RESUMEN

The aim of the present work was to evaluate the effects of Thalassia testudinum hydroethanolic extract, its polyphenolic fraction and thalassiolin B on the activity of phase I metabolizing enzymes as well as their antimutagenic effects. Spectrofluorometric techniques were used to evaluate the effect of tested products on rat and human CYP1A and CYP2B activity. The antimutagenic effect of tested products was evaluated in benzo[a]pyrene (BP)-induced mutagenicity assay by an Ames test. Finally, the antimutagenic effect of Thalassia testudinum (100 mg/kg) was assessed in BP-induced mutagenesis in mice. The tested products significantly (p < 0.05) inhibit rat CYP1A1 activity, acting as mixed-type inhibitors of rat CYP1A1 (Ki = 54.16 ± 9.09 µg/mL, 5.96 ± 1.55 µg/mL and 3.05 ± 0.89 µg/mL, respectively). Inhibition of human CYP1A1 was also observed (Ki = 197.1 ± 63.40 µg/mL and 203.10 ± 17.29 µg/mL for the polyphenolic fraction and for thalassiolin B, respectively). In addition, the evaluated products significantly inhibit (p < 0.05) BP-induced mutagenicity in vitro. Furthermore, oral doses of Thalassia testudinum (100 mg/kg) significantly reduced (p < 0.05) the BP-induced micronuclei and oxidative damage, together with an increase of reduced glutathione, in mice. In summary, Thalassia testudinum metabolites exhibit antigenotoxic activity mediated, at least, by the inhibition of CYP1A1-mediated BP biotransformation, arresting the oxidative and mutagenic damage. Thus, the metabolites of T. testudinum may represent a potential source of chemopreventive compounds for the adjuvant therapy of cancer.

Asunto(s)

Antimutagênicos/farmacología , Benzo(a)pireno/toxicidad , Citocromo P-450 CYP1A1/antagonistas & inhibidores , Inhibidores Enzimáticos del Citocromo P-450/farmacología , Flavonoides/farmacología , Hydrocharitaceae/metabolismo , Polifenoles/farmacología , Salmonella typhi/efectos de los fármacos , Activación Metabólica , Animales , Antimutagênicos/aislamiento & purificación , Benzo(a)pireno/metabolismo , Citocromo P-450 CYP1A1/metabolismo , Citocromo P-450 CYP1A2/metabolismo , Inhibidores del Citocromo P-450 CYP1A2/aislamiento & purificación , Inhibidores del Citocromo P-450 CYP1A2/farmacología , Inhibidores Enzimáticos del Citocromo P-450/aislamiento & purificación , Daño del ADN/efectos de los fármacos , Flavonoides/aislamiento & purificación , Humanos , Isoenzimas , Cinética , Micronúcleos con Defecto Cromosómico/inducido químicamente , Pruebas de Micronúcleos , Estrés Oxidativo/efectos de los fármacos , Polifenoles/aislamiento & purificación , Ratas , Salmonella typhi/genética

RESUMEN

Ageratina havanensis (Kunth) R. M. King & H. Robinson is a species of flowering shrub in the family Asteraceae, native to the Caribbean and Texas. The aim of this work was to compare the quantitative chemical composition of extracts obtained from Ageratina havanensis in its flowering and vegetative stages with the antioxidant potential and to determine the effects on P-glycoprotein (P-gp) function. The quantitative chemical composition of the extracts was determined quantifying their major flavonoids by UPLC-ESI-MS/MS and by PCA analysis. The effects of the extracts on P-gp activity was evaluated by Rhodamine 123 assay; antioxidant properties were determined by DPPH, FRAP and inhibition of lipid peroxidation methods. The obtained results show that major flavonoids were present in higher concentrations in vegetative stage than flowering stage. In particular, the extracts obtained in the flowering season showed a significantly higher ability to sequester free radicals compared to those of the vegetative season, meanwhile, the extracts obtained during the vegetative stage showed a significant inhibitory effect against brain lipid peroxidation and a strong reductive capacity. This study also showed the inhibitory effects of all ethanolic extracts on P-gp function in 4T1 cell line; these effects were unrelated to the phenological stage. This work shows, therefore, the first evidence on: the inhibition of P-gp function, the antioxidant effects and the content of major flavonoids of Ageratina havanensis. According to the obtained results, the species Ageratina havanensis (Kunth) R. M. King & H. Robinson could be a source of new potential inhibitors of drug efflux mediated by P-gp. A special focus on all these aspects must be taking into account for future studies.

Asunto(s)

Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/metabolismo , Ageratina/química , Antioxidantes/química , Antioxidantes/farmacología , Activación del Canal Iónico/efectos de los fármacos , Extractos Vegetales/química , Extractos Vegetales/farmacología , Cromatografía Líquida de Alta Presión , Relación Dosis-Respuesta a Droga , Estructura Molecular , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Espectrometría de Masa por Ionización de Electrospray , Espectrometría de Masas en Tándem

RESUMEN

Medium and high polarity extracts from Maytenus species are known to contain polyphenolic compounds such as proanthocyanidins. The high polarity and structural complexity of these compounds make very difficult their isolation even by modern chromatographic techniques. Maytenus cajalbanica (Borhidi & O. Muñiz) Borhidi & O. Muñiz is endemic from Cuba. So far, there are reports neither of phytochemical work nor of biological evaluation of extracts from this subspecies. The goal of this work is to determine the polyphenolic profile and the antioxidant capacity of the ethanolic extract from the barks of Maytenus cajalbanica. FIA/ESI/IT/MSn analysis allowed the identification of 5 flavan-3-ol monomers, 33 proanthocyanidins, 2 free flavonoids and their respective glycosides as major compounds of the ethanolic extract, which showed a strong radical scavenging capacity and a significant ferric reduction power. FIA/ESI/IT/MSn technique led the rapid, effective and sensitive determination of the polyphenolic profile of Maytenus cajalbanica without previous separation.

Asunto(s)

Antioxidantes/farmacología , Maytenus/química , Extractos Vegetales/farmacología , Polifenoles/análisis , Espectrometría de Masa por Ionización de Electrospray/métodos , Antioxidantes/química , Compuestos de Bifenilo/química , Etanol/química , Flavonoides/análisis , Glicósidos/análisis , Picratos/química , Corteza de la Planta/química , Extractos Vegetales/química , Polifenoles/química , Proantocianidinas/análisis

RESUMEN

The protective effect of the supplementation with an aqueous-ethanolic extract obtained from Ulva lactuca (Delile) green seaweed on benzo[a] pyrene-induced damage in mice was evaluated. Animals were treated with oral doses of U. lactuca extract (100 and 400 mg/kg) for 9 weeks. They were exposed to 50 mg/kg of oral doses of benzo(a)pyrene starting from the second week and up to the fifth week. Groups treated with benzo(a)pyrene only (second to fifth weeks), sunflower oil (vehicle, 9 weeks), or U. lactuca extract (100 and 400 mg/kg, 9 weeks) were also included in the study. The treatment with 400 mg/kg of the extract ameliorated the oxidative damage, decreased IL-1ß and TNF-α levels, and favorably regulated the antioxidant defenses compared with benzo(a)pyrene-exposed group. The benzo(a)pyrene-induced DNA damage was also reduced, as it was evidenced by the lower micronucleus formation in U. lactuca extract-supplemented animals. The extract protected the hepatic tissue, and it reduced the liver activity/expression of CYP1A1. These results altogether suggested a chemoprotective effect of U. lactuca extract against benzo(a)pyrene-induced-toxicity in mice, probably associated with an inhibitory effect of carcinogen bioactivation.

Asunto(s)

Citocromo P-450 CYP1A1/antagonistas & inhibidores , Algas Marinas , Ulva , Animales , Benzo(a)pireno/toxicidad , Suplementos Dietéticos , Hígado/efectos de los fármacos , Hígado/metabolismo , Masculino , Ratones , Ratones Endogámicos BALB C

RESUMEN

OBJECTIVES: Reported antioxidant, anti-inflammatory and neuroprotective properties for one aqueous-ethanolic extract from Thalassia testudinum which grows in the Caribbean Sea compelled us to explore about extract cytotoxic effects. METHODS: Cell viability was assayed on tumour (HepG2, PC12, Caco-2 and 4T1) and non-tumour (VERO, 3T3, CHO, MCDK and BHK2) cell lines. The extract effects upon primary cultures of rat and human hepatocytes and human lymphocytes were assayed. KEY FINDINGS: The extract exhibited cytotoxicity against cancer cells compared to normal cells, and the IC50 values were 102 µg/ml for HepG2, 135 µg/ml for PC12, 165 µg/ml for Caco-2 and 129 µg/ml for 4T1 cells after 48 h, whereas IC50 could not be calculated for normal cells. Additional data from a high-content screening multiparametric assay indicated that after 24-h exposure, the extract (up to 100 µg/ml) induced death in HepG2 cells through oxidative stress-associated mechanism, DNA damage and hypercalcaemia. Comet assay corroborated extract-induced DNA damage. CONCLUSIONS: Thalassia testudinum extract is more cytotoxic and produced more DNA damage on human hepatoma cells than to other non-tumour cells. A possible mechanism is suggested for extract-induced cytotoxicity based on oxidative stress, nuclear damage and hypercalcaemia in HepG2 cells. T. testudinum may be a source for antitumour agents.

Asunto(s)

Antineoplásicos Fitogénicos/farmacología , Etanol/química , Neoplasias/tratamiento farmacológico , Extractos Vegetales/farmacología , Solventes/química , Agua/química , Adulto , Animales , Antineoplásicos Fitogénicos/aislamiento & purificación , Antineoplásicos Fitogénicos/toxicidad , Células CACO-2 , Región del Caribe , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Células Hep G2 , Humanos , Hydrocharitaceae , Concentración 50 Inhibidora , Linfocitos/efectos de los fármacos , Linfocitos/patología , Masculino , Neoplasias/patología , Células PC12 , Extractos Vegetales/aislamiento & purificación , Extractos Vegetales/toxicidad , Cultivo Primario de Células , Ratas , Ratas Sprague-Dawley

RESUMEN

BACKGROUND: The aqueous extract of the Allophylus cominia (L) Sw (Sapindaceae) leaves has shown anti-diabetic, anti-obesity and anti-inflammatory properties. In the Caribbean region, it is typically used for the treatment of type-2 diabetes. METHODS: Considering the herb-drug interaction, the aim of this study was to evaluate the potential effects of the A. cominia extract on the cytochrome P450 (CYP) (rat hepatocyte model) and P-glycoprotein (P-gp) (4T1 cell line) systems. RESULTS: The extract did not decrease the cell viability after being assayed by the MTT test at up to 1500 µg/mL for 72 h. The exposure of the cultured rat hepatocytes to the product (up to 250 µg/mL) for 48 h increased the activities of CYP-1A2, 2C9, and 2E1 by 1.46-, 1.60-, and 1.51-fold, respectively, compared with the controls. The activities of CYP-2B6, 2D6, and 3A4 were not significantly altered, whereas the activity of P-gp decreased by 2- and 4-fold. In addition, the extracts at 100 and 200 µg/mL significantly increased doxorubicin cytotoxicity in these cells 24 h after treatment. CONCLUSIONS: The findings indicate that the A. cominia extract modulates the CYP and P-gp systems increasing sensitivity to doxorubicin. Further studies are necessary to evaluate the potential herb-drug interaction or chemosensitive properties.

Asunto(s)

Sistema Enzimático del Citocromo P-450/efectos de los fármacos , Sistema Enzimático del Citocromo P-450/metabolismo , Interacciones de Hierba-Droga , Extractos Vegetales/farmacología , Sapindaceae/química , Subfamilia B de Transportador de Casetes de Unión a ATP/efectos de los fármacos , Subfamilia B de Transportador de Casetes de Unión a ATP/metabolismo , Animales , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Relación Dosis-Respuesta a Droga , Doxorrubicina/farmacología , Femenino , Masculino , Ratones , Extractos Vegetales/química , Hojas de la Planta/química , Ratas

RESUMEN

The chemical composition and biological properties of Ulva fasciata aqueous-ethanolic extract were examined. Five components were identified in one fraction prepared from the extract by gas chromatography-mass spectrometry, and palmitic acid and its ethyl ester accounted for 76% of the total identified components. Furthermore, we assessed the extract's antioxidant properties by using the DPPH, ABTS, and lipid peroxidation assays and found that the extract had a moderate scavenging effect. In an experiment involving preexposition and coexposition of the extract (1-500 µg/mL) and benzo[a]pyrene (BP), the extract was found to be nontoxic to C9 cells in culture and to inhibit the cytotoxicity induced by BP. As BP is biotransformed by CYP1A and CYP2B subfamilies, we explored the possible interaction of the extract with these enzymes. The extract (25-50 µg/mL) inhibited CYP1A1 activity in rat liver microsomes. Analysis of the inhibition kinetics revealed a mixed-type inhibitory effect on CYP1A1 supersome. The effects of the extract on BP-induced DNA damage and hepatic CYP activity in mice were also investigated. Micronuclei induction by BP and liver CYP1A1/2 activities significantly decreased in animals treated with the extract. The results suggest that Ulva fasciata aqueous-ethanolic extract inhibits BP bioactivation and it may be a potential chemopreventive agent.

RESUMEN

The present study examines the possible effect of the glucosylxanthone mangiferin (MG) on pain-related behaviors in a tonic acute pain model (formalin test at 5%) and in a chronic constriction injury (CCI) model to clarify the underlying transient and long-term mechanisms. Acute administration of MG (10-100mg/kg, i.p.) reduced licking/biting exclusivity in the tonic phase of formalin test in a naloxone and yohimbine-sensitive manner. This effect was enhanced by a nonselective nitric oxide synthase (NOS) inhibitor (NG-monomethyl-L-arginine) and by a non-competitive N-methyl-D-aspartate (NMDA) antagonist (ketamine), but it was reversed by the NOS substrate (L-arginine). Pre-treatment with intrathecal yohimbine prevented the anti-hypernociceptive effect of systemic MG. Pre-treatment during 4 days before surgical and 3 days after CCI with MG (50mg/kg, i.p.) reduced mechanical hypernociception and decreased the signs of Wallerian degeneration (WD) of the sciatic nerve. MG improved the PC-12 cellular viability exposure to glutamate-mediated neuronal death, also involved in neuropathic pain. The findings of this study suggest that MG shows ability to decrease tonic pain in the formalin test. A transient activity of this xanthone on nociceptive pathways mediated by α2 adrenergic receptors in cooperation with the opioid system could be involved, at least in part, in this effect. Its neuroprotective effect by preventing WD in mononeuropathic rats could be implicated in the mechano-antihypernociceptive long term mechanisms.

Asunto(s)

Analgésicos/uso terapéutico , Modelos Animales de Enfermedad , Neuralgia/tratamiento farmacológico , Xantonas/uso terapéutico , Animales , Conducta Animal/efectos de los fármacos , Masculino , Células PC12 , Ratas , Ratas Sprague-Dawley , Xantonas/farmacología

RESUMEN

The aqueous standard extract of Mangifera indica L stem bark (MSBE) is used as a food supplement in Cuba. In this study, the genotoxic effect of MSBE was measured using different variants of the in vitro Comet assay in human lymphocytes and rat hepatocytes incubated with MSBE at 37C for 1 hour. Lymphocytes were incubated with MSBE for the subcellular (at two different pH conditions) and the standard Comet assays, in presence of catalase or S9 microsomal fraction. Hydrogen peroxide, benzo(a)pirene and UV radiation were used as positive controls. Results from standard and subcellular Comet assays clearly showed that MSBE (50 ug/mL) induced primary DNA damage to lymphocytes. This genotoxic effect was slightly reduced when lymphocytes were incubated with MSBE plus catalase, which suggests that hydrogen peroxide is involved in this DNA injury. S9 fraction also decreased MSBE-induced damage to DNA in human lymphocytes. Not genotoxic effect was observed when rat hepatocytes were exposed at MSBE, suggesting that the metabolic activity can be involved in the elimination of the DNA damage generated by the MSBE. In conclusion, MSBE causes primary DNA injury of human lymphocytes in vitro Comet assay, but not in rat hepatocytes in similar conditions.

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El extracto acuoso de la corteza de Mangifera indica L. (MSBE) es usado como suplemento alimenticio en Cuba. En este estudio se determinaron los efectos genotóxicos de MSBE mediante diferentes variantes del ensayo Cometa in vitro en linfocitos humanos y hepatocitos de rata incubados con MSBE a 37C por 1 hora. Los linfocitos fueron incubados con MSBE para la realización de los ensayos Cometa subcelular (a dos condiciones de pH diferentes) y estándar, en presencia de catalasa o fracción microsomal S9. Peróxido de hidrógeno, benzo(a)pireno y radiación UV fueron usados como controles positivos. Los resultados de los ensayos Cometa, tanto subcelular como estándar, mostraron que MSBE (50 ug/mL) indujo daño primario al ADN de los linfocitos. Este efecto genotóxico fue ligeramente reducido cuando las células fueron incubadas con MSBE más catalasa, lo que sugiere que el peróxido de hidrógeno está involucrado en este daño al ADN. La fracción S9 también decreció el daño inducido por MSBE al ADN en linfocitos humanos. No fueron observados efectos genotóxicos cuando los hepatocitos de rata fueron expuestos a MSBE, sugiriendo que la actividad metabólica pudiera estar involucrada en la eliminación del daño al ADN generado por MSBE. En conclusión, MSBE causa daño primario al ADN de linfocitos humanos en el ensayo Cometa in vitro, pero no en hepatocitos de rata bajo condiciones similares.

Asunto(s)

Humanos , Masculino , Ratas , Extractos Vegetales/farmacología , Mangifera/farmacología , Mangifera/química , Catalasa , Ensayo Cometa , Daño del ADN , Genotoxicidad , Hepatocitos , Linfocitos , Ratas Sprague-Dawley , Supervivencia Celular

RESUMEN

The aqueous stem bark extract of Mangifera indica L. (MSBE) has been reported to have antioxidant, anti-inflammatory and analgesic properties. In previous studies, we showed that MSBE and mangiferin, its main component, lower the activity of some cytochrome P-450 (P450) enzymes in rat hepatocytes and human liver microsomes. In the present study, the effects of MSBE and mangiferin on several P450 enzymes and UDP-glucuronosyltransferases (UGTs) in human-cultured hepatocytes have been examined. After hepatocytes underwent a 48-h treatment with sub-cytotoxic concentrations of the products (50-250 µg/mL), a concentration-dependent decrease of the activity of the five P450 enzymes measured (CYP1A2, 2A6, 2C9, 2D6 and 3A4) was observed. For all the activities, a reduction of at least 50% at the highest concentration (250 µg/mL) was observed. In addition, UGT activities diminished. MSBE considerably reduced UGT1A9 activity (about 60% at 250 µg/mL) and lesser effects on the other UGTs. In contrast, 250 µg/mL mangiferin had greater effects on UGT1A1 and 2B7 than on UGT1A9 (about 55% vs. 35% reduction, respectively). Quantification of specific mRNAs revealed reduced CYP3A4 and 3A5 mRNAs content, and an increase in CYP1A1, CYP1A2, UGT1A1 and UGT1A9 mRNAs. No remarkable effects on the CYP2A6, 2B6, 2C9, 2C19, 2D6 and 2E1 levels were observed. Our results suggest that the activity and/or expression of major P450 and UGT enzymes is modulated by MSBE and that potential herb-drugs interactions could arise after a combined intake of this extract with conventional medicines. Therefore, the potential safety risks of this natural product derived by altering the ADMET properties of co-administered drugs should be examined.

Asunto(s)

Sistema Enzimático del Citocromo P-450/metabolismo , Glucuronosiltransferasa/metabolismo , Hepatocitos/efectos de los fármacos , Mangifera/química , Extractos Vegetales/farmacología , Células Cultivadas , Hepatocitos/enzimología , Humanos , Corteza de la Planta/química

RESUMEN

Mangifera indica stem bark extract (MSBE) is a Cuban natural product which has shown strong antioxidant properties. In this work, the antimutagenic effect of MSBE was tested against 10 well-known mutagens/carcinogens in the Ames test in the absence or presence of metabolic fraction (S9). The chemical mutagens tested included: cyclophosphamide, mitomycin C, bleomycin, cisplatin, dimethylnitrosamine (DMNA), benzo[a]pyrene (BP), 2-acetylaminofluorene (2-AAF), sodium azide, 1-nitropyrene (1-NP) and picrolonic acid. Protective effects of the extract were also evaluated by comparing the efficiency of S9 fraction obtained from rats treated during 28 days with oral doses of MSBE (50-500 mg/kg) with that obtained from rats treated with vehicle (control) to activate bleomycin and cyclophosphamide in the Ames test. MSBE concentrations between 50 and 500 µg/plate significantly reduced the mutagenicity mediated by all the chemicals tested with the exception of sodium azide. Higher mutagenicity was found when bleomycin and cyclophosphamide (CP) were activated by control S9 than by MSBE S9. In addition, inhibition of CYP1A1 microsomal activity was observed in the presence of MSBE (10-20 µg/ml). We can conclude that besides its potent antioxidant activity previously reported, MSBE may also exert a chemoprotective effect due to its capacity to inhibit CYP activity.

Asunto(s)

Antimutagênicos/farmacología , Antioxidantes/farmacología , Citocromo P-450 CYP1A1/antagonistas & inhibidores , Hígado/efectos de los fármacos , Mangifera , Microsomas Hepáticos/efectos de los fármacos , Extractos Vegetales/farmacología , Animales , Bleomicina , Carcinógenos , Cuba , Ciclofosfamida , Hígado/metabolismo , Microsomas Hepáticos/metabolismo , Pruebas de Mutagenicidad , Mutágenos , Corteza de la Planta , Tallos de la Planta , Ratas , Ratas Sprague-Dawley

RESUMEN

Meeting report of the "Second Symposium on Pharmacology of Cytochrome P450 and Transporters" organized by the Cuban Society of Pharmacology in collaboration with the European Society of Pharmacogenetics and Theranostics (ESPT) and the Ibero-American Network of Pharmacogenetics and Pharmacogenomics (www.ribef.com). The Symposium covered different topics on pharmacogenetics and its clinical implications, focusing on Latin-American populations. The activities of the ESPT were also presented and discussed. The topics addressed were regulatory aspects, the use of pharmacogenetics in pre-clinical research, herbal medicine, and natural products, ending with a discussion about translation into clinical practice, specifically for cardiovascular disorders and psychiatry. Finally, the implication for population diversity in Latin America was also discussed. The RIBEF initiative represents a promising step towards the inclusion of Latin American populations among those to benefit from the implementation of pharmacogenetics in clinical practice. Among current RIBEF activities, the CEIBA.FP Consortium aims to study the variability of pheno- and genotypes in Hispanics that are relevant to pharmacogenetics. For this purpose, populations from Mexico, Cuba, Nicaragua, Costa Rica, Ecuador, Colombia, Brasil, Perú, Chile, Uruguay, Argentina, Portugal, and Spain are currently being studied. The meeting's main conclusion was that population pharmacogenetic studies as well as academic clinical trials might need to be conducted in the different geographic locations/countries. This is important in order to improve drug safety, dosage recommendations, and pharmacovigilance programs, because environmental and ethnic factors vary across locations.

Asunto(s)

Enfermedades Cardiovasculares/tratamiento farmacológico , Medicina de Hierbas , Trastornos Mentales/tratamiento farmacológico , Farmacogenética , Enfermedades Cardiovasculares/genética , Humanos , América Latina , Trastornos Mentales/genética

RESUMEN

On 26-30 June 2011 the Cuban Society of Pharmacology organized the Second International Congress on Immunopharmacology (Immunopharmacology 2011), held at the beautiful Convention Centre 'Plaza América' and the Meliá Varadero Hotel, in Varadero beach, Cuba. The main topics of the congress were immunopharmacology (including inflammation, cancer immunotherapy and immunomodulation), neuroimmunology, and the pharmacology of cytochrome P450 and transporters, among other relevant and updated related topics. Immunopharmacology 2011 offered an outstanding scientific program with the active contribution of 90 speakers from 23 foreign countries, as well as more than 170 Cuban researchers from the most important local institutions devoted to the development of immunology and pharmacology sciences.

Asunto(s)

Logro , Inmunoterapia/tendencias , Informe de Investigación/tendencias , Ensayos Clínicos como Asunto/métodos , Ensayos Clínicos como Asunto/tendencias , Cuba , Humanos , Inmunoterapia/métodos , Farmacogenética/métodos , Farmacogenética/tendencias

RESUMEN

Mango (Mangifera indica L.) stem bark aqueous extract (MSBE) is a natural product with antioxidant, anti-inflammatory, analgesic, and immunomodulatory effects. Its formulations (e.g., tablets, capsules, syrup, vaginal oval, and suppositories) are known by the brand name of Vimang. In view of the ethnomedical, preclinical, and clinical uses of this extract and the necessity to assess its possible toxicological effect on man, a toxicological analysis of a standard extract is reported in this paper. Acute toxicity was evaluated in mice and rats by oral, dermal, and intraperitoneal (i.p.) administration. The extract, by oral or dermal administration, showed no lethality at the limit doses of 2,000 mg/kg body weight and no adverse effects were found. Deaths occurred with the i.p. administration at 200, but not 20 mg/kg in mice. MSBE was also studied on irritant tests in rabbits, and the results showed that it was nonirritating on skin, ocular, or rectal mucosa. The extract had minimal irritancy following vaginal application.

Asunto(s)

Antioxidantes/toxicidad , Mangifera/química , Extractos Vegetales/toxicidad , Administración Cutánea , Administración Oral , Animales , Antioxidantes/administración & dosificación , Antioxidantes/aislamiento & purificación , Relación Dosis-Respuesta a Droga , Femenino , Inyecciones Intraperitoneales , Masculino , Medicina Tradicional , Ratones , Corteza de la Planta , Extractos Vegetales/administración & dosificación , Conejos , Ratas , Ratas Sprague-Dawley , Pruebas de Toxicidad Aguda

RESUMEN

Different medicinal plants are widely used in Cuba and Mexico to treat several disorders. This paper reports in vitro inhibitory effects on the P450 system of herbal products commonly used by people in Cuba and Mexico in traditional medicine for decades. Experiments were conducted in human liver microsomes. The catalytic activities of CYP1A1/2, 2D6, and 3A4 were measured using specific probe substrates. The Heliopsis longipes extract exhibited a concentration-dependent inhibition of the three enzymes, and similar effects were produced by affinin (an alkamide isolated from the H. longipes extract) and two catalytically reduced alkamides. Mangifera indica L. and Thalassia testudinum extracts, two natural polyphenol-rich extracts, diminished CYP1A1/2 and 3A4 activities, but not the CYP2D6 activity. These results suggest that these herbs inhibit the major human P450 enzymes involved in drug metabolism and could induce potential herbal-drug interactions.

Asunto(s)

Inhibidores Enzimáticos del Citocromo P-450 , Microsomas Hepáticos/efectos de los fármacos , Extractos Vegetales/farmacología , Asteraceae/química , Femenino , Flavonoides/farmacología , Interacciones de Hierba-Droga , Humanos , Hydrocharitaceae/química , Masculino , Mangifera/química , Medicina Tradicional , Microsomas Hepáticos/enzimología , Fenoles/farmacología , Fitoterapia , Plantas Medicinales/metabolismo , Polifenoles , Alcamidas Poliinsaturadas/farmacología

RESUMEN

D-003 is a mixture of very-long-chain aliphatic acids with cholesterol-lowering and concomitant anti-platelet effects. The microsomal cytochrome P-450 system comprises a superfamily of proteins present in hepatic and extrahepatic tissues that is responsible for the metabolism of many drugs. The present study was undertaken to investigate the effects of D-003 on in vivo drug-metabolizing hepatic enzymes. Two experimental series (n = 6 animals/group) were performed. In the first series rats were randomly distributed in one control and two groups treated with D-003 at 1,000 and 2,000 mg/kg for 14 days. In the second one they were distributed in one control and three groups treated with D-003 (250, 500, and 1,000 mg/kg) for 6 months. All treatments were orally administered by gastric gavage. Control rats were orally treated only with acacia gum/water vehicle. The content of microsomal P-450, b (5) cytochromes, total sulfhydryl groups, nonprotein sulfhydryl groups, and protein-bound sulfhydryl groups as well as the activities of NADPH cytochrome c reductase, aminopyrine demethylase, dimethylnitrosamine N-demethylase, 7-ethoxyresorufin O-deethylation, 7-pentoxyresorufin O-depentylation, and cytosolic glutathione S-transferase were assessed. D-003 administered up to 2,000 mg/kg or 1,000 mg/kg during 14 days or 6 months did not affect the activities of the hepatic drug-metabolizing enzymes investigated. It is concluded that D-003 is not metabolized by the liver cytochrome system and that potential risk derived from drug-to-drug interactions between D-003 and concomitant drugs appears to be low.

Asunto(s)

Sistema Enzimático del Citocromo P-450/metabolismo , Ácidos Grasos/farmacología , Hígado/enzimología , Administración Oral , Animales , Relación Dosis-Respuesta a Droga , Interacciones Farmacológicas , Inducción Enzimática/efectos de los fármacos , Masculino , Microsomas Hepáticos/efectos de los fármacos , Microsomas Hepáticos/metabolismo , Distribución Aleatoria , Ratas , Ratas Sprague-Dawley , Factores de Tiempo

RESUMEN

D-003 is a mixture of very long chain aliphatic acids purified from sugar cane wax, wherein octacosanoic acid represents the major component. Previous experimental studies have shown that D-003 inhibits platelet aggregation in rodents. Also, its lowers total (TC) and low-density lipoprotein cholesterol (LDL-C) in normocholesterolemic rabbits in a dose-dependent manner and inhibits cholesterol biosynthesis in fibroblast cultures. The present study was performed to investigate the in vitro cytotoxic and genotoxic potential effects of D-003 assessed through two tests: the neutral red (NR) assay and the Ames test. Positive and negative controls were included in each experimental series. Compared with controls, no cytotoxicity was evident after 24 and 72 h of treatment with doses up to 1,000 microg/ml in the NR assay. On the other hand, D-003 (5-5,000 microg/plate) did not increase the frequency of reverse mutations in the Ames test in both alternatives with or without S9 mix metabolic activation and a pre-incubation step. The positive control chemicals included in each experiment, namely, treatment with sodium dodecyl sulphate (SDS) in the NR assay and sodium azide (NaAz), 2-aminofluorene (AF), and dimethylnitrosamine (DMNA) in the Ames test, induced the expected changes, such as a decrease in optical density (OD) values in the NR assay and an increase in the frequency of reverse mutations in the Ames test. The present results indicate that D-003 did not show evidence of cytotoxic or genotoxic potential in tests able to detect the ability of chemicals to disrupt cells (NR assay) or to induce gene mutations (Ames test).

Asunto(s)

Ácidos Grasos/efectos adversos , Inhibidores de Agregación Plaquetaria/efectos adversos , Células 3T3 , Animales , Relación Dosis-Respuesta a Droga , Ácidos Grasos/metabolismo , Indicadores y Reactivos/farmacología , Ratones , Pruebas de Mutagenicidad , Mutación , Rojo Neutro/farmacología , Salmonella typhimurium/metabolismo , Factores de Tiempo

RESUMEN

Policosanol is a cholesterol-lowering drug purified from sugar cane. Previous toxicological studies have not demonstrated any policosanol-related toxicity, even with long-term oral administration at 500 mg/kg, a dose 1,724 times larger than the maximal therapeutic dose (20 mg/day) recommended to date. The present study was undertaken to investigate the oral toxicity of policosanol administered for 6 months in doses up to 5,000 mg/kg to Sprague-Dawley rats. Animals were randomly distributed in five groups (15 animals per dose per sex): a control and four groups given oral policosanol (50, 500, 2,500, or 5,000 mg/kg). Eight treated rats (6 males, 2 females) died during the study, five of them (4 males, 1 female) from among those receiving the highest dose (5,000 mg/kg). According to necropsy, all deaths were related to gavage manipulation of higher doses. Although the differences were not significant, body weight gain and food consumption in the groups receiving 2,500 or 5,000 mg/kg tended to be lower than in the control group. Nevertheless, no drug-related toxicity symptoms were detected. Analysis of blood biochemistry, hematology, organ weight ratios, and histopathological findings did not show significant differences compared with controls, nor any tendency with the dose. Therefore, the present study did not show any new evidence of oral toxicity of policosanol, and the findings observed were a consequence of long-term administration by gastric gavage of the highly concentrated suspensions needed to reach the higher doses. It is concluded that policosanol chronically administered by the oral route is safe and that no drug-related toxicity was demonstrated.

RESUMEN

D-003 is a mixture of very long chain aliphatic acids purified from sugar cane wax with cholesterol-lowering effects. The present study was undertaken to investigate the in vivo cytotoxic and genotoxic potential of D-003 using three established assays: bone marrow micronucleus, sperm morphology, and single cell gel electrophoresis (Comet) assay. In a first experimental series, CEN/NMRI mice (6-8 animals per sex per group) were administered D-003 by gastric gavage at 5, 50, or 500 mg/kg for 90 days, then sacrificed 24 hours after the last administration. The effects on bone marrow micronucleus were evaluated only in female mice. D-003 (5-500 mg/kg) did not increase the frequency of micronucleated polychromatic erythrocytes, nor the ratio of polychromatic to normochromatic erythrocytes, compared with the controls. The assessment of the effects on sperm morphology showed that D-003 did not change the sperm count or the frequency of all types of abnormal head shapes, compared with the controls. In a second series, the micronucleus assay was performed in mice of both sexes given 2,000 mg/kg for 6 days. Likewise, in this series, neither cytotoxic nor genotoxic effects were found. Finally, five male Sprague-Dawley rats were treated with D-003 (1,250 mg/kg) by oral gavage for 90 days, and Comet assay on liver cells was performed. No single-strand breaks or alkali-labile site induction on DNA was observed. These results indicate that D-003 does not show evidence of cytotoxic or genotoxic activity on either somatic or germ cells in rodents.