Astaxanthin Induces Apoptosis in MCF-7 Cells through a p53-Dependent Pathway

Astaxanthin (3,3'-dihydroxy-β,β-carotene-4,4'-dione; AXT) is a xanthophyll β-carotenoid found in microalgae, seafood, fungi, complex plants, flamingos, and quail. It is well known that AXT plays a role as a drug with antioxidant and antitumor properties. Furthermore, several studies have reported that the reagent shows anti-inflammatory and neuroprotective effects. Recently, it was found that AXT acts as a peroxisome proliferator-activated receptor γ (PPARγ) modulator. To investigate the effect of AXT on MCF-7 cells (a human breast cancer cell line), the cells were treated with various concentrations of AXT. The treatment induced the decrease in cell number in a dose-dependent manner. Additionally, the Annexin V-positive cells were increased by the AXT treatment. These results indicated that apoptosis was induced in the tumor cells through the treatment of AXT. To elucidate the connection between apoptosis and p53, the levels of p53 and p21 proteins were assessed. Consequently, it was observed that the expression of p53 and p21 increased proportionally to the concentration of the AXT treatment. These findings suggest that the apoptosis of MCF-7 cells induced by AXT operates through a p53-dependent pathway, implying that AXT could potentially have a beneficial role in future breast cancer treatments. Thus, our results will provide a direction for future cancer challenges.