An extract of Graptopetalum paraguayense prepared by a method that includes: extracting a Graptopetalum paraguayense (GP) starting material with an alcoholic solvent to produce an alcoholic extract and a residue; separating the residue from the alcoholic extract; extracting the residue with an aqueous dimethyl sulfoxide (DMSO) solvent to produce a DMSO extract; subjecting the DMSO extract to ultrafiltration using a filter having a selected molecular weight cutoff; drying a fraction retained by the filter to obtain the extract of Graptopetalum paraguayense. Uses of an extract of Graptopetalum paraguayense for the treatment or prevention of liver fibrosis, hepatic cirrhosis, liver cancer, recurrence of liver fibrosis after surgery, or recurrence of liver cancer after surgery.