The present invention relates to certain polyhydroxylated pentacyclic triterpene acids of formula (I) for use as HMG-CoA reductase inhibitors in the prophylactic and/or therapeutic treatment of a disease, disorder or condition that responds to a reduction of the HMG-CoA reductase activity in a mammal, preferably a human being. The present invention further relates to certain mixtures and plant extracts comprising euscaphic acid and tormentic acid, wherein the amount of euscaphic acid to tormentic acid exceeds a certain ratio. Further, the present invention also relates to a formulation, preferably pharmaceutical or nutraceutical formulation, comprising one or more of said compounds of formula (I), a composition according to the present invention or a plant extract according to the present invention. Also, the present invention relates to a process for obtaining certain polyhydroxylated pentacyclic triterpene acids of formula (I), a composition according to the present invention or a plant extract according to the present invention.