Abstract

THE ANTINEOPLASTIC ACTIVITY OF ECHITAMIDINE-N-OXIDEGLUCOPYRANOSIDE ISOLATED FROM STEM BARK EXTRACT OF ALSTONIA SCHOLARIS IN KB CELLS

Dr. D. Subba Reddy*

Abstract

The antineoplastic activity of an isolated bioactive constituent, EOG (Echitamidine-N-Oxide-Glucopyranoside) from stem bark of Alstonia scholaris was studied in KB cells by clonogenic, micronucleus, comet and apoptosis assays. Exposure of KB cell to 0, 1, 5, 10, 20, 30, 40, 50 or 100 μg/ml EOG for varying times caused a concentrationdependent reduction in the cell survival up to 6 h post-treatment followed by a marginal but non-significant decline thereafter up to 24 h. Therefore, 6 h treatment time was considered as an optimum time for EOG exposure and further studies were conducted using this treatment time. The inhibitory concentration (IC50) of EOG was found to be 25 μg/ml. The EOG treatment induced micronuclei in a concentration manner at all assessment times and a maximum rise in micronuclei frequency was observed at 30 h post treatment. The comet assay studies revealed that the exposure of KB cells to various concentrations of EOG induced DNA damage in concentration dependent fashion and the greatest damage was observed at 6h post-treatment as indicated by increased migration of DNA into comet tails and rise in Olive tail Moment. The EOG induced apoptosis in KB cells in a concentration dependent manner and the comparison with doxorubicin which was used as positive control revealed that EOG was as effective as doxorubicin in inducing apoptotic death. The present study demonstrates that EOG killed KB cells in a concentration dependent manner and this cell killing effect of EOG was due to induction of DNA damage and apoptosis.

Keywords: Echitamidine-N-Oxide-Glucopyranoside (EOG), Clonogenic assay, Micronuclei, Comet assay.