Effects of maslinic acid, a natural triterpene, on glycogen metabolism in cultured cortical astrocytes.

Maslinic acid (2- alpha,3- beta-dihydroxyolean-12-en-28-oic acid) is a triterpenoid compound present in plants of Olea europaea. In the present study, we investigated the effect of maslinic acid on astrocytic glycogen metabolism. Glycogen phosphorylase (GP) activity in homogenates of cultured astrocytes was analyzed, and maslinic acid exhibited GP inhibition with an IC (50) value of 5.7 microM. Moreover, the influence of maslinic acid on glycogen synthesis and glycogenolysis was also investigated. Pre-incubation with maslinic acid dose-dependently increased cellular glycogen content and prevented the excessive glycogenolysis induced by norepinephrine. In conclusion, maslinic acid is suggested to be a potent inhibitor of astrocytic glycogen phosphorylase. Georg Thieme Verlag KG Stuttgart.New York.