• The Journal of Internal Korean Medicine
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• v.34 no.4
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• pp.375-383
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• 2013

Objectives : This study was performed to investigate the metabolic site of some medicinal herbs in the liver associated with CYP (Cytochrome P450). Methods : Cytochrome P450 is the major enzymes involved in drug metabolism and bioactivation. CYP3A4 and CYP2D6, the major CYP isoforms in humans, catalyse the major proportion of drugs available on the market. Scintillation proximity assay (SPA) is often used in studies to identify compounds that inhibit CYP3A4 and CYP2D6. 28 herbal extracts and radioisotopes were attached competitively to SPA beads, and followed by measuring the remaining radioisotopes in the medium. Erythromycin and dexamethasone, inhibitors of CYP3A4 and CYP2D6, were used as controls respectively. Results : Most of the 28 herbal extracts showed dose-dependent affinity to the CYP3A4 while some of the herbs showed affinity to the CYP2D6. Conclusions : These results suggest that most of the 28 herbal extracts are metabolized safely in the liver, combined with CYP3A4 and CYP2D6.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.149.3-150
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• 2003

CYP3A4 is the most abundant human CYP and oxidizes a diversity of substrates. including various drugs. steroids. and carcinogens. A variety of metal ions are known to affect microsomal monooxygenase activities. Effects of a series of divalent metal ions on the CYP3A4-catalyzed reaction of reconstituted system containing purified CYP3A4. NADPH-P450 reductase (NPR), and cytochrome b5 (b5) were examined. (omitted)

• Proceedings of the Korean Society of Toxicology Conference
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• 2001.05a
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• pp.143-143
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• 2001

Human cytochrome P450 (CYP or P450) 3A4 (CYP3A4) is the most abundant among P450s in human liver. We previously reported that the expression of CYP3A4 in membranes prepared from E. coli coexpressed the bicistronic construct of CYP3A4 and NADPH-P450 reductase with cytochrome b$_{*}$ (b5) was showed 20-60% higher than that in membranes from E. coli expressed only the bicistronic construct with culturing longer times (48-72h).(omitted)

• Proceedings of the Korean Society of Toxicology Conference
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• 2003.10b
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• pp.166-166
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• 2003

Cytochrome P-450 3A4 (CYP3A4) is major enzyme in human liver, the role of this is detoxification and metabolizing more than 50% clinical drugs in use. The transcription of CYP3A4 is regulated by the Pregnenolone X receptor (PXR),of which human form is Steroid and Xenobiotics receptor (SXR).(omitted)

• Biomolecules & Therapeutics
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• v.3 no.4
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• pp.245-250
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• 1995

The carbon tetrachloride($CCl_4$) has been demonstrated to have a hepatotoxic effect in human or many other species. To investigate the enzyme induction of mixed function oxygenases in liver of male Sprague-Dawley rats a single 0.1, 0.5 mι/kg dose of carbon tetrachloride were given. At 24 hr after a single dose of 0.1 mι CC1$_4$/kg weight, methanol extract of Hedera rhombea leaves was administered with 100, 500 mg/kg weight. Assays of 7-ethoxyresorufin-Ο-deethylation(EROD),7-benzyloxyresorufin-Ο-deathylation(BROD),4-nitro-phenol-UDP-glucuronosyltransferase(UDPGT), Western blot and RNA slot blot were used as representatives of the activities of cytochrome P-450 enzymes. The change of the activity of CYP1A1 form measured by EROD assay and Western analysis using 1-7-1 monoclonal antibody was not observed. The activity CYP2B1 form by BROD assay and using 2-66-3 monoclonal antibody was remarkably increased. Elevated level of CYP2B1 mRNA was shown by slot hybridization with 2B1-specific probe. Administration of methanol extract of Hedera rhombea leaves reversed the enzyme activity and the level of mRNA, which suggest the chemoprotective effect of methanol extracts of Hedera rhombea leaves to carbon tetrachloride hepatotoxlcity.

• Biomolecules & Therapeutics
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• v.17 no.4
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• pp.455-460
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• 2009

Foods of plant origin, especially fruits and vegetables, have attracted attention because of their potential benefits to human health. In this report, Rubi Fructus (RF), the dried unripe fruit of Rubus coreanus Miq (Rosaceae) and ellagic acid (EA) purified from RF were used to test their potential hepatoprotective effect against acetaminophen (AAP)-induced hepatotoxicity in rats. RF extract (RFext) and EA reduced the elevated levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) in serum and the content of lipid peroxide in liver by AAP administration, while the increment of the cellular glutathione (GSH) content and the induction of glutathione S-transferase (GST) and glutathione peroxidase (GSH-PX) which were decreased by AAP administration. RFext and EA from RFext did not affect the two major form of cytochrome P450s, cytochrome P450 2E1 (CYP2E1) and cytochrome P450 1A2 (CYP1A2), but downregulated the cytochrome P450 3A4 (CYP3A4) related to the conversion of AAP to N-acetyl-P-benzoquinone imine (NAPQI). These results suggest that RFext and EA from RF exhibit a hepatoprotective effect not only by increasing antioxidant activities but also by down-regulating CYP3A4 in the AAP-intoxicated rat.

• Biomolecules & Therapeutics
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• v.32 no.4
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• pp.474-480
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• 2024

Streptomyces avermitilis genome includes 33 genes encoding monooxygenation-catalyzing cytochrome P450 enzymes. We investigated the structure of CYP107P2 and its interactions with terpenoid compounds. The recombinant CYP107P2 protein was expressed in Escherichia coli and the purified enzyme exhibited a typical P450 spectrum upon CO-binding in its reduced state. Type-I substrate-binding spectral titrations were observed with various terpenoid compounds, including α-pinene, β-pinene, α-terpinyl acetate, and (+)-3-carene. The calculated binding affinities (Kd) ranged from 15.9 to 50.8 µM. The X-ray crystal structure of CYP107P2 was determined at 1.99 Å resolution, with a well-conserved overall P450 folding conformation. The terpenoid compound docking models illustrated that the structural interaction between monoterpenes and CYP107P2, with the distance between heme and terpenes ranging from 3.4 to 5.4 Å, indicates potential substrate binding for P450 enzyme. This study suggests that CYP107P2 is a Streptomyces P450 enzyme capable of catalyzing terpenes as substrates, signifying noteworthy advancements in comprehending a novel P450 enzyme's involvement in terpene reactions.

• Journal of fish pathology
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• v.33 no.2
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• pp.153-161
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• 2020

Cytochrome P450(CYP) gene is involved in the biotransformation of drugs and environmental pollutants. In this study, we analyzed the nucleotide sequence of the Anguilla japonica CYP1(AjCYP1) family gene and examined the relative expression of AjCYP1A, AjCYP1B and AjCYP1C1 in response to the exposure to environmental pollutants. After exposure to B[a]P 20mg/kg bw, the expression of AjCYP1 family gene increased over time. Among four tissues examined (liver, spleen, gill and kidney), AjCYP1 family gene was expressed significantly in the kidney. Compared with the control group, AjCYP1A was expressed about 5-fold at 48 hr, AjCYP1B about 6-fold at 24 hr, and AjCYP1C1 about 4-fold at 24 hr. However, after exposure to B[a]P 200mg/kg bw, AjCYP1A did not change in all tissues. On the other hand, AjCYP1B was expressed at about 4-fold at 24 hr in the spleen and 4-fold at 48 hr in the gill. Finally AjCYP1C1 was expressed 3.7-fold and 4.3-fold in the spleen and kidneys at 48 hr, respectively. Taken together, our results suggest that the expression of AjCYP1 gene in eel tissues might be used as a useful tool to assess the exposure to environmental pollutants in aquaculture system.

• Journal of Sasang Constitution and Immune Medicine
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• v.24 no.4
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• pp.84-91
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• 2012

Objectives : The purpose of this study is to investigate the inhibitory or inductive potentials of Yuldahanso-tang (YDT) and Chungsimyonja-tang (CST), herbal formulas for Taeeumin, on cytochrome P450 (CYP450) drug metabolizing enzyme. The mechanisms for the herbal formula-drug interaction has not been well reported in spite of the chance for co-administration with conventional drugs. Methods : To evaluate the interaction potential of YDT-drug or CST-drug, the fluorescence-based enzyme assays on CYP450 isozymes including CYP3A4, CYP2C19, CYP2D6 and CYP2E1 were established in vitro. The inhibitory effects of herbal formulas were characterized with $IC_{50}$ values. Results : YDT showed inhibitory effects on CYP2D6 and CYP2E1-mediated metabolism, while it exhibited week inhibition on CYP3A4 and CYP2C19 relatively. CST exerted relatively weak inhibitory effects on the four CYP450 isozymes compared to that of YDT. Conclusions : These results suggest that the herbal formula-drug interaction could be occur when YDT are co-administered with drugs mediated by CYP2D6 or CYP2E1.

• Korean Journal of Pharmacognosy
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• v.34 no.1 s.132
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• pp.86-90
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• 2003

For the determination of inhibiting cytochrome P450(CYP)3A4 activity, an improvement HPLC method was established by using a new internal standard and solvent system. Moreover, CYP3A4 amount for a optimum reaction of enzyme was determined by a comparative study with a variety concentration of enzyme. Using a established method, inhibitory effect of CYP3A4 that is drug metabolizing enzyme Investigated on EtOAc extracts of 5-class spices. As a result of experiment, EtOAc extract of white pepper (Piper nigrum L.) showed strong inhibitory activity. On a continuous experiment, the fraction 2, 4 and 5 of while pepper extract showed remarkable inhibitory activity. Pipeline, a main constituent of pepper was not included in these fraction. It is suggested that major compounds for the inhibitory activity of white pepper may be other ingredient that is not piperine.