Methotrexate

Etoposide (CAS number 33419-42-0) was purchased as a 20 mg·mL⁻¹ injectable solution from Teva Santé (Paris, France). Methotrexate (CAS number RN 59-05-2) was purchased as a 55 mM injectable solution from Mylan (Saint Priest, France). All other compounds (Table 1) were purchased as a powder from Sigma-Aldrich (Lyon, France).

Metformin (Santa Cruz Biotechnology, USA) and curcumin (Merck, Germany) were dissolved in RPMI 1640 culture medium (Bio-Idea, Iran) and DMSO (Shellmax, China), respectively. Anticancer drugs cisplatin (Mylan, USA), carboplatin (Mylan, USA), oxaliplatin (Sobhan, Iran), epirubicin (Ebewe, Austria), doxorubicin (Ebewe, Austria), docetaxel (Sanofi, France), paclitaxel (Sobhan, Iran), and methotrexate (Mylan, USA) were used. Cell proliferation kit (MTT) was provided from Roche (Switzerland). Matrigel Basement Membrane Matrix Growth Factor Reduced (Cat No. 354230) and Transwells (Cat No. 3422) were products of Corning (USA). Human AGS gastric cell line and human HDF normal cell line were purchased from the American Type Culture Collection (ATCC), were cultivated in RPMI 1640 and DMEM/F12 culture media, respectively, supplemented with heat-inactivated fetal bovine serum (FBS, Gibco, USA, 10 % v/v), 100 units/mL penicillin, and 100 μg/mL streptomycin (Bio-Idea, Iran).

Methotrexate was supplied by Mylan Company (France). PSO was purchased from Elhawag Company for Natural oils and Cosmetics (Egypt) licensed under no. 159, 2,150 in 2009. Glutathione, acetylthiocholine iodide, 5,5'-dithiobis-2-nitrobenzoic acid (DTNB), and phosphate buffers were obtained from Sigma Aldrich.