Plant Science Research, Vol. 39, 2017

Cytotoxic potential of bark extract of Hymenodictyon orixense (Roxb.) Mabb. - a medicinally important tree, on root meristematic tissues of Allium cepa L.

There exist a large number of bioactive compounds in plants, out of which a few have been  examined and these continue to be important sources of cytotoxic agents. Now-a-days, worldwide  effort has been made to find out new cytotoxic compounds from plants. The present study deals  with cytotoxic effect of anthroquinone isolated from Hymenodictyon orixense bark extract on  Allium cepa root meristems. Two concentrations (20μg and 50 μg) of bark crude extract of H.  orixense were studied under 6 h and 24 h of treatment on root meristematic tissues. The direct  effect of cytotoxic chemicals of bark methanolic extract revealed significant reduction of mitotic  index. The mitotic index reduced significantly (~1.7 to ~2.5 fold) in 24 h of treatment at 20 ìg/  ml and 50 ìg/ml concentration respectively as compared to control. Different cytological  abnormalities like clumping of chromosomes, DNA fragmentation, spindle arrest, diplochromatin,  chromosome erosion and chromosome break were observed. The preliminary investigation  showed that this plant-derived anthraquinone can destroy the cells in micromolar concentration  and hence may be a potential anticancer drug.