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1.
J Toxicol Sci ; 42(4): 461-473, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28717105

RESUMEN

The herb Ephedra sinica (also known as Chinese ephedra or Ma Huang), used in traditional Chinese medicine, contains alkaloids identical to ephedrine and pseudoephedrine as its principal active constituents. Recent studies have reported that ephedrine has various side effects in the cardiovascular and nervous systems. In addition, herbal Ephedra, a plant containing many pharmacologically active alkaloids, principally ephedrine, has been reported to cause acute hepatitis. Many studies reported clinical cases, however, the cellular mechanism of liver toxicity by ephedrine remains unknown. In this study, we investigated hepatotoxicity and key regulation of mitophagy in ephedrine-treated LX-2 cells. Ephedrine triggered mitochondrial oxidative stress and depolarization. Mitochondrial swelling and autolysosome were observed in ephedrine-treated cells. Ephedrine also inhibited mitochondrial biogenesis, and the mitochondrial copy number was decreased. Parkin siRNA recovered the ephedrine-induced mitochondrial damage. Excessive mitophagy lead to cell death through imbalance of autophagic flux. Moreover, antioxidants and reducing Parkin level could serve as therapeutic targets for ephedrine-induced hepatotoxicity.


Asunto(s)
Enfermedad Hepática Inducida por Sustancias y Drogas/etiología , Efedrina/toxicidad , Células Estrelladas Hepáticas/efectos de los fármacos , Mitocondrias Hepáticas/efectos de los fármacos , Mitocondrias Hepáticas/metabolismo , Mitofagia/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Antioxidantes/uso terapéutico , Autofagia , Muerte Celular , Células Cultivadas , Enfermedad Hepática Inducida por Sustancias y Drogas/terapia , Ephedra sinica/química , Efedrina/aislamiento & purificación , Dosificación de Gen/efectos de los fármacos , Humanos , Lisosomas/efectos de los fármacos , Mitocondrias Hepáticas/genética , Mitocondrias Hepáticas/patología , Dilatación Mitocondrial/efectos de los fármacos , Terapia Molecular Dirigida , Biogénesis de Organelos , ARN Interferente Pequeño/efectos de los fármacos , Ubiquitina-Proteína Ligasas/genética
2.
Braz. j. pharm. sci ; 52(1): 59-68, Jan.-Mar. 2016. tab, graf
Artículo en Inglés | LILACS | ID: lil-789072

RESUMEN

ABSTRACT The association of p-synephrine, ephedrine, salicin, and caffeine in dietary supplements and weight loss products is very common worldwide, even though ephedrine has been prohibited in many countries. The aim of this study was to evaluate a 28-day oral exposure toxicity profile of p-synephrine, ephedrine, salicin, and caffeine mixture (10:4:6:80 w/w respectively) in male and female Wistar rats. Body weight and signs of toxicity, morbidity, and mortality were observed daily. After 28 days, animals were euthanized and blood collected for hematological, biochemical, and oxidative stress evaluation. No clinical signs of toxicity, significant weight loss or deaths occurred, nor were there any significant alterations in hematological parameters. Biochemical and oxidative stress biomarkers showed lipid peroxidation, and hepatic and renal damage (p < 0.05; ANOVA/Bonferroni) in male rats (100 and 150 mg/kg) and a reduction (p < 0.05; ANOVA/Bonferroni) in glutathione (GSH) levels in all male groups. Female groups displayed no indications of oxidative stress or biochemical alterations. The different toxicity profile displayed by male and female rats suggests a hormonal influence on mixture effects. Results demonstrated that the tested mixture can alter oxidative status and promote renal and hepatic damages.


RESUMO A associação de p-sinefrina, efedrina, salicina, e cafeína em suplementos alimentares e produtos para perda de peso é muito utilizada em todo o mundo, embora a efedrina tenha sido proibida em muitos países. O objetivo deste estudo foi avaliar o perfil de toxicidade à exposição oral de 28 dias à associação de p-sinefrina, efedrina, salicina e cafeína (na proporção de 10:4:6:80 m/m respectivamente) em ratos Wistar machos e fêmeas. Diariamente, os animais foram observados quanto ao peso corporal, sinais de toxicidade, morbidade e mortalidade. Após 28 dias, os animais foram sacrificados e o sangue coletado para avaliações hematológicas, bioquímicas e de estresse oxidativo. Não se observaram sinais clínicos de toxicidade, tampouco perda significativa de peso, mortes, ou quaisquer alterações significativas nos parâmetros hematológicos. Biomarcadores do estresse oxidativo e bioquímicos mostraram peroxidação lipídica, danos renais e hepáticos (p < 0,05; ANOVA/Bonferroni) em ratos machos (100 e 150 mg/kg) e a redução (p < 0,05; ANOVA/Bonferroni) nos níveis de glutationa reduzida (GSH) em todos os grupos de machos tratados. Nas fêmeas, não houve indícios de estresse oxidativo, nem alterações bioquímicas. O diferente perfil de toxicidade entre os gêneros sugere influência hormonal nos efeitos de mistura administrada. A associação testada pode alterar o estado oxidativo e promover danos renais e hepáticos.


Asunto(s)
Ratas , Cafeína/toxicidad , Biomarcadores/análisis , Sinefrina/toxicidad , Salicinum/toxicidad , Estrés Oxidativo , Efedrina/toxicidad , Pérdida de Peso/efectos de los fármacos , Suplementos Dietéticos/análisis
3.
Food Chem Toxicol ; 78: 207-13, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25684415

RESUMEN

Some dietary supplements may contain cardiac stimulants and potential cardiotoxins. In vitro studies may identify ingredients of concern. A beating human cardiomyocyte cell line was used to evaluate cellular effects following phenylethylamine (PEA), higenamine, ephedrine or caffeine treatment. PEA and higenamine exposure levels simulated published blood levels in humans or animals after intravenous administration. Ephedrine and caffeine levels approximated published blood levels following human oral intake. At low or midrange levels, each chemical was examined plus or minus 50 µM caffeine, simulating human blood levels reported after consumption of caffeine-enriched dietary supplements. To measure beats per minute (BPM), peak width, etc., rhythmic rise and fall in intracellular calcium levels following 30 min of treatment was examined. Higenamine 31.3 ng/ml or 313 ng/ml significantly increased BPM in an escalating manner. PEA increased BPM at 0.8 and 8 µg/ml, while 80 µg/ml PEA reduced BPM and widened peaks. Ephedrine produced a significant BPM dose response from 0.5 to 5.0 µM. Caffeine increased BPM only at a toxic level of 250 µM. Adding caffeine to PEA or higenamine but not ephedrine further increased BPM. These in vitro results suggest that additional testing may be warranted in vivo to further evaluate these effects.


Asunto(s)
Alcaloides/toxicidad , Cafeína/toxicidad , Suplementos Dietéticos/toxicidad , Efedrina/toxicidad , Miocitos Cardíacos/efectos de los fármacos , Fenetilaminas/toxicidad , Tetrahidroisoquinolinas/toxicidad , Animales , Cardiotónicos/toxicidad , Cardiotoxicidad/patología , Células Cultivadas , Corazón/efectos de los fármacos , Humanos , Ratas , Pruebas de Toxicidad
4.
Int J Toxicol ; 31(2): 184-91, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22408069

RESUMEN

p-Synephrine is an adrenergic amine found in Citrus aurantium L. fruits and has been used for weight loss in dietary supplements. There are commercial products containing this substance associated to caffeine, salicin, and ephedrine. The aim of this study was to evaluate the acute toxicity of this mixture in mice of both sexes. The significative results observed after acute oral administration to male and female mice of 300, 350, and 400 mg/kg total of p-synephrine, ephedrine, salicin, plus caffeine in a 10:4:6:80 w/w ratio included a reduction in locomotor activity and ptosis in all treated groups for both sexes. Seizures were also observed in male (400 mg/kg) and female groups (350 and 400 mg/kg). Gasping and tearing were observed in males. Salivation (400 mg/kg), agitation (350 and 400 mg/kg), and piloerection (all treated groups) were significantly observed only in females. Deaths occurred in males at 350 and 400 mg/kg treated groups and the necropsy showed cardiopulmonary hemorrhage. A reduction in locomotor activity was confirmed through the spontaneous locomotor activity test, in which the number of crossings considerably decreased (P < .01) in all treated groups. The rotarod test showed a decrease in motor coordination at 400 mg/kg. Body temperature decreased significantly (P < .01) in all treated groups compared to controls. The results suggested clear signs of toxicity of p-synephrine, ephedrine, salicin, and caffeine association; this toxicity augments the attentiveness on commercial products containing this mixture, given the expressive number of adverse events related to its utilization.


Asunto(s)
Fármacos Antiobesidad/toxicidad , Alcoholes Bencílicos/toxicidad , Cafeína/toxicidad , Efedrina/toxicidad , Glucósidos/toxicidad , Sinefrina/toxicidad , Adrenérgicos/toxicidad , Animales , Ataxia/inducido químicamente , Temperatura Corporal , Estimulantes del Sistema Nervioso Central/toxicidad , Combinación de Medicamentos , Femenino , Masculino , Ratones , Actividad Motora/efectos de los fármacos
5.
BMJ Case Rep ; 20112011 Dec 13.
Artículo en Inglés | MEDLINE | ID: mdl-22669965

RESUMEN

A 36-year-old man presented to the emergency department acutely unwell after being found collapsed while running a halfmarathon. He presented with a reduced Glasgow coma score, was tachycardic, agitated, hypoxic and profusely sweating. He had taken a 'supplement' given to him prior to the race by a friend, as he was concerned about not finishing. This contained both caffeine and a large dose of ephedrine (60 mg in total). After initial resuscitation he was intubated, and was transferred to critical care. He subsequently developed rhabdomyolysis, requiring haemofiltration.


Asunto(s)
Suplementos Dietéticos/toxicidad , Efedrina/toxicidad , Sustancias para Mejorar el Rendimiento/toxicidad , Rabdomiólisis/inducido químicamente , Carrera , Simpatomiméticos/toxicidad , Adulto , Humanos , Masculino
6.
Arch Toxicol ; 83(1): 95-9, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18651134

RESUMEN

Formulations containing Ephedra sinica Stapf. (Ephedraceae) and Citrus aurantium L. (Rutaceae) are consumed worldwide for body weight control. Considering the related adverse effects and the risk potential, the aim of this study is to evaluate the effects of the thermogenic compounds ephedrine, p-sinephrine, E. sinica and C. aurantium in the female reproductive system through the uterotrophic assay in immature female rats. The animals (n = 6-7) received E. sinica 85.5 and 855.0 mg/kg/day, C. aurantium 25.0 and 50.0 mg/kg/day, ephedrine 5.0 mg/kg/day and p-synephrine 50.0 mg/kg/day for three consecutive days by oral gavage. For detection of antiestrogenicity, tamoxifen 20.0 mg/kg/day, E. sinica 855.0 mg/kg/day, C. aurantium 50.0 mg/kg/day, ephedrine 5.0 mg/kg/day and p-synephrine 50.0 mg/kg/day were administered to estrogen-treated females. Macroscopical alterations were evaluated in liver, kidneys, adrenals and uterus. All analyzed substances showed an antiestrogenic potential, but only ephedrine at 0.5 mg/kg/day presented a significative antiestrogenic effect (P < 0.01). Adrenals relative mass were reduced (P < 0.01) in all tested compounds when compared to the control, which seems to be related to the alfa-1-adrenoceptor agonist activity, which promote a vasoconstriction and reduction of the liquid in the organ. The endocrine system is highly complex and there are a number of ways in which a chemical may interfere with it, other in vivo and in vitro assays are being necessary to support this mechanism of action.


Asunto(s)
Citrus/química , Ephedra sinica/química , Efedrina/toxicidad , Sinefrina/toxicidad , Administración Oral , Glándulas Suprarrenales/efectos de los fármacos , Glándulas Suprarrenales/metabolismo , Adrenérgicos/aislamiento & purificación , Adrenérgicos/toxicidad , Agonistas alfa-Adrenérgicos/aislamiento & purificación , Agonistas alfa-Adrenérgicos/toxicidad , Animales , Relación Dosis-Respuesta a Droga , Efedrina/aislamiento & purificación , Moduladores de los Receptores de Estrógeno/aislamiento & purificación , Moduladores de los Receptores de Estrógeno/toxicidad , Femenino , Extractos Vegetales/administración & dosificación , Extractos Vegetales/toxicidad , Ratas , Ratas Wistar , Sinefrina/aislamiento & purificación , Útero/efectos de los fármacos , Útero/metabolismo
7.
Toxicol Pathol ; 35(5): 657-64, 2007 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-17676524

RESUMEN

Ma Huang (equivalent to 0, 12.5, 25, or 50 mg/kg ephedrine) or ephedrine (0, 6.25, 12.5, 25 mg/kg) were administered as one bolus oral dose to male F344 rats with and without caffeine. The herbal medicine Ma Huang (ephedra) in combination with caffeine caused rapid clinical signs of toxicity including salivation, hyperactivity, ataxia, and eventually lethargy, and failure to respond to stimuli. When this syndrome of clinical signs emerged, animals were moribund sacrificed, and a histological analysis for heart lesions performed. Cardiotoxicity included hemorrhage, necrosis, and degeneration in the ventricles or interventricular septum within 2-4 hours after treatment with Ma Huang (ephedra)/caffeine or ephedrine (the principal active component in Ma Huang)/caffeine. There was a steep dose response curve for cardiotoxicity with minimal toxicity seen at levels of Ma Huang (equivalent to 12.5 mg/kg ephedrine) with caffeine. However, cardiotoxic lesions occurred in 28% of animals with Ma Huang dosages equivalent to 25 mg/kg ephedrine with 15 or 30 mg/kg caffeine, and in 90% of animals at Ma Huang exposures equivalent to 50 mg/kg ephedrine with 15 or 30 mg/kg caffeine. Cardiotoxic lesions occurred in 47% of animals in the 25 mg/kg ephedrine groups with caffeine at 7.25, 15, or 30 mg/kg. There was no statistical difference in the occurrence of cardiotoxic lesions when 15 or 30 mg/kg caffeine was combined with Ma Huang equivalent to 25 or 50 mg/kg ephedrine; likewise there was no statistical difference in the occurrence of cardiotoxic lesions when 7.25, 15, or 30 mg/kg caffeine was combined with 25 mg/kg ephedrine. These results show that the cardiotoxic effects of the herbal medicine, Ma Huang, are similar to that of ephedrine, the principal active ingredient in the herbal medicine. The combination of Ma Huang or ephedrine with caffeine enhanced the cardiotoxicity over that with the herbal medicine or the active ingredient alone.


Asunto(s)
Cafeína/toxicidad , Ephedra sinica/toxicidad , Efedrina/toxicidad , Corazón/efectos de los fármacos , Animales , Masculino , Modelos Animales , Miocardio/patología , Ratas , Ratas Endogámicas F344
8.
Lupus ; 14(4): 293-307, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-15864916

RESUMEN

The dietary supplement and adrenergic receptor agonist ephedrine has been a controversial topic as its safety has been questioned. Beta-adrenergic receptor (beta-AR) activation causes immunomodulation, which may contribute to promotion of autoimmune pathology. This report investigated the ability of ephedrine to exacerbate processes associated with autoimmune disease in a lupus-prone mouse model. To mimic human supplementation, ephedrine was administered to NZM391 (lupus-prone) and BALB/c (nonlupus prone) mice orally twice a day for three months at a dose of 50 and 100 microg/day. Some ephedrine-treated NZM391 mice also were preadministered the beta-AR antagonist propranolol to investigate beta-AR involvement. Mice were bled monthly, and sera were assayed for a variety of lupus manifestations and immunological measurements. In NZM391 males and females, both doses of ephedrine significantly increased lupus manifestations, including IgG production and organ-directed autoantibody titers, and significantly lowered the ratio of IgG2a/IgG1 compared to controls. Ephedrine significantly decreased female lifespan and significantly increased circulating populations of plasma cells (CD38(hi) CD19(lo) cytoplasmic IgG+) and CD40+ B1a cells, while preventing an age-related decrease in the B1a cell population expressing a high level of CD5. While ephedrine induced gender-specific immunomodulation in BALB/c mice, increases in the lupus manifestations of anti-dsDNA titers and serum urea nitrogen were not detected. Preadministration of propranolol decreased lupus manifestations and serum levels of IgG and IgE in ephedrine-treated mice, but did not block the shift towards IgG1 production. These findings indicate that ephedrine via beta-AR can exacerbate lupus symptoms in NZM391 mice and that blockade of the beta-ARs on B cells, and not T cells, apparently was of greater importance as the inhibition of lupus symptoms corresponded to an inhibition of immunoglobulin levels, not a change of Th1/Th2 balance.


Asunto(s)
Agonistas Adrenérgicos beta/toxicidad , Suplementos Dietéticos/toxicidad , Efedrina/toxicidad , Lupus Eritematoso Sistémico/etiología , Antagonistas Adrenérgicos beta/farmacología , Animales , Fármacos Antiobesidad/toxicidad , Autoanticuerpos/biosíntesis , Subgrupos de Linfocitos B/efectos de los fármacos , Subgrupos de Linfocitos B/inmunología , Femenino , Inmunoglobulina G/biosíntesis , Longevidad/efectos de los fármacos , Lupus Eritematoso Sistémico/inmunología , Masculino , Ratones , Ratones Endogámicos BALB C , Células Plasmáticas/efectos de los fármacos , Propranolol/farmacología , Subgrupos de Linfocitos T/efectos de los fármacos , Subgrupos de Linfocitos T/inmunología
9.
Am J Physiol Heart Circ Physiol ; 288(5): H2219-24, 2005 May.
Artículo en Inglés | MEDLINE | ID: mdl-15653753

RESUMEN

Human consumption of ephedrine and caffeine in dietary supplements has been associated with a number of adverse effects including changes in the ECG, myocardial infarction, hyperthermia, and, in rare instances, death. The purpose of this study was to investigate the potential mechanisms associated with the cardiotoxicity of combined ephedrine and caffeine ingestion. Seven- and fourteen-week-old Fischer 344 rats treated with ephedrine in combination with caffeine exhibited increases in heart rate (HR), temperature, and corrected QT interval. Of the 14-wk-old rats treated with 25 mg/kg ephedrine plus 30 mg/kg caffeine, 57% died within 3-5 h of treatment, whereas none of the similarly treated 7-wk-old rats nor any of the rats treated with vehicle died. One hour after treatment with this dose of ephedrine plus caffeine, 14-wk-old rats exhibited a larger increase in HR (as % increase over baseline) than 7-wk-old rats. Furthermore, the 14-wk-old rats that died had a higher HR and temperature than the 14-wk-old rats that lived. Histopathological studies suggested interstitial hemorrhage and myofiber necrosis in the 14-wk-old rats treated with the highest concentration of ephedrine and caffeine. This study showed enhanced susceptibility to ephedrine plus caffeine in 14-wk-old rats compared with 7-wk-old rats. The greater mortality in the 14-wk-old rats was associated with increases in body temperature, HR, and myocardial necrosis.


Asunto(s)
Cafeína/toxicidad , Estimulantes del Sistema Nervioso Central/toxicidad , Efedrina/toxicidad , Fiebre/inducido químicamente , Frecuencia Cardíaca/efectos de los fármacos , Factores de Edad , Animales , Temperatura Corporal/efectos de los fármacos , Sinergismo Farmacológico , Electrocardiografía/efectos de los fármacos , Fiebre/mortalidad , Fiebre/patología , Técnicas In Vitro , Masculino , Músculos Papilares/efectos de los fármacos , Músculos Papilares/patología , Ratas , Ratas Endogámicas F344
10.
Toxicol Sci ; 83(2): 388-96, 2005 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-15537744

RESUMEN

Because of possible side effects of herbal medicines containing ephedrine and guarana-derived caffeine, including increased risk of stroke, myocardial infarction, and sudden death, the Food and Drug Administration recently banned the sale of ephedra-containing products, specifically over-the-counter dietary supplements. We report cardiac in 7- and 14-week-old male F344 rats exposed by gavage to ephedrine(25 mg/kg) and caffeine (30 mg/kg) administered in combination for one or two days. The ephedrine-caffeine dosage was approximately 12- and 1.4-fold, respectively, above average human exposure, based on a mg/m2 body surface-area comparison. Several (5/7) of the exposed 14-week-old rats died or were sacrificed in extremis 4-5 h after the first dosing. In these hearts, changes were observed chiefly in the interventricular septum but also left and right ventricular walls. Massive interstitial hemorrhage, with degeneration of myofibers, occurred at the subendocardial myocardium of the left ventricle and interventricular septum. Immunostaining for cleaved caspase-3 and hyperphosphorylated H2A.X, a histone variant that becomes hyperphosphorylated during apoptosis, indicated multifocal generalized positive staining of degenerating myofibers and fragmenting nuclei, respectively. The Barbeito-Lopez trichrome stain revealed generalized patchy yellow myofibers consistent with degeneration and/or coagulative necrosis. In ephedrine-caffeine-treated animals terminated after the second dosing, foci of myocardial degeneration and necrosis were already infiltrated by mixed inflammatory cells. The myocardial necrosis may occur secondarily to intense diffuse vasoconstriction of the coronary arterial system with decreased myocardial perfusion. Our work shows the direct relationship between combined ephedrine and caffeine exposure and cardiac pathology.


Asunto(s)
Adrenérgicos/toxicidad , Cafeína/toxicidad , Estimulantes del Sistema Nervioso Central/toxicidad , Muerte Súbita/etiología , Efedrina/toxicidad , Infarto del Miocardio/inducido químicamente , Enfermedad Aguda , Administración Oral , Animales , Cafeína/administración & dosificación , Caspasa 3 , Caspasas/metabolismo , Estimulantes del Sistema Nervioso Central/administración & dosificación , Combinación de Medicamentos , Interacciones Farmacológicas , Efedrina/administración & dosificación , Corazón/efectos de los fármacos , Hemorragia/inducido químicamente , Hemorragia/patología , Masculino , Infarto del Miocardio/metabolismo , Infarto del Miocardio/patología , Miocardio/metabolismo , Miocardio/patología , Necrosis , Ratas , Ratas Endogámicas F344 , Coloración y Etiquetado
11.
J Toxicol Clin Toxicol ; 41(6): 849-53, 2003.
Artículo en Inglés | MEDLINE | ID: mdl-14677795

RESUMEN

The temporal association of symptoms consistent with ephedrine toxicity after ingestion of ephedrine-containing dietary supplements is heavily relied upon to confirm exposure. Few reports in the literature attempt to associate toxicity with serum levels of these drugs. We report a case of ephedrine-induced cardiac ischemia confirmed by a plasma level. A 22-year-old woman ingesting an ephedrine- and caffeine-containing product for 2 days presented with multiple symptoms, including palpitations, nausea, tremulousness, abdominal pain, and vomiting. The initial electrocardiogram (ECG) revealed a normal sinus rhythm with 1 mm of ST segment depression in leads V3 and V4, along with inverted T waves in leads V1-V4. Her symptoms and ST segment depression resolved over several hours with medical management. The amplitude of her T wave inversions notably diminished with therapy; however, they did not completely resolve. Troponins at presentation and the following morning were negative, and an echocardiogram showed only trace tricuspid regurgitation. A serum ephedrine level, drawn approximately 6 to 7 hr after ingestion, was 150 ng/mL. She was discharged from the hospital after being instructed to avoid ephedrine-containing products.


Asunto(s)
Efedrina/toxicidad , Isquemia Miocárdica/inducido químicamente , Vasoconstrictores/toxicidad , Adulto , Ecocardiografía , Electrocardiografía/efectos de los fármacos , Efedrina/sangre , Femenino , Humanos , Isquemia Miocárdica/sangre , Troponina/sangre , Vasoconstrictores/sangre
12.
Toxicol Lett ; 125(1-3): 151-66, 2001 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-11701234

RESUMEN

Multiple doses of the dietary supplement L-ephedrine can cause severe hyperthermia and modest dopamine depletions in the rat brain. Since D-amphetamine treatment can result in neurodegeneration, the potential of L-ephedrine to produce similar types of degeneration was investigated. Adult male rats, some implanted in the caudate/putamen (CPu) for microdialysis, were given four doses of 25 mg/kg L-ephedrine or 5 mg/kg D-amphetamine (2 h between doses) at an ambient temperature of 23 degrees C. L-ephedrine-induced degeneration in the forebrain was dependent on the degree of hyperthermia. Layer IV of the parietal cortex was the most sensitive to L-ephedrine treatment with peak body temperatures of at most 40.0 degrees C necessary to produce degeneration. Extensive neurodegeneration in the parietal cortex after L-ephedrine treatment was as pronounced as that previously described for D-amphetamine treatment and also occurred in the intralaminar, ventromedial and ventrolateral thalamic nuclei in rats with severe hyperthermia (peak body temperatures>41.0 degrees C). The neurodegeneration induced by L-ephedrine may have resulted in part from excitotoxic mechanisms involving the indirect pathways of the basal ganglia and related areas. No differences were observed between microdialysis and non-implanted rats with respect to degree of tyrosine hydroxylase (TH) loss in the CPu after either D-amphetamine or L-ephedrine treatment. However, neurodegeneration resulting from D-amphetamine and L-ephedrine was reduced in the microdialysis animals in the hemisphere ipsilateral to the probe, which raises concerns when using the technique of in vivo microdialysis to evaluate neurodegeneration. The results of this study, in conjunction with human clinical evaluation of ephedrine neurotoxicity, indicate that regionally specific damage may occur in the cortex of some humans exposed to ephedrine in the absence of stroke or hemorrhage.


Asunto(s)
Núcleo Caudado/efectos de los fármacos , Efedrina/toxicidad , Fiebre/inducido químicamente , Microdiálisis , Enfermedades Neurodegenerativas/inducido químicamente , Lóbulo Parietal/efectos de los fármacos , Putamen/efectos de los fármacos , Tálamo/efectos de los fármacos , Animales , Dextroanfetamina/toxicidad , Efedrina/sangre , Masculino , Ratas , Ratas Sprague-Dawley , Tirosina 3-Monooxigenasa/metabolismo
13.
Toxicol Sci ; 56(2): 424-30, 2000 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10911002

RESUMEN

Ma-huang is a traditional Chinese medicinal herb derived from EPHEDRA: sinica Stapf and other EPHEDRA: species, used to treat asthma, nose and lung congestion, and fever with anhidrosis. It contains 0.5-2.5% by weight of total alkaloids, of which ephedrine accounts for 30 to 90%. Recently, large amounts of ma-huang were used as a source of ephedrine in many dietary supplements formulated for weight reduction, because ephedrine has been found effective in inducing weight loss in diet-restricted obese patients. However, indiscriminate consumption of ma-huang-containing products has resulted in many cases of poisoning, some of which were fatal. The objective of this study is to investigate the relative toxicity of ma-huang extracted under different conditions. The toxicities of various extracts were assayed using MTT colorimetry on a battery of cell lines, while ephedrine alkaloids were analyzed with HPLC. The results are summarized as follows. (1) The cytotoxicity of all ma-huang extracts could not be totally accounted for by their ephedrine contents, suggesting the presence of other toxins in the extracts. (2) Grinding was a significant condition enhancing the toxicity of the extracts. (3) The relatively high sensitivity of the Neuro-2a cell line to the toxicity of ma-huang extracts suggests that the toxic principles were acting on neuronal cells. (4) One condition to produce a ma-huang extract with high ephedrine-to-toxins ratio would be to boil the whole herb for two h.


Asunto(s)
Medicamentos Herbarios Chinos/toxicidad , Ephedra sinica , Efedrina/toxicidad , Supervivencia Celular/efectos de los fármacos , Colorimetría , Efedrina/aislamiento & purificación , Humanos , Hígado/efectos de los fármacos , Preparaciones de Plantas , Sales de Tetrazolio/metabolismo , Tiazoles/metabolismo , Células Tumorales Cultivadas
14.
Nihon Yakurigaku Zasshi ; 75(2): 201-6, 1979 Mar.
Artículo en Japonés | MEDLINE | ID: mdl-535822

RESUMEN

Effect of various combinations of Platycodi Radix water soluble extracts (Pla), 1-ephedrine (1-eph), d-pseudoephedrine (d-pseudo) and Ipecacuanhae Radix water soluble extracts (Ipe) on acute toxicity were examined in mice. Oral LD50 of Ipe, d-pseudo and 1-eph was 490 (415--578) mg/kg, 1550 (1360--1767) mg/kg and 1400 (1102--1778) mg/kg, respectively, while that of Pla was over 10 g. LD50 of Pla Ipe, d-pseudo and 1-eph given intraperitoneally was 1400 (1228--1596) mg/kg 235 (210--263) mg/kg, 245 (229--262) mg/kg and 300 (259--348) mg/kg, respectively. The ratio of the predicted LD50 value, which was calculated on the assumption that each component drug would be additively toxic when combined, to the observed LD50 value was used for comparison. The combination of d-pseudo with Pla gave a significantly greater LD50 value than the predicted LD50 value, while the combination of 1-eph with Pla showed a LD50 value which was not significantly different from Finney's additive model. A combination of d-pseudo with 1-eph and Ipe, and of 1-eph with Ipe showed a LD50 value which was not significantly different from that of the additive model.


Asunto(s)
Efedrina/toxicidad , Extractos Vegetales/toxicidad , Plantas Medicinales , Animales , Combinación de Medicamentos , Interacciones Farmacológicas , Dosificación Letal Mediana , Masculino , Ratones , Estereoisomerismo
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