An alkaloid isolated from the stem wood of the Chinese tree, Camptotheca acuminata. This compound selectively inhibits the nuclear enzyme DNA topoisomerase, type I. Several semisynthetic analogs of camptothecin have demonstrated antitumor activity. [PubChem] |
Categories | Enzyme Inhibitors Antineoplastic Agents, Phytogenic
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Synonyms | (+)-camptothecin (+)-camptothecine (s)-(+)-camptothecin (s)-camptothecin 20(S)-Camptothecin 21,22-Secocamptothecin-21-oic acid lactone Camptothecine D-camptothecin
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indication
Investigated for the treatment of cancer.
pharmacology
Camptothecin demonstrated strong anticancer activity in preliminary clinical trials but also low solubility and adverse drug reaction. Camptothecin is believed to be a potent topoisomerase inhibitor that interferes with the essential function of topoisomerase in DNA replication.
mechanism of action
Camptothecin binds to the topoisomerase I and DNA complex (the covalent complex) resulting in a ternary complex, and thereby stabilizing it. This prevents DNA relegation and therefore causes DNA damage which results in apoptosis.
toxicity
Acute oral toxicity (LD
50) in mouse: 50.1 mg/kg