Herbal-drug interaction through the pregnane X receptor / Interacción de medicamentos y hierbas a través del receptor de pregnanos X

The interaction potential of Cynara scolymus L., Mikania glomerata Spreng.,Rhamnus purshiana DC and Uncaria tomentosa (Willd. Ex Roem. & Schult.) with conventional drugs metabolized by the CYP3A4 metabolic route was tested in HeLa cell lines, using the in vitro model of the hPXR. The herbal medicines C. scolymus (1.5 mg/mL dry extract) did not affect the receptor. On the other hand, M. glomerata (5.5 mg/mL dry extract), R. purshiana (1.5 mg/mL dry extract), and U. tomentosa (2.0 mg/mL dry extract) showed to be hPXR agonist, suggesting a potential interaction with the conventional drugs metabolized by the same isoforms of the CYP superfamily. The results from this study contribute to the use safer and more effective of these herbal medicines.

Se evaluó el potencial de interacción de Cynara scolymus L., Mikania glomerata Spreng., Rhamnus purshiana DC y Uncaria tomentosa (Willd. Ex Roem. & Schult.) con fármacos convencionales metabolizados por la ruta metabólica CYP3A4 en líneas celulares HeLa, utilizando el modelo in vitro del hPXR. Las hierbas medicinales C. scolymus (1,5 mg/mL de extracto seco) no afectaron al receptor. Por otro lado, M. glomerata (5.5 mg/mL de extracto seco), R. purshiana (1.5 mg/mL de extracto seco) y U. tomentosa (2.0 mg/mL de extracto seco) mostraron ser agonistas de hPXR, lo que sugiere una potencial interacción con los fármacos convencionales metabolizados por las mismas isoformas de la superfamilia CYP. Los resultados de este estudio contribuyen a un uso más seguro y eficaz de estos medicamentos a base de hierbas medicinales.

The dietary supplement of Ginkgo biloba: a comprehensive review of its potential interactions based on pre-clinical and clinical evidences / El suplemento dietético de Ginkgo biloba: una revisión exhaustiva de sus posibles interacciones basada en evidencias clínicas y preclínicas

This review present Gingko biloba (GB) interactions, based on clinical and pre-clinical presentations. Literature was retrieved using databases; ScienceDirect, PubMed, Google scholar, Web of Science, Scopus etc. 14/45 interactions were found with clinical presentations. More interactions (80%) were reported with drugs followed by herbs (11.1%), and nutraceuticals (6.7%) with major mechanisms of interaction observed as; inhibition of Cytochrome metabolizing enzymes (44.4%) and platelet-activating factor (PAF) i.e. 15.6%. Major clinical features were; increased bleeding (eye, parietal), hematomas (subdural), and seizures as well as increased blood pressure, priapism, loss of infection/antiviral failure, and coma. Drugs with major interactions belonged to anti-platelet/anti-coagulant and NSAIDs. Synergistic effects were observed for GB vs herbs (except cannabis which showed rhabdomyolysis), foods, and nutraceuticals (except pyridoxine where neurotoxicity was seen). GB use should be monitored and the patient may seek proper advice from a healthcare professional.

Esta revisión presenta las interacciones de Gingko biloba (GB), basadas en presentaciones clínicas y preclínicas. La literatura se recuperó utilizando bases de datos; ScienceDirect, PubMed, Google Scholar, Web of Science, Scopus, etc. Se encontraron 14/45 interacciones con presentaciones clínicas. Se informaron más interacciones (80%) con fármacos seguidos de hierbas (11,1%) y nutracéuticos (6,7%) con los principales mecanismos de interacción observados como; inhibición de las enzimas metabolizadoras del citocromo (44,4%) y factor activador de plaquetas (PAF), es decir, 15,6%. Las principales características clínicas fueron; aumento de sangrado (ojo, parietal), hematomas (subdural) y convulsiones, así como aumento de la presión arterial, priapismo, pérdida de infección / insuficiencia antiviral y coma. Los fármacos con interacciones importantes pertenecían a los antiplaquetarios/anticoagulantes y los AINE. Se observaron efectos sinérgicos para GB frente a hierbas (excepto cannabis que mostró rabdomiólisis), alimentos y nutracéuticos (excepto piridoxina donde se observó neurotoxicidad). Se debe controlar el uso de GB y el paciente puede buscar el asesoramiento adecuado de un profesional de la salud.

Jugos de fruta y productos herbáceos como perpetradores de interacciones farmacocinéticas mediadas por enzimas metabolizadoras y transportadores de membrana. Relevancia en clínica / Pharmacokinetic interactions of fruit juices and herbal preparations

Drug disposition in the human body is strongly influenced by transporters and metabolizing enzymes expressed in key organs including intestine, liver and kidney. Since drugs and chemicals present in foods such as fruit juices and herb-based products are substrates of the above-mentioned proteins, there is a high probability of pharmacokinetic interactions. Findings from preclinical and clinical studies helped to characterize the mechanisms by which the components of fruit juices and herbs act as perpetrators of pharmacokinetic interactions. The aim of this review is to provide an overview of pharmacokinetic fruit juice- and herb-drug interactions that could be relevant in the clinical setting.

Polyphasic characterization of Gluconacetobacterdiazotrophicus isolates obtained from different sugarcane varieties / Caracterização polifásica de isolados de Gluconacetobacterdiazotrophicus obtidos de diferentes variedades de cana-de-açúcar

A polyphasic approach was applied to characterize 35 G. diazotrophicus isolates obtained from sugarcane varieties cultivated in Brazil. The isolates were analyzed by phenotypic (use of different carbon sources) and genotypic tests (ARDRA and RISARFLP techniques). Variability among the isolates was observed in relation to the carbon source use preference. Glucose and sucrose were used by all isolates in contrast to myo-inositol, galactose and ribose that were not metabolized. The results of the analysis showed the presence of two groups clustered at 68 percent of similarity. The genetic distance was higher when RISA-RFLP analysis was used. Analysis of 16S rDNA sequences from isolates showed that all of them belonged to the G. diazotrophicus species. Neither effect of the plant part nor sugarcane variety was observed during the cluster analysis. The observed metabolic and genetic variability will be helpful during the strain selection studies for sugarcane inoculation in association with sugarcane breeding programs.

Foi realizado a caracterização polifásica de 35 isolados obtidos de variedades de cana-de-açúcar cultivadas no Brasil, através de testes fenotípicos (uso de fontes diferentes de carbono) e genotípicos (técnicas de ARDRA e RISA-RFLP). Houve variação entre os isolados com relação à utilização de fontes de carbono. Glicose e sacarose foram usadas por todos isolados, diferentemente de mio-inositol, galactose e ribose que não foram metabolizados. Os resultados da análise polifásica dos dados confirmam a formação de dois grupos, que apresentaram 68 por cento de similaridade. Observou-se maior distância genética entre os isolados quando a técnica de RISA-RFLP foi aplicada. O sequênciamento da região 16S do rDNA mostrou que todos os isolados pertencem à espécie G. diazotrophicus. Não foi observado efeito da parte da planta ou variedade de cana-de-açúcar no agrupamento dos isolados. Em conjunto, esses resultados poderão auxiliar no estudo de seleção de estirpes para inoculação em cana-de-açúcar, orientando programas de melhoramento vegetal.

The practice of polypharmacy involving herbal and prescription medicines in the treatment of diabetes mellitus, hypertension and gastrointestinal disorders in Jamaica

The interference in the metabolism of a drug by another drug, food or other foreign chemical is commonly observed and often leads to clinically significant adverse drug reactions. In Jamaica, there is an extensive use of natural products as medicines, although there is little information on whether natural medicines are used along with prescription medicines, which might increase the likelihood of drug adversities. This current pilot survey was initiated to gain information on the prevalence of such polypharmacy practices. Two concurrent surveys were carried out in Kingston (an urban parish) and Clarendon (a rural parish) in 743 patients above age 14 years with diabetes mellitus, hypertension and gastrointestinal disorders of persons who visited health centres and pharmacies. Patrons visiting these places at various times of the day were informed of the nature of the questionnaire and willing participants with the above disease conditions and who were on prescription medicines were included in the survey. The results indicated that 80 of the respondents reported combining natural products in their treatment along with prescription medicines, with only 13 of those patients informing their physicians of such practices. Such polypharmacy practices were independent of the type of disease among both males and females and was statistically most prevalent (p < 0.001) in the 47-57-year age group. There was a significant association (p < 0.001) between such treatment practices and place of residence with 92 of the rural community engaging in polypharmacy but 70 of the urban did likewise. Therefore, being aware of the prevalence of multiple therapy practices would be especially useful when designing a pharmaco-vigilance system