE作用最大的佛手提取物的活性部位。结果：不同溶剂佛手提取物中甲醇提取物对ACE的抑制活性最高,抑制率达到77%。佛手提取物40%甲醇洗脱部位对ACE抑制活性较高。结论：采用甲醇提取,大孔吸附树脂吸附,40%甲醇洗脱,获得对ACE酶具有较强抑制作用的佛手活性部位是可行的。     

The antioxidant, angiotensin converting enzyme inhibition activity, and phenolic compounds of bamboo shoot extracts

This study was undertaken to evaluate the functional properties of two of the most popular species of edible bamboo shoots in Korea (Phyllostachys pubescens and Phyllostachys nigra). Powdered bamboo shoots were extracted with methanol and an aqueous suspension of the obtained methanol extract was partitioned successively with chloroform, ethyl acetate, and butanol, leaving a residual water extract. All obtained extracts were evaluated for their antioxidant capacity and antimicrobial activity, angiotensin converting enzyme (ACE) inhibition activity, and ascorbic acid and phenolic compound content. Methanol and water fractions showed a particularly high ascorbic acid contents. The ethyl acetate fraction contained a high concentration of phenolic compounds. Among all extracts, the ethyl acetate and butanol fractions showed particularly high antioxidant activity. Methanol extract had a significantly higher ACE inhibitory activity than other extracts. None of the extracts inhibited the tested bacteria.     

乳酸菌抑制ACE及病原菌代谢产物研究进展

主要对乳酸菌及其发酵乳产品产生降血压的血管紧张素转换酶(ACE)抑制肽及乳酸菌消除肠道微生物降解氨基酸产生致癌因子的作用进行了阐述,表明了乳酸菌在降血压及抗癌方面具有巨大的应用前景。      

Fractionation of angiotensin I converting enzyme inhibitory activity from pea and whey protein in vitro gastrointestinal digests

In vitro gastrointestinal digestion of pea and whey protein produced high angiotensin I converting enzyme (ACE) inhibitory activity with IC₅₀ values of 0.070 and 0.041 mg protein ml^?1 respectively. Ultrafiltration/centrifugation using a membrane with a molecular weight cut‐off of 3000 Da decreased the IC₅₀ value to 0.055 mg protein ml^?1 for pea permeate and 0.014 mg protein ml^?1 for whey permeate. Further fractionation by reverse phase HPLC gave IC₅₀ values as low as 0.016 mg protein ml^?1 for pea and 0.003 mg protein ml^?1 for whey. Consequently, these purification steps enriched the ACE inhibitory activity of the pea digest more than four times and that of the whey digest more than 13 times. HPLC profiles after digestion and ultrafiltration indicate that high ACE inhibitory activity is due to short and more hydrophobic peptides. The results also suggest that potent ACE inhibitory peptides were present alongside low active peptides in whey hydrolysate, while all peptides had more or less the same ACE inhibitory activity in pea hydrolysate. In addition, the hydrolysates and enriched fractions will resist in vivo gastrointestinal digestion after oral administration. Hence these ACE inhibitory peptides, as part of functional foods, can play significant roles in the prevention and treatment of hypertension. Copyright © 2004 Society of Chemical Industry     

Renin and angiotensin converting enzyme inhibition with antioxidant properties of African yam bean protein hydrolysate and reverse-phase HPLC-separated peptide fractions

Enzymatic hydrolysate of African yam bean seed proteins was prepared by treatment with alcalase. The African yam bean seed protein hydrolysate (APH) was further separated into six fractions (F1–F6) on a C12 reverse-phase HPLC column. With exception of F6, amino acid composition analysis showed increase in content of hydrophobic amino acids as residence time on the column increased. Some of the peptide fractions had significantly higher (p < 0.05) superoxide and DPPH radical scavenging activities as well as higher inhibition of linoleic acid oxidation when compared to the unfractionated APH. Iron-chelating ability of APH and peptide fractions was positively related to inhibition of linoleic acid oxidation, which suggests the role of metal-catalyzed reactions during lipid peroxidation. However, peptide fractionation had no effect on ferric reducing antioxidant power. F4 and F6 fractions had significantly higher ACE- and renin-inhibitory properties, respectively. The results showed that a higher residency time on the column (reflecting stronger net hydrophobic character) enhanced peptide-induced renin inhibition but lower net hydrophobic character was better for ACE inhibition. There was no direct relationship between ACE and renin inhibitions, indicating different modes of enzyme-catalyzed reactions. We concluded that the APH and peptide fractions may have potential uses as antioxidants and modulators of the renin–angiotensin system for the management of oxidative stress and cardiovascular disorders, respectively.     

Effect of enzyme type and hydrolysis conditions on the in vitro angiotensin I‐converting enzyme inhibitory activity and ash content of hydrolysed whey protein isolate

Removal of salts from protein hydrolysate mixture on large scale is very difficult and relatively inefficient. Selecting practical proteinase system and hydrolysis conditions for the production of whey protein isolate (WPI) enzymatic hydrolysates with high angiotensin I‐converting enzyme (ACE) inhibitory activity and low ash content is very useful. The effect of alcalase, neutrase, trypsin and their combined system, i.e. alcalase‐neutrase and trypsin‐neutrase, under two different hydrolysis conditions, i.e. pH‐controlled and pH‐spontaneous drop, on the formation of ACE‐inhibitory peptides and the characteristics of WPI hydrolysate was investigated. Results showed that the ACE‐inhibitory activity of WPI hydrolysate obtained with alcalase was significantly higher than that of its trypsin or neutrase hydrolysate obtained at the same hydrolysis time by both pH‐controlled and pH‐spontaneous drop method (P < 0.05). The WPI hydrolysate obtained after 3 h incubation with alcalase plus 2 h with neutrase under pH‐spontaneous drop condition possessed the highest ACE‐inhibitory activity of 54.30% and the lowest ash content of 2.95%. This is practical as a functional ingredient in the food industry because of its high ACE‐inhibitory capability, commercial availability in large supply of alcalase and neutrase and no needing for additional desalting process.     

Antioxidant and angiotensin I converting enzyme inhibitory activity of Bambusae caulis in Liquamen

Bambusae caulis in Liquamen (BCL) is a nutritious liquid that can be extracted from heat-treated bamboo stems. It is also an important herbal medicine in Asia. In this study, antioxidant and angiotensin I converting enzyme (ACE) inhibitory activity of BCL were investigated. BCL significantly quenched DPPH and peroxyl radicals measured by electron spin resonance (ESR) spectroscopy, while IC₅₀ values were 79.85 and 28.85 μg/ml, respectively. The ability of BCL to inhibit the oxidative damage of DNA was assessed in vitro by measuring the conversion of supercoiled pBR322 plasmid DNA to the open circular form. It was found that BCL significantly protected hydroxyl radical-induced DNA damage in a dose-dependant manner, while also inhibiting apoptosis in hydrogen peroxide-induced PC-12 cells and angiotensin I converting enzyme (ACE) activity. These findings suggest that BCL may be a beneficial ingredient in functional foods and/or pharmaceuticals.     

酪蛋白源ACE抑制肽的评价方法和研究进展

血管紧张素转化酶(angiotensin converting enzyme,ACE)在血压调节方面起着重要作用。近年来,ACE抑制肽已成为生物活性肽研究领域的热点。文章综述了ACE抑制肽的作用机制、评价方法和酪蛋白源ACE抑制肽的国内外研究进展。     

In vitro study on digestion of peptides in Emmental cheese: analytical evaluation and influence on angiotensin I converting enzyme inhibitory peptides

A simple in vitro protocol simulating gastrointestinal digestion of proteins and peptides to investigate the effect of digestive enzymes on the biological activity of peptides present in dairy products was developed. This protocol consisted in a 30 min incubation with pepsin followed by a 4 h incubation with trypsin or pancreatin. It was applied to an Emmental cheese water-soluble extract (WSE) and to a casein solution (as a control). Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) allowed to monitor the digestion of proteins. Reversed-phase high-performance liquid chromatography (RP-HPLC) allowed to monitor the conversion of proteins and peptides into peptides and amino acids: it is proposed to use the mean retention time corresponding to the overall retention time distribution of molecules to assess the effect of digestive enzymes. The biological activity focused in this study was the angiotensin I converting enzyme (ACE) inhibitory activity. Digestion of Emmental WSE induced an increase of the ACE inhibition as compared to undigested WSE while a 10 kDa ultrafiltered WSE lost a part of its ACE inhibitory activity after digestion process. These results strongly suggest that digestive enzymes diminished the ACE inhibition by the peptides present in Emmental cheese WSE, while the digestion of peptides of high molecular weight would generate new ACE inhibitory peptides.     

具有血管紧张素转化酶抑制活性的益生菌筛选鉴定及其发酵特性的研究

目的 筛选具有血管紧张素转化酶(ACE)抑制作用的微生物, 提供适用于降高血压发酵产品的菌株。方法 从7种发酵食品中分离菌株后, 利用体外ACE酶抑制率法筛选ACE抑制率大于80%的菌株, 再通过耐盐和耐NaNO2实验, 筛选出目的菌, 并对其进行生物学特性测定和分子生物学鉴定。结果 从发酵食品中分离得到98株菌中, 筛选出F2和D2两个目的菌, F2和D2的ACE酶抑制率分别为83.13%和98.00%, 且均能耐受6%的NaCl及100 mg/kg的NaNO2。结论 筛选出的F2菌株为地衣芽孢杆菌, 对金黄色葡萄球菌抑菌效果显著; D2为球形芽孢杆菌, 具有脂肪酶活性; 且F2和D2菌均具有蛋白酶活性。     

Production of angiotensin I converting enzyme inhibitory (ACE-I) peptides during milk fermentation and their role in reducing hypertension

Fermented milk is a potential source of various biologically active peptides with specific health benefits. Angiotensin converting enzyme inhibitory (ACE-I) peptides are one of the most studied bioactive peptides produced during milk fermentation. The presence of these peptides is reported in various fermented milk products such as, yoghurt, cheese, sour milk, etc., which are also available as commercial products. Many of the ACE-I peptides formed during milk fermentation are resistant to gastrointestinal digestion and inhibit angiotensin converting enzyme (ACE) in the rennin angiotension system (RAS). There are various factors, which affect the formation ACE-I peptides and their ability to reach the target tissue in active form, which includes type of starters (lactic acid bacteria (LAB), yeast, etc.), substrate composition (casein type, whey protein, etc.), composition of ACE-I peptide, pre and post-fermentation treatments, and its stability during gastrointestinal digestion. The antihypertensive effect of fermented milk products has also been proved by various in vitro and in vivo (animal and human trials) experiments. This paper reviews the literature on fermented milk products as a source of ACE-I peptides and various factors affecting the production and activity of ACE-I peptides.     

A novel angiotensin I converting enzyme inhibitory peptide from tuna frame protein hydrolysate and its antihypertensive effect in spontaneously hypertensive rats

Tuna frame protein was hydrolysed using Alcalase, Neutrase, pepsin, papain, α-chymotrypsin and trypsin. Peptic hydrolysate exhibited the highest ACE I inhibitory activity among them and was fractionated into three ranges of molecular weight (below 1, 1–5 and 5–10 kDa) using an ultrafiltration membrane bioreactor system. The 1–5 kDa fraction showed the highest ACE inhibitory activity and was used for subsequent purification steps. During consecutive purification, a potent ACE inhibitory peptide from tuna frame protein (PTFP), which was composed of 21 amino acids, Gly-Asp-Leu-Gly-Lys-Thr-Thr-Thr-Val-Ser-Asn-Trp-Ser-Pro-Pro-Lys-Try-Lys-Asp-Thr-Pro (MW: 2,482 Da, IC₅₀: 11.28 μm), was isolated. Lineweaver–Burk plots suggest that PTFP plays as a non-competitive inhibitor against ACE. Furthermore, antihypertensive effect in spontaneously hypertensive rats (SHR) also revealed that oral administration of PTFP can decrease systolic blood pressure significantly (P < 0.01). These results suggest that the PTFP would be a beneficial ingredient for nutraceuticals and pharmaceuticals against hypertension and its related diseases.