Flower extract of Allium atroviolaceum triggered apoptosis, activated caspase-3 and down-regulated antiapoptotic Bcl-2 gene in HeLa cancer cell line

Cervical cancer accounts for the second most frequent cancer and also third leading cause of cancer mortality (15%) among women worldwide. The major problems of chemotherapeutic treatment in cervical cancer are non-specific cytotoxicity and drug resistance. Plant-derived products, known as natural therapies, have been used for thousands of years in cancer treatment with a very low number of side effects. Allium atroviolaceum is a species in the genus Allium and Liliaceae family, which could prove to have beneficial effects on cancer treatment, although there is a lack of corresponding attention. The methanolic extract from the A. atroviolaceum flower displayed marked anticancer activity on HeLa human cervix carcinoma cells with much lower cytotoxic effects on normal cells (3T3). The A. atroviolaceum extract induced apoptosis, confirmed by cell cycle arrest at the sub-G0 (apoptosis) phase, characteristic morphological changes, evident DNA fragmentation, observed by fluorescent microscope, and early and late apoptosis detection by Annexin V. Furthermore, down-regulation of Bcl-2 and activation of caspase-9 and -3 strongly indicated that the mitochondrial pathway was involved in the apoptosis signal pathway. Moreover, combination of A. atroviolaceum extract with doxorubicin revealed a significant reduction of IC50 and led to a synergistic effect. In summary, A. atroviolaceum displayed a significant anti-tumour effect through apoptosis induction in HeLa cells, suggesting that the A. atroviolaceum flower might have therapeutic potential against cervix carcinoma. (C) 2017 Published by Elsevier Masson SAS.