• Nutrition Research and Practice
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• v.8 no.6
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• pp.632-637
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• 2014

BACKGROUND/OBJECTIVES: The purpose of the current study was to investigate the effect of red pericarp glutinous rice rich in polyphenols (Jakwangchalbyeo, red rice) on serum and hepatic levels of cholesterol and hepatic protein expression linked to synthesis and degradation of cholesterol in a hypercholesterolemic mice diet as compared with brown rice. MATERIALS/METHODS: C57BL/6 male mice were randomly divided into four groups (n = 5 each), which were fed different diets for a period of 12 weeks: American Institute of Nutrition (AIN)-93G diet, AIN-93G diet with 2% cholesterol, brown rice with 2% cholesterol, or red rice with 2% cholesterol. RESULT: Consumption of red rice resulted in a significant decrease in serum level of low-density lipoprotein cholesterol and hepatic levels of triglyceride and total-cholesterol. Expression of acyl-coenzyme A cholesterol acyltransferase-2 (ACAT-2), sterol regulatory element binding protein-2 (SREBP-2), and 3-hydroxyl-3-methylglutaryl coenzyme A (HMG-CoA) reductase was decreased, while expression of phosphorylated adenosine monophosphate activated protein kinase (p-AMPK)/AMPK ratio, cholesterol 7-${\alpha}$-hydroxylase (CYP7a1), and sterol 12-${\alpha}$-hydroxylase (CYP8b1) was increased in mice fed red rice. Brown rice had similar effects on cholesterol metabolism, but the effect of red rice was significantly greater than that of brown rice. CONCLUSIONS: The current study suggested that red rice had a hypocholesterolemic effect by lowering hepatic cholesterol synthesis through ACAT-2, HMG-CoA reductase, and SREBP-2, and by enhancing hepatic cholesterol degradation through CYP7a1 and CYP8b1 in mice fed a hypercholesterolemic diet.

• Journal of Microbiology and Biotechnology
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• v.30 no.11
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• pp.1750-1759
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• 2020

The characterization of cytochrome P450 CYP125A13 from Streptomyces peucetius was conducted using cholesterol as the sole substrate. The in vitro enzymatic assay utilizing putidaredoxin and putidaredoxin reductase from Pseudomonas putida revealed that CYP125A13 bound cholesterol and hydroxylated it. The calculated K_D value, catalytic conversion rates, and Km value were 56.92 ± 11.28 μM, 1.95 nmol min^-1 nmol^-1, and 11.3 ± 2.8 μM, respectively. Gas chromatography-mass spectrometry (GC-MS) analysis showed that carbon 27 of the cholesterol side-chain was hydroxylated, characterizing CYP125A13 as steroid C27-hydroxylase. The homology modeling and docking results also revealed the binding of cholesterol to the active site, facilitated by the hydrophobic amino acids and position of the C27-methyl group near heme. This orientation was favorable for the hydroxylation of the C27-methyl group, supporting the in vitro analysis. This was the first reported case of the hydroxylation of cholesterol at the C-27 position by Streptomyces P450. This study also established the catalytic function of CYP125A13 and provides a solid basis for further studies related to the catabolic potential of Streptomyces species.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2001.11a
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• pp.109-109
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• 2001

The present study was done to investigate the relationship between Kupffer cells and alteration of cytochrome P-450 (CYP)-dependent drug metabolizing enzyme activities during polymicrobial sepsis. Male rats were subjected to polymicrobial sepsis by cecal ligation and puncture (CLP) followed by fluid resuscitation. The gadolinium chloride (GdC1$_3$, 10 mg/kg), blocker of Kupffer cells, was pretreated intravenously at 48 h and 24 h prior to the induction of CLP. All assay parameters were determined at 24 h after CLP or sham operation. In CLP-treated rats, the mortality rate of animals increased to 50% and serum alanine (ALT) and aspartate aminotransferase (AST) levels also significantly elevated. However, this increase was not suppressed by GdC1$_3$ pretreatment. Microsomal lipid peroxidation markedly increased after CLP operation. This increase was significantly attenuated by pretreatment. Total cytochrome P-450 content and NADPH-cytochrome P-450 reductase activity were not changed after CLP operation, but GdC1$_3$pretreatment reduced total cytochrome P-450 content, The hepatic microsomal CYP 1A1, 1A2, 2Bl and 2El activities in CLP-induced rats were also not significantly different from sham-operated rats. However, GdC1$_3$pretreatment showed a moderate increase in CYP1A1 and 1A2 activities. Our findings suggest that Kupffer cells may be partly responsible for producing hepatocellular dysfunction during sepsis.

• Journal of Pharmaceutical Investigation
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• v.41 no.5
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• pp.301-307
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• 2011

The aim of this study was to investigate the effects of kaempferol on the pharmacokinetics of nimodipine in rats. Nimodipine and kaempferol interact with cytochrome P450 (CYP) enzymes and P-glycoprotein (P-gp), and the increase in the use of health supplements may result in kaempferol being taken concomitantly with nimodipine as a combination therapy to treat orprevent cardiovascular disease. The effect of kaempferol on P-gp and CYP3A4 activity was evaluated and Pharmacokinetic parameters of nimodipine were determined in rats after an oral (12 mg/kg) and intravenous (3 mg/kg) administration of nimodipine to rats in the presence and absence of kaempferol (0.5, 2.5, and 10 mg/kg). Kaempferol inhibited CYP3A4 enzyme activity in a concentration-dependent manner with 50% inhibition concentration ($IC_{50}$) of $17.1{\mu}M$. In addition, kaempferol significantly enhanced the cellular accumulation of rhodamine-123 in MCF-7/ADR cells overexpressing P-gp. Compared to the oral control group, the area under the plasma concentration-time curve ($AUC_{0-\infty}$) and the peak plasma concentration ($C_{max}$) of nimodipine significantly increased, respectively. Consequently, the absolute bioavailability of nimodipine in the presence of kaempferol (2.5 and 10 mg/kg) was 29.1-33.3%, which was significantly enhanced compared to the oral control group (22.3%). Moreover, the relative bioavailability of nimodipine was 1.30- to 1.49-fold greater than that of the control group. The pharmacokinetics of intravenous nimodipine was not affected by kaempferol in contrast to those of oral nimodipine. Kaempferol significantly enhanced the oral bioavailability of nimodipine, which might be mainly due to inhibition of the CYP3A4-mediated metabolism of nimodipine in the small intestine and /or in the liver and to inhibition of the P-gp efflux transporter in the small intestine by kaempferol. The increase in oral bioavailability of nimodipine in the presence of kaempferol should be taken into consideration of potential drug interactions between nimodipine and kaempferol.

• Mass Spectrometry Letters
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• v.8 no.4
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• pp.98-104
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• 2017

Ginseng (Panax ginseng Meyer) is a well-known health functional food used as a traditional herbal drug in Asian countries owing to its diverse pharmacological effects. Herb-drug interactions may cause unexpected side effects of co-administered drugs by the alteration of pharmacokinetics through effects on cytochrome P450 activity. In this study, we investigated the herb-drug interactions between Korean red ginseng extract (KRG) and five CYP-specific probes in mice. The pharmacokinetics of KRG extract induced-drug interactions were studied by cassette dosing of five CYP substrates for CYP1A, 2B, 2C, 2D, and 3A and the LC-MS/MS analysis of the blood concentration of metabolites of each of the five probes. The linearity, precision, and accuracy of the quantification method of the five metabolites were successfully confirmed. The plasma concentrations of five metabolites after co-administration of different doses of the KRG extract (0, 0.5, 1, and 2 g/kg) were quantified by LC-MS/MS and dose-dependent pharmacokinetic parameters were determined. The pharmacokinetic parameters of the five metabolites were not significantly altered by the dose of the KRG extract. In conclusion, the single co-administration of KRG extract up to 2 g/kg in vivo did not cause any significant herb-drug interactions linked to the modulation of CYP activity.

• Molecular & Cellular Toxicology
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• v.3 no.3
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• pp.195-197
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• 2007

Currently praziquantel is used for treatment of not only clonorchiasis but also other trematodes and cestodes. But cure rate of praziquantel is just 60-80% for most trematodes. It needs for the treatment-failed patients to have more drugs. The cause of failure of treatment is not studied. We just know that the blood level of praziquantel is severely different among the people. We guess that this factor may influence the results of treatment. In an endemic area of human clonorchiasis in Heilongjiang Providence, China, 78 subjects were selected for the study. Three doses of 25 mg/kg (total 75 mg/kg) of praziquantel were administered to 78 clonorchiasis patients. After three weeks of treatment, stool examination was undertaken once again to confirm the cured and uncured subjects. To analyze SNP (single nucleotide polymorphism) of CYP3A5 PS2-1, CYP3A5 PS2-2, and CYP3A5*6, PCR method was done with specifically designed primers. The mutation rates of all sites were not significant statistically. The number of subjects was too small, so we need more subjects and other delivery proteins of bile ducts (ex. MRP etc.) were also considered for effects of praziquantel. We analyzed, for the first time, the entire CYP3A5 gene in a French population, using a polymerase chain reaction- single strand conformational polymorphism (PCR-SSCP) strategy.

• Environmental Analysis Health and Toxicology
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• v.19 no.4
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• pp.335-344
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• 2004

Diesel exhaust particle (<2.5 ${\mu}{\textrm}{m}$, DEP$_{2.5}$) is known to be probarbly carcinogenic (IARC group 2A). DEP$_{2.5}$ contains organic compounds such as polycyclicaromatic hydrocarbon (PAH), heterocyclic compounds, phenols, and nitroarenes. Reactive oxygen species (ROS) are generated by DEP$_{2.5}$ without any biological activation system. Therefore, an alternative mechanism by which DEP$_{2.5}$ could be carcinogenic is known by the generation of oxidative DNA damage. The aim of this study was to investigate genotoxic effects of DEP$_{2.5}$ using single cell gel electrophoresis. In order to evaluate the mechanisms of DEP$_{2.5}$ genotoxicity, the rat micro-some mediated and DNA repair enzyme treated comet assays together with routine comet assay were performed. DEP$_{2.5}$ was collected from diesel engine bus and dichloromethane extract was obtained. The organic extract of DEP$_{2.5}$ revealed DNA damage itself in NIH/3T3 cells. And it showed both oxidative and microsome mediated DNA damages. Vitamin C as an model antioxidant reduced DNA damage in endonuclase III treated comet assay. One of flavonoid, galangin as a CYP1A1 inhibitor reduced DNA damage in the presence of S-9 mixture. Our results show that DEP$_{2.5}$ are genotoxic and a great source of oxidative stress, but antioxidants can significantly reduce oxidative DNA damages. And DEP$_{2.5}$ may contain indirect mutagens which can be inhibited by CYP inhibitors.d by CYP inhibitors.

• Toxicological Research
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• v.23 no.2
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• pp.135-142
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• 2007

Formononetin is an isoflavonoid phytoestrogen found in certain foodstuffs such as soy and red clover. In this study, we examined the action of formononetin with the carcinogen activation pathway mediated through the aryl hydrocarbon receptor (AhR) in MCF-7 breast carcinoma cells. Treating the cells with formononetin alone caused the accumulation of CYP1A1 mRNA as well as elevation in CYP1A1-specific 7-ethoxyresorufin O-deethylase (EROD) activity in a dose dependent manner. However, a concomitant treatment with 7,12-dimethylbenz[a]anthracene (DMBA) and formononetin markedly reduced both the DMBA-inducible EROD activity and CYP1A1 mRNA level. Under the same conditions, formononetin inhibited the DMBA-induced AhR transactivation, as shown by reporter gene analysis using a xenobiotic responsive element (XRE). Additionally, formononetin inhibited both DMBA-inducible nuclear localization of the aryl hydrocarbon receptor (AhR) and metabolic activation of DMBA, as measured by the formation of the DMBA-DNA adducts. Furthermore, formononetin competed with the prototypical AhR ligand, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), for binding to the AhR in an isolated rat cytosol. These results suggest that formononetin might be considered as a natural ligand to bind on AhR and consequently produces a potent protective effect against DMBA-induced genotoxicity. Therefore, that's the potential to act as a chemopreventive agent that is related to its effect on AhR pathway as antagonist/agonist.

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.1
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• pp.155-161
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• 2008

Carbon tetrachloride $(CCl_4)-induced$ liver injury depends on a toxic agent that has to be metabolized by the liver NAPDH-cytochrome P450 enzyme system to a highly reactive intermediate. Although several isoforms of cytochrome P450 may metabolize $CC1_4$, attention has been focused largely on the cytochrome P450 2E1 (CYP2E1), which is ethanol-inducible. Alternations in the activity of CYP2E1 affect the susceptibility to hepatic injury from $CC1_4$. In this study, the liver protective effect of the hot water extracts of Scutellaria radix (SR) was investigated. The SR exhibited a hepatoprotective activity against $CCl_4-induced$ liver damage in Chang liver cells. The expression of CYP2E1, measured by RT-PCR and Western blot analysis, was significantly decreased by SR treatment in Chang cells. Based on these findings, it is suggested that hepatoprotective effect of SR possibly related to downregulation of CYP2E1 expression.

• YAKHAK HOEJI
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• v.43 no.6
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• pp.827-833
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• 1999

In this study, we have investigated the effect of Biphenyl Dimethyl Dicarboxylate (DDB), a synthetic analogue of Schizandrin C isolated from Schizandrae Fructus on cytochrome $P_450$ lAl and 2Bl, and the protective mechanism against $CCl_4-induced$ hepatotoxicity in rat liver. After DDB was administered into male rats for different periods of time (1~7 days) and with different doses (25, 50, 100 and 200 mg/kg), mRNA levels of CYPlAl were measured by polymearse chain reaction (PCR) and assayed the activities of CYPlAl specific ethoxyresorufin-O-dealkylase (EROD) and CYP2Bl specific benzyloxyresorufin-O-dealkylase (BROD). DDB treatment resulted in increase in CYP2Bl mRNA level and BROD activity, whereas there was no change in CYPlAl mRNA level and EROD activity. This effect of DDB was time-and dose-dependent and reached maximal level by 3 day and 200 mg/kg treatment. In addition, rats were pre-treated with DDB at doses of 25, 50 or 100 mg/kg daily for 4 days, 3-hr after final treatment on the 4th day, $CCl_4$ 0.3ml/kg was intraperitonially injected into the rats to examine the effect of DDB on $CCl_4-induced$ hepatic injury. Serum levels of ALT and AST were determined and histopathological examination was done in rat liver. Furthermore, we have measured hepatic microsomal malondialdehyde(MDA) level, a parameter of lipid peroxidation. Based on serum ALT level and lipid peroxidation, pretreatment of DDB, 50 mg/kg appeared the most protective effect against $CCl_4-induced$ heapatotoxity. These results indicate that DDB stimulates CYP2Bl mRNA level and BROD activity in time and dose dependent manner and suggest that protective effect of DDB on $CCl_4-induced$ hepatotoxicity may be mediated through free radical scavenging.