Cytotoxic and genotoxic action of Tagetes patula flower methanol extract and patuletin using the Allium test

Tagetes patula is used to treat cancer patients in alternative healthcare systems. However, its cytotoxic and genotoxic effects have not been reported. Therefore, the methanol extract of T. patula flower, the ethyl acetate fraction, and the pure compound patuletin were evaluated using the Allium test. The methanol extract and fraction contained ~3% and ~36% patuletin, respectively, with ~98% purity. The methanol extract caused inhibition of Allium root growth displaying an IC 50 value of ~500 µg/mL, while the fraction and patuletin were more potent by ~2 and ~5 times, respectively. The Allium root tips demonstrated a decline in prophase, metaphase, anaphase, and telophase stages with concomitant decrease in percent mitotic index in the methanol extract (~5.64), fraction, and patuletin (~4) as compared to the control (~7.61). However, in only methanol extract-treated root tips, an increase in metaphase stage was noted. In addition, the methanol extract predominantly induced c-type, misaligned, and multipolar chromosomal abnormalities while the fraction and patuletin displayed fragments and sticky chromosomes. The fraction and patuletin also produced micronuclei (~2%) . In conclusion, T. patula flower methanol extract and ethyl acetate fraction are cytotoxic and genotoxic, which most likely could be due to the patuletin. Further preclinical and clinical studies are required to justify its clinical use.