• Korean Journal of Pharmacognosy
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• 제40권4호
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• pp.394-399
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• 2009

Aldose reductase (AR) is a critical enzyme in the development of the diabetic complications. AR, the first enzyme in the polyol pathway, catalyzes the reduction of the aldehyde form of glucose to sorbitol with concomitant conversion of NADPH to $NADP^+$. None of aldose reductase inhibitor (ARI) has achieved worldwide use because of limited efficacy or undesirable side effects. Therefore, evaluating natural sources for ARI potential may lead to the development of safer and more effective agents against diabetic complications. Forty eight Chinese herbal medicines have been investigated for inhibitory activities on AR. Among them, seven herbal medicines, Buddleja officinalis (whole plant), Lonicera japonica (leaf and flower), Polygonum aviculare (aerial part), Polygonum aviculare (whole plant), Salvia miltiorrhiza (root), Schisandra chinensis (stem), and Zanthoxylum armatum (leaf and stem) exhibited a significant inhibitory activity against AR. Particularly, L. japonica and P. aviculare showed two times more potent inhibitory activity than the positive control, 3,3-tetramethyleneglutaric acid (TMG).

• Korean Journal of Medicinal Crop Science
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• 제28권1호
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• pp.21-28
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• 2020

Background: Owing to its high efficiency in lipid and protein production, peanut (Arachis hypogaea L.) is considered one of most important crops world-wide. The kernels of peanuts are undoubtedly the most important product this plant, whereas the skin is almost completely neglected in nutraceutical terms. However, peanut skin contains potentially health-promoting phenolics and dietary fiber, and there is considerable potential for commercial exploitation. In this study, we evaluated the α-glucosidase inhibitory activity of an extract of peanut skin (PS). Methods and Results: The α-glucosidase inhibitory effects of 80% ethanol extracts of peanut (A. hypogaea L. 'Sinpalkwang') skin were evaluated and found to have a half-maximal inhibitory concentration (IC₅₀) value of 1.2 ㎍/㎖. Progress curves for enzyme reactions were recorded spectrophotometrically, and the inhibition kinetics revealed time-dependent inhibition with enzyme isomerization. Furthermore, using ultra-high performance liquid chromatography combined with quadrupole-orbitrap mass spectrometry, we identified 26 compounds in the peanut skin extract, namely, catechin, epicatechin, and 24 proanthocyanidins. Conclusions: The results suggest that peanut skin can be utilized as an effective source of α-glucosidase inhibition in functional foods and nutraceuticals.

• KSBB Journal
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• 제28권5호
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• pp.332-337
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• 2013

The gene encoding for xylose isomerase from the thermophilic bacterium Thermotoga maritima was cloned and recombinantly expressed in E. coli cells. Optimal activity was shown at $90^{\circ}C$ and pH 8.0. Treatment of saponin by recombinant xylose isomerase increased the growth inhibitory effect against human gastric cancer (AGS) cells and human colon cancer (HT-29) cells. On the other hand, treatment of fucoidan by the enzyme could not change the growth inhibitory effect against the same cancer cells. One ${\mu}g/ml$ of enzyme-treated saponin exhibited the same or higher growth inhibitory effect against both cancer cells compared with 100 ${\mu}g/ml$ of enzymeuntreated saponin. These results would be useful in the development of functional food or drug.

• Journal of the Korean Society of Food Science and Nutrition
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• 제26권5호
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• pp.775-783
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• 1997

Morphologically different 18 strains were isolated and examined for their abilities to inhibit ACE. Those strains were cultured in the medium containing 10% of soybean extract at 37$^{\circ}C$ for 48hr or fermented with boiled soybean at 3$0^{\circ}C$ for 60 days. The concentration of inhibitors to inhibit 50% of ACE activity, $IC_{50}$ was measured on the culture broth of each strain and also on the hot-water extract from 20, 40 and 60 day fermented Doenjang by each strain. As a result, SCB-3 which is isolated from Meju showed the highest ACE inhibitoryactivity on the cultured broth and 40 day matured Doenjang. Then, $IC_{50}$ of SCB-3 was 0.02 mg/ml and 0.26mg/ml respectively. SCB-3 was identified as a Bacillus subtilis based upon its morphological, biochemical and physiological properties. Changes in general components and ACE inhibitory activity of Doenjang fermented by SCB-3 were examined during 90 days. Total acidity of Doenjang was increased from 1.39% to 1.66% and pH was decreased from 6.02 to 5.79 after 90 days fermentation. Total sugar contents were decreased from 16.4% to 15.1% and reducing sugar contents was also decreased from 2.45% to 1.62%. Total nitrogen contents were nearly not changed, but amino nitrogen contents were drastically increased from 196mg% to 541mg%. The numbers of total microorganism were increased to 1.1$\times$$10^{8}$ cells/g after 45 days. Protease activity was increased to 622.1U/g after 75 days. The highest ACE inhibitory activity was shown in 60 day fermented Doenjang and $IC_{50}$ of the hot-water extract was 0.31mg/ml.

• Asian-Australasian Journal of Animal Sciences
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• 제29권12호
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• pp.1774-1781
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• 2016

The purpose of this study was to evaluate the antioxidative activities of Crab meat analogue prepared with protein hydrolysates obtained from mechanically deboned chicken meat (MDCM) from spent laying hens. 2,2-diphenyl-1-picrylhydrazyl hydrate (DPPH) radical-scavenging activity was increased by adding MDCM hydrolysates during storage, and activity correlated with the concentration of DPPH added up to 6 weeks of storage. Hydroxyl radical-scavenging activity was increased in all analogues containing MDCM hydrolysates. At 0 days of storage, angiotensin I-converting enzyme (ACE)-inhibitory activity was increased by the addition of MDCM hydrolysates. Activity did not correlate after 6 weeks of storage, in which ACE-inhibitory activity was increased with low concentrations of MDCM hydrolysates, but no ACE-inhibitory activity was observed at higher concentrations. The liver-protecting activity of crab meat analogue was shown to be around 60% of the positive control; however, it was not significantly different among the samples during storage. These results support the use of MDCM as a source of health-promoting constituents in crab meat analogue.

• The Korean Journal of Food And Nutrition
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• 제25권2호
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• pp.246-252
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• 2012

After a mixed carbohydrate diet, inhibition of ${\alpha}$-amylase and ${\alpha}$-glucosidase involved in the digestion and absorption of carbohydrates can significantly decrease the postprandial increase of blood glucose level. In the course of screening these useful enzyme inhibitors, we selected five kinds of bean, using an in-vitro enzyme inhibition assay method. To evaluate the effect of germination process on the functionality of the bean, we investigated the inhibitory activities of the water extracts of non-germinated bean and germinated bean against ${\alpha}$-amylase and ${\alpha}$-glucosidase, relevant to postprandial hyperglycemia. We also investigated the oxygen radical absorbance capacity(ORAC), total phenolics content, and postprandial blood glucose lowering effect in rats(Sprague-Dawley rat model). Most germinated beans showed significantly higher ${\alpha}$-glucosidase inhibitory activity, compared with non-germinated beans. Among germinated beans, Glycine max had the highest ${\alpha}$-glucosidase inhibitory activity(53.3%). The water extract of germinated Phaseolus vulgaris L. had the highest ${\alpha}$-amylase inhibitory activity(95.1%), followed by Glycine max(58.7%), and Glycine max L. Merr(54.1%). Furthermore, the five germinated beans also showed high antioxidant activities in ORAC assay. Results suggested that the germination process may improve and enhance the anti-hyperglycemia potential and antioxidant activity of the bean.

• Korean Journal of Fisheries and Aquatic Sciences
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• 제43권5호
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• pp.437-444
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• 2010

Extracts of the marine microalgae Nannochloropsis oculata were obtained using 80% methanol (MeOH) and water. The 80% MeOH extract was further fractionated with n-hexane, chloroform, ethyl acetate (EtOAc), n-butanol (n-BuOH), and water to isolate the active fraction. Seven samples were prepared and their angiotensin converting enzyme (ACE), $\alpha$-glucosidase, and cancer cell growth inhibitory activities in vitro were determined. The most profound ACE inhibitory activity was observed in the chloroform fraction, while the others had moderate effects. By contrast, greater $\alpha$-glucosidase inhibitory activity was found in the EtOAc fraction, n-hexane fraction, and water extract of N. oculata. The antiproliferative effects of the extracts and fractions against HL-60, U937, CT-26, and SK-Hep1 cancer cells were also determined. The n-BuOH fraction had the strongest antiproliferative effects on CT-26 cells in a time-dependant manner (P<0.05). These results suggest that the extracts and fractions from N. oculata could be used as a potential functional food or as pharmaceutical ingredients.

• Journal of Ginseng Research
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• 제38권1호
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• pp.28-33
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• 2014

Background: Panax notoginseng has been used as a general tonic agent to invigorate human body for millennia in China and continued to be used until present. Methods: Some chromatographic methods were performed to isolate pure triterpenoids, and their structures were determined by nuclear magnetic resonance (NMR) experiments. Anti-diabetes activities of isolated compounds were evaluated through their inhibitory activity of protein tyrosine phosphatase 1B (PTP1B) enzyme. Results and Conclusion: Three new dammarane-type triterpenoids, notoginsenoside-LX (1), notoginsenoside-LY (2), and notoginsenoside-FZ (3) together with eighteen known compounds were isolated from the Panax notoginseng leaves. The structure-activity relationship of the compounds with dammaranetype triterpenoids and their PTP1B inhibitory activity were also reported. Results showed that compounds 2, 15, 20, and 21 can significantly inhibit the enzyme activity of PTP1B in a dose-dependent manner, with inhibitory concentration 50 ($IC_{50}$) values of $29.08{\mu}M$, $21.27{\mu}M$, $28.12{\mu}M$, and $26.59{\mu}M$, respectively. The results suggested that Panax notoginseng leaves might have potential as a new therapeutic agent for the treatment of diabetes.

• Korean Journal of Plant Resources
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• 제25권2호
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• pp.169-175
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• 2012

For the elucidation of action mechanism on anti-HIV of natural resources, the extracts of $Campsis$ $grandiflora$ were tested for their inhibitory effects on HIV-1 replication and its essential enzymes as the reverse transcriptase (RT), protease and ${\alpha}$-glucosidase. In the assay of HIV-1-infected human T-cell line, water extracts of stem inhibited the HIV-1-induced cytopathic effects with IC (inhibitory concentration) of 100 ${\mu}g$/ml. Moreover water extracts (100 ${\mu}g$/ml) of stem showed strong activity of 37.9% on anti-HIV-1 RT using Enzyme Linked Oligonucleotide Sorbent Assay (ELOSA) method. In the HIV-1 protease inhibition assay, methanol extracts of stem and leaf extract showed 33.6% and 31.5% inhibition of the enzyme activity to cleave an oligopeptide resembling one of the cleavage sites in the viral polyprotein which can only be processed by HIV-1 protease, but did not exhibited glucosidase inhibitory activities. From these results, it is suggested that the inhibition of the viral replication $in$ $vitro$ is due to the inhibition of reverse transcriptase by water extracts of stem of $Campsis$ $grandiflora$.

• Korean Journal of Food Science and Technology
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• 제35권4호
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• pp.733-737
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• 2003

To develop a high-valuable Korean traditional rice wine having antihypertension, effects of some cereal kojis and legumes on alcohol fermentation and angiotensin I-converting enzyme (ACE) inhibitory activity of Korean traditional rice wine were investigated. Korean traditional rice wine brewed by addition of 10% Indian-millet koji into the mash showed the greatest ACE inhibitory activity of 43.0% and good ethanol productivity. The ACE inhibitory activity increased up to 69.2% by addition of 50% of mungbean powder and 1% of dandelion petal into the mash.