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1.
Microbes Environ ; 38(3)2023.
Article in English | MEDLINE | ID: mdl-37690850

ABSTRACT

Modifying the duckweed microbiome is a major challenge for enhancing the effectiveness of duckweed-based wastewater treatment and biomass production technologies. We herein examined the potential of the exogenous introduction of predatory bacteria to change the duckweed microbiome. Bacteriovorax sp. HI3, a model predatory bacterium, colonized the core of the Lemna microbiome, and its predatory behavior changed the microbiome structure, which correlated with colonization density. These results reveal that bacterial predatory interactions may be important drivers that shape the duckweed microbiome, suggesting their potential usefulness in modifying the microbiome.


Subject(s)
Araceae , Microbiota , Proteobacteria , Wastewater , Araceae/microbiology , Microbiota/genetics , Proteobacteria/genetics , Water Purification , Wastewater/microbiology , Genome, Bacterial , Bacteriolysis
2.
Clin Case Rep ; 10(12): e6791, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36578796

ABSTRACT

A 69-year-old man presented bradycardia with a constant blocked atrial bigeminy and heart failure. Successful catheter ablation of blocked atrial bigeminy with bradycardia resulted in myocardial reverse remodeling and restoration of the normal sinus rhythm from the ectopic atrial rhythm.

3.
Sensors (Basel) ; 22(7)2022 Mar 23.
Article in English | MEDLINE | ID: mdl-35408071

ABSTRACT

Automated crop monitoring using image analysis is commonly used in horticulture. Image-processing technologies have been used in several studies to monitor growth, determine harvest time, and estimate yield. However, accurate monitoring of flowers and fruits in addition to tracking their movements is difficult because of their location on an individual plant among a cluster of plants. In this study, an automated clip-type Internet of Things (IoT) camera-based growth monitoring and harvest date prediction system was proposed and designed for tomato cultivation. Multiple clip-type IoT cameras were installed on trusses inside a greenhouse, and the growth of tomato flowers and fruits was monitored using deep learning-based blooming flower and immature fruit detection. In addition, the harvest date was calculated using these data and temperatures inside the greenhouse. Our system was tested over three months. Harvest dates measured using our system were comparable with the data manually recorded. These results suggest that the system could accurately detect anthesis, number of immature fruits, and predict the harvest date within an error range of ±2.03 days in tomato plants. This system can be used to support crop growth management in greenhouses.


Subject(s)
Internet of Things , Solanum lycopersicum , Flowers , Fruit , Surgical Instruments
4.
Int Heart J ; 63(1): 159-162, 2022.
Article in English | MEDLINE | ID: mdl-35095065

ABSTRACT

We report here the case of a 92-year-old woman with atrial fibrillation bradycardia in which leadless pacemaker implantation was performed with a difficult delivery of the catheter sheath due to an extremely large right atrium. Using a snare technique with correction of the direction of the force on the catheter toward the right ventricle (RV) can result in successful delivery of the pacemaker catheter and stable placement of the pacemaker system in the RV septum. This specific snare technique has the potential to facilitate leadless pacemaker implantation safely in a severely dilated chamber of the heart, making this technique effective to use in clinical practice.


Subject(s)
Atrial Fibrillation/therapy , Bradycardia/therapy , Cardiac Catheterization/methods , Pacemaker, Artificial , Prosthesis Implantation/methods , Aged, 80 and over , Atrial Fibrillation/complications , Atrial Fibrillation/diagnosis , Bradycardia/complications , Bradycardia/diagnosis , Female , Heart Atria/diagnostic imaging , Heart Atria/pathology , Heart Ventricles/diagnostic imaging , Heart Ventricles/pathology , Humans
5.
Hum Cell ; 35(1): 379-383, 2022 Jan.
Article in English | MEDLINE | ID: mdl-34590290

ABSTRACT

Down's syndrome is one of the most common human congenital genetic diseases and affected patients have increased risk of periodontal disease. To examine involvement of the disease with periodontal disease development, we established immortalized periodontal ligament cells obtained from a Down's syndrome patient by use of SV40T-Ag and hTERT gene transfection. Expressions of SV40T-Ag and hTERT were observed in periodontal ligament cell-derived immortalized cells established from healthy (STPDL) and Down's syndrome patient (STPDLDS) samples. Primary cultured periodontal ligament cells obtained from a healthy subject (pPDL) had a limited number of population doublings (< 40), while STPDL and STPDLDS cells continued to grow with more than 80 population doublings. Primary cultured periodontal ligament cells obtained from the patient showed a chromosome pattern characteristic of Down's syndrome with trisomy 21, whereas STPDLDS samples showed a large number of abnormal chromosomes in those results. Gene expression analysis revealed that expression of DSCR-1 in STPDLDS is greater than that in STPDL. These results suggest that the newly established STPDLDS cell line may be a useful tool for study of periodontal disease in Down's syndrome patients.


Subject(s)
Antigens, Polyomavirus Transforming/genetics , Down Syndrome , Peptide Fragments/genetics , Periodontal Ligament/cytology , Telomerase/genetics , Transfection/methods , Cell Line , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Down Syndrome/genetics , Gene Expression , Healthy Volunteers , Humans , Male , Middle Aged , Muscle Proteins/genetics , Muscle Proteins/metabolism , Periodontal Diseases
6.
J Clin Periodontol ; 44(4): 353-362, 2017 Apr.
Article in English | MEDLINE | ID: mdl-28092104

ABSTRACT

AIM: Gingivitis commonly progresses to periodontitis in permanent dentition but rarely in deciduous teeth. Little is known about the biochemical differences between gingiva of deciduous and permanent teeth. Here, we compared the protein profiles of gingival crevicular fluids (GCF) from the gingiva of deciduous and permanent teeth. MATERIALS AND METHODS: Forty children with mixed dentition (Hellman's dental age IIIA) were selected and GCF samples were collected from deciduous cuspids and central incisors in the maxilla. Pairs of GCF samples were labelled using isobaric tags to permit quantitative comparison of protein abundance in the samples using liquid chromatography-electron spray ionization-tandem mass spectrometry. RESULTS: Sixty-two proteins were upregulated in deciduous teeth GCF and 54 in permanent teeth GCF. In particular, neutrophil-derived proteins, including myeloperoxidase and lactoferrin, were repeatedly higher in deciduous teeth GCF than in permanent teeth GCF. These differences were verified using ELISA (p < 0.01). In contrast, immunoglobulin components were upregulated in permanent teeth GCF. CONCLUSIONS: Neutrophil-related proteins were enriched in deciduous teeth GCF and immunoglobulins in permanent teeth GCF. This suggests that neutrophil accumulation plays a protective role in innate immunity against bacterial infection in gingival tissue of deciduous teeth.


Subject(s)
Dentition, Mixed , Gingival Crevicular Fluid/chemistry , Proteomics , Child , Female , Humans , Male
7.
Bioorg Med Chem ; 19(9): 2835-41, 2011 May 01.
Article in English | MEDLINE | ID: mdl-21493073

ABSTRACT

To search for a new class of antidiabetic compounds, effects of 44 flavonoids on the adipogenesis of 3T3-L1 cells were examined. Among them, 3,4',7-trimethylkaempferol, tetramethylkaempferol, and pentamethylquercetin concentration-dependently enhanced the accumulation of triglyceride, a marker of adipogenesis. With regard to structural requirements of flavonoids for the activity, it was fond that: (1) most flavonoids having hydroxy groups lacked the effect; (2) flavonols with methoxy groups showed stronger effects particularly those with a methoxy group at the 3-position; and (3) a methoxy group of flavonols at the B ring was also important. 3,4',7-Trimethylkaempferol, tetramethylkaempferol, and pentamethylquercetin significantly increased the amount of adiponectin released into the medium and the uptake of 2-deoxyglucose into the cells. Furthermore, tetramethylkaempferol and pentamethylquercetin also increased mRNA levels of adiponectin, glucose transporter 4 (GLUT4), and fatty acid-binding protein (aP2). Both compounds also increased the mRNA levels of peroxisome proliferator-activated receptor (PPAR)γ2 and CCAAT/enhancer-binding protein (C/EBP)α, ß, and/or δ, although, different from troglitazone, they did not activate PPARγ directly in a nuclear receptor cofactor assay.


Subject(s)
Adipogenesis , Flavonoids/chemistry , 3T3-L1 Cells , Animals , CCAAT-Enhancer-Binding Protein-alpha/genetics , CCAAT-Enhancer-Binding Protein-alpha/metabolism , CCAAT-Enhancer-Binding Protein-beta/genetics , CCAAT-Enhancer-Binding Protein-beta/metabolism , CCAAT-Enhancer-Binding Protein-delta/genetics , CCAAT-Enhancer-Binding Protein-delta/metabolism , Deoxyglucose/metabolism , Fatty Acid-Binding Proteins/genetics , Fatty Acid-Binding Proteins/metabolism , Flavonoids/pharmacology , Glucose Transporter Type 4/genetics , Glucose Transporter Type 4/metabolism , Mice , PPAR gamma/genetics , PPAR gamma/metabolism , Structure-Activity Relationship
8.
Nutr Cancer ; 59(1): 99-105, 2007.
Article in English | MEDLINE | ID: mdl-17927508

ABSTRACT

We examined the protective effect of dietary folate on benzene-induced chromosomal damage in bone marrow of mice regarding folate levels in diet and tissue. Male mice were fed either a deficient, basal, or high folate diet (0, 2, or 8 mg/kg diet, respectively) for 4 wk followed by a single dose of benzene. Plasma folate levels corresponded to those of dietary intake. Meanwhile, bone marrow, erythrocyte, and liver folate were decreased to 40% in the deficient group and almost saturated in the high group. Plasma homocysteine levels negatively correlated to levels of tissue folate. Chromosomal damage, evaluated by micronucleus assay, was not affected by folate status alone but was markedly enhanced by benzene, particularly in the deficient group (P < 0.05 vs. the basal and high groups). The activities of hepatic drug-metabolizing enzymes did not enhance benzene metabolism in the deficient groups, indicating that enhanced chromosomal damage was solely due to the low folate status. These results suggest that a low folate status can increase the risk of benzene-induced chromosomal damage in bone marrow, but excess folate intake does not enhance protection, as it is saturated in tissue.


Subject(s)
Bone Marrow Cells/drug effects , Chromosome Aberrations/drug effects , Folic Acid Deficiency/physiopathology , Folic Acid/administration & dosage , Vitamin B Complex/administration & dosage , Administration, Oral , Animals , Benzene/toxicity , Bone Marrow Cells/cytology , DNA Damage/drug effects , Dose-Response Relationship, Drug , Erythrocytes/chemistry , Erythrocytes/metabolism , Folic Acid/metabolism , Folic Acid Deficiency/drug therapy , Folic Acid Deficiency/metabolism , Homocysteine/blood , Liver/chemistry , Liver/enzymology , Liver/metabolism , Male , Mice , Micronucleus Tests , Random Allocation , Vitamin B Complex/metabolism
9.
J Pharm Pharmacol ; 59(6): 871-7, 2007 Jun.
Article in English | MEDLINE | ID: mdl-17637180

ABSTRACT

In a search for substances related to the marked induction of hepatic cytochrome P450 (CYP) by ginkgo biloba extract (GBE), mice were given either GBE (1000 mg kg(-1)) or fractions of GBE for 5 days. The content and activity of CYPs were induced markedly by a bilobalide-rich fraction, but not by flavonoid-rich fractions. The level of induction by the bilobalide-rich fraction was almost the same as that induced by the unfractionated GBE, suggesting that bilobalide is largely responsible for the CYPs induction. To confirm these findings, mice were given various doses of bilobalide (10.5, 21 and 42 mg kg(-1)), or GBE (1000 mg kg(-1), containing bilobalide at 42 mg kg(-1)). Treatment with bilobalide induced CYPs markedly and in a dose-dependent manner, and the level of induction was quite similar between bilobalide (42 mg kg(-1)) and GBE. Treatment with GBE and with bilobalide greatly induced pentoxyresorufin O-dealkylase activity. These findings indicate that bilobalide is the major substance in GBE that induces hepatic CYPs.


Subject(s)
Cyclopentanes/pharmacology , Cytochrome P-450 Enzyme System/biosynthesis , Furans/pharmacology , Ginkgo biloba , Ginkgolides/pharmacology , Microsomes, Liver/drug effects , Animals , Cyclopentanes/administration & dosage , Dose-Response Relationship, Drug , Enzyme Induction , Furans/administration & dosage , Ginkgolides/administration & dosage , In Vitro Techniques , Male , Mice , Mice, Inbred ICR , Microsomes, Liver/enzymology , Plant Extracts/chemistry , Plant Extracts/pharmacology
10.
Urology ; 69(6): 1216-20, 2007 Jun.
Article in English | MEDLINE | ID: mdl-17572227

ABSTRACT

OBJECTIVES: To elucidate the in vitro and ex vivo effects of saw palmetto extract (SPE) on autonomic receptors in the rat lower urinary tract. METHODS: The in vitro binding affinities for alpha 1-adrenergic, muscarinic, and purinergic receptors in the rat prostate and bladder were measured by radioligand binding assays. Rats received vehicle or SPE (0.6 to 60 mg/kg/day) orally for 4 weeks, and alpha 1-adrenergic and muscarinic receptor binding in tissues of these rats were measured. RESULTS: Saw palmetto extract inhibited specific binding of [3H]prazosin and [N-methyl-3H]scopolamine methyl chloride (NMS) but not alpha, beta-methylene adenosine triphosphate [2,8-(3)H]tetrasodium salt in the rat prostate and bladder. The binding activity of SPE for muscarinic receptors was four times greater than that for alpha 1-adrenergic receptors. Scatchard analysis revealed that SPE significantly reduced the maximal number of binding sites (Bmax) for each radioligand in the prostate and bladder under in vitro condition. Repeated oral administration of SPE to rats brought about significant alteration in Bmax for prostatic [3H]prazosin binding and for bladder [3H]NMS binding. Such alteration by SPE was selective to the receptors in the lower urinary tract. CONCLUSIONS: Saw palmetto extract exerts significant binding activity on autonomic receptors in the lower urinary tract under in vitro and in vivo conditions.


Subject(s)
Plant Extracts/pharmacology , Prostate/drug effects , Receptors, Adrenergic, alpha-1/drug effects , Receptors, Muscarinic/drug effects , Receptors, Purinergic/drug effects , Urinary Bladder/drug effects , Androgen Antagonists/pharmacology , Animals , In Vitro Techniques , Male , Models, Animal , Rats , Rats, Sprague-Dawley , Serenoa
11.
Life Sci ; 78(19): 2188-93, 2006 Apr 04.
Article in English | MEDLINE | ID: mdl-16288784

ABSTRACT

We investigated the effects of curcumin, a major antioxidant constituent of turmeric, on hepatic cytochrome P450 (CYP) activity in rats. Wistar rats received curcumin-containing diets (0.05, 0.5 and 5 g/kg diet) with or without injection of carbon tetrachloride (CCl(4)). The hepatic CYP content and activities of six CYP isozymes remained unchanged by curcumin treatment, except for the group treated with the extremely high dose (5 g/kg). This suggested that daily dose of curcumin does not cause CYP-mediated interaction with co-administered drugs. Chronic CCl(4) injection drastically decreased CYP activity, especially CYP2E1 activity, which is involved in the bioactivation of CCl(4), thereby producing reactive free radicals. Treatment with curcumin at 0.5 g/kg alleviated the CCl(4)-induced inactivation of CYPs 1A, 2B, 2C and 3A isozymes, except for CYP2E1. The lack of effect of curcumin on CYP2E1 damage might be related to suicidal radical production by CYP2E1 on the same enzyme. It is speculated that curcumin inhibited CCl(4)-induced secondary hepatic CYPs damage through its antioxidant properties. Our results demonstrated that CYP isozyme inactivation in rat liver caused by CCl(4) was inhibited by curcumin. Dietary intake of curcumin may protect against CCl(4)-induced hepatic CYP inactivation via its antioxidant properties, without inducing hepatic CYPs.


Subject(s)
Antioxidants/therapeutic use , Carbon Tetrachloride Poisoning/prevention & control , Curcumin/therapeutic use , Cytochrome P-450 Enzyme System/metabolism , Liver/drug effects , Animals , Antioxidants/administration & dosage , Body Weight/drug effects , Carbon Tetrachloride Poisoning/enzymology , Curcumin/administration & dosage , Dose-Response Relationship, Drug , Enzyme Activation , Liver/enzymology , Liver/pathology , Male , Organ Size/drug effects , Rats , Rats, Wistar
12.
Food Chem Toxicol ; 44(2): 286-92, 2006 Feb.
Article in English | MEDLINE | ID: mdl-16140449

ABSTRACT

Theanine increases the antitumor effect of doxorubicin (DOX) with decreasing adverse reaction. We clarified the mechanism by which theanine decreases the adverse reaction of DOX on any metabolizing enzymes of theanine. There was no change in the activity of any CYPs and the cytochrome P450 content by theanine treatment. Namely, it was considered that the decrease of DOX adverse reactions by theanine was not connected with CYP activity. In other words, it is shown that theanine has no effect on the metabolism of other medicines and is safe as a food (tea) or supplement. Glutathione S-transferase activity did not change in the theanine-alone group whereas increased in the theanine and DOX-combined group. These results suggested that theanine combination increased the conjugate with DOX and GSH, promoted the efflux of GS-DOX conjugates from the liver, and decreased DOX concentration in the liver. In medium containing theanine with glutaminase in vitro, glutamate gradually generated, showing that glutaminase reacted with theanine. Furthermore, the generation of glutamate increased by reaction of theanine and gamma-glutamyltranspeptidase (gamma-GTP), showed that gamma-GTP converted theanine to glutamate. It is expected that theanine metabolism occurred by hydrolysis and rearrangement reaction by gamma-GTP in the liver. Namely, it is suggested that the metabolism of theanine mediated by glutaminase and gamma-GTP and the increase of glutamate mediated GSH is important for theanine-induced action. In conclusion, it appeared that theanine does not change the biodistribution of combined drugs but it modulates biodistribution or damage to the relative site of GSH, and shows preventive effects in tissue.


Subject(s)
Glutamates/metabolism , Glutamates/therapeutic use , Pharmaceutical Preparations/metabolism , Animals , Antibiotics, Antineoplastic/toxicity , Cytochromes/metabolism , Cytosol/drug effects , Cytosol/enzymology , Doxorubicin/toxicity , Glutaminase/metabolism , Guanosine Triphosphate/pharmacology , Liver/drug effects , Liver/enzymology , Male , Mice , Microsomes, Liver/drug effects , Microsomes, Liver/enzymology , Mixed Function Oxygenases/metabolism
13.
Biol Pharm Bull ; 28(9): 1702-6, 2005 Sep.
Article in English | MEDLINE | ID: mdl-16141543

ABSTRACT

We previously showed that theanine, is a major amino acid in green tea, enhanced doxorubicin (DOX) induced antitumor activity. Besides, theanine induced the elevation of glutathione (GSH) level attributable to the increase of glutamate in the liver of mice, namely theanine would reduce the adverse reaction of DOX. Consequently, theanine was thought to be effective against the tissue changes with GSH level reduction. On the other hand, it is suggested excessive uptake of alcohol causes a production of free radicals, a decrease of GSH level, and an increase in the amount of lipid peroxide (LPO) in liver, and shifting to an alcoholic liver injury. Then, aiming at the prevention and medical treatment of a hepatic toxicity by the food components with little toxicity, we have studied the effect of theanine (i.p.) on ethanol metabolism and hepatic toxicity using ethanol (p.o.) single-administered mice. On the 1st hour after ethanol administration, the ethanol concentrations in blood of the theanine combined groups decreased compared with the ethanol-alone group. The alcohol dehydrogenase and aldehyde dehydrogenase activities in the liver increased by combined theanine. Since the elevation of cytochrome P450 (CYP) 2E1 activity was controlled in the theanine-combined groups, it was considered that these disorders attributable to CYP2E1 in ethanol long-term uptake might be avoidable by theanine. Although LPO increased in 3 h after by single-administration of ethanol, the increase was controlled by theanine-administration and was improved until the normal level. In conclusion, it was indicated that theanine was effective against alcoholic liver injury.


Subject(s)
Central Nervous System Depressants/metabolism , Central Nervous System Depressants/toxicity , Chemical and Drug Induced Liver Injury/prevention & control , Ethanol/metabolism , Ethanol/toxicity , Glutamates/pharmacology , Aldehyde Dehydrogenase/metabolism , Animals , Central Nervous System Depressants/pharmacokinetics , Chemical and Drug Induced Liver Injury/enzymology , Chemical and Drug Induced Liver Injury/pathology , Cytochrome P-450 CYP2E1/metabolism , Cytochrome P-450 Enzyme System/metabolism , Ethanol/pharmacokinetics , Glutathione/metabolism , Glutathione Transferase/metabolism , Injections, Intraperitoneal , Lipid Peroxidation/drug effects , Liver/enzymology , Liver/pathology , Mice , Tissue Distribution
14.
Oncol Rep ; 13(6): 1247-50, 2005 Jun.
Article in English | MEDLINE | ID: mdl-15870950

ABSTRACT

The present study was designed to investigate the effects of Bowman-Birk inhibitor (BBI) on up-regulation of connexin (Cx) expression to estimate BBI's tumor-suppressor effect in mice with M5076 ovarian sarcoma. The relative tumor weight (p<0.05, r(2)=0.301) and proliferating cell nuclear antigen (PCNA, p<0.01, r(2)=0.493) were negatively correlated with the doses of BBI. In contrast, the relative density of Cx43 was positively correlated with the doses of BBI (p<0.05, r(2)=0.351). Therefore, it suggests that the anti-carcinogenic effects of BBI induced negative growth control caused by the expression of Cx43 genes in mice with M5076 ovarian sarcoma.


Subject(s)
Connexin 43/metabolism , Ovarian Neoplasms/drug therapy , Sarcoma, Experimental/drug therapy , Trypsin Inhibitor, Bowman-Birk Soybean/therapeutic use , Trypsin Inhibitors/therapeutic use , Animals , Female , Male , Mice , Mice, Inbred C57BL , Mice, Inbred DBA , Ovarian Neoplasms/metabolism , Ovarian Neoplasms/pathology , Proliferating Cell Nuclear Antigen/metabolism , Sarcoma, Experimental/metabolism , Sarcoma, Experimental/pathology , Tumor Cells, Cultured
15.
Cancer Lett ; 212(2): 177-84, 2004 Aug 30.
Article in English | MEDLINE | ID: mdl-15279898

ABSTRACT

We previously showed that theanine, a specific glutamate derivative in green tea, decreased doxorubicin (DOX)-induced adverse reactions such as the induction of the lipid peroxide level and the reduction of glutathione peroxidase activity in normal tissues. In order to clarify how theanine attenuates the adverse reactions of DOX, we have focused on the effects of theanine on glutamate and glutathione (GSH) levels in normal tissues. The administration of theanine to mice increased the glutamate concentration in the liver and heart, and not in tumors. In vitro examinations indicated that theanine was metabolized to glutamate mainly in the liver. Moreover, theanine inhibited GSH reduction induced by DOX in the liver and heart. Therefore, these results suggested that theanine attenuated the DOX-induced adverse reactions involved in oxidative damage, due to increase in glutamate and the recovery of GSH levels in normal tissues.


Subject(s)
Doxorubicin/pharmacology , Glutamates/pharmacology , Glutamic Acid/pharmacology , Glutathione/pharmacology , Tea , Animals , Antibiotics, Antineoplastic/adverse effects , Antibiotics, Antineoplastic/pharmacology , Cell Line, Tumor , Doxorubicin/adverse effects , Female , Glutamates/metabolism , Glutamic Acid/metabolism , Glutathione/metabolism , Glutathione Peroxidase/metabolism , Humans , Lipid Peroxidation , Liver/metabolism , Male , Mice , Mice, Inbred C57BL , Models, Biological , Models, Chemical , Myocardium/metabolism , Neoplasm Transplantation , Oxidative Stress , Oxygen/metabolism , Temperature , Time Factors
16.
Life Sci ; 75(9): 1113-22, 2004 Jul 16.
Article in English | MEDLINE | ID: mdl-15207658

ABSTRACT

We examined hepatic cytochrome P450 (CYP)-mediated interactions between Ginkgo biloba extract (GBE) and tolbutamide, an oral anti-diabetic agent, in aged and young rats. Tolbutamide was orally given to rats with or without GBE treatment, and time-dependent changes in blood glucose were monitored. The basal activity of six CYP subtypes in liver was lower in the aged rats than in the young rats, while the inductions of these enzymes by 5 day pretreatment of 0.1% GBE diet were more in the aged rats. Further, the pretreatment of GBE significantly attenuated the hypoglycemic action of tolbutamide in the aged rats, corresponding well to the enhanced activity of (S)-warfarin 7-hydroxylase, which is responsible for CYP2C9 subtype, a major isoform metabolizing tolbutamide. In contrast, the simultaneous administration of GBE with tolbutamide potentiated the hypoglycemic action of this drug. The in vitro experiments revealed that GBE competitively inhibited the metabolism of tolbutamide by (S)-warfarin 7-hydroxylase in the rat liver microsomes. In the young rats, the 5 day pretreatment with GBE significantly attenuated the hypoglycemic action of tolbutamide, but a simultaneous treatment had little influence on the tolbutamide effect. In conclusion, the present study has shown that the simultaneous and continuous intake of GBE significantly affects the hypoglycemic action of tolbutamide, possibly via a hepatic CYP enzyme-mediated mechanism, particularly in the aged rats. Therefore, it is anticipated that the intake of GBE as a dietary supplement with therapeutic drugs should be cautious, particularly in elderly people.


Subject(s)
Cytochrome P-450 Enzyme System/metabolism , Ginkgo biloba/chemistry , Liver/drug effects , Plant Extracts/pharmacology , Tolbutamide/metabolism , Analysis of Variance , Animals , Aryl Hydrocarbon Hydroxylases/metabolism , Blood Glucose/drug effects , Blood Glucose/metabolism , Chromatography, High Pressure Liquid , Cytochrome P-450 CYP2C9 , Drug Interactions , Liver/enzymology , Male , Microsomes, Liver/metabolism , Rats , Rats, Wistar
17.
Toxicol Lett ; 150(3): 341-9, 2004 May 02.
Article in English | MEDLINE | ID: mdl-15110086

ABSTRACT

To clarify the effect of 1-methyl-3-propyl-7-N,N-dimethylpropylamide-xanthine (MPDAX) on doxorubicin (DOX) transport, we examined the efficacy of MPDAX as an amplifier of the antitumor activity of DOX in mice bearing tumors with different properties as to DOX transport across cell membranes. MPDAX significantly enhanced the DOX-induced antitumor activity on DOX-sensitive tumors. It is expected that the increase in antitumor activity caused by MPDAX contributes to the increased DOX concentration in tumors due to the MPDAX-induced change in DOX transport via the transporter expressed in sensitive tumor cells. In contrast, in M5076, a lower sensitive to DOX, MPDAX decreased the tumor weight by half at an otherwise ineffective dose of DOX. Furthermore, in P388/DOX, DOX has no effect, but MPDAX caused an elevation of the DOX-induced antitumor activity with an increase in the DOX concentration in the tumors. The results suggested that MPDAX is a novel amplifier for antitumor agents as it significantly increased the antitumor activity toward tumors with different properties. The DOX concentrations in the MPDAX + DOX group for all tumor lines were about two-fold those in the DOX alone group. Furthermore, MPDAX and DOX exhibited significant inhibitory effects on uridine and thymidine uptake. It is known that nucleoside transporters increase the membrane permeability of DOX. We speculated that MPDAX inhibits the cell membrane transport of uridine and thymidine via nucleoside transporters. MPDAX, acting via nucleoside transporters, increases the DOX-induced antitumor activity toward many tumor types and is an useful biochemical modulator.


Subject(s)
Antineoplastic Agents/pharmacokinetics , Doxorubicin/pharmacokinetics , Neoplasms, Experimental/drug therapy , Xanthines/pharmacology , Animals , Antineoplastic Agents/therapeutic use , Biological Transport/drug effects , Cell Line, Tumor , Doxorubicin/therapeutic use , Drug Synergism , Male , Mice , Mice, Inbred Strains , Neoplasm Transplantation , Neoplasms, Experimental/metabolism , Neoplasms, Experimental/pathology , Thymidine/metabolism , Tissue Distribution/drug effects , Uridine/metabolism
18.
Food Chem Toxicol ; 42(6): 953-7, 2004 Jun.
Article in English | MEDLINE | ID: mdl-15110104

ABSTRACT

Herb-drug interactions, especially cytochrome P450 (CYP)-mediated interactions, cause an enhancement or attenuation in efficacy of co-administered drugs. In a previous study, we reported that repeated oral ingestion of Ginkgo biloba extract (GBE) markedly induced hepatic drug metabolizing enzymes in rats. In this study, we focused on the recovery of GBE-induced hepatic drug metabolizing enzymes after the discontinuation of GBE in rats. Feeding of a 0.5% GBE diet to rats for 1 week markedly increased liver weight, content of total CYP, activities of 6 CYP subtypes and glutathione S-transferase (GST). The content and activities of CYP enzymes were recovered to almost basal levels within 1 week after the discontinuation of GBE, while the activity of GST gradually decreased and recovered to the control level after 3 weeks. These results indicated that GBE-induced hepatic drug metabolizing enzymes in rats, especially CYPs, were rapidly recovered by discontinuation of GBE in rats even after excess treatment, and suggested that interactions of GBE with drugs could be avoided by discontinuation of GBE.


Subject(s)
Cytochrome P-450 Enzyme System/drug effects , Cytochrome P-450 Enzyme System/pharmacology , Ginkgo biloba/chemistry , Glutathione Transferase/drug effects , Glutathione Transferase/pharmacology , Animals , Drug Interactions , Kinetics , Liver/enzymology , Male , Plant Extracts/pharmacology , Rats , Rats, Wistar
19.
Shokuhin Eiseigaku Zasshi ; 45(6): 295-301, 2004 Dec.
Article in Japanese | MEDLINE | ID: mdl-15794086

ABSTRACT

In previous papers, we showed that Ginkgo biloba extract (GBE) induced hepatic cytochrome P450 (CYP) activity, in particular pentoxyresorufin O-dealkylase (PROD; corresponding to CYP2B type) in rats, and that GBE influenced the efficacy of co-administered drugs. In this study, to clarify the nature of the induction, we examined the effects of GBE samples from different sources and some major constituents of GBE on rat hepatic CYP in vitro and in vivo. In the study in vitro, eight GBE samples dose-dependently inhibited PROD activity in microsomes prepared from GBE-treated rats, and the inhibitory ratio correlated well with the content of proanthocyanidin in the GBE samples. Moreover, among six GBE constituents examined, proanthocyanidin markedly inhibited the PROD activity. However, administration of two GBE extracts with different proanthocyanidin contents to rats induced hepatic CYP activity, including PROD, to similar extents, and proanthocyanidin alone did not induce PROD activity. Furthermore, GBE samples extracted with both acetone-water and ethanol-water showed similar induction of CYPs in rats in vivo. These results suggest that most GBE samples available in Japan induce CYPs in rats regardless of the preparation method of the GBE, and that proanthocyanidin is not responsible for the induction. Further studies will be necessary to identify the constituent(s) of GBE involved in the induction of CYPs in vivo.


Subject(s)
Cytochrome P-450 Enzyme System/metabolism , Ginkgo biloba , Microsomes, Liver/enzymology , Plant Extracts/pharmacology , Proanthocyanidins/pharmacology , Animals , Cells, Cultured , Cytochrome P-450 CYP2B1/antagonists & inhibitors , Dose-Response Relationship, Drug , Drug Interactions , Enzyme Induction/drug effects , Male , Plant Extracts/chemistry , Proanthocyanidins/analysis , Rats , Rats, Wistar
20.
Biochim Biophys Acta ; 1653(2): 47-59, 2003 Dec 05.
Article in English | MEDLINE | ID: mdl-14643924

ABSTRACT

Biochemical modulation has played an important role in the development of cancer chemotherapy. The combined effects of theanine, a specific amino acid in green tea, and glutamate transporter inhibitors on the antitumor activity of doxorubicin (DOX), were investigated and we clarified the biochemical mechanisms of action of these modulators. In M5076 ovarian sarcoma-bearing mice, theanine significantly enhanced the inhibitory effect of DOX on tumor growth and increased the DOX concentration in the tumor, compared to DOX-alone group. Furthermore, the oral administration of theanine or green tea similarly enhanced the antitumor activity of DOX. Moreover, the combination of theanine with DOX suppressed the hepatic metastasis of ovarian sarcoma. In contrast, an increase in DOX concentration was not observed in normal tissues, such as liver and heart. Namely, theanine did not enhance, rather it tended to normalize the increase of lipid peroxide (LPO) levels and reduction of glutathione peroxidase activity as indicators of the DOX-induced side toxicity. On the other hand, in vitro experiments proved that theanine inhibited the efflux of DOX from tumor cells, supporting a theanine-induced increase in the DOX concentration in tumors in vivo. Moreover, theanine significantly inhibited the glutamate uptake by M5076 cells similar to specific inhibitors. Two astrocytic high-affinity glutamate transporters, GLAST and GLT-1, were expressed in M5076 cells. These results suggested that the inhibition of DOX efflux was induced by theanine-mediated inhibition of glutamate transporters. The reduction in the concentration of glutamate in tumor cells caused by theanine induced decreases in the intracellular glutathione (GSH) and GS-DOX conjugate levels. As the expression of MRP5 in M5076 cells was confirmed, it is suggested that the GS-DOX conjugate was transported extracellularly via the MRP5/GS-X pump in M5076 cells and that theanine affected this route. Namely, theanine increases the concentration of DOX in a tumor in vivo through inhibition of the glutamate transporter via the GS-X pump. Similarly, dihydrokainate (DHK) and L-serine-O-sulfate (SOS), specific glutamate transporter inhibitors, indicated the enhancement of the DOX antitumor activity via inhibition of glutamate uptake. Therefore, we revealed the novel mechanism of enhancement of antitumor efficacy of DOX via the inhibition of glutamate transporters. Similarly, theanine enhanced the antitumor activities of other anthracyclines, cisplatin and irinotecan. Consequently, the modulating effect of theanine on the efficacy of antitumor agents is expected to be applicable in clinical cancer chemotherapy.


Subject(s)
Amino Acid Transport System X-AG/antagonists & inhibitors , Antineoplastic Agents/therapeutic use , Doxorubicin/therapeutic use , Glutamates/pharmacology , Neoplasms/drug therapy , Amino Acid Transport System X-AG/metabolism , Animals , Doxorubicin/metabolism , Drug Synergism , Enzyme Inhibitors/pharmacology , Humans , Mice , Neoplasms/metabolism
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