Successive purification of the extract from Canarium album and Euphorbia nematocypha, guided by antihepatotoxic activity in primary cultured rat hepatocytes, led to the isolation of brevifolin (1), hyperin (2), ellagic acid (3) and 3,3'-di-O-methylellagic acid (4) as hepatoprotective compounds. Compounds 1,3 and 4 also reduced carbon tetrachloride (CCl4)-induced liver damage in mice. The hepatoprotective activities of 1, 2, 3 and 4 in vitro and in vivo are apparently due to their antioxidative effects, which were exhibited by further studies using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals and CCl4-induced lipid peroxidation systems.