Spinasterol and schottenol, two phytosterols present in argan oil and in cactus pear seed oil, were synthesized from commercially available stigmasterol by a four steps reactions. In addition, the effects of these phytosterols on cell growth and mitochondrial activity were evaluated on 158N murine oligodendrocytes, C6 rat glioma cells, and SK-N-BE human neuronal cells with the crystal violet test and the MTT test, respectively. The effects of spinasterol and schottenol were compared with 7-ketocholesterol (71CC) and ferulic acid, which is also present in argan and cactus pear seed oil. Whatever the cells considered, dose dependent cytotoxic effects of 71CC were observed whereas no or slight effects of ferulic acid were found. With spinasterol and schottenol, no or slight effects on cell growth were detected. With spinasterol, reduced mitochondrial activities (30-50%) were found on 158N and C6 cells; no effect was found on SK-N-BE. With schottenol, reduced mitochondrial activity were revealed on 158N (50%) and C6 (10-20%) cells; no effect was found on SK-N-BE. Altogether, these data suggest that spinasterol and schottenol can modulate mitochondrial activity and might therefore influence cell metabolism.