1966 Wall and so for the first time the United States from China in the trunk of C. acuminata plants, bark and fruit were isolated camptothecin (Camptbthecin, referred to as the CPT).Experimental study of HCPT, the toxic side effects limit its use, resulting in research was interrupted. 1986 Hsiang other study found that camptothecin is so far the only effect of a class of topoisomerase I in the anti-cancer drugs, it attracted people's attention on the CPT.
Experimental Study of hydroxycamptothecin, at present, a variety of camptothecin anticancer drugs have entered clinical studies and use. HCPT can selectively inhibit topoisomerase I, thereby interfering with DNA replication. HCPT for cell cycle specific drugs acting on the S, G1 and Gz on the role of the inferior to S phase. Anti-tumor effect in vitro study showed the drug significantly inhibited a variety of tumors, especially the role of ascites tumor more significant, and solid tumors have a certain effect.
Experimental study of hydroxycamptothecin, when given 2mg/kg, the mouse sarcoma 180, 37 sarcoma, cervical cancer, sarcoma 14 and rat Walke inhibition rates were 35.4%, 44.5%, 3% and 46.9% However, no effect on mouse melanoma. After intravenous injection of 3H with the base of camptothecin, in the course of the blood in the biphasic disappearance curve of radioactivity levels in various tissues in the gallbladder after administration of the highest 1h, equivalent to 20-50 times the amount of general organization, followed by small intestine, in decreasing order of strength of other organizations in the liver, bone marrow, stomach, lung and kidney.
Mainly via biliary excretion, 24h 38% of the total discharge volume, of which 29.6% with fecal excretion, the urine less than 9%.