An extract of the crude drug “ukon”, the rhizomes of Curcuma longa, exhibited intense preventive activity against carbon tetrachloride-induced liver injury in vivo and in vitro. The extract was subjected to fractionation by monitoring the activity by the in vitro assay methods employing carbon tetrachloride- and galactosamine-produced cytotoxicity in primary cultured rat hepatocytes. Curcuminoids were shown to possess significant antihepatotoxic action. The liver protective effects of some analogues of ferulic acid and p-coumaric acid, probable metabolites of the curcuminoids, were also evaluated. 1 Part 8 in Liver-protective drugs. This paper also constitutes Part 53 in the series on the validity of the Oriental medicines.