The ethanolic extracts from the roots, the underground trunk and the leaves of Aiouea trinervis were active in the brine shrimp (Artemia salina) lethality assay (LD (50): 1.93, 0.92 and 262.1 microg/mL, respectively). Fractionation of the extracts led to the isolation of four butanolides, namely (-)-epilitsenolides C (2) and C (1) ( 1 and 2), isoobtusilactone A ( 3) and obtusilactone A ( 4), two of which ( 1 and 2) are reported for the first time as genuine natural products. The lignans (+)-sesamin ( 5) and (+)-methylpiperitol ( 6) and polyprenol-12 ( 7) were isolated as well. Their structures were determined with spectral methods (1D-, 2D-NMR and MS). Compounds 1, 2, 3, 5 and 6 were tested for their cytotoxic activities in Hep (2) human cancer cells. The butanolides 2 and 3 were the most active (IC (50): 5.96 microg/mL and 4.95 microg/mL, respectively) whereas the other compounds showed moderate IC (50) values ranging from 12.20 microg/mL to 25.64 microg/mL. The genotoxic properties of the crude ethanolic extracts and of compounds 3 and 5 were also evaluated in this study on CHO K1 and HTC mammalian cells with single-cell gel electrophoresis (comet assay). The crude extracts as well as the compounds tested induced DNA migration in this assay, which was indicative of DNA damage (genotoxic effect).