Abstract

Mitotic studies were carried out on Allium cepa (onion) root cells treated with different concentrations of aqueous leaf extract of Vernonia amygdalina (bitter leaf). The onion root cells showed reduced mitotic indices with corresponding increase in concentration of the bitter leaf extract [200 g/L (C₂), 400 g/L (C₃) and 500 g/L (C₄)]. Chromosomal aberrations, such as endopolyploidization, lagging of chromo-somes and cells with giant chromosomes, were also observed in onion roots treated with same. No chromosomal aberration was observed in the control and in onion roots treated with 100 g/L (C₁) of the leaf extract. These observations indicate that abnormal use of this medicinal herb could cause genetic damage. Low concentration and wide spacing of dosage are, therefore, suggested for its dietary intake or use in herbal medicine.

Key words: Vernonia amygdalina, Allium cepa, chromosome aberration, cytotoxicity, herbal medicine.