• 대한예방한의학회지
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• 제12권1호
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• pp.73-87
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• 2008

In recent years, there has been a globally increasing application of herbal medicines and dietary supplements to treat various chronic diseases and to promote health. However, there are increasing clinical reports on the organ toxicities associated with consumption of herbal medicines. In general, most xenobiotics are metabolized by Phase I reaction(the main enzyme : cytochrome P450) and Phase II reaction. However, reactive oxygen species, free radicals and electrophils are produced inevitably during xenobiotics metabolism. These toxic species and metabolites are increased whenever the endogenous substances and enzymes for Phase II reaction not available. In addition, herbal-drug interactions are pharmacokinetic, with most actually or theoretically affecting the metabolism of the affected product by way of the cytochrome P450 enzymes. This review updated the knowledge on metabolic activation of herbal components and its clinical and toxicological implications. Also, the possible way for preventing the side-effects by herbal-medicine use was suggested.

• Plant Biotechnology Reports
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• 제5권1호
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• pp.89-103
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• 2011

Two rice varieties, viz. Nonabokra and Pokkali, have been evaluated for their responses to salinity in terms of some physiological and biochemical attributes. During the exposure to salinity (200 mM concentration of sodium chloride for 24, 48, and 72 h), a significant increase in sodium was recorded which was also concomitant with the changes of other metabolic profiles like proline, phenol, polyamine, etc. The protein oxidation was significantly increased and also varied between the two cultivars. The changes in activities of anti-oxidative enzymes under stress were significantly different to the control. The detrimental effects of salinity were also evident in terms of lipid peroxidation, chlorophyll content, protein profiles, and generation of free radicals; and these were more pronounced in Pokkali than in Nonabokra. The assessment and analysis of these physiological characters under salinity could unravel the mechanism of salt responses revealed in this present study and thus might be useful for selection of tolerant plant types under the above conditions of salinity.

• Toxicological Research
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• 제30권1호
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• pp.33-38
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• 2014

The human cytochrome P450 2J2 catalyzes an epoxygenase reaction to oxidize various fatty acids including arachidonic acid. In this study, three recombinant enzyme constructs of P450 2J2 were heterologously expressed in Escherichia coli and their P450 proteins were successfully purified using a $Ni^{2+}$-NTA affinity column. Deletion of 34 amino acid residues in N-terminus of P450 2J2 enzyme (2J2-D) produced the soluble enzyme located in the cytosolic fraction. The enzymatic analysis of this truncated protein indicated the typical spectral characteristics and functional properties of P450 2J2 enzyme. P450 2J2-D enzymes from soluble fraction catalyzed the oxidation reaction of terfenadine to the hydroxylated product. However, P450 2J2-D enzymes from membrane fraction did not support the P450 oxidation reaction although it displayed the characteristic CO-binding spectrum of P450. Our finding of these features in the N-terminal modified P450 2J2 enzyme could help understand the biological functions and the metabolic roles of P450 2J2 enzyme and make the crystallographic analysis of the P450 2J2 structure feasible for future studies.

• BMB Reports
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• 제47권7호
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• pp.361-368
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• 2014

Lipid components in biological membranes are essential for maintaining cellular function. Phosphoinositides, the phosphorylated derivatives of phosphatidylinositol (PI), regulate many critical cell processes involving membrane signaling, trafficking, and reorganization. Multiple metabolic pathways including phosphoinositide kinases and phosphatases and phospholipases tightly control spatio-temporal concentration of membrane phosphoinositides. Metabolizing enzymes responsible for PI 4,5-bisphosphate (PI(4,5)P2) production or degradation play a regulatory role in Toll-like receptor (TLR) signaling and trafficking. These enzymes include PI 4-phosphate 5-kinase, phosphatase and tensin homolog, PI 3-kinase, and phospholipase C. PI(4,5)P2 mediates the interaction with target cytosolic proteins to induce their membrane translocation, regulate vesicular trafficking, and serve as a precursor for other signaling lipids. TLR activation is important for the innate immune response and is implicated in diverse pathophysiological disorders. TLR signaling is controlled by specific interactions with distinct signaling and sorting adaptors. Importantly, TLR signaling machinery is differentially formed depending on a specific membrane compartment during signaling cascades. Although detailed mechanisms remain to be fully clarified, phosphoinositide metabolism is promising for a better understanding of such spatio-temporal regulation of TLR signaling and trafficking.

• 한국균학회지
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• 제23권1호통권72호
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• pp.86-91
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• 1995

Rhizopus oryzae의 카드뮴 적응 및 해독기작과 이에 관련된 세포내 생리 생화학적 변화를 조사하였다. R. oryzae는 카드뮴을 첨가 배양하였을 때 카드뮴 영향하에서는 carbohydrate metabolic pathway에 관련된 효소 활성(MDH, GPI)이 촉진되고 과산화물 제거에 관여하는 효소가 새롭게 유도(CAT2)된 반면, lactate를 이용하는 효소(LDH, ADH)의 활성이 감소된 사실은 중금속 영향하에서 세포의 성장과 에너지 공급을 위해 에너지 수율이 낮은 lactate를 이용하는 경로보다는 에너지 수율이 높은 TCA cycle 경로에 작용하는 효소들과 독성과산화물 제거에 관여하는 효소의 더 많은 derepression이 필요하다는 것을 알 수 있었다.

• BMB Reports
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• 제49권6호
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• pp.349-354
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• 2016

The archaeon Sulfolobus solfataricus P1 carboxylesterase is a thermostable enzyme with a molecular mass of 33.5 kDa belonging to the mammalian hormone-sensitive lipase (HSL) family. In our previous study, we purified the enzyme and suggested the expected amino acids related to its catalysis by chemical modification and a sequence homology search. For further validating these amino acids in this study, we modified them using site-directed mutagenesis and examined the activity of the mutant enzymes using spectrophotometric analysis and then estimated by homology modeling and fluorescence analysis. As a result, it was identified that Ser151, Asp244, and His274 consist of a catalytic triad, and Gly80, Gly81, and Ala152 compose an oxyanion hole of the enzyme. In addition, it was also determined that the cysteine residues are located near the active site or at the positions inducing any conformational changes of the enzyme by their replacement with serine residues.

• 대한의생명과학회지
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• 제22권2호
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• pp.53-59
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• 2016

Alcoholism is a significant health problem in the world. The liver is the first and primary target organ for alcohol metabolism. Alcohol dehydrogenase and aldehyde dehydrogenase play important roles in the metabolism of alcohol and aldehyde. In this study, I aimed to investigate the eliminatory effects of a Phellinus spp. extract on alcohol metabolism in drunken Sprague-Dawley (SD) rats. Male SD rats were given Phellinus spp. extract at 30 min after 40% (5 g/kg) alcohol ingestion. To assay the effect of Phellinus spp. extract on blood alcohol concentration, blood samples were taken from the tail vein at 1, 3 and 5 h after alcohol ingestion. The concentrations of alcohol, alcohol dehydrogenase, and aldehyde dehydrogenase in Phellinus spp. extract treated rat were significantly lower than that of the control with a time-dependent manner. In addition, the alanine aminotransferase and aspartate aminotransferase activities of Phellinus spp. extract-treated groups were altered compared to those of the control group. These results suggest that Phellinus spp. extract intake can have a positive effect on the reduction of alcohol, alcohol dehydrogenase, and aldehyde dehydrogenase concentrations in the blood and may alleviate acute alcohol-induced hepatotoxicity by altering alcohol metabolic enzyme activities. Phellinus spp. extract is thus a good nutraceutical candidate.

• 대한의생명과학회지
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• 제20권3호
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• pp.124-128
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• 2014

Alcoholism is a significant global health problem. Alcohol dehydrogenase and aldehyde dehydrogenase play important roles in the metabolism of alcohol and aldehyde. In this study, we aimed to investigate the eliminatory effects of a fruit extract drink on alcohol metabolism in drunken Sprague-Dawley (SD) rats. Male SD rats were given a fruit extract drink or a commercial product (10 mL/kg) 30 min prior to 40% (5 g/kg) ethanol ingestion. To assay the effect of the fruit extract drink on blood ethanol concentration, blood samples were taken from the saphenous vein at 3 and 5 h after ethanol ingestion. The blood concentrations of alcohol, alcohol dehydrogenase, and aldehyde dehydrogenase were significantly lower in the fruit extract drink group than in the control group, in a time-dependent manner. However, the alanine aminotransferase and aspartate aminotransferase activities of all experimental groups were unaltered compared to those of the control group. These results suggested that fruit extract drink intake can have a positive effect on the reduction of alcohol, alcohol dehydrogenase, and aldehyde dehydrogenase concentrations in the blood and may alleviate acute ethanol-induced hepatotoxicity by altering alcohol metabolic enzyme activities.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1994년도 제2회 추계심포지움
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• pp.135-140
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• 1994

Over past decades, numerous in vitro model has been developed to investigate drug metabolism. In the order of complexity we found the isolated perfused liver, hepatocytes in co-culture with epithelial cells, hepatocytes in suspension and in primary culture and subcellular hepatic microsomal fractions. Because they can be easily prepared from both animals (pharmacological and toxicological species) and humans (whole livers as well as biopsies obtained during surgery) hepatocytes in primary culture provide the most powerful model to better elucidate drug behavior at an early stage of preclinical development such as : 1. the characterization of main biotransformation reactions. 2. the identification of phase I and phase II isozymes involved in such reactions 3. the evaluation of interspecies differences allowing the selection of a second toxicological animal species more closely related to man on the basis of metabolic profiles 4. the detection of the inducing and/or inhibitory effects of a drug on metabolic enzymes, the prediction of drug interactions 5. the estimation of inter-individual variability in biotransformation reactions. The use of hepatocytes, and in particular those obstained from humans, at an early stage of drug development allows the obtention of more predictive preclinical data and a better knowledge of drug behavior in humans before the first administration of the drug in healthy volunteers.

• 식물조직배양학회지
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• 제24권4호
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• pp.233-238
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• 1997

Salicylic acid (SA) is involved in the establishment of systemic acquired resistance (SAR) in many plant including tobacco. Considering the important role of SA in disease resistance, biosynthetic and metabolic pathways of SA in tobacco have been studied extensively: The initial step for biosynthetic pathway of SA is conversion of phenylalanine to trans-cinnamic acid, followed by decarboxylation of trans-cinnamic acid to benzoic acid and ie subsequent ring hydroxylation at the C-2 position to form SA. In TMV inoculated tobacco, most of the newly synthesized SA is glucosylated or methylated. Methyl salicylate has been identified as a biologically active, volatile signal. In contrast, the two glucosylated forms accumulate in the vicinity of lesions and consist of SA glucoside, a major metabolite, and SA glucose ester, a relatively minor from. Two enzymes involved in SA biosynthesis and metabolism have been purified and characterized : benzoic acid 2-hydroxylase which catalyzes conversion of benzoic acid to SA; UDP-Glucose: SA 1-O-D glucosyltransferase which converts SA to SA glucose ester. Further studies of the biosynthetic and metabolic pathways of SA will help to elucidate the SAR signal transduction pathway and provide potential tools for the manipulation of disease resistance.