RESUMEN
In the present study, the intracellular free calcium concentration ([Ca(2+)](i)) in acutely isolated rat dorsal root ganglia (DRG) neurons modulated by loureirin B, an active component of "dragon's blood" which is a kind of Chinese herbal medicine, was determined by the means of Fura-2 based microfluorimetry. It was found that loureirin B could evoke the elevation of [Ca(2+)](i) in a dose-dependent manner. However, the elevation of [Ca(2+)](i) evoked in the calcium free solution was much smaller than that in the standard external cell solution, suggesting that most change of [Ca(2+)](i) was generated by the influx of extracellular Ca(2+), not by the activities of intracellular organelles like Ca(2+) stores and mitochondria. In addition, the mixture of loureirin B and caffeine also induced [Ca(2+)](i) rise, but the peak of [Ca(2+)](i) rise induced by the mixture was significantly lower than that by caffeine alone, which means the triggering pathway and the targets of caffeine are probably involved in loureirin B-induced [Ca(2+)](i) rise. Moreover, compared to the transients induced by caffeine, KCl and capsaicin, the loureirin B-induced [Ca(2+)](i) rise is much slower and more stable. These results indicate that the capability of loureirin B of inducing the [Ca(2+)](i) rise is solid and unique.
Asunto(s)
Calcio/metabolismo , Neuronas Aferentes/efectos de los fármacos , Resinas de Plantas/farmacología , Animales , Cafeína/farmacología , Ganglios Espinales/efectos de los fármacos , Ganglios Espinales/metabolismo , Neuronas Aferentes/metabolismo , RatasRESUMEN
The active fraction extracted from dragon's blood displayed an inhibitory effect on alpha-glucosidase activity with an IC50 of 0.152 microg/mL, which is nearly half of the crude material. Its inhibition on alpha-glucosidase was noncompetitive. In addition, when this fraction was orally administered to mice dosed with Acarbose (20 mg/kg), the active fraction (100, 300, 500 mg/kg) significantly suppressed increase of blood glucose levels after sucrose loading in a dose-dependent manner. These results suggest that this extract from dragon's blood exerts an anti-diabetic effect by suppressing intestinal carbohydrate absorption and thereby reducing the postprandial increase of blood glucose.
Asunto(s)
Diabetes Mellitus Experimental/tratamiento farmacológico , Dracaena/química , Inhibidores de Glicósido Hidrolasas , Hipoglucemiantes/aislamiento & purificación , Extractos Vegetales/uso terapéutico , Acarbosa , Animales , Glucemia/efectos de los fármacos , Metabolismo de los Hidratos de Carbono/efectos de los fármacos , Diabetes Mellitus Experimental/inducido químicamente , Inhibidores Enzimáticos/uso terapéutico , Absorción Intestinal , RatonesRESUMEN
A new dihydrochalcone, 4'-hydroxy-4,2'-dimethoxy-dihydrochalcone, was isolated from Chinese dragon's blood, the red resin of Dracaena cochinchinensis. Its structure was established by spectrum analysis.