EFFECTS OF REPEATED TREATMENTS WITH AN EXTRACT OF GINKGO-BILOBA (EGB-761) AND BILOBALIDE ON GLUCOSE-UPTAKE AND GLYCOGEN-SYNTHESIS IN RAT ERYTHROCYTES - AN EX-VIVO STUDY

The metabolic action of an extract of Ginkgo biloba (EGb 761) has been examined in an ex vivo study of rat erythrocytes. Oral administration of EGb 761 (100 mg/kg/day) for 5 days to Wistar rats caused an increa se in the in vitro uptake of glucose by erythrocytes, especially in hi gh-glucose (13.32 mM) medium, an effect that was associated with an in crease in intracellular energy metabolism and reflected as a significa nt reduction in free glucose concentration. In contrast, the lactate c oncentration of the erythrocytes and lactate release to the bathing me dium were not modified. Conversion of glucose into glycogen was signif icantly increased in the erythrocytes of EGb 761-treated animals. Take n together, these findings indicate that in vivo administration of EGb 761 exerts an action favoring the transformation of glucose into glyc ogen, its storage form. Oral administration of the EGb 761 constituent bilobalide (4 or 8 mg/kg/day) for 5 days caused similar changes in th e uptake of glucose and its conversion into glycogen. However, in cont rast to the total extract, bilobalide treatment did not increase the e nergy-yielding consumption of glucose.