Genotoxicity and sperm defects induced by 5-FU in male mice and the possible protective role of Pentas lanceolata-iridoids

•5-FU was demonstrated to be a genotoxic agent. It induced significant increase in micronucleated polychromatic erythrocytes, chromosome anomalies (CAs) and also cytotoxic effects in bone marrow cells (somatic cells). It also induced highly significant percentage of CAs in mouse spermatocytes (germ cells) and a dramatic increase in the percentage of morphological sperm defects.•The results clearly indicated that the genotoxicity of 5-FU in germ cells and its effects on sperm morphology are serious and may lead to reproductive toxicity, infertility or heritable defects.•The biosafety of Pentas lanceolata iridoid-rich fraction and its possible protective role in combined treatment with 5-FU are well established in the present work.