174APOPTOSIS IN THE HUMAN LARYNGEAL CARCINOMA (HEp-2) CELL LINE BY BULBINE NATALENSIS AND B. FRUTESCENS FRACTIONSMany plants that belong to the genus Bulbine have compounds in their roots and leaves which are considered important for traditional treatments. The stems and roots of Bulbine species are believed to contain anticancer compounds such as anthraquinones, including chrysophanol and knipholone. However, in general, people utilise plants of the Bulbine genus for the treatment of rashes, itches, wounds, burns, cracked lips and cracked skin. This study assessed the effect of aqueous and organic fractions of Bulbine natalensis and Bulbine frutescens on the human laryngeal carcinoma cell line (HEp-2) for apoptosis. The MTT assay was used to determine the cytotoxicity of the fractions administered and to select fractions for analysis of bax and caspase-3 gene expression, which are induced during programmed cell death type 1, known as apoptosis. All of the B. natalensis fractions induced expression of caspase-3, while the tested B. frutescens aqueous root fractions failed to induce expression of caspase-3. The variation in bax gene expression indicated that HEp-2 cell death was due to apoptosis and other unknown forms of cell death that may or may not activate caspase-3 gene expression..reddyla@dut.ac.zaResearch372012Apoptosis,bax and caspase-3 markers,cytotoxicity,autophagyRishan Singh,Lalini ReddyDepartment of Biotechnology and Food Technology, Durban University of Technology, P.O. Box 1334, Durban, South Africa.,Department of Biotechnology and Food Technology, Durban University of Technology, P.O. Box 1334, Durban, South Africa.