• Nutrition Research and Practice
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• v.5 no.2
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• pp.93-100
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• 2011

Inhibition of angiotensin I-converting enzyme (ACE) activity is the most common mechanism underlying the lowering of blood pressure. In the present study, five organic extracts of a marine brown seaweed Ecklonia cava were prepared by using ethanol, ethyl acetate, chloroform, hexane, and diethyl ether as solvents, which were then tested for their potential ACE inhibitory activities. Ethanol extract showed the strongest ACE inhibitory activity with an $IC_{50}$ value of 0.96 mg/ml. Five kinds of phlorotannins, phloroglucinol, triphlorethol-A, eckol, dieckol, and eckstolonol, were isolated from ethanol extract of E. cava, which exhibited potential ACE inhibition. Dieckol was the most potent ACE inhibitor and was found to be a non-competitive inhibitor against ACE according to Lineweaver-Burk plots. Dieckol had an inducible effect on the production of NO in EAhy926 cells without having cytotoxic effect. The results of this study indicate that E. cava could be a potential source of phlorotalnnins with ACE inhibitory activity for utilization in production of functional foods.

• YAKHAK HOEJI
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• v.45 no.1
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• pp.93-100
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• 2001

Drug inetraction between of enalapril-induced angiotensin converting enzym) inhibitory effect and Ginkgo biloba Ext.-induced antioxidant action was evaluated in spontaneously hypertensive rats. Combination treatment of enalapril (20 mg/kg/day p.o.) and Ginkgo biloba Ext. (60 mg/kg/day, p.o.) for 6 weeks in drinking water to SHRs resulted the inhibition of ACE activity in lung tissue, angiotensin I-induced pressure response and plasma angiotensin II concentration as similar to enalapril alone treatment. But these effects were sustained after 1 week withdrawal of enalapril and Ginkgo biloba Ext. co-administeration. Also, coadministered group did not increase the concentration of bradykinin in lung tissue, which were different from enalapril alone treated group. Co-administration of enalapril and Ginkgo biloba Ext. inhibited the hemolysis induced by UV B type, even Ginkgo biloba Ext. alone treated group did not. These results suggested that Ginkgo biloba Ext. sustained ACE inhibitory effect and reduced the inhibitory effect of bradykinin inactivation induced by enalapril, meanwhile, enalapril increased the antioxidant effect of Ginkgo biloba Ext.

• Food Science of Animal Resources
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• v.43 no.1
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• pp.184-194
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• 2023

Recently, interest in food-derived bioactive peptides as promising ingredients for the prevention and improvement of hypertension is increasing. The purpose of this study was to determine the structure and antihypertensive effect of an antioxidant peptide purified from velvet antler in a previous study and evaluate its potential as a various bioactive peptide. Molecular weight (MW) and amino acid sequences of the purified peptide were determined by quadrupole time-of-flight electrospray ionization mass spectroscopy. The angiotensin I-converting enzyme (ACE) inhibition activity of the purified peptide was assessed by enzyme reaction methods and in silico molecular docking analysis to determine the interaction between the purified peptide and ACE. Also, antihypertensive effect of the purified peptide in spontaneously hypertensive rats (SHRs) was investigated. The purified antioxidant peptide was identified to be a pentapeptide Asp-Asn-Arg-Tyr-Tyr with a MW of 730.31 Da. This pentapeptide showed potent inhibition activity against ACE (IC₅₀ value, 3.72 μM). Molecular docking studies revealed a good and stable binding affinity between purified peptide and ACE and indicated that the purified peptide could interact with HOH2570, ARG522, ARG124, GLU143, HIS387, TRP357, and GLU403 residues of ACE. Furthermore, oral administration of the pentapeptide significantly reduced blood pressure in SHRs. The pentapeptide derived from enzymatic hydrolysate of velvet antler is an excellent ACE inhibitor. It might be effectively applied as an animal-based functional food ingredient.

• Applied Biological Chemistry
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• v.51 no.2
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• pp.93-101
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• 2008

This study was conducted to obtain a good probiotic strain of L. acidophilus from infant feces which have the acid and bile tolerance. The selection criteria for the strain included antimicrobial activity, serum cholesterol reduction, resistance to the hydrogen peroxide, angiotensin converting enzyme (ACE) inhibition activity and iron solubility. To this end, five probiotic Lactobacillus strains have been isolated from infant feces. Especially, L. acidophilus SD 105 had strong antimicrobial activity against Listeria sp., high deconjugation activity in the medium which contained 0.5% of glycocholate (GCA) and high resistance to the hydrogen peroxide. L. acidophilus SD 102 showed the highest ACE inhibition activity among the tested cultures and L. acidophilus SD 103 showed iron solubility of more than 70%.

• Korean Journal of Food Science and Technology
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• v.29 no.6
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• pp.1316-1318
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• 1997

The isolated ${\kappa}-Casein$ on gel permeation chromatography was hydrolyzed by chymosin, trypsin, and pepsin. The 3% TCA soluble portion of the hydrolysates were dialyzed on the angiotensin-I converting enzyme (ACE) inhibition rate (%,) and inhibitory activity $(IC_{50})$ were determined. The trypsin hydrolysate exhibited the highest ACE inhibition rate while the chymosin hydrolysation showed the lowest activity. The hydrolysate was dialyzed using dialysis membrane with various molecular cut-offs, and $IC_{50}$ was determined. As the pore size of the dialysis tubing increased, the ACE inhibitory activity decreased.

• Korean Journal of Food Science and Technology
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• v.33 no.1
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• pp.84-88
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• 2001

About 100 bacterial strains producing proteolytic enzymes were isolated from Korean traditional soy paste Doenjang. Among them, strain SYG3 producing the highest level of angiotensin converting enzyme (ACE) inhibitor into the culture medium was selected and identified as Bacillus pumilus according to the Bergey's mannual of systematic bacteriology. Soybean powder as a nitrogen source and glucose as a carbon source supported high level of ACE inhibitor production. The presence of 3% NaCl also enhanced the production of ACE inhibitor in the medium. The optimum initial pH of the medium and culture temperature for the production of ACE inhibitor were 7.0 and $32^{\circ}C$, respectively. The maximal level of ACE inhibitory effect was obtained after 36 hours of cultivation under the optimized conditions, which was about 98% of inhibition ratio.

• Journal of Microbiology and Biotechnology
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• v.16 no.9
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• pp.1399-1404
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• 2006

The roots of Aralia continentalis (AC) have been used traditionally in Korean as a folk medicine for anti-inflammation and as an anti-rheumatic. In this study, we report that the ethyl acetate-soluble traction (ACE) of the methanolic extract of AC root inhibited the cell growth of various human cancer cell lines and induced apoptosis of HL-60, human promyelocytic leukemia cells. Its $IC_{50}$ values on growth inhibition were estimated to be $56.3{\mu}g/ml$ on HL-60, $87.2{\mu}g/ml$ on HepG2, $93.2{\mu}g/ml$ on HeLa, $135.5{\mu}g/ml$ on DU-145, and $135.8{\mu}g/ml$ on HT-29 cells. Interestingly, ACE showed no antiproliferative effect on normal lymphocyte cells used as control. Furthermore, nuclear DAPI staining revealed the typical nuclear features of apoptosis in the HL-60 cells exposed to $80{\mu}g/ml$ ACE, and a flow cytometric analysis of the HL-60 cells using propidium iodide showed that the apoptotic cell population increased gradually from 5% at 0 h to 16% at 12 h and 20% at 24 h after treated with $50{\mu}g/ml$ of ACE. TUNEL assay also revealed the apoptotic induction of the HL-60 cells treated with ACE. To obtain further information on the ACE-induced apoptosis, the expression level of certain apoptosis-associated proteins was examined using a Western blot analysis. Treatment of the HL-60 cells with ACE resulted in the activation of caspase-3, and subsequent proteolytic cleavage of poly(ADP-ribose) polymerase (PARP). The above results confirmed that the apoptosis in the HL-60 cells was induced by ACE, and that caspase-3-mediated PARP cleavage was involved in the process.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.182-182
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• 1994

Angiotensin converting enzyme (ACE)을 비가역적으로 불활성화시킴으로써 오랫동안 작용할 수 있는 고혈압치료제로서의 ACE억제제를 개발하기 위하여pseudomechanism-based inhibition이라는 새로운 억제기전을 가질 것으로 추정되는 아래 그림과 같은 기본 분자구조를 갖는 epoxide 유도체들을 합성하여 in vitro에서 ACE활성 억제효과를, HPLC법을 이용하여 측정하였다. 그 결과 합성되어진 epoxide 유도체들은, epoxide group대신에 sulfhydryl 또는 carboxyl group으로 치환되어져 있는 기존의 ACE 억제제들보다도 효능이 현저히 저하됨으로써, ACE의 $Zn^{2+}$ binding site와는 배위결합력이 미약하다는 것을 의미하여 준다. 또한 유도체들의 phenylring에 chloride, hydroxyl, nitro group과 같은 polar group 의 도입으로 말미암아 ACE 억제효과가 저하됨으로써 이 부위에서의 hydrophobic interaction이 ACE를 억제하는데 중요하다는 것을 시사해 주며 이외에도 이미 알려진 바와같이 carbonyl carbon과 인접한 carbon atom에 methyl group의 도입이 억제효과에 중요한 역활을 하였다. 따라서 향후에는 ACE의 $Zn^{2+}$ binding site와 강력한 배위결합을 하는 carboxyl group을 도입하고 epoxide의 위치를 변경시키며 또한 hydrophobic interaction하는 부위의 구조를 변화시켜 보다 효능이 우수한 새로운 기전의 ACE억제제를 개발해 나가고자 한다.

• Korean Journal of Food Science and Technology
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• v.29 no.6
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• pp.1269-1274
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• 1997

This study was researched to purify and characterize variety bioactive material acethylmannan from Aloe vera. Purified acethylmannan was mannose (67%), acetyl group (23%) and the rest glucose, galactose that consisting of long chain polydispered ${\beta}-1,4$ linked mannan polymers. The sugar and acetyl group in molecular were linked molar ration one third. $IC_{50}$ value (i.e that concentration which exhibits 50% more enzyme inhibition than control) on angiotensin converting enzyme were 0.58 mM. This compound were found to be a competitive inhibition of Angiotensin Converting Enzyme with apparent Ki values of 0.068 mM.

• Tuberculosis and Respiratory Diseases
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• v.69 no.6
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• pp.418-425
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• 2010

Background: Little is known about the long-term effects of angiotensin-converting enzyme (ACE) treatment on post-tuberculosis emphysema. This study evaluated the effects of ACE inhibition on cardiac function and gas exchange in patients with post-tuberculosis emphysema. Methods: At baseline and at 6 months after initiation of ACE inhibition therapy, patients underwent pulmonary function testing, arterial blood gas analysis, and echocardiography, both at rest and post exercise. Cardiac output (CO) and right ventricular ejection fraction (RVEF) were measured at those time points as well. Results: After ACE inhibition; resting and post-exercise RVEF ($Mean{\pm}SEM,\;61.5{\pm}1.0,\;67.6{\pm}1.2%$, respectively) were higher than at baseline ($56.9{\pm}1.2,\;53.5{\pm}1.7%$). Resting and post-exercise CO ($6.37{\pm}0.24,\;8.27{\pm}0.34L/min$) were higher than at baseline ($5.42{\pm}0.22,\;6.72{\pm}0.24L/min$). Resting and post-exercise $PaO_2$ ($83.8{\pm}1.6,\;74.0{\pm}1.2mmHg$, respectively) were also higher than at baseline ($74.2{\pm}1.9,\;66.6{\pm}1.6mmHg$). Post-exercise $PaCO_2$($46.3{\pm}1.1mmHg$) was higher than at baseline ($44.9{\pm}1.1;\; Resting\;42.8{\pm}0.8\;vs.\;42.4{\pm}0.9mmHg$). Resting and post-exercise A-a $O_2$ gradient ($12.4{\pm}1.4,\;17.8{\pm}1.5 mmHg$) were lower than at baseline ($22.5{\pm}1.5,\;26.9{\pm}1.6mmHg$). Conclusion: In post-tuberculosis emphysema, RVEF and CO were augmented with a resultant increase in peripheral oxygen delivery after ACE inhibition. These findings suggest that an ACE inhibitor may have the potential to alleviate co-morbid cardiac conditions and benefit the patients with post-tuberculosis emphysema.