Cytotoxicity and genotoxicity studies of two free-radical generators (AAPH and SIN-1) in human microvascular endothelial cells (HMEC-1) and human peripheral lymphocytes

► AAPH was cytotoxic but not genotoxic in HMEC-1 cells as well as in peripheral lymphocytes. ► In HMEC-1 cells, AAPH and SIN-1 induced cell cycle block at the G2/M phase. ► SIN-1 was cytotoxic on HMEC-1 cells and induced a significant increase in apoptotic cells and micronuclei. ► SIN-1 was particularly cytoxic in separated lymphocyte as compared to whole blood cultures with HEPES. ► Genotoxicity was observed in both lymphocyte cultures in the absence of HEPES due to the reduced cytotoxicity.