Current Advances in Anticancer Properties of Heptamethine Carbocyanine DZ‐1 Conjugated to Artesunate: Generation of Reactive Oxygen Species

Heptamethine cyanine dyes and anticancer agents based conjugates are being developed for enhanced targeting and killing of cancer cells. DZ‐1 dye conjugated agents induced cytotoxicity and mechanism of action have been shown in previous studies. In this study, a conjugated form of DZ‐1 and artesunate (DZ‐1‐ART) was used to evaluate its cytotoxicity and elucidate the mechanism of actions in various cancer cell lines. Cells survival assays indicated dose‐dependent cytotoxic activities of DZ‐1‐ART in HCT116, BxPC‐3, and OVCAR‐3 cell lines. Immunoblotting and terminal deoxynucleotidyl transferase dUTP nick‐end labeling assay confirmed involvement of apoptosis in DZ‐1‐ART‐induced cytotoxicity. To elucidate the anticancer mechanism of the action of DZ‐1‐ART, MitoTracker and JC‐1 assay were used. The results showed that translocation of DZ‐1‐ART in the mitochondria was followed by disruption of mitochondrial outer membrane potential. Dichlorofluorescin diacetate assay confirmed the generation of reactive oxygen species (ROS) in DZ‐1‐ART treated cancer cells. An antioxidant, N‐acetyl cysteine treatment with DZ‐1‐ART showed reduction in cell death as well as suppression of ROS generation. When compared to HCT116 wild‐type cells, Bak and Bax‐deficient HCT116 cells also showed similar levels of cytotoxicity of DZ‐1‐ART. Taken together, this study's results reported that DZ‐1‐ART could induce mitochondria‐mediated, ROS‐generated, and Bak and Bax‐independent apoptosis in cancer cells.