Anticancer effects of astaxanthin and α-tocopherol in esophageal cancer cell lines.

Abstract

Background/Aims: Astaxanthin (AX) has been attributed with potential for protecting the organism against different types of cancer due to its anti-oxidant activity. Also several in vivo and in vitro studies suggest certain naturally occurring vitamin E (i.e. ？-tocopherol) as promising anticancer agents. We assessed the effect of AX and ？-tocopherol (AT) respectively and their combination on human esophageal cancer cell lines to investigate the mechanism of anticancer effect and their therapeutic potential. Materials and Methods: Two human esophageal cancer cell lines (TE-1, TE-4) were exposed to AX (6 to 10？g/mL) and AT (20 to 100？M) for 24 hours. Quantification of proliferation was performed by MTT assay. Cell cycle machinery proteins such as p-AKT, p-p38, cyclin D1, p27 and caspase-3 were investigated by Western blot. Results: Significant inhibition of cell proliferation of AX and AT was observed in TE-4 cell line by a dose-dependent manner. Furthermore, AX and AT as single agents increased the protein expression of p27 and cleaved caspase-3 in TE-4 cell line. The combination of the two agents decreased the expression of cyclin D1, however they did not demonstrate pro-apoptotic effect. Conclusions: AX and AT as single agents are effective at inhibition of cell proliferation and