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1.
Artículo en Inglés | MEDLINE | ID: mdl-35368765

RESUMEN

Background: Chronic kidney disease (CKD) is a critical public health issue with a huge financial burden for both patients and society worldwide. Unfortunately, there are currently no efficacious therapies to prevent or delay the progression of end-stage renal disease (ESRD). Traditional Chinese medicine practices have shown that Cordyceps militaris (C. militaris) mycelia have a variety of pharmacologically useful properties, including antitumor, immunomodulation, and hepatoprotection. However, the effect of mycelial C. militaris on CKD remains unclear. Methods: Here, we investigated the effects of C. militaris mycelia on mice with CKD using four types of media: HKS, HKS with vitamin A (HKS + A), CM, and CM with vitamin A (CM + A). Results: The results at day 10 revealed that the levels of blood urea nitrogen (BUN) were significantly lower in the HKS (41%), HKS + A (41%), and CM + A (34%) groups compared with those in the corresponding control groups (nephrectomic mice). The level of serum creatinine in the HKS + A group decreased by 35% at day 10, whereas the levels in the HKS and CM + A groups decreased only by 14% and 13%, respectively, on day 30. Taken together, this is the first report using four new media (HKS, HKS + A, CM, and CM + A medium) for C. militaris mycelia. Each medium of mycelial C. militaris on CKD exhibits specific effect on BUN, serum creatinine, body weight, total protein, and uric acid. Conclusions: Taken together, this is the first report using four new media (HKS, HKS + A, CM, and CM + A medium) for C. militaris mycelia. Each medium of mycelial C. militaris on CKD exhibits specific effects on BUN, serum creatinine, body weight, total protein, and uric acid. We concluded that treatment with C. militaris mycelia cultured in HKS or CM + A medium could potentially prevent the deterioration of kidney function in mice with CKD.

2.
Front Pharmacol ; 11: 575704, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33328984

RESUMEN

Cordyceps militaris (C. militaris) is a fungus with a long history of widespread use in folk medicine, and its biological and medicinal functions are well studied. A crucial pharmacological effect of C. militaris is immunomodulation. In this review, we catalog the immunomodulatory effects of different extracts of C. militaris, namely total extracts, polysaccharides and cordycepin. Total extracts obtained using water or 50% ethyl alcohol and polysaccharides from C. militaris were discovered to tend to promote type 1 immunity, whereas total extracts obtained using 70-80% ethyl alcohol and cordycepin from C. militaris were more likely to promote type 2 immunity. This article is the first to classify the immunomodulatory effects of different extracts of C. militaris. In addition, we discovered a relationship between different segments or extracts and differing types of immunity. This review can provide the readers a comprehensive understanding on the immunomodulatory effects of the precious folk medicine and guidance on its use for both health people and those with an immunodeficiency.

3.
Mater Sci Eng C Mater Biol Appl ; 110: 110676, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32204104

RESUMEN

Obesity and type 2 diabetes have become serious health problems in 21st century. Development of non-invasive treatment to treat obesity and type-2 diabetes is still unmet needs. For targeting on this, one of the promising treatments is to implant an intestine sleeve in the gastrointestinal tract for limitation of food absorption. In this context, biodegradable polymer intestine sleeve was composed of polycaprolactone (PCL), poly-DL-lactic acid (PDLLA) and disk-shape nano-clay (Laponite®), and fabricated as an implantable device. Here, Laponite® as a rheological additive to improve the compatibility of PCL and PDLLA, and the polymers/clay composites were also evaluated by scanning electron microscopy SEM analysis and mechanical measurements. The mass ratio 90/10/1 of PCL/PDLLA/Laponite® composite was selected for fabrication of intestine sleeve, because of the highest toughness and flexibility, which are tensile strength of 91.9 N/mm2 and tensile strain of 448% at the failure point. The prepared intestine sleeve was implanted and deployed at the duodenum in type2 diabetic rats, providing significant benefits in control of the body weight and blood glucose, while compared with the non-implanted type 2 diabetic rats. More importantly, the food intake records and histopathological section reports presented that the implanted rats still have normal appetites and no noticeable acute symptoms of inflammation in the end of the test. These appreciable performances suggested the implantation of biocompatible polymer composites has a highly potential treatment for obesity and type 2 diabetes.


Asunto(s)
Arcilla/química , Diabetes Mellitus Experimental/terapia , Diabetes Mellitus Tipo 2/terapia , Intestinos/cirugía , Nanocompuestos/química , Obesidad/terapia , Polímeros/química , Prótesis e Implantes , Animales , Diabetes Mellitus Tipo 2/patología , Intestinos/diagnóstico por imagen , Nanocompuestos/ultraestructura , Obesidad/patología , Poliésteres/química , Implantación de Prótesis , Ratas Sprague-Dawley , Resistencia a la Tracción
4.
J Pharmacol Exp Ther ; 358(1): 125-37, 2016 07.
Artículo en Inglés | MEDLINE | ID: mdl-27189974

RESUMEN

The amyloid-ß peptide (Aß)-in particular, the 42-amino acid form, Aß1-42-is thought to play a key role in the pathogenesis of Alzheimer's disease (AD). Thus, several therapeutic modalities aiming to inhibit Aß synthesis or increase the clearance of Aß have entered clinical trials, including γ-secretase inhibitors, anti-Aß antibodies, and amyloid-ß precursor protein cleaving enzyme inhibitors. A unique class of small molecules, γ-secretase modulators (GSMs), selectively reduce Aß1-42 production, and may also decrease Aß1-40 while simultaneously increasing one or more shorter Aß peptides, such as Aß1-38 and Aß1-37. GSMs are particularly attractive because they do not alter the total amount of Aß peptides produced by γ-secretase activity; they spare the processing of other γ-secretase substrates, such as Notch; and they do not cause accumulation of the potentially toxic processing intermediate, ß-C-terminal fragment. This report describes the translation of pharmacological activity across species for two novel GSMs, (S)-7-(4-fluorophenyl)-N2-(3-methoxy-4-(3-methyl-1H-1,2,4-triazol-1-yl)phenyl)-N4-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidine-2,4-diamine (BMS-932481) and (S,Z)-17-(4-chloro-2-fluorophenyl)-34-(3-methyl-1H-1,2,4-triazol-1-yl)-16,17-dihydro-15H-4-oxa-2,9-diaza-1(2,4)-cyclopenta[d]pyrimidina-3(1,3)-benzenacyclononaphan-6-ene (BMS-986133). These GSMs are highly potent in vitro, exhibit dose- and time-dependent activity in vivo, and have consistent levels of pharmacological effect across rats, dogs, monkeys, and human subjects. In rats, the two GSMs exhibit similar pharmacokinetics/pharmacodynamics between the brain and cerebrospinal fluid. In all species, GSM treatment decreased Aß1-42 and Aß1-40 levels while increasing Aß1-38 and Aß1-37 by a corresponding amount. Thus, the GSM mechanism and central activity translate across preclinical species and humans, thereby validating this therapeutic modality for potential utility in AD.


Asunto(s)
Secretasas de la Proteína Precursora del Amiloide/metabolismo , Péptidos beta-Amiloides/antagonistas & inhibidores , Compuestos de Anilina/farmacología , Compuestos de Anilina/farmacocinética , Encéfalo/efectos de los fármacos , Hidrocarburos Aromáticos con Puentes/farmacología , Hidrocarburos Aromáticos con Puentes/farmacocinética , Pirimidinas/farmacología , Pirimidinas/farmacocinética , Péptidos beta-Amiloides/líquido cefalorraquídeo , Péptidos beta-Amiloides/genética , Compuestos de Anilina/química , Animales , Encéfalo/enzimología , Encéfalo/metabolismo , Hidrocarburos Aromáticos con Puentes/química , Línea Celular , Perros , Relación Dosis-Respuesta a Droga , Evaluación Preclínica de Medicamentos , Femenino , Humanos , Macaca fascicularis , Pirimidinas/química , Ratas Sprague-Dawley , Receptores Notch/metabolismo , Especificidad de la Especie , Distribución Tisular
5.
Exp Ther Med ; 10(5): 1817-1823, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26640555

RESUMEN

The aim of the present study was to examine the effect of the traditional Chinese medicine Qili qiangxin on cardiomyocyte apoptosis following myocardial infarction (MI) in a rat model. MI was induced in rats by ligation of the anterior descending coronary artery. Survivors were randomly divided into the sham operation, MI, and Qili qiangxin groups (4 g/kg per day). After 28 days, infarction size was measured. In the non-infarcted zones (NIZ), the apoptotic index (AI) was measured by terminal deoxynucleotidyl transferase (TdT)-mediated digoxigenin-conjugated dUTP nick-end labeling (TUNEL). Expression of Fas was detected by immunohistochemistry, and the expression of xanthine oxidase (XO) and caspase-3 by western blot analysis. In addition, the XO and ·O2-, ·OH-scavenging activity of myocardial tissue in NIZ was measured by colorimetry. Compared to the MI group, AI and the expression of Fas and caspase-3 were significantly decreased in NIZ. The activity of XO was also considerably reduced while ·O2- and ·OH-scavenging activity was significantly increased in the Qili qiangxin group. Ventricular remodeling was attenuated but there were no significant differences in infarct size (IS) or XO expression levels between the Qili qiangxin and MI groups. In conclusion, the results suggest that Qili qiangxin may inhibit cardiomyocyte apoptosis in NIZ in rats. The potential mechanism involved may be associated with its ability to reduce reactive oxygen species (ROS) and to depress the expression of Fas and caspase-3.

6.
Saudi Med J ; 31(9): 999-1004, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20844811

RESUMEN

OBJECTIVE: To evaluate the effects of the different types of manipulation on prostate total specific antigen (tPSA), free prostate specific antigen (fPSA), and free-to-total prostate specific antigen (f/tPSA). METHODS: A total of 160 males were enrolled from January 2006 to December 2009 in the Urology Department, Beijing Anzhen Hospital affiliated to the Capital Medical University, Beijing, China. Of these patients, 23 had digital rectal examination (DRE), 21 had urethral catheterization, 28 had rigid cystoscopy, 35 had prostate biopsy, 35 underwent transurethral resection of the prostate (TURP), and 18 underwent suprapubic prostatectomy. Blood samples were taken before, at 24 hours, and 4 weeks after the manipulation for PSA tests. RESULTS: The DRE had no significant effect on PSA. Catheterization and cystoscopy exerted significant increases in tPSA at 24 hours. However, these small increases may not be clinically significant. The fPSA and f/tPSA were not significantly changed. There was a marked increase in tPSA and fPSA, associated with a decrease in f/tPSA at 24 hours after biopsy. No significant alterations were found in tPSA, fPSA, and f/tPSA at 4 weeks after catheterization, cystoscopy, and biopsy. The TURP and prostatectomy caused significant increases in tPSA and fPSA at 24 hours, associated with decreases in f/tPSA. The tPSA and fPSA values were below the baseline levels at 4 weeks after TURP and prostatectomy, however, f/tPSA remained constant. CONCLUSION: The DRE, catheterization, and cystoscopy had no crucial effect on PSA. Prostatic biopsy, TURP and prostatectomy significantly affected the PSA levels, and their longitudinal courses should be considered while evaluating different forms of PSA levels.


Asunto(s)
Antígeno Prostático Específico/análisis , Próstata/metabolismo , Anciano , Anciano de 80 o más Años , Biopsia con Aguja/efectos adversos , Cistoscopía/efectos adversos , Tacto Rectal/efectos adversos , Humanos , Masculino , Persona de Mediana Edad , Próstata/patología , Prostatectomía/efectos adversos , Resección Transuretral de la Próstata/efectos adversos , Cateterismo Urinario/efectos adversos
7.
Psychopharmacology (Berl) ; 187(4): 415-23, 2006 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16810505

RESUMEN

RATIONALE: The multidrug resistance transporter, P-glycoprotein (P-gp), is involved in efflux transport of several antipsychotics in the blood-brain barrier (BBB). OBJECTIVES: In the present study, we evaluated the inhibitory effect of the antipsychotics, i.e., risperidone, olanzapine, quetiapine, clozapine, haloperidol, chlorpromazine, a major metabolite of risperidone, 9-OH-risperidone, and a positive control inhibitor, PSC833, on the cellular uptake of a prototypic substrate of P-gp, rhodamine (Rhd) 123, in LLC-PK1 and L-MDR1 cells. MATERIALS AND METHODS: After incubation of the antipsychotics (1-100 microM) and the positive (10 microM PSC833) or negative (1% dimethyl sulfoxide) controls with 5 microM Rhd 123 for 1 h, the effects of the antipsychotics on the intracellular accumulation of Rhd 123 were examined using a flow cytometric method. RESULTS: All the antipsychotics showed various degrees of inhibitory effects on P-gp activity. The rank order of the concentration of inhibitor to cause 50% of the maximal increment of intracellular Rhd 123 fluorescence (EC(50)) was: PSC833 (0.5 microM) < olanzapine (3.9 microM) < chlorpromazine (5.8 microM) < risperidone (6.6 microM) < haloperidol (9.1 microM) < quetiapine (9.8 microM) < 9-OH-risperidone (12.5 microM) < clozapine (30 microM). Considering that the antipsychotics' plasma concentrations are generally lower than 1 microM, the present results suggest that olanzapine and risperidone are the only agents that may inhibit P-gp activity in the BBB. However, most of the antipsychotics are extensively accumulated in tissues. In addition, when given orally, the drug concentrations in the gastrointestinal tract are likely to be high. CONCLUSIONS: Pharmacokinetic interactions due to inhibition of P-gp activity by the antipsychotics appear possible and warrant further investigation.


Asunto(s)
Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/antagonistas & inhibidores , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/metabolismo , Antipsicóticos/farmacología , Evaluación Preclínica de Medicamentos , Risperidona/farmacología , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/genética , Animales , Benzodiazepinas/farmacología , Clorpromazina/farmacología , Clozapina/farmacología , Ciclosporinas/farmacología , Dibenzotiazepinas/farmacología , Relación Dosis-Respuesta a Droga , Evaluación Preclínica de Medicamentos/métodos , Interacciones Farmacológicas , Citometría de Flujo/métodos , Colorantes Fluorescentes/metabolismo , Haloperidol/farmacología , Isoxazoles/farmacología , Riñón/efectos de los fármacos , Riñón/metabolismo , Células LLC-PK1 , Hígado/efectos de los fármacos , Hígado/metabolismo , Olanzapina , Palmitato de Paliperidona , Pirimidinas/farmacología , Fumarato de Quetiapina , Rodamina 123/metabolismo , Porcinos , Transfección
8.
Phytother Res ; 19(10): 901-6, 2005 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-16261523

RESUMEN

St John's wort extract (SJW; Hypericum perforatum L.) is taken extensively as a putative herbal antidepressant. It has been shown to induce the activity of cytochrome P-450 3A4 (CYP3A4) and to increase the clearance of numerous drugs and steroids such as cortisol and ethinyl estradiol. This study was conducted to determine if SJW exposure also alters the concentrations of circulating androgenic steroid hormones. The study was conducted using healthy volunteers (6M, 6F) studied before and after a 14-day treatment period with a SJW preparation previously demonstrated to induce the activity of CYP3A4. Plasma concentrations of testosterone, dihydrotestosterone (DHT), dehydroepiandrosterone sulfate (DHEAS), sex hormone-binding globulin (SHBG) and the combined concentrations of androsterone sulfate (AoS) and epiandrosterone sulfate (epiAoS) were measured by immunoassay methods. The results of analysis demonstrated that SJW did not significantly alter the majority of the androgens studied (p > 0.05) although the combined concentrations of the 5alpha-reduced steroids, AoS and epiAoS, significantly declined following treatment in all subjects (p = 0.02), and in males (p = 0.04). Furthermore, the testosterone to DHT ratio was increased in both men and women. Although the latter increase did not reach statistical significance, it is also consistent with the possible inhibition of 5alpha-reductase by SJW. It is concluded that despite significant induction of CYP3A4, short term administration of SJW does not significantly alter the concentrations of most circulating androgens in men and women but may produce a dimunition in some of the circulating 5alpha-reduced androgens.


Asunto(s)
Andrógenos/sangre , Antidepresivos/farmacología , Hypericum , Fitoterapia , Extractos Vegetales/farmacología , Adulto , Androsterona/análogos & derivados , Androsterona/sangre , Antidepresivos/administración & dosificación , Antidepresivos/uso terapéutico , Estudios Cruzados , Citocromo P-450 CYP3A , Sistema Enzimático del Citocromo P-450/efectos de los fármacos , Sulfato de Deshidroepiandrosterona/sangre , Dihidrotestosterona/sangre , Femenino , Humanos , Masculino , Proyectos Piloto , Extractos Vegetales/administración & dosificación , Extractos Vegetales/uso terapéutico , Valores de Referencia , Globulina de Unión a Hormona Sexual/efectos de los fármacos , Testosterona/sangre
9.
Pharmacotherapy ; 25(10): 1337-40, 2005 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-16185177

RESUMEN

STUDY OBJECTIVE: To determine if a standardized ginkgo supplement significantly alters concentrations of circulating androgenic steroids in humans. DESIGN: Open-label, fixed-treatment order, crossover study. SETTING: University general clinical research center. SUBJECTS: Eleven healthy volunteers (six men, five women). INTERVENTION: Volunteers received ginkgo biloba 240 mg/day for 14 days. MEASUREMENTS AND MAIN RESULTS: Plasma concentrations of cortisol, 11-deoxycortisol, 17alpha-hydroxyprogesterone, testosterone, dihydrotestosterone, dehydroepiandrosterone sulfate, sex hormone-binding globulin, androstenedione, and free testosterone, as well as free androgen index and combined concentrations of androsterone sulfate and epiandrosterone sulfate, were analyzed in all subjects before and after their 14-day course of ginkgo biloba. Ginkgo biloba did not significantly alter endogenous steroid levels compared with baseline values (p < 0.05). CONCLUSION: A 14-day oral administration of a widely used, standardized ginkgo extract at a generally advocated dosage of 240 mg/day did not significantly alter concentrations of major circulating steroids in men and women.


Asunto(s)
Extractos Vegetales/farmacología , Esteroides/sangre , Adulto , Androstenodiona/sangre , Estudios Cruzados , Sulfato de Deshidroepiandrosterona/sangre , Dihidrotestosterona/sangre , Femenino , Ginkgo biloba , Humanos , Hidrocortisona/sangre , Masculino , Proyectos Piloto , Globulina de Unión a Hormona Sexual/análisis , Testosterona/sangre
10.
Drug Metab Dispos ; 32(12): 1333-6, 2004 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-15328251

RESUMEN

Valerian (Valeriana officinalis) is a popular dietary supplement. The objective of this study was to assess the influence of a valerian extract on the activity of the drug-metabolizing enzymes cytochrome P450 2D6 (CYP2D6) and 3A4. Probe drugs dextromethorphan (30 mg; CYP2D6 activity) and alprazolam (2 mg; CYP3A4 activity) were administered orally to healthy volunteers (n = 12) at baseline and again after exposure to two 500-mg valerian tablets (1000 mg) nightly for 14 days. The valerian supplement contained a total valerenic acid content of 5.51 mg/tablet. Dextromethorphan to dextorphan metabolic ratios (DMRs) and alprazolam pharmacokinetics were determined at baseline and after valerian treatment. The DMR was 0.214 +/- 0.025 at baseline and 0.254 +/- 0.026 after valerian supplementation (p > 0.05). For alprazolam, the maximum concentration in plasma was significantly increased after treatment with valerian (25 +/- 7 ng/ml versus 31 +/- 8 ng/ml; p < 0.05). There were no significant differences in other pharmacokinetic parameters at baseline and after valerian exposure (all p values > or = 0.05; time to reach maximum concentration in plasma, 3.0 +/- 3.2 versus 3.1 +/- 2.1 h; area under the plasma concentration versus time curve, 471 +/- 183 versus 539 +/- 240 hx ng x ml(-1); half-life of elimination, 13.5 +/- 4.3 versus 12.2 +/- 5.6 h). Our results indicate that although a modest increase was observed in the alprazolam Cmax, typical doses of valerian are unlikely to produce clinically significant effects on the disposition of medications dependent on the CYP2D6 or CYP3A4 pathways of metabolism.


Asunto(s)
Citocromo P-450 CYP2D6/metabolismo , Sistema Enzimático del Citocromo P-450/metabolismo , Valeriana/química , Adulto , Alprazolam/farmacocinética , Cromatografía Líquida de Alta Presión , Estudios Cruzados , Citocromo P-450 CYP3A , Dextrometorfano/farmacocinética , Dextrorfano/farmacocinética , Interacciones Farmacológicas , Femenino , Semivida , Humanos , Masculino , Preparaciones Farmacéuticas/metabolismo , Extractos Vegetales/administración & dosificación , Extractos Vegetales/farmacología
11.
Drug Metab Dispos ; 32(9): 906-8, 2004 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-15319329

RESUMEN

Green tea extract is a widely used dietary supplement. The objective of this study was to assess the influence of a decaffeinated green tea (DGT; Camellia sinensis) extract on the activity of the drug-metabolizing enzymes cytochrome P-450 2D6 and 3A4. Probe drugs dextromethorphan (30 mg, CYP2D6 activity) and alprazolam (ALPZ; 2 mg, CYP3A4 activity) were administered orally to healthy volunteers (n = 11) at baseline, and again after treatment with four DGT capsules/day for 14 days. Each DGT capsule contained 211 +/- 25 mg of green tea catechins and <1 mg of caffeine. Dextromethorphan metabolic ratios (DMRs) and alprazolam pharmacokinetics were determined at baseline and after DGT treatment. There were no significant differences in ALPZ pharmacokinetics at baseline and after DGT treatment (all P values >/= 0.05; maximum concentration in plasma, 33 +/- 8 versus 34 +/- 13 ng/ml; time to reach maximum concentration in plasma, 1.4 +/- 1.2 versus 1.4 +/- 1.2 h; area under the plasma concentration versus time curve, 480 +/- 119 versus 510 +/- 107 h. ng. ml(-1); half-life of elimination, 12.3 +/- 1.7 versus 13.1 +/- 3.4 h). The DMR was 0.053 +/- 0.045 at baseline and 0.041 +/- 0.032 after DGT supplementation (P > 0.05). The plasma concentration of the green tea flavonoid, (-)-epigallocatechin gallate, reached 1.3 +/- 1.8 microM 2 h after DGT treatment. Our results indicate that DGT is unlikely to alter the disposition of medications primarily dependent on the CYP2D6 or CYP3A4 pathways of metabolism.


Asunto(s)
Camellia sinensis/química , Catequina/análogos & derivados , Catequina/farmacología , Citocromo P-450 CYP2D6/fisiología , Sistema Enzimático del Citocromo P-450/fisiología , Extractos Vegetales/farmacología , Administración Oral , Adulto , Alprazolam/administración & dosificación , Alprazolam/sangre , Alprazolam/farmacocinética , Cápsulas , Catequina/sangre , Catequina/química , Citocromo P-450 CYP3A , Dextrometorfano/administración & dosificación , Dextrometorfano/sangre , Dextrometorfano/farmacocinética , Suplementos Dietéticos/análisis , Esquema de Medicación , Femenino , Semivida , Humanos , Masculino , Extractos Vegetales/química , Extractos Vegetales/metabolismo , Hojas de la Planta/química , Factores de Tiempo
12.
Clin Pharmacol Ther ; 74(6): 536-42, 2003 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-14663456

RESUMEN

Saw palmetto (Serenoa repens) is the most commonly used herbal preparation in the treatment of benign prostatic hyperplasia. The objective of this study was to determine whether a characterized saw palmetto product affects the activity of cytochrome P450 (CYP) 2D6 or 3A4 in healthy volunteers (6 men and 6 women). The probe substrates dextromethorphan (CYP2D6 activity) and alprazolam (CYP3A4 activity) were administered orally at baseline and again after exposure to saw palmetto (320-mg capsule once daily) for 14 days. Dextromethorphan metabolic ratios and alprazolam pharmacokinetics were determined at baseline and after saw palmetto treatment. The mean ratio of dextromethorphan to its metabolite was 0.038 +/- 0.044 at baseline and 0.048 +/- 0.080 after 14 days of saw palmetto administration (P =.704, not significant [NS]), indicating a lack of effect on CYP2D6 activity. The area under the plasma alprazolam concentration versus time curve was 476 +/- 178 h. ng. mL(-1) at baseline and 479 +/- 125 h. ng. mL(-1) after saw palmetto treatment (P =.923, NS), indicating a lack of effect on CYP3A4 activity. The elimination half-life of alprazolam was 11.4 +/- 3.1 hours at baseline and 11.6 +/- 2.7 hours after saw palmetto treatment (P =.770, NS), also indicating a lack of effect on CYP3A4 activity. Our results indicate that extracts of saw palmetto at generally recommended doses are unlikely to alter the disposition of coadministered medications primarily dependent on the CYP2D6 or CYP3A4 pathways for elimination. These conclusions must be weighed in the context of the study's limited assessments and regarded as only the initial investigation into the drug interaction potential of saw palmetto.


Asunto(s)
Alprazolam/farmacocinética , Antagonistas de Andrógenos/farmacología , Ansiolíticos/farmacocinética , Antitusígenos/metabolismo , Citocromo P-450 CYP2D6/metabolismo , Sistema Enzimático del Citocromo P-450/metabolismo , Dextrometorfano/metabolismo , Extractos Vegetales/farmacología , Adulto , Antagonistas de Andrógenos/administración & dosificación , Área Bajo la Curva , Citocromo P-450 CYP3A , Relación Dosis-Respuesta a Droga , Interacciones Farmacológicas , Femenino , Semivida , Humanos , Masculino , Tasa de Depuración Metabólica , Serenoa
13.
JAMA ; 290(11): 1500-4, 2003 Sep 17.
Artículo en Inglés | MEDLINE | ID: mdl-13129991

RESUMEN

CONTEXT: St John's wort is a popular herbal product used to treat depression but it has been implicated in drug interactions. OBJECTIVE: To assess the potential of St John's wort administration to alter the activity of the cytochrome P450 (CYP) enzymes extensively involved in drug metabolism. DESIGN, SETTING, AND PARTICIPANTS: Open-label crossover study with fixed treatment order conducted March 2002 to February 2003 in a US general clinical research center involving 12 healthy volunteers (6 men and 6 women) aged 22 to 38 years before and after 14 days of administration of St John's wort. INTERVENTION: Participants were given probe drugs (30 mg of dextromethorphan and 2 mg of alprazolam) to establish baseline CYP 3A4 and CYP 2D6 activity. After a minimum 7-day washout period, participants began taking one 300-mg tablet 3 times per day. After 14 days of St John's wort administration, participants were given the probe drugs along with 1 St John's wort tablet to establish postadministration CYP activity; the St John's wort dosing regimen was continued for 48 hours. MAIN OUTCOME MEASURES: Changes in plasma pharmacokinetics of alprazolam as a probe for CYP 3A4 activity and the ratio of dextromethorphan to its metabolite, dextrorphan, in urine as a probe for CYP 2D6 activity. RESULTS: A 2-fold decrease in the area under the curve for alprazolam plasma concentration vs time (P<.001) and a 2-fold increase in alprazolam clearance (P<.001) were observed following St John's wort administration. Alprazolam elimination half-life was shortened from a mean (SD) of 12.4 (3.9) hours to 6.0 (2.4) hours (P<.001). The mean (SD) urinary ratio of dextromethorphan to its metabolite was 0.006 (0.010) at baseline and 0.014 (0.025) after St John's wort administration (P =.26). CONCLUSIONS: A 14-day course of St John's wort administration significantly induced the activity of CYP 3A4 as measured by changes in alprazolam pharmacokinetics. This suggests that long-term administration of St John's wort may result in diminished clinical effectiveness or increased dosage requirements for all CYP 3A4 substrates, which represent at least 50% of all marketed medications.


Asunto(s)
Sistema Enzimático del Citocromo P-450/metabolismo , Interacciones Farmacológicas , Hypericum , Extractos Vegetales/farmacología , Adulto , Alprazolam/farmacocinética , Estudios Cruzados , Citocromo P-450 CYP2D6/metabolismo , Citocromo P-450 CYP3A , Dextrometorfano/metabolismo , Inducción Enzimática/efectos de los fármacos , Femenino , Humanos , Masculino , Especificidad por Sustrato
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