An in vivo method of treating a disorder selected from the group consisting of hypercholesterolemia, familial hypercholesterolemia, hyperlipidemia, arteriosclerosis, and fatty liver in a mammal in need thereof, the method comprising administering to the mammal an effective amount of a compound selected from the group consisting of 1,11-O-o-methylbenzylidene-7-O-p-cyanobenzoyl-1,7,11-trideacetyl pyripyropene A (PRD125), 7-p-cyanobenzoyl-7-deacetyl pyripyropene A (PRD017), and 7-O-p-cyanobenzoyl-1,11-di(O-isobutyryl)-1,7,11-trideacetyl pyripyropene A (PRD056), or a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate thereof, as an active component, wherein the administering inhibits the functions of proprotein convertase subtilisin/kexin type 9 (PCSK9) in the mammal.