Effects of Diallyl Disulfide in Elephant Garlic Extract on Breast Cancer Cell Apoptosis in Mitochondrial Pathway

Abstract

As a close relative of garlic, elephant garlic contains abundant allicin, which means the extract of elephant garlic might induce apoptosis in breast cancer cells. The elephant garlic was extracted in alcohol with Solvent-Microwave Extraction. The main component was analyzed by liquid chromatography. The MCF-7 (michigan cancer foundation-7) cells were cultured in vitro. The apoptosis rate was determined with Annexin V-FITC/PI staining based flow cytometry (FCM). Mitochondrial transmembrane potential variation in the cells was observed with JC-1 probe and fluorescence confocal microscopy. Caspase-3 was determined with fluorescence Western Blot. The main component of alcohol extract of elephant garlic was Diallyl Disulfide (DADS), and its relative content was 17.04 %. The early apoptosis of MCF-7 cells could be induced by the alcohol extract solutions and it involved the activation of mitochondrial pathway. The results indicated that the extract and DADS standards exerted pro-apoptotic effects on breast cancer cells in a dose-response manner. From the results of fluorescence confocal microscopy, it showed that the Red/Green fluorescence ratio of mitochondrial membrane potential in MCF-7 cells could be significantly decreased after inducing with DADS reference substances for 24 h. In addition, mitochondrial depolarization could be observed as adding the extract. The activated Caspase-3 was detected with Western Blot. It was demonstrated that the expression level of procaspase-3 had gone up with increased concentration of alcohol extract. The expression level was also increased with the treatment of DADS and the protein band was clear.