Lipophilic compounds, but not fucoxanthin, mediate the genotoxic effect of photoautotrophic grown Phaeodactylum tricornutum in Caco-2 and HT-29 cells

•P. tricornutum showed a dose-dependent genotoxic effect in Caco-2 and HT-29 cells.•Strand breaks can be repaired after a recovery time of 2 h (temporary effect).•Lipophilic constituents, but not fucoxanthin, mediated the genotoxic activity.•There was no effect on cell proliferation or induction of apoptosis/necrosis.•The processing of P.tricornutum revealed no further adverse cellular effects.