• Food Science and Biotechnology
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• 제18권5호
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• pp.1186-1192
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• 2009

The purpose of this study was to evaluate the protective effects of Chlorella vulgaris extract (CVE) against carbon tetrachloride ($CCl_4$)-induced hepatotoxicity in mice. The mice received silymarin (100 mg/kg), intragastrieally (i.g.) and CVE (50, 100, and 200 mg/kg, i.g.), respectively, every other day, for 4 weeks before $CCl_4$ administration. Twenty-four hr after the administration of $CCl_4$, the serum and liver were analyzed. Our study found that in the CVE groups, aspartate aminotransferase (AST), and alanine aminotransferase (ALT) levels had decreased significantly and the tissue injury was notably diminished compared to the $CCl_4$ group. The antioxidant activities of CVE groups, such as superoxide dismutase (SOD), catalase, and glutathione (GSH), were significantly increased and the activity of nitric oxide synthase (NOS) was remarkably increased in a CVE concentration-dependent manner. In the CVE groups, cytochrome P450 2B1/2B2 (CYP2B1/2) content was decreased. These results indicate that CVE has protective effects against $CCl_4$-induced hepatotoxicity via stimulation of the antioxidant activity and nitric oxide (NO) production, and through inhibition of CYP2B1/2.

• Journal of Ginseng Research
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• 제42권3호
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• pp.370-378
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• 2018

Background: Ginseng has been the subject of many experimental and clinical studies to uncover the diverse biological activities of its constituent compounds. It is a traditional medicine that has been used for its immunostimulatory, antithrombotic, antioxidative, anti-inflammatory, and anticancer effects. Ginseng may interact with concomitant medications and alter metabolism and/or drug transport, which may alter the known efficacy and safety of a drug; thus, the role of ginseng may be controversial when taken with other medications. Methods: We extensively assessed the effects of Korean Red Ginseng (KRG) in rats on the expression of enzymes responsible for drug metabolism [cytochrome p450 (CYP)] and transporters [multiple drug resistance (MDR) and organic anion transporter (OAT)] in vitro and on the pharmacokinetics of two probe drugs, midazolam and fexofenadine, after a 2-wk repeated administration of KRG at different doses. Results: The results showed that 30 mg/kg KRG significantly increased the expression level of CYP3A11 protein in the liver and 100 mg/kg KRG increased both the mRNA and protein expression of OAT1 in the kidney. Additionally, KRG significantly increased the mRNA and protein expression of OAT1, OAT3, and MDR1 in the liver. Although there were no significant changes in the metabolism of midazolam to its major metabolite, 1'-hydroxymidazolam, KRG significantly decreased the systemic exposure of fexofenadine in a dose-dependent manner. Conclusion: Because KRG is used as a health supplement, there is a risk of KRG overdose; thus, a clinical trial of high doses would be useful. The use of KRG in combination with P-glycoprotein substrate drugs should also be carefully monitored.

• 한국발생생물학회지:발생과생식
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• 제11권3호
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• pp.195-203
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• 2007

자웅이체형 어류의 성결정 및 성분화는 일반적으로 각 개체의 유전형을 따른다. 자연환경에서는 자신이 가진 유전정보의 조절에 따라 성분화 시기에 아로마테이즈 유전자의 발현이 증가하거나 감소하고, 그 결과 스테로이드 호르몬들의 조성이 결정되어 각기 다른 방향으로 성분화하는 것으로 알려져 있다. 본 연구에서는 해산 태생 어류인 조피볼락(Sebasts schlegeli)의 ovarian type aromatase (P450aromA)와 brain type aromatase (P450aromB)의 유전자를 부분적으로 클로닝하여, 이들의 염기서열을 밝혔으며, 각 유전자에 대한 primer를 제작한 후 성분화 기간 중 이 유전자들의 발현을 조사하였다. 조피볼락 아로마테이즈 유전자들은 조사를 시작한 출산 후 35일째에 여러 개체의 머리와 몸에서 각각 발현되었으나, 52일째에는 아로마테이즈 유전자들의 발현 개체수가 현저히 감소하였다. 그리고 출산 59일째에는 발현 개체 수가 다시 증가하였다. P450aromA과 P450aromB의 발현 양상은 전반적으로 유사하였으나, 45일째에는 P450aromB의 발현 개체수가 P450aromA 발현 개체 수보다 훨씬 많았다. 조직학적 분석을 통해 제시된 이 종의 성분화 시기는 지금까지 출산 $50{\sim}65$일 전후로 알려져 왔으나, 본 연구에서 나타난 아로마테이즈 유전자들의 발현 결과를 볼 때, 이 종의 실질적인 성분화는 알려진 것보다 최소한 $1{\sim}2$주 정도 빨리 진행될 가능성이 있다. 본 연구의 결과는 또한 태생어류의 성분화도 난생어류의 성분화에서 보고된 것과 마찬가지로 아로마테이즈의 작용과 밀접하게 연관되어 있다는 사실을 시사한다.

• Journal of Microbiology and Biotechnology
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• 제29권1호
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• pp.44-54
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• 2019

Geldanamycin and its derivatives, inhibitors of heat shock protein 90, are considered potent anticancer drugs, although their biosynthetic pathways have not yet been fully elucidated. The key step of conversion of 4,5-dihydrogeldanamycin to geldanamycin was expected to catalyze by a P450 monooxygenase, Gel16. The adequate bioconversions by cytochrome P450 mostly rely upon its interaction with redox partners. Several ferredoxin and ferredoxin reductases are available in the genome of certain organisms, but only a few suitable partners can operate in full efficiency. In this study, we have expressed cytochrome P450 gel16 in Escherichia coli and performed an in vitro assay using 4,5-dihydrogeldanamycin as a substrate. We demonstrated that the in silico method can be applicable for the efficient mining of convenient endogenous redox partners (9 ferredoxins and 6 ferredoxin reductases) against CYP Gel16 from Streptomyces hygroscopicus. The distances for ligand FDX4-FDR6 were found to be $9.384{\AA}$. Similarly, the binding energy between Gel16-FDX4 and FDX4-FDR6 were -611.88 kcal/mol and -834.48 kcal/mol, respectively, suggesting the lowest distance and binding energy rather than other redox partners. These findings suggest that the best redox partners of Gel16 could be NADPH ${\rightarrow}$ FDR6 ${\rightarrow}$ FDX4 ${\rightarrow}$ Gel16.

• 한국임상약학회지
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• 제18권2호
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• pp.120-123
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• 2008

The purpose of this study was to investigate the effect of naringin, one of flavonoids, on the pharmacokinetics and bioavailability of nimodipine in rabbits. Pharmacokinetic parameters of nimodipine were determined in rabbits after oral administration of nimodipine (16 mg/kg) with or without naringin (1, 5 or 15 mg/kg). Nimodipine was analyzed by high performance liquid chromatography using Hypersil ODS column. Naringin significantly (p<0.05) increased the area under the plasma concentration-time curve (AUC) and the peak concentration ($C_{max}$) of nimodipine at 5 and 15 mg/kg. The absolute bioavailability (AB%) of nimodipine by prescence of naringin (5 or 15 mg/kg) increased from 32.2-36.9% (p<0.05) compared to the control (22.0%). However, presence of naringin had no significant effect on the elimination rate constant ($K_{el}$) of nimodipine. There were no apparent changes of the time of peak concentration ($T_{max}$) of nimodipine by coadministration. These results suggest that the increased bioavailability and the significant changes of these pharmacokinetic parameters of nimodipine by naringin may be attributed to the potential of narigin to inhibit cytochrome P450 (CYP) 3A4 and P-glycoprotein efflux pump in the liver and intestinal mucosa.

• Molecular & Cellular Toxicology
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• 제4권3호
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• pp.199-204
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• 2008

The bio-molecules involved in defense mechanisms can be used as efficient biomarkers for physiological changes in organisms caused by both of internal and external stress. Thus, the expression level of genes which encoding such molecules serve as critical 'early warning system' for environmental assessment as well as health diagnosis of biological organisms. In this study, Cytochrome P450, Heat shock protein 90, Ubiquitin and ${\beta}$-actin gene were isolated for the first time from a red alga Gracilaria textorii. The quantitative differential gene expression analyses of three genes, GteCYP1A, GteHsp90 and Gte-UB, were carried out in G. textorii sporophytes collected from two different localities, polluted Sujeong (Masan, Korea) and potentially unpolluted Danggeum (Daemaemuldo Is., Korea). The transcripts of all three tested genes were highly expressed in the Sujeong population. The results suggest: 1) the Sujeong site was more polluted than the Danggeum site; 2) G. textorii could be applicable to marine environment monitoring in coastal regions.

• 대한한방내과학회지
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• 제32권2호
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• pp.188-202
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• 2011

Objectives : Oxidative stress seems to play a major role in mechanisms by which ethanol causes liver injury. Previous studies have shown that treatment with Chungganhaeju-tang (Qingganjiejiu-tang, CGHJT) has protective effects on alcoholic liver disease. The aim of this study was to investigate the effects of Chungganhaeju-tang on oxidative stress. Materials and Methods : In vitro, we evaluated the inhibitory activities of CGHJT on DPPH (1,1-diphenyl-2-picryl-hydrazyl), xanthine oxidase, trypsin, and hyaluronidase, and measured cell viability, and proliferation. In the cell culture model, we measured the activities of superoxide dismutase (SOD), and catalase (CAT) after CGHJT treatment in C34 and E47 cell lines, HepG2 cells transfected with/without the cytochrome P450 2E1 (CYP2E1) gene. In vivo, we measured malondialdehyde levels in the liver tissue and alcohol concentration in the blood. Results : CGHJT showed significant free radical scavenging activity against DPPH and xanthine oxidase in the in vitro study, and increased cell viability, proliferation, and activities of superoxide dismutase, catalase in C34 and in E47 cell lines. CGHJT reduced malondialdehyde levels and blood alcohol concentration in vivo, as well. Conclusions : This study suggests that CGHJT has antioxidant effects on oxidative stress by reducing lipid peroxidation and inhibiting the ethanol induced suppression of antioxidant enzyme activities.

• Journal of Pharmaceutical Investigation
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• 제38권5호
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• pp.313-317
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• 2008

This study investigated the effect of naringin, a flavonoid, on the bioavailability of etoposide administered orally to rats. Etoposide (6 mg/kg) was administered orally to rats alone or with naringin (1, 4 or 12 mg/kg). Compared with the control group, the co-administration of etoposide with 4 and 12 mg/kg of naringin significantly (p<0.05) increased the area under the plasma concentration-time curve (AUC) and the peak plasma concentration ($C_{max}$) of the oral etoposide. Consequently, the absolute bioavailability (AB) of etoposide in the presence (4 and 12 mg/kg) of naringin was significantly (p<0.05) increased by $9.4{\sim}10.6%$ compared with the control group (7.4%). The relative bioavailability (RB) of etoposide was increased 1.13- to 1.44-fold compared to the control group. Enhanced bioavailability of etoposide might be due to inhibition of both cytochrome P450 (CYP) 3A4 in the intestine or liver and P-glycoprotein (P-gp) transport efflux of etoposide in the intestinal membrane. This data indicate that careful consideration of the dosage for therapy with etoposide is required in a case of clinical application of the co-administration of etoposide and naringin.

• Clinical and Experimental Pediatrics
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• 제48권5호
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• pp.476-480
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• 2005

Immunosuppressive therapy in pediatric renal transplant recipients is changing consequence of the increasing number of available immunosuppressive agents. The optimal use of immunosuppressive agents requires a thorough understanding of the pharmacokinetic characteristics, but the information on the pharmacokinetic characteristics of these drugs in pediatric transplant recipients is still limited. In general, patients younger than 5 years old show higher clearance rates, therefore the need for higher dosages in younger patients seems evident. By the therapeutic drug monitoring, trough($C_{min}$) and peak level($C_{max}$) are measured and the area under the blood concentration-time curve(AUC), which is taken as being representative of total systemic exposure can be calculated. Cyclosporine A (CSA) has poor bioavailability, which contributes to high inter- and intra-patient pharmacokinetic variability. CSA concentration measured 2 hours after administration($C_2$) has better correlation with the AUC than $C_{min}$ and is an alternative technique that predicts the AUC. Tacrolimus(Tac) has a great deal of inter-individual variability like CSA but intra-individual variability in systemic exposure is considered to be low. Both CSA and Tac are metabolized by a cytochrome P-450 enzyme isoform(CYP3A4). We should consider changing the dosages when CSA or Tac is used in combination with the medicines that inhibit or induce the CYP3A4. In case of steroid-free immunosuppressive therapy, the blood concentration of Tac should be frequently checked and dosage adjustment may be needed.

• Journal of Pharmaceutical Investigation
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• 제39권4호
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• pp.243-248
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• 2009

The purpose of this study was to investigate the effects of morin, an antioxidant, on the bioavailability of doxorubicin (DOX) in rats. Thus, DOX was administered intravenously (10 mg/kg) or orally (50 mg/kg) with or without oral morin (0.5, 3 and 10 mg/kg). In the presence of morin, the total area under the plasma concentration-time curve (AUC) of DOX was significantly greater than that of the control. In the presence of 3 and 10 mg/kg of morin, the peak concentration $C_{MAX}$) was significantly higher than that of the control. Consequently, the absolute bioavailability (AB) of DOX in the presence of morin was 3.7-8.3%, which was significantly enhanced compared with those of the control group (2.7%). The relative bioavailability (RB) of DOX was 1.36 to 3.02 times higher than those of the control group. Compared to the intravenous control, the presence of morin increased the AUC of DOX, but was not significantly affected. The enhanced bioavailability of oral DOX by oral morin may be due to the inhibition of both P-glycoprotein (P-gp) and cytochrome P450 (CYP) 3A in the intestine and/or liver by morin. This result may suggest that the development of oral DOX combination with morin is feasible, which is more convenient than the i.v. dosage forms. The present study raised the awareness about the potential drug interactions by concomitant use of DOX with morin.