Astaxanthin Co-treatment with Low Dose Methotrexate Increases the Cell Cycle Arrest and Ameliorates the...

Methotrexate (MTX), an antimetabolite agent, is widely used for acute lymphoblastic leukemia treatment, despite its association with significant organ dysfunction. Astaxanthin (AST) is a natural carotenoid which has recently been emerged as a promising anti-tumor and anti-inflammatory agent. In this study, we aimed to evaluate the effectiveness of astaxanthin and low-dose methotrexate co-treatment in acute lymphoblastic leukemia cell line. The expression of Dihydrofolate reductase (DHFR), Thymidylate synthase (TYMS), apoptotic, anti-apoptotic as well as inflammatory genes was investigated using qRT-PCR. Flow cytometry was performed for cell cycle quantitative evaluation. Clonogenic assay was used to assess NALM6 cells proliferation capacity following treatment with AST, MTX, and co-treatment. To compare the antioxidant property of each group, the ferric ion reducing anti-oxidant power assay was performed. A reduction in viability was observed in the presence of MTX, AST, and their combined treatment. Both AST alone and in combination with MTX caused cell cycle arrest and a reduction in the expression of DHFR and TYMS. While MTX, AST, and their combination could reduce STAT3 and BCL-XL gene expression, they could act as positive regulators for the expression of BAX and CASP3, TNFα, and IL6. AST and MTX co-treatment inhibited the colony formation ability. FRAP assay also revealed that AST and AST+MTX increased the antioxidant capacity. Our data suggests that AST can improve MTX treatment efficacy and their combination therapy can be considered as a promising strategy for the management of acute lymphoblastic leukemia.