astaxanthin co-treatment with low dose methotrexate increases the cell cycle arrest and ameliorates the methotrexate-induced inflammatory response in nalm-6

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.