RESUMEN
This study was aimed to investigate the capacity of a standardized root water extract of Eurycoma longifolia (Tongkat Ali, TA), Physta® to modulate human immunity in a middle-aged Japanese population. This randomized, double-blind, placebo-controlled, parallel study was conducted for 4 weeks. Eighty-four of 126 subjects had relatively lower scores according to Scoring of Immunological Vigor (SIV) screening. Subjects were instructed to ingest either 200 mg/day of TA or rice powder as a placebo for 4 weeks [TA and Placebo (P) groups] and to visit a clinic in Tokyo twice (weeks 0 and 4). SIV, immunological grade, immunological age, and other immune parameters were measured. Eighty-three subjects completed the study; 40 in the TA group and 41 in the P group were statistically analyzed, whereas two were excluded from the analyses. At week 4, the SIV and immunological grade were significantly higher in the TA group than those in P group (p < 0.05). The numbers of total, naïve, and CD4(+) T cells were also higher in the TA group than those in P group (p < 0.05). No severe adverse events were observed. The results suggest that ingestion of the root water extract of TA (Physta®) enhances comprehensive immunity in both middle-aged men and women. This study is registered in UMIN-CTR (UMIN000011753).
Asunto(s)
Eurycoma/química , Sistema Inmunológico/efectos de los fármacos , Inmunomodulación , Extractos Vegetales/uso terapéutico , Adulto , Método Doble Ciego , Femenino , Humanos , Masculino , Persona de Mediana Edad , Raíces de Plantas/química , Linfocitos T/efectos de los fármacos , Agua/químicaRESUMEN
Concomitant consumption of grapefruit juice (GFJ) causes increases in the plasma concentration of a variety of drugs due to inhibition of intestinal CYP3A enzyme. Dihydropyridine calcium channel blockers belong to the category of drugs that are most prone to undergo such interaction. Increases in area under the plasma concentration-time curve (AUC) due to GFJ differ greatly depending on the dihydropyridine administered. Therefore, a meta-analysis of each dihydropyridine was performed based on available literature. The criteria for using a publication were: subjects were healthy adults, dihydropyridines were taken with GFJ concomitantly or within one hour after intake of the juice, and the control group administered water in place of GFJ. In these studies, the investigations on GFJ interactions with 13 dihydropyridines such as amlodipine, azelnidipine, benidipine, cilnidipine, efonidipine, felodipine, manidipine, nicardipine, nifedipine, nimodipine, nisoldipine, nitrendipine and pranidipine were reported. As a result of meta-analyses, statistically significant interactions were not identified in amlodipine. Next, correlation analyses between the physicochemical properties and interaction strengths of the dihydropyridines were performed to clarify the cause of the variation in the strengths that was dependent on the dihydropyridine. LogP, molecular weight, topological polar surface area (tPSA), molar refractivity, water diffusion, molecular volume, molecular density, molecular polarizability, and refractive index were calculated from the chemical structures. The interaction strength was defined as the logarithmic values of the increasing AUC ratio. The correlation analyses indicated a relationship of logP and tPSA with the interaction strengths. These findings suggest that the wide difference in the potency of interaction of each dihydropyridine may be explained by the presence of hydrophobic and electrostatic interactions between dihydropyridines and intestinal CYP3A enzyme.
Asunto(s)
Bloqueadores de los Canales de Calcio/química , Bloqueadores de los Canales de Calcio/farmacología , Citrus paradisi , Dihidropiridinas/química , Dihidropiridinas/farmacología , Interacciones Alimento-Droga , Área Bajo la Curva , Bebidas , Citocromo P-450 CYP3A/química , Citocromo P-450 CYP3A/metabolismo , Humanos , Mucosa Intestinal/metabolismo , Relación Estructura-Actividad CuantitativaRESUMEN
BACKGROUND: We have previously reported on the relative cytotoxicity of a total of 38 1,2,3,4-tetrahydroisoquinoline derivatives against human oral squamous cell carcinoma cell lines and human normal oral cells, and the correlation between the cytotoxicity and 17 chemical descriptors. However, the correlation between the tumor-specificity of these compounds and the chemical descriptors has never been investigated so far. Using these previous data, we investigated various parameters for their applicability in predicting tumor specificity. MATERIALS AND METHODS: Original data of 50% cytotoxic concentration (CC(50)) values exceeding the maximum concentration in experimental conditions were corrected by the introduction of a harmonic mean, reducing the number of compounds analyzed to 30. The mean pCC(50) (=-log CC(50)) values for normal and tumor cells were defined as N and T, respectively. Tumor specificity was defined as the ratio of the difference of these values to their sum: (T-N)/(T+N). The chemical descriptors were obtained by quantum chemical calculations using semi-empirical (AM1, PM3, and PM6) and density functional theory methods. The relationship between the chemical descriptors and tumor specificity was analyzed by linear regression and artificial neural networks. RESULTS: Out of 17 chemical descriptors, water-accessible surface area showed the highest correlation coefficient with tumor specificity, regardless of the method of calculation. Furthermore, neural network analysis demonstrated the importance of quantum chemical calculations in predicting the specificity of tetrahydroisoquinoline derivatives. CONCLUSION: The present study suggests the applicability of quantum chemical descriptor in the estimation of tumor specificity of related compounds.
Asunto(s)
Carcinoma de Células Escamosas/tratamiento farmacológico , Química Farmacéutica/métodos , Neoplasias de la Boca/tratamiento farmacológico , Tetrahidroisoquinolinas/química , Animales , Antineoplásicos/farmacología , Línea Celular Tumoral , Diseño de Fármacos , Humanos , Modelos Químicos , Modelos Moleculares , Conformación Molecular , Redes Neurales de la Computación , Relación Estructura-Actividad Cuantitativa , Análisis de Regresión , Agua/químicaRESUMEN
We performed a meta-analysis to assess antihypertensive effect, lipid metabolism, insulin resistance index, and body weight changes in patients with borderline diabetes and diabetes treated with angiotensin II receptor blockers (ARB) and dihydropyridine calcium channel blockers (CCB). Literatures for analysis were searched in MEDLINE, the Cochrane Library, and Japana Centra Revuo Medicina. Reports on randomized controlled trials in which the therapeutic results in borderline and diabetic patients were compared between those treated with ARB and CCB were retrieved, and 16 reports met the objective of this study. The efficacy in the two drug treatment groups were divided into 8 outcomes and evaluated. The efficacy outcomes on handling continuous data were integrated using the weighted mean difference, in which the random-effects model was selected for the statistical model. The statistical heterogeneity of each outcome was also tested. The systolic and diastolic blood pressures were significantly reduced in the CCB compared to the ARB treatment group. No significant differences were noted between the two groups in the triglyceride or low-density lipoprotein cholesterol level or body weight changes. It was shown that the CCB was more effective than ARB for the improvement of systolic and diastolic blood pressures in patients with borderline diabetes and diabetes, while no significant differences were noted in the efficacy other than the antihypertensive effect between ARB and CCB treatment groups. This study would provide information in selecting antihypertensive agents for borderline and diabetic patients.
Asunto(s)
Antagonistas de Receptores de Angiotensina/uso terapéutico , Antihipertensivos/uso terapéutico , Presión Sanguínea , Bloqueadores de los Canales de Calcio/uso terapéutico , Diabetes Mellitus/tratamiento farmacológico , Diabetes Mellitus/fisiopatología , MEDLINE , Peso Corporal , Diabetes Mellitus/metabolismo , Humanos , Resistencia a la Insulina , Metabolismo de los Lípidos , Modelos Estadísticos , Ensayos Clínicos Controlados Aleatorios como AsuntoRESUMEN
Previous studies have shown anti-inflammatory potential of alkaline extract of the leaves of Sasa senanensis Rehder (SE). The aim of the present study was to clarity the molecular entity of SE, using various fractionation methods. SE inhibited the production of nitric oxide (NO), but not tumour necrosis factor-α by lipopolysaccharide (LPS)-stimulated mouse macrophage-like cells. Lignin carbohydrate complex prepared from SE inhibited the NO production to a comparable extent with SE, whereas chlorophyllin was more active. On successive extraction with organic solvents, nearly 90% of SE components, including chlorophyllin, were recovered from the aqueous layer. Anti-HIV activity of SE was comparable with that of lignin-carbohydrate complex, and much higher than that of chlorophyllin and n-butanol extract fractions. The CYP3A inhibitory activity of SE was significantly lower than that of grapefruit juice and chlorophyllin. Oral administration of SE slightly reduced the number of oral bacteria. When SE was applied to HPLC, nearly 70% of SE components were eluted as a single peak. These data suggest that multiple components of SE may be associated with each other in the native state or after extraction with alkaline solution.
Asunto(s)
Álcalis/administración & dosificación , Antiinflamatorios/administración & dosificación , Macrófagos/efectos de los fármacos , Extractos Vegetales/administración & dosificación , Sasa/química , Estomatitis/tratamiento farmacológico , Animales , Infecciones por Bacteroidaceae/tratamiento farmacológico , Infecciones por Bacteroidaceae/inmunología , Infecciones por Bacteroidaceae/microbiología , Línea Celular , Clorofilidas/farmacología , Citrus paradisi/química , Infecciones por VIH/tratamiento farmacológico , Humanos , Lignina/farmacología , Lipopolisacáridos/farmacología , Macrófagos/citología , Macrófagos/metabolismo , Masculino , Ratones , Microsomas Hepáticos/efectos de los fármacos , Óxido Nítrico/metabolismo , Porphyromonas gingivalis/efectos de los fármacos , Porphyromonas gingivalis/crecimiento & desarrollo , Ratas , Estomatitis/inmunología , Estomatitis/microbiología , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
Methyldopa, an antihypertensive, is a very close analogue of DOPA. Drug interaction accompanied by degradation in a banana juice mixture was reported for DOPA. However, the effect of banana on methyldopa has not been reported. Therefore, we have investigated the impact of banana juice on methyldopa. The drug and supernatant of banana pulp were mixed, and the mixture was observed for changes in color, drug concentration, and ultraviolet-visible absorption spectra at 30 °C. The originally clear and colorless mixture started to acquire a yellow coloration after about 30 seconds after the mixing. The color tone increasingly deepened, then blistered solid particles that do not dissolve were observed after 3 hours. Concentration of methyldopa in the mixture decreased by 60% after 5 min, to 0.5% after 30 min of the mixing. From these findings, it was suggested that the drastic alterations were caused by banana polyphenol oxidase that plays a role in the biosynthesis of melanin pigment from levodopa in banana pulp. Because the degradation of methyldopa occurs extremely fast, it was suggested concomitant use of this anti-hypertensive and banana juice consumption should be avoided in clinical practice.
RESUMEN
To investigate the relation between tendency of feverishness and patient profile in pegylated interferon (peginterferon) and ribavirin combination therapy, we performed a retrospective survey of the medical charts of patients with chronic hepatitis C that have been on interferon therapy for the past two years. The sample was 36 patients (18 males, 18 females, aged 30 to 67 years, average of 57.5 years) who were hospitalized for the introduction of peginterferon-alpha 2b and ribavirin combination therapy and did not use NSAIDs before the administration of interferon. We examined body temperature and laboratory values (AST, ALT, WBC, Hb, PLT, BUN, Cr, HCV RNA level, and HCV genotype) for one week from the initiation of peginterferon administration to one week after the administration. Tendency of feverishness was classified into two groups according to the time to reach maximum body temperature. The early fever-developing group reached maximum body temperature within 12 hours of the administration, and the slow fever-developing group reached maximum body temperature after 12 hours post administration. The early fever-developing group had a significantly higher maximum body temperature (early group, 38.5 degrees C+/-0.55; slow group, 37.8 degrees C+/-0.55), more persistent fever (early group, 71.0 h+/-31.3; slow group, 36.5 h+/-41.8), and a higher percentage of females (early group, 80.0%; slow group, 28.6%). Moreover, females and elderly patients developed significantly higher fever (temperature difference 0.78 degrees C) early (8.5 h) after peginterferon administration. These results indicate the need for careful observation of females and elderly patients in the early stage of an initial treatment of chronic hepatitis C with peginterferon.
Asunto(s)
Envejecimiento , Antivirales/efectos adversos , Fiebre/inducido químicamente , Hepatitis C Crónica/tratamiento farmacológico , Interferón-alfa/efectos adversos , Ribavirina/efectos adversos , Caracteres Sexuales , Adulto , Anciano , Antivirales/administración & dosificación , Quimioterapia Combinada , Femenino , Humanos , Interferón alfa-2 , Interferón-alfa/administración & dosificación , Masculino , Persona de Mediana Edad , Polietilenglicoles , Proteínas Recombinantes , Estudios Retrospectivos , Ribavirina/administración & dosificación , Factores de Riesgo , Índice de Severidad de la EnfermedadRESUMEN
A formulation study of intravesical oxybutynin (OB) preparations was carried out in order to improve the effectiveness in intravesical instillation therapy for spastic neurogenetic bladder. Sodium hyaluronate (HYA) was introduced to enhance the muco-adhesiveness of the instillation preparation, and the physicochemical properties of the OB formulation were evaluated in comparison with a conventional formulation containing hydroxypropylcellulose (HPC). The viscous properties and in vitro adhesiveness increased with the amount of the polymeric additives, and retention properties of OB in rabbit bladder were comparable after addition of 0.4% HYA and 1.0% HPC. HYA was able to enhance the intravesical retention properties of OB instillation solution to a lesser degree than HPC, it seemed to be a useful additive in the OB instillation due to its safety and mucosal-protective effect.
Asunto(s)
Administración Intravesical , Ácidos Mandélicos/química , Descanso/fisiología , Adhesividad , Animales , Ácido Hialurónico/química , Concentración de Iones de Hidrógeno , Masculino , Conejos , Retención en Psicología , Vejiga Urinaria/metabolismo , ViscosidadRESUMEN
It has been reported that the intestinal absorption of celiprolol, an antihypertensive drug, is inhibited when it is taken with orange juice; it has been suggested that element(s) in citrus juice are responsible for this. In the present study, the pharmacokinetic interaction between celiprolol and orange juice was characterized through in vivo experiments with rats. Celiprolol 5 mg/kg was injected into the rat duodenum together with 5 ml/kg of neutralized orange juice or the same concentration of hesperidin as in the orange juice. Plasma celiprolol concentrations were measured by liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS). Concomitant administration of orange juice or hesperidin with celiprolol significantly decreased the area under the plasma concentration-time curve (AUC) by 74% and 75%, respectively, compared with control. These findings suggest that hesperidin is responsible for the decreased absorption of celiprolol and that orange juice taken with celiprolol has an inhibiting effect on intestinal absorption of the drug.
Asunto(s)
Antihipertensivos/farmacocinética , Celiprolol/farmacocinética , Citrus sinensis/química , Interacciones Alimento-Droga , Hesperidina/farmacología , Animales , Área Bajo la Curva , Bebidas , Cromatografía Liquida , Absorción Intestinal , Masculino , Ratas , Ratas Wistar , Espectrometría de Masa por Ionización de ElectrosprayRESUMEN
It is well known fact that the strengths of drug interactions with grapefruit juice (GFJ) differ greatly depending on the 1,4-dihydropyridine calcium channel antagonist (DHP) used. However, there are no available data on the relationship between interactions with GFJ and its physicochemical attributes. Therefore we endeavored to study the correlation between calculated logP values, indicating lipophilicity, from chemical structures of DHPs as well as water diffusion, molecular volume, molecular polarization, molecular density, refractive index, topologic polar surface area, and calculated molar refractivity. Thirteen forms of DHP, amlodipine, azelnidipine, benidipine, cilnidipine, efonidipine, felodipine, manidipine, nicardipine, nifedipine, nimodipine, nisoldipine, nitrendipine, and pranidipine were analyzed due to clinical trials performed with GFJ and these agents. The pharmacokinetic interaction strengths were defined in common logarithmic values of increasing ratios of area under the plasma concentration-time curve (AUC) with GFJ intake compared with controls. Physicochemical properties including three categories of predicted logP values were calculated from the structures of DHPs and their estimated relationship with the interactions. As a result, the logP values indicated significant positive correlations with the interaction strengths. This finding suggests that lipophilicity is an important factor in the strengths of pharmacokinetic interactions of DHPs with GFJ intake.
Asunto(s)
Antihipertensivos/farmacocinética , Bloqueadores de los Canales de Calcio/farmacocinética , Citrus paradisi , Dihidropiridinas/farmacocinética , Interacciones Alimento-Droga , Antihipertensivos/química , Bloqueadores de los Canales de Calcio/química , Fenómenos Químicos , Química Física , Dihidropiridinas/química , Humanos , Relación Estructura-ActividadRESUMEN
The secondary and adverse effects when biguanides, alpha-glycosidase inhibitor or thiazolidine derivative was used with sulphonylurea agent (SU) as compared with those with SU alone in Type 2 diabetes patients by using Systematic Review. Two-agent concurrent treatment groups, taken from studies in which subjects were assigned to a group given only a sulfonylurea agent and a group given a sulfonylurea agent with the other glycemic control agent (combination of a sulfonylurea agent and a biguanide agent (I), combination of a sulfonylurea agent and an alpha-glucosidase inhibitor (II), and combination of a sulfonylurea agent and thiazolidinedione (III)), were studied in a randomized controlled trial. The secondary efficacy outcome measures were total cholesterol (TC), triglyceride (TG), HDL-C, LDL-C, and change in body weight. The incidence of hypoglycemia, feeling of fullness, diarrhea, liver dysfunction, and edema was investigated as a safety outcome measure, and the clinical significance of concurrent treatment with a sulfonylurea agent in addition to the other glycemic control agent was investigated. With respect to (II), an antidiabetic effect was showed. As for (III), it had the disadvantage of increased body weight. Furthermore, increase of HDL-C levels, in particular, was observed. The improving effect of (III) on serum lipids may be clinically effective for considering the pathologic condition of diabetes, which is often complicated by hyperlipidemia.
Asunto(s)
Biguanidas/administración & dosificación , Biguanidas/efectos adversos , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Inhibidores Enzimáticos/administración & dosificación , Inhibidores Enzimáticos/efectos adversos , Glicósido Hidrolasas/antagonistas & inhibidores , Hipoglucemiantes/administración & dosificación , Hipoglucemiantes/efectos adversos , Lípidos/sangre , Compuestos de Sulfonilurea/administración & dosificación , Compuestos de Sulfonilurea/efectos adversos , Tiazolidinas/administración & dosificación , Tiazolidinas/efectos adversos , Administración Oral , Peso Corporal , Diabetes Mellitus Tipo 2/fisiopatología , Quimioterapia Combinada , Hemoglobina Glucada/análisis , Humanos , Ensayos Clínicos Controlados Aleatorios como AsuntoRESUMEN
Dulcin (DL), now banned, was once a widely used artificial sweetener. DL possesses an ureido group that is metabolized by direct glucuronidation in rabbit liver microsomes. Dulcin N-glucuronide (DNG) is the only type of ureido N-glucuronide known to date; ureido glucuronidation in humans has not been previously reported. Accordingly, the glucuronidation of DL was studied using human liver microsomes (HLM) and expressed human UDP-glucuronosyltransferase (UGT) enzymes. The average K (m) and V (max) values from nine HLM samples were 2.10 mM and 0.156 nmol/mg/min, respectively. Of the six human UGT isoforms screened for their ability to glucuronidate DL, only UGT1A1 and UGT1A9 showed activity. The apparent K (m) values using UGT1A1 and UGT1A9 were 5.06 and 6.99 mM, and the apparent V (max) values were 0.0461 and 0.106 nmol/min/mg, respectively. Phenolphthalein, a substrate for UGT1A9, inhibited DL glucuronidation in HLM competitively (K (i) = 0.356 mM), but bilirubin, a substrate for UGT1A1, did not. These results suggest that UGT1A9 is a key enzyme catalyzing the glucuronidation of DL.
Asunto(s)
Glucuronosiltransferasa/fisiología , Hígado/enzimología , Compuestos de Fenilurea/metabolismo , Bilirrubina/farmacología , Glucurónidos/metabolismo , Humanos , Isoenzimas/fisiología , Fenolftaleína/farmacologíaRESUMEN
Grapefruit juice (GJ) contains components that may increase the bioavailability of drugs; however, approaches to the removal of these components have been little investigated. It is known that furanocoumarin derivatives (FCs), such as bergamottin (BG) and 6',7'-dihydroxybergamottin (DHB) in GJ, induce such drug interactions. In the present study, it was found that the heat treatment of grapefruit juice decreases concentrations of BG and DHB as well as their interactions both in vitro and in vivo. We incubated GJ for 10, 20, 30, 40, 50, and 60 min at 37, 62, 72, and 95 degrees C; FCs in each sample were then measured, using high-performance liquid chromatography (HPLC). The concentrations of BG and DHB were decreased in a time- and temperature-dependent manner, by 82.5 and 97.9% respectively, after incubation for 1 h at 95 degrees C. In contrast, the concentration of bergaptrol (BT) increased in a time- and temperature-dependent manner (27.7% after 60 min at 95 degrees C). In addition, the effect of each GJ sample on testosterone 6beta-oxidation in human liver microsomes was observed. The inhibitory effects of GJ heated to 95 degrees C were decreased in a time-dependent manner, as in the case of BG and DHB concentrations. Furthermore, 2 ml of GJ treated for 60 min at 95 degrees C was administered into the rat duodenum. After 30 min, nifedipine (NFP) was administered intraduodenally at a dose of 3 mg/kg body weight. The concentrations of NFP in the plasma samples were determined by HPLC. No significant increase in the AUC of NFP was observed in the rats given heat-treated GJ. These results suggest that the heat treatment of GJ reduces the concentrations of FCs, thus eliminating the potential for drug interactions.
Asunto(s)
Bebidas/análisis , Citrus paradisi , Interacciones Alimento-Droga , Calor , Animales , Área Bajo la Curva , Bloqueadores de los Canales de Calcio/administración & dosificación , Bloqueadores de los Canales de Calcio/sangre , Bloqueadores de los Canales de Calcio/farmacocinética , Cromatografía Líquida de Alta Presión , Citocromo P-450 CYP3A/metabolismo , Inhibidores del Citocromo P-450 CYP3A , Duodeno/efectos de los fármacos , Duodeno/metabolismo , Furocumarinas/análisis , Furocumarinas/química , Furocumarinas/farmacología , Hidroxitestosteronas/análisis , Hidroxitestosteronas/metabolismo , Intubación Gastrointestinal , Masculino , Microsomas Hepáticos/efectos de los fármacos , Microsomas Hepáticos/metabolismo , Estructura Molecular , Nifedipino/administración & dosificación , Nifedipino/sangre , Nifedipino/farmacocinética , Ratas , Ratas Wistar , Factores de TiempoRESUMEN
Little information is available about drug interactions with cranberry juice (CJ). Using microsomes from the human liver and rat small intestine, this study was designed to determine whether CJ could inhibit CYP3A-mediated nifedipine (NFP) oxidase activity; it showed that CJ was a potent inhibitor of human and rat CYP3A. Preincubation with 10% vol/vol of CJ and 1 mM NADPH for 10 min resulted in significant inhibition of the NFP oxidation activity of human and rat CYP3A (18.2 and 12.6% decreases, respectively, compared with preincubation experiments without NADPH). In addition, the pharmacokinetic interaction between CJ and NFP in vivo was confirmed in rats. In comparison with a control group, the area under the concentration-time curve (AUC) of NFP was approximately 1.6-fold higher when CJ (2 mL) was injected intraduodenally 30 min before the intraduodenal administration of NFP (30 mg kg(-1)). However, the mean residence time, the volume of distribution and the elimination rate constant were not changed significantly. These data suggest that CJ component(s) inhibit the function of enteric CYP3A. In conclusion, it was found that CJ inhibits the CYP3A-mediated metabolism of NFP in both rats and humans. Furthermore, CJ alters NFP pharmacokinetics in rats.
Asunto(s)
Bebidas , Bloqueadores de los Canales de Calcio/farmacocinética , Interacciones Alimento-Droga , Nifedipino/farmacocinética , Vaccinium macrocarpon , Animales , Interacciones Farmacológicas , Furocumarinas/farmacología , Humanos , Técnicas In Vitro , Mucosa Intestinal/metabolismo , Masculino , Microsomas/metabolismo , Microsomas Hepáticos/metabolismo , Oxidación-Reducción , Ratas , Ratas WistarRESUMEN
In the present study, UV-irradiated grapefruit juice was used to investigate the effects of UV light on nifedipine pharmacokinetics. Grapefruit juice in quartz vessels was UV irradiated (302 nm) with a transilluminator for 0 to 6 h at 4 degrees C, and furanocoumarins, potent contributors to the pharmacokinetic interaction, in each juice sample were measured using HPLC. The concentrations of all three types of furanocoumarins, bergamottin, 6',7'-dihydroxybergamottin, and bergaptol, decreased in a time-dependent manner. Concentrations of bergamottin, 6',7'-dihydroxybergamottin, and bergaptol were decreased to 1.66, 1.98, and 5.58%, respectively, after UV irradiation for 6 h. Two milliliters of untreated and UV-irradiated grapefruit juice were preadministered into the duodenum in rats to assess the effects of UV irradiation on nifedipine pharmacokinetics in vivo. After 30 min, nifedipine was intraduodenally administered at a dose of 3 mg/kg body weight. The nifedipine concentrations in the plasma samples were determined using HPLC. A significant increase in the area under the concentration-time curve of nifedipine was observed in untreated grapefruit juice to 1.6-fold that in the control group, but not in the UV-irradiated grapefruit juice. These findings suggest that UV irradiation is useful to eliminate pharmacokinetic interactions with grapefruit juice.
Asunto(s)
Bebidas/efectos de la radiación , Citrus paradisi/química , Interacciones Alimento-Droga , Furocumarinas/farmacología , Nifedipino/farmacocinética , Rayos Ultravioleta , Animales , Cromatografía Líquida de Alta Presión , Citrus paradisi/efectos de la radiación , Interacciones Farmacológicas , Furocumarinas/análisis , Furocumarinas/efectos de la radiación , Masculino , Nifedipino/sangre , Ratas , Ratas WistarRESUMEN
We studied a reverse phase HPLC method employing a simple acetonitrile: 0.1% phosphoric acid aqueous solution gradient as the mobile phase for the determination of furanocoumarin (FC) derivatives, such as bergamottin (BG) and 6',7'-dihydroxybergamottin (DHB), using UV detection. Anthracene was added to samples as an internal standard. A Capcell Pak SG-Phenyl column (4.6 mm [inner diameter] x 25 cm; particle size 5 mm; Shiseido) was used, and the flow rate was set at a constant 1 ml/min. A photodiode array detector was used because it reveals the characteristic UV-absorption spectrum of FCs, commonly with 311 nm as the maximum wavelength. Furanocoumarin derivatives in pomelo juice (PJ) were detected by the method and compared with those in grapefruit juice (GJ) and orange juice (OJ). GJ contained 3 kinds of FCs, BG, DHB and bergaptol (BT). OJ had no FCs. On the other hand, PJ contained 8 kinds of FCs including BT, BG and DHB. This FC detection system may be effective for identifying foods and beverages that interact adversely with drugs.
Asunto(s)
Bebidas/análisis , Cromatografía Líquida de Alta Presión/métodos , Citrus/química , Furocumarinas/análisis , Cromatografía Líquida de Alta Presión/instrumentación , Interacciones Alimento-DrogaRESUMEN
It has been reported that grapefruit juice (GJ) causes pharmacokinetic interactions with many drugs after co-ingestion, but the effects of the juice of sweetie fruit, a cross between a pomelo and a grapefruit, on the pharmacokinetics of medicines have not been clear. The present study investigated the drug interaction capability of sweetie juice (SJ). The effect of SJ on nifedipine (NFP) pharmacokinetics in rats was studied. Two milliliters of SJ, GJ, or saline was administered to the rat duodenum. After 30 min, NFP was administered intraduodenally at a dose of 3 mg/kg body weight. The NFP concentrations in the plasma samples were determined by high performance liquid chromatography (HPLC). Although GJ increased the area under the plasma concentration-time curve (AUC) of NFP (1.6-fold), SJ had no significant effect on the NFP pharmacokinetics in rats. Furthermore, concentrations of furanocoumarin derivatives in SJ were measured by HPLC equipped with a photodiode array detector, and compared with those in GJ. SJ contained lower concentrations of bergamottin (0.53 microg/ml), 6', 7'-dihydroxybergamottin (0.19 microg/ml), and bergaptol (0.2 microg/ml) than the GJ used in this study (6.3 microg/ml, 3.6 microg/ml, and 9.4 microg/ml, respectively). In conclusion, the results suggest that SJ had no effect on the NFP pharmacokinetics in rats due to low furanocoumarin concentrations in SJ.
Asunto(s)
Citrus , Interacciones Alimento-Droga , Nifedipino/farmacocinética , Animales , Bebidas , Cromatografía Líquida de Alta Presión , Citrus/química , Furocumarinas/análisis , Masculino , Ratas , Ratas WistarRESUMEN
PURPOSE: Identify (R)-BOP-T in rat bile after administration of (R)-BOT over a 12 h period. METHODS: Each benoxaprofen (BOP) enantiomer was administered i.v. to bile duct-cannulated rats at a dose of 5 mg/kg. The optical isomers of BOP and its metabolites in plasma, urine, and bile were quantified using a chiral HPLC column. The amounts of BOP glucuronide (BOP-G), BOP taurine conjugate (BOP-T), and BOP enantiomers excreted into the bile over 12 h after administration of (R)-BOP were as follows: (R)-BOP-G and (S)-BOP-G, 2.1 +/- 0.5 and 6.2 +/- 1.4% of the dose; (R)-BOP-T and (S)-BOP-T, 5.6 +/- 1.8 and 0.7 +/- 0.3% of the dose; (R)-BOP and (S)-BOP, 0.7 +/- 0.1 and 1.7 +/- 0.2% of the dose, respectively, whereas after (S)-BOP administration, (S)-BOP-G and (S)-BOP were mainly excreted into the bile (14.3 +/- 1.8 and 3.0 +/- 0.4% of the dose, respectively). Only after (R)-BOP administration was the taurine conjugate of BOP found in the bile, and the configuration was R. BOP-T could not be found in the bile after (S)-BOP administration. To investigate the stereoselectivity of the conjugation enzymes responsible for BOP-T formation, in vitro studies were performed using rat hepatic organelles. RESULTS: When (R)-BOP was used as a substrate, rat hepatic mitochondrial and microsomal fractions exhibited stereoselective BOP-T formation activity, with microsomal activity approximately 3.0 times greater than that of the mitochondria. That of (S)-BOP was approximately 2.1. Mean (R)/(S) ratios of BOP enantiomer for BOP-T formation in the mitochondrial and microsomal incubations were approximately 1.7 and 2.4, respectively. CONCLUSION: Although in the in vivo studies, only (R)-BOP-T originated from (R)-BOP was found in the bile, the configuration of BOP-T formed by the incubations of (R)-BOP or (S)-BOP with rat hepatic mitochondria or microsomes was S for both.
Asunto(s)
Microsomas Hepáticos/metabolismo , Mitocondrias Hepáticas/metabolismo , Propionatos/química , Taurina/química , Animales , Masculino , Propionatos/sangre , Ratas , Ratas Sprague-Dawley , Estereoisomerismo , Taurina/sangreRESUMEN
Dulcin (DL), 4-ethoxyphenylurea, a synthetic chemical about 200 times as sweet as sucrose, has been proposed for use as an artificial sweetener. DL is excreted as a urinary ureido-N-glucuronide after oral administration to rabbits. The phenylurea N-glucuronide is the only ureido conjugate with glucuronic acid known at present; therefore, DL is interesting as a probe to search for new functions of UDP-glucuronosyltransferases (UGTs). Seven UGT isoforms (UGT1A3, UGT1A4, UGT1A6, UGT1A7, UGT2B13, UGT2B14, and UGT2B16) have been identified from rabbit liver, but these UGTs have not been investigated using DL as a substrate. In this work, the identities of UGT isoforms catalyzing the formation of DL glucuronide were investigated using rabbit liver microsomes (RabLM) and cloned/expressed as rabbit UGT isoforms. DL-N-glucuronide (DNG) production was determined quantitatively in RabLM and homogenates of COS-7 cells expressing each UGT isoform by using electrospray liquid chromatography-tandem mass spectrometry. Analysis of DNG formation using RabLM, by Eadie-Hofstee plot, gave a Vmax of 0.911 nmol/min/mg protein and the Km of 1.66 mM. DNG formation was catalyzed only by cloned expressed rabbit UGT1A7 and UGT2B16 (Vmax of 3.98 and 1.16 pmol/min/mg protein and a Km of 1.23 and 1.69 mM, respectively). Substrate inhibition of UGT1A7 by octylgallate confirmed the significant contribution of UGT1A7 to the formation of DNG. Octylgallate was further shown to competitively inhibit DNG production by RabLM (Ki = 0.149 mM). These results demonstrate that UGT1A7 is the major isoform catalyzing the N-glucuronidation of DL in RabLM.
Asunto(s)
Ácido Gálico/análogos & derivados , Glucurónidos/metabolismo , Glucuronosiltransferasa/metabolismo , Hígado/enzimología , Compuestos de Fenilurea/farmacocinética , Animales , Western Blotting , Células COS , Chlorocebus aethiops , Cromatografía Líquida de Alta Presión , Cromatografía Liquida , Inhibidores Enzimáticos/farmacología , Ácido Gálico/farmacología , Glucuronosiltransferasa/antagonistas & inhibidores , Glucuronosiltransferasa/genética , Técnicas In Vitro , Isoenzimas , Cinética , Espectroscopía de Resonancia Magnética , Masculino , Microsomas Hepáticos/efectos de los fármacos , Microsomas Hepáticos/metabolismo , Proteínas/metabolismo , Conejos , Espectrometría de Masa por Ionización de Electrospray , TransfecciónRESUMEN
Stomatitis is a harmful side effect induced by high and/or multiple dosing of cytotoxic drugs such as 5-fluorouracil. Allopurinol mouthwash has been used to prevent stomatitis induced by cancer chemotherapy. In the present study, the pharmaceutical utility of allopurinol mouthwash (Alkox-mw), which consists of polyethylene(oxide) (Alkox) and iota-carrageenan (INA), was investigated as a possible material for a new oral dosage preparation for improving the adhesiveness onto the oral mucosa. From the observation of the gel formation, which was studied as a function of the variety of the added Alkox and/or INA, the preferential compositions of Alkox-mw (Alkox:INA % ratio) seemed to be 1.0:(0-1.0) and (0-3.0):0.4, respectively. The adhesiveness and the spinnability of various allopurinol mouthwashes were also investigated using a creep meter. The adhesiveness of Alkox-mw increased with the increase in the amount of added Alkox. Furthermore, the adhesion force of Alkox-mw was greater than that of allopurinol mouthwash consisting of sodium carboxymethylcellulose (CMC-Na). From the in vitro assessment of mimicking the effusion of the allopurinol mouthwashes from the surface of the oral mucosa, the effusion of Alkox-mws was retarded by the added Alkox. The results obtained in the present study suggest that Alkox-mws may be useful as a new dosage form that adheres to the oral mucosa.