Aloe vera-induced apoptotic cell death through ROS generation, cell cycle arrest, and DNA damage in human breast cancer cells

This study aimed to evaluate the in vitro cytotoxicity of ethanolic extract of Aloe vera (AVE) against human cancer cell lines. Cytotoxic effect of AVE was evaluated by MTT and NRU assays in human breast (MCF-7) and lung (A-549) cancer cell lines. AVE-induced morphological changes were also visualized under phase contrast microscope. Further, intracellular reactive oxygen species (ROS) and mitochondrial membrane potential (MMP) levels were detected using DCF-DA and Rh-123 stains, respectively under a fluorescence microscope. Cell cycle progression was measured by flow cytometric analysis. DNA damage was detected by single cell gel electrophoresis (comet assay). The profile of genes related to apoptosis (p53, bax, bcl-2, caspase-3 and -9) was assessed by quantitative real time PCR. AVE exhibited significant cytotoxicity in a dose dependent manner to both MCF-7 and A-549 cells with an IC 50 values of 195 μg/mL and 298 μg/mL, respectively. Moreover, AVE induces overproduction of ROS and decreases MMP level in MCF-7 cells. Flow cytometric analysis confirmed that AVE-induced SubG1 cell cycle arrest. The increased p53, bax, capsase-3 and -9 gene expression levels and decreased bcl-2 gene expression level positively correlated AVE-induced MCF-7 cell apoptosis. In conclusion, this study provides mechanistic details of anticancer potential of A. vera. This study also proved that AVE could be a promising anticancer agent in preventing and treating cancer diseases.