Methotrexate, USP and EP Grade, 1mg

Methotrexate is a cell cycle arresting agent with varying effects. Methotrexate has been reported to arrest the cell cycle in late G1/S thus leading to the inhibition of the synthesis of DNA, RNA, thymidylates, and proteins. The main mechanism of action is reported to involve the inhibition of enzymes involved in purine metabolism which leads to the accumulation of adenosine or the suppression of intercellular adhesion molecule expression by T cells. Additionally, this compound has been observed to inhibit DHFR. Methotrexate is used for chemotherapy either alone or in combination with other agents. It is effective for the treatment of a number of cancers including: breast, head and neck, leukemia, lymphoma, lung, osteosarcoma, bladder, and trophoblastic neoplasms. It is also used in treatment of autoimmune diseases, ectopic pregnancy, and for the induction of medical abortions. It is used to inhibit dihydrofolate reductase in DHFR-based protein expression systems. Also effective in treatment of pyrimethamine-resistant Plasmodium vivax malaria parasites. Potent inhibitor of dihydrofolate reductase and agent for antitumor studies. Use to inhibit dihydrofolate reductase in DHFR-based protein expression systems. Also shows immunosuppressive effects in, e.g., rheumatoid arthritis. Methotrexate is an allosteric inhibititor of dihydrofolate reductase (DHFR), the enzyme that catalyzes the conversion of dihydrofolate to tetrahydrofolate. Since tetrahydrolfolate is required for purine and pyrimidine synthesis, methotrexate treatment results in the inhibition of DNA and RNA synthesis.