Apoptotic effect of astaxanthin from white shrimp shells on lung cancer A549 cells

Purpose: To investigate the anti-cancer potential of astaxanthin from Litopenaeus vannamei encapsulated in liposomes (ASX) to treat lung cancer A549 cells. Methods: Lung adenocarcinoma A549 cells were cultured and treated with ASX, following which cell viability and nuclear staining were performed. Generation of ROS was identified by the DCFH-DA assay while tetramethylrhodamine ethyl ester was used to determine the mitochondrial membrane potential. Flow cytometry was applied to investigate caspase-3/7 activity and cell cycle distribution. Results: ASX inhibited growth of A549 in a concentration- and time- dependent manner. The IC50 values at 24, 48 and 72 h were 53.73, 22.85, 17.46 μg/mL, respectively (p < 0.05). After incubation with ASX, the morphological changes were observed in A549 cells following Hoechst 33342/PI fluorescent staining. ASX increased ROS generation and was associated with the collapse of mitochondrial membrane potential, which subsequently triggered the activation of caspase-3/7 activity leading to apoptosis (p < 0.05). In addition, A549 cells accumulated in the G0/G1 phase. Conclusion: The results suggest that ASX is a valuable nutraceutical agent to target A549 lung cancer cells via ROS-dependent pathway as well as blockage of cell cycle progression.