• Korean Journal of Food Science and Technology
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• v.25 no.3
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• pp.238-242
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• 1993

For the Purpose of utilizing tannins in the functional foods and crude drugs, the enzyme inhibition of tannins isolated from Korean green tea were determined. Acetone extract from Korean green tea showed inhibition effect against the angiotensin converting enzyme. The galloyl tannins showed higher inhibition activity against angioteosin converting enzyme than the nongalloyl tannins. In terms of stereo isomers, (-)-epicatechins had higher inhibition activity than the (+ )-catechins. The synergistic activity was also observed. Tannins isolated from Korean green tea appeared to be incompetitive inhibitor against the angiotensin converting enzyme.

• Journal of Environmental Science International
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• v.17 no.12
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• pp.1325-1330
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• 2008

This study was carried out with the detection for multiresidue of the carbamate pesticide such as carbaryl and cabofuran by enzyme-inhibition method. The check time for determination of acetylcholinesterase(AChE) activity was selected at 60 sec. The AChE activity in chicken brain determined by the Ellman's method was $162{\mu}$mol/min/g protein. $I_{50}$ for AChE by carbamate pesticide with wet kit was 0.169mg/L of carbaryl and 0.089mg/L of cabofuran, respectively. The incubation time for enzyme kit with substrate kit was 30min for determination of AChE activity. Enzyme kit with substrate kit was stable at $4^{\circ}C\;and\;25^{\circ}C$ for 5 days. Limit detection concentration of carbaryl with dry kit for AChE was 0.05mg/L. The dry kit such as wet kit applied Enzyme-Inhibition(EI) method with AChE was confirmed the multi residue method to detect the carbamate pesticides.

• The Journal of Korean Medicine
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• v.17 no.2 s.32
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• pp.264-276
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• 1996

This study was carried out to evaluate the effect of Samhwasan on the Na-K-ATPase activity of heart muscle. The Na-K-ATPase activity was prepared from rabbit heart ventricles. Samhwasan markedly inhibited the Na- K - ATPase activity in a dose-dependent manner with an estimated $I_{50}$ of 0.56%. Hill coefficient was 1.70, indicating that the enzyme has more than one binding site for the Samhwasan. Inhibition of enzyme activity by Samhwasan increased as pretreatment time was prolonged. Inhibition by the drug was not affected by a change in enzyme protein concentration. Kinetic studies of substrate activation of the enzyme indicated classical noncompetitive inhibition, showing significant reduction in Vmax without a change in Km value. Inhibitory effect by Samhwasan was not altered by changes in concentration of $Mg^{2+}$, $Na^+$ or $K^+$, dithiothreitol. a sulfhydryl reducing reagent, did not protect the inhibition of Na-K-ATPase activity by Samhwasan combination of Samhwasan and ouabain showed a cumulative inhibition fashion. These results suggest that Samhwasan inhibits Na-K-ATPase activity of heart ventricles with an unique binding site different from that of ATP, $Mg^{2+}$, $Na^+$ or $K^+$ and ouabain.

• Food Science and Preservation
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• v.21 no.1
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• pp.75-81
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• 2014

In this study, the biological activity of water and ethanol extracts from Saururus chinensis by ultra-fine grinding for functional food source are examined. It is more effective to use ethanol than water when extracting phenolic compounds. Approximately 2.5 times higher extraction yield were shown when it was ultra-fine grinded because the particle size decreases, thereby increasing the extraction yield. Normal grinded sample extracts showed 69.8% of DPPH inhibition effect, while fine grinded and ultra-fine grinded sample extracts showed 70.7% and 83.8% each, respectively. Normal extract, as well as fine grinded and ultra-fine grinded extracts, showed over 97% of ABTS inhibition effect, thereby indicating only a slight difference in the anti-oxidative activity with the grinding method. Higher PF was determined with fine grinded and ultra-fine grinded extracts than the normal grinded extract, while ultra-fine grinded 50% ethanol extracts showed the highest anti-oxidative activity value of 1.8 PF. The fine grinded and ultra-fine grinded particle sizes are smaller than the normal grinded particle size, thus increasing the inhibition rate of the TBARS. Furthermore, the ethanol extract was revealed to have a higher effect than the water extracts. The xanthin oxidase inhibition, on the other hand, was identified as ultra-fine grinded that led to the increase in the enzyme inhibition effect. In the angiotensin-converting enzyme, water extracts with normal grinding did not show inhibition activity, while 50% ethanol extracts showed 24% inhibition activity. Moreover, the ethanol extracts showed higher inhibition effect compared to the water extracts. Ultra-fine grinded 50% ethanol extracts showed a slight antibacterial effect on the Staphylococcus aureus and Escherichia coli, while the other extracts showed none. The result suggests that Saururus chinensis extracts by ultra-fine grinding may be more useful than normal grinding as potential sources due to anti-oxidation, angiotensin converting enzyme and xanthine oxidase inhibition.

• Journal of Ginseng Research
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• v.7 no.1
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• pp.80-87
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• 1983

In an endeavour to elucidate effects of ginseng on some characteristics of enzymes, malate dehydrogenase (EC 1.1.1.37) was chosen as a model enzyme and effects of ginseng saponin on the enzyme such as optimum pH, product inhibition, optimum temperature and the activity was investigated. The product inhibition by NADH-a reaction product of the enzyme-was increased 33% by 0.3% ginseng saponin. And the optimum pH of the enzyme was 8.3 but in the presence of 0.3% ginseng saponin it increased to 8.5. The enzyme activity and the optimum temperature was not affected by ginseng saponin in the concentration of 1.0% and 0.3%, respectively. In this work, the possibility of contribution of ginseng saponin to the adaptogen activity is suggested; Potentiation of the regulatory activity of an enzyme may contribute to the normalization of the physiological state and consequently may increase the nonspecific resistance of an organism.

• YAKHAK HOEJI
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• v.43 no.3
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• pp.334-341
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• 1999

Thyroid peroxidase is a biochemical target protein for the antithyroid drugs. Ethanol extracts from one hundred and thirty seven natural products were screened for the inhibition of thyroid peroxidase activity. Thyroid peroxidase was purified from porcine thyroids, and the inhibition of peroxidase activity was evaluated using guaiacol oxidation (C-C coupling) assay. Twenty one natural products expressed a remarkable inhibition (>50%) of peroxidase activity at $330{\mu\textrm{g}}$ solid weight/m. The 50% inhibitory concentration ($IC_{50}$) of 70% ethanol extract from six potent natural products ranged from 3.1 to $31.2{\;}{\mu\textrm{g}}$ solid weight/m, in contrast to the range ($0.33~0.54{\;}{\mu\textrm{g}}/ml$) of $IC_{50}$ values fro catechin and epigallocatechin gallate as positive controls. Noteworthy, the extract of Camellia taliensis showed irreversible inhibition of the enzyme. It is suggested that extract from some natural products such as Camellia taliensis, Rheum undulatum or Euphorbia perinensis, exhibiting a potent inhibition of peroxidase activity, may be developed as sources of potent antithyroid agents.

• Korean Journal of Food Science and Technology
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• v.25 no.5
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• pp.456-460
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• 1993

The present study was conducted to investigate Angiotensin I-converting enzyme(ACE) inhibition activity of the components of traditional tea materials in Korea. Angiotensin I-converting enzyme(ACE) inhibition activity of water soluble fractions obtained from the samples were strong in Zingiberis rhizoma, Acantopanacis cortex, Schizandrae fructus, Perilla semen, Cassiae torae semen, Zizyphy fructus in order. ACE inhibition activity of fractions obtained from methanol extract of Cassiae torae semen were strong in ethyl acetate fraction, ethyl ether fraction, water fraction, chloroform fraction in order. Compound C showed the strongest ACE inhibition activity among compound A, B, C, D separated from Cassiae torae semen, but Compound C separated from Cassiae torae semen was lower than bradykinin in the ACE inhibition activity.

• Applied Biological Chemistry
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• v.41 no.8
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• pp.608-610
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• 1998

To investigate the inhibitory activity of 2-hydroxy-3-amino-4-phenylbutyrate-harboring aminopeptidase N inhibitors, p-nitro-AHPA-peptide derivatives (1 and 2) and an AHPA-peptide derivative (3) were synthesized by chain elongation from C-terminal end using DCC/HOBt as a coupling reagent. The peptides $1{\sim}3$ exerted strong inhibitory activities against aminopeptidase N with $IC_{50}$ values of 1.8, 7.3 and $24.0\;{\mu}g/ml$, respectively, and cytotoxicity on cancer cell lines in vitro.

• The Journal of Internal Korean Medicine
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• v.19 no.1
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• pp.431-441
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• 1998

This study was undertaken to determine whether Buthus exract(BTE) affects Na^+-K^+-ATPase$ activity of nervous tissues. The enzym activity was measured in synaptosomal fraction prepared from rabbit brain cortex. Na^+-K^+-ATPase$ activity was inhibited by BTE over concentration range of 0.05-0.5% in a dose-dependent manner. The enzyme activity was increased by an increase in $Na^+$ concentration from 5 to 100mM, $K^+$ concentration from 0.5 to 10mM, and $Mg^{2+}$ concentration from 0.2 to 5mM. These changes in ion concentrations did not produce any effect on the inhibitory effect of BTE on $Na^+-K^+-ATPase$ activity. An increase in ATP concentration from 0.1 to 3mM caused an increase in the enzyme activity. The inhibition of the enzyme activity by BTE were not different between two ATP concentrations. A sulfhydryl group protector DTT prevented PCMB-induced inhibition of $Na^+-K^+-ATPase$ activity, but the BTE-induced inhibition was not altered by DTT. The inhibition of enzyme activity by combination of ouabain and BTE was not different from that by Buthus alone. These results suggest that Buthus exerts inhibitory effect on $Na^+-K^+-ATPase$ activity in cerebral synaptosomes, and the action mechansim is similar to that of ouabain.

• Journal of Acupuncture Research
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• v.18 no.2
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• pp.150-160
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• 2001

Objectives ; This study was undertaken to determine whether Carthami-Flos aquacapuncture (CFA) exerts protective effect against oxidant-induced inhibition of $Na^+-K^+$-ATPase activity in cerebral synaptosomes. Methods and Results ; The enzyme activity was dependent on incubation time and enzyme protein concentrations. An oxidant t-butylhydroperoxide (tBHP) at 1 mM concentration caused a significant inhibition of $Na^+-K^+$-ATPase activity, which was prevented by addition of 0.01% CFA. tBHP inhibition and CFA protection were independent on incubation time or enzyme protein concentrations. The enzyme activity was increased by ATP in a dose dependent manner. Effects of tBHP and CFA were not affected by ATP cocentrations. tBHP (1 mM) produced a significant increase in lipid peroxidation in cerebral synaptosomes, which was prevented by 0.01% CFA. CFA decreased oxygen free radicals generated induced by the phorbol-ester in a dose-dependent manner in human neutrophil. Conclusions ; These results suggest that CFA exerts protective effect against tBHP-induced inhibition of $Na^+-K^+$-ATPase activity, which is due to by an antioxidant action resulting from a direct scavenging effect of oxygen free radicals in the cerebral synaptosomes.