This product is a pyrimidine anti-metabolite drug that mainly acts on cells in the S proliferation phase. It interferes with cell proliferation by inhibiting the synthesis of cell DNA. After entering the human body, cytarabine is phosphorylated by kinase and converted into cytarabine triphosphate and cytarabine diphosphate. The former can strongly inhibit the synthesis of DNA polymerase, and the latter can inhibit the conversion of cytidine diphosphate to deoxycytidine diphosphate, thereby inhibiting cell DNA polymerization and synthesis. This product is a cell cycle-specific drug, which is most sensitive to cells in the S proliferation phase, and has a weaker effect on inhibiting RNA and protein synthesis.

Immune bidirectional regulatory drug. It has the function of inducing and promoting the differentiation, maturation and activation of T lymphocytes and their subsets, regulating the ratio of T lymphocytes to make CD4/CD8 tend to normal; regulating and enhancing the function of human cellular immune function, can promote the maturation of T lymphocytes in peripheral blood after mitogen activation, increase the secretion of various lymphokines (such as: a, gamma interferon, interleukin 2 and interleukin 3) after T cells are activated by various antigens or mitogens, and increase the level of lymphokine receptors on T cells. It also enhances lymphocyte response by activating T helper cells. In addition, this product may affect the chemotaxis of NK precursor cells, which become more cytotoxic after exposure to interferon.

Pemetrexed is an antifolate preparation with a core pyrrolopyrimidine group in its structure. It inhibits cell replication and thus tumor growth by destroying the normal metabolic process dependent on folate in cells. In vitro studies have shown that pemetrexed can inhibit the activity of thymidylate synthase, dihydrofolate reductase and glycinamide nucleotide formyltransferase, which are enzymes necessary for the synthesis of folate and participate in the bioresynthesis of thymine nucleotides and purine nucleotides. Polyglutamate is a time-concentration dependent process in tumor cells, while the concentration in normal tissues is very low. The half-life of polyglutamate metabolites in tumor cells is prolonged, thereby prolonging the duration of drug action in tumor cells. Preclinical studies have shown that pemetrexed can inhibit the growth of mesothelioma cell lines (MSTO-211H, NCI-H2052) in vitro. Studies on the mesothelioma cell line MSTO-211H have shown that pemetrexed has a synergistic effect in combination with cisplatin.

It has a destructive or inhibitory effect on the morphology or proliferation of liver cancer BEL-7402, esophageal cancer CaEs-17, laryngeal cancer SMMC-7721, cervical cancer Hela and other cell lines; it has a certain inhibitory effect on mouse Ehrlich ascites carcinoma, sarcoma 180 and solid liver cancer; it can increase the respiratory control rate and lysosomal enzyme activity of the tumor cell microsomes of ascites liver cancer H22 mice, inhibit cancer cell DNA synthesis, and destroy the cancer cell skeleton and ultrastructure; interfere with cancer cell division, block it in the M phase, and affect its cycle speed, destroy the cancer cell skeleton (microfilaments, microtubules), affect the ultrastructure of cancer cells, lead to damage to mitochondria, microvilli and plasma membrane, block the M phase of the cell division cycle and interfere with cancer cell division.

This product is a selective 5-HT3 receptor antagonist. Its mechanism of action may be to antagonize the 5-HT3 receptors in the peripheral vagus nerve endings and central chemoreceptor areas, thereby blocking the vomiting reflex caused by factors such as chemotherapy and surgery that promote the release of 5-HT from intestinal chromaffin cells and excite the vagus afferent nerves. This product has high selectivity and no side effects such as extrapyramidal reactions and excessive sedation.