RESUMEN
ETHNOPHARMACOLOGICAL RELEVANCE: Tecoma stans aqueous extract (TAE) is widely used as a traditional antidiabetic remedy in Mexico; its rational use is controversial. We provide evidence of its main antidiabetic activities. AIM OF THE STUDY: To evaluate in vivo and in vitro intestinal alpha-glucosidases inhibition as the possible mode of action of TAE on type 2 diabetes mellitus (DM2) animal models, and to test the effects of its sub-chronic administration on lipids and glucose blood levels. MATERIALS AND METHODS: In healthy and streptozotocin (STZ)-induced diabetic male Sprague-Dawley rats, glucose or cornstarch was administered after an oral dose of TAE, acarbose, tolbutamide or vehicle, in order to build starch and glucose tolerance curves (STC and GTC). An intestinal brush border preparation was used to evaluate the TAE alpha-glucosidases inhibitory activity. Moreover, in STZ-induced diabetic rats TAE, tolbutamide or vehicle was administered for 21 days for evaluate their effects on fasting glucose cholesterol and triglycerides. Also, TAE total phenolic compounds were quantified. RESULTS: In STC, TAE decreased hyperglycemic peak values in both healthy and STZ-treated rats, in a magnitude similar to that of acarbose. The in vitro preparation showed a dose-dependent inhibition of glucose release from starch. Sub-chronic administration of TAE significantly reduced cholesterol and triglycerides levels. Moreover, we confirmed that acute and sub-chronic administration of TAE (500mg/kg) in both rat models did not diminish fasting glucose and did not modify the GTC. CONCLUSIONS: The study present evidence that the main antidiabetic effect of TAE is due to intestinal alpha-glucosidase inhibition by decreasing the postprandial hyper-glycaemia peak; in addition, TAE sub-chronic administration reduces triglycerides and cholesterol, without modifying fasting glucose.
Asunto(s)
Bignoniaceae , Colesterol/sangre , Diabetes Mellitus Experimental/tratamiento farmacológico , Hipoglucemiantes/uso terapéutico , Fitoterapia , Extractos Vegetales/uso terapéutico , Triglicéridos/sangre , Acarbosa/farmacología , Animales , Bignoniaceae/química , Glucemia/metabolismo , Diabetes Mellitus Experimental/metabolismo , Femenino , Prueba de Tolerancia a la Glucosa , Inhibidores de Glicósido Hidrolasas , Hipoglucemiantes/farmacología , Mucosa Intestinal/metabolismo , Intestinos/efectos de los fármacos , Masculino , Ratones , Ratones Endogámicos BALB C , Fenoles/análisis , Extractos Vegetales/farmacología , Ratas , Ratas Sprague-Dawley , Almidón , Tolbutamida/farmacologíaRESUMEN
Cecropia obtusifolia and Marrubium vulgare have been widely used in Mexican traditional medicine for the control of type 2 diabetes. In order to evaluate the clinical effect produced by the aqueous extract from these species on type 2 non-controlled diabetes mellitus, a total of 43 outpatients were included. Based on the European NIDDM (policy group) criteria, only patients with poor response to the conventional treatment were selected. All patients maintained their medical treatment and also received a prepared infusion of the dry leaves of the plant treatment for 21 days. In a double-blind manner, the patients were randomly grouped as follows: 22 patients were treated with C. obtusifolia and 21 with M. vulgare. The fasting blood glucose values were reduced by 15.25% on patients treated with C. obtusifolia, while cholesterol and triglycerides were decreased by 14.62% and 42.0%, respectively (ANOVA p< 0.02). In the case of patients treated with M. vulgare, the plasma glucose level was reduced by 0.64% and cholesterol and triglycerides by 4.16% and 5.78%, respectively. When the results were compared between groups, significant differences in glucose and cholesterol diminution were found. The obtained results showed that the infusion prepared with the leaves of C. obtusifolia (containing 2.99+/-0.14mg of chlorogenic acid/g of dried plant) produced beneficial effects on carbohydrate and lipid metabolisms when it was administered as an adjunct on patients with type 2 diabetes with poor response to conventional medical treatment.
Asunto(s)
Glucemia/efectos de los fármacos , Cecropia/química , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Marrubium/química , Administración Oral , Adulto , Método Doble Ciego , Femenino , Humanos , Hipercolesterolemia/tratamiento farmacológico , Hipertrigliceridemia/tratamiento farmacológico , Masculino , Persona de Mediana Edad , Extractos Vegetales/administración & dosificación , Extractos Vegetales/química , Extractos Vegetales/farmacología , Hojas de la Planta/químicaRESUMEN
Baccharis serraefolia is a widely used plant to treat diarrhoea in Mexican traditional medicine. Although the methanolic extract of this plant has shown an important dose-dependent spasmolytic activity, its underlying mechanism has not been studied. In the present work, the methanolic extract of B. serraefolia significantly delayed the onset of tonic seizures induced by strychnine and pentylenetetrazol; besides, it diminished the death rate and number of animals that exhibited convulsions. It produced potentiation of the hypnotic effect of pentobarbital. Oral administration produced an inhibition of gastrointestinal transit in mice as effective as that produced by loperamide. As to the effect on smooth muscles, the active extract produced an inhibition of contraction induced electrically, which could not be reversed by naloxone. The calcium concentration-contraction curve showed a rightward displacement when the extract was added to isolated guinea pig ileum depolarized with high K+ and cumulative concentrations of Ca2+. The results suggest that the methanolic extract does not interact with classical opiate receptors and its effects, at least that produced on smooth muscle, may be due to a probable interference with calcium influx and/or calcium release from an intra-cellular store.