Cervical cancer (CC) is the third most common cancers in women worldwide and the fourth major cause of cancer death in the woman in developing countries, remaining a critical public health problem. High-risk human papilloma viruses (HPVs) such as HPV 16, 18, 31 and 33 have been attributed to be the major risk factors for cervical cancer. Platinum based chemotherapy in combination with radiotherapy or surgery is now mainly used to treat CC, but the efficacy is limited especially in advanced-stage disease. Furthermore, these treatments could easily lead to adverse reactions and drug resistance. Therefore, the discovery of new highly selective and efficacy drugs has been the main focus of the research. Thus, the study aimed to investigate, in vitro, the cytotoxic and pro apoptotic effects of leaves and roots fractions from Croton blanchetianus (CB) against human cervical cancer HeLa and SiHa cells.
Samples were obtained from a crude ethanolic extract after acid-base extraction with chloroform at pH 2 (CBaF from leaves; CBaR from roots) and at pH 9 (CBbF from leaves; CBbR from roots). Phytochemical screening was evaluated by thin layer chromatography using Sulfuric Vanilin, Dragendorff and Natural A Reagent as stain. Cytotoxic activity and apoptosis rates were determined with MTT and Annexin V/PI assays, respectively. Nuclear morphological changes were evaluated by fluorescence with DAPI stanning and flow cytometry was used to cycle assay.
According to results, all fractions exhibited terpenoids, alkaloids and flavonoids, except CBbF that showed no flavonoids. All fractions decreased significantly cell viability of HeLa and SiHa in a concentration- and time-dependent manner (p<0,05), as well as, they induced cellular and nuclear morphological changes, apoptosis and cell cycle arrest (p<0,05).
This is the first study that demonstrated cytotoxic and pro apoptotic effects of Croton blanchetianus on HeLa and SiHa cells. Therefore, Croton blanchetianus appears to be a valuable natural source for the development of agents for the treatment of cervical cancer. However, the present study points to the need for further phytochemical research to isolate the biologically active products of these fractions responsible for the observed activities and to elucidate their action mechanisms.