ATC Group: L01C Plant alkaloids and other natural products

Cabazitaxel is an antineoplastic agent that acts by disrupting the microtubular network in cells. Cabazitaxel binds to tubulin and promotes the assembly of tubulin into microtubules while simultaneously inhibiting their disassembly.

Colchicine is considered to act against the inflammatory response to urate crystals, by possibly inhibiting the migration of granulocytes into the inflamed area. Other properties of colchicine, such as interaction with the microtubules, could also contribute to the operation. Onset of action is approximately 12 hours after oral administration and is maximal after 1 to 2 days.

Docetaxel is an antineoplastic agent which acts by promoting the assembly of tubulin into stable microtubules and inhibits their disassembly which leads to a marked decrease of free tubulin.

The main effect of etoposide appears to be at the late S and early G₂ portion of the cell cycle in mammalian cells. The predominant macromolecular effect of etoposide seems to be the rupture of the double strand by an interaction with DNA-topoisomerase II or by the formation of free radicals. Etoposide has been shown to cause metaphase arrest in chick fibroblasts.

Irinotecan is a semi-synthetic derivative of camptothecin. It is an antineoplastic agent which acts as a specific inhibitor of DNA topoisomerase I.

Paclitaxel is an antimicrotubule agent that promotes the assembly of microtubules from tubulin dimers and stabilises microtubules by preventing depolymerisation. This stability results in the inhibition of the normal dynamic reorganisation of the microtubule network that is essential for vital interphase and mitotic cellular functions.

Podophyllotoxin is a metaphase inhibitor in dividing cells binding to at least one binding site on tubulin. Binding prevents tubulin polymerisation required for microtubule assembly. At higher concentrations, podophyllotoxin also inhibits nucleoside transport through the cell membrane.

Teniposide is a phase-specific cytotoxic drug, acting in the late S or early G₂ phase of the cell cycle, thus preventing cells from entering mitosis. Teniposide has a broad spectrum of in vivo antitumor activity against murine tumors, including hematologic malignancies and various solid tumors.

Topotecan involves the inhibition of topoisomerase-I, an enzyme intimately involved in DNA replication.

Trabectedin binds to the minor groove of deoxyribonucleic acid (DNA), bending the helix to the major groove. This binding to DNA triggers a cascade of events affecting several transcription factors, DNA binding proteins, and DNA repair pathways, resulting in perturbation of the cell cycle. Trabectedin has been shown to exert antiproliferative in vitro and in vivo activity against a range of human tumour cell lines and experimental tumours, including malignancies such as sarcoma, breast, non-small cell lung, ovarian and melanoma.

Vinblastine appears to bind to or crystallise critical microtubular proteins of the mitotic spindle, thus preventing their proper polymerisation and causing metaphase arrest. In high concentrations, vinblastine also exerts complex effects on nucleic acid and protein synthesis.

Vincristine is an antineoplastic drug with broad-spectrum anti-tumor activity in man. The drug may act by mitotic inhibition, causing an arrest of cell division in metaphase.

Vindesine is an antineoplastic agent derived from vinblastine, like the other vinca alkaloids it causes mitotic arrest in metaphase by binding to microtubular protein.

Vinflunine binds to tubulin at or near to the vinca binding sites inhibiting its polymerisation into microtubules, which results in treadmilling suppression, disruption of microtubule dynamic, mitotic arrest and apoptosis.

Vinorelbine is an antineoplastic drug of the vinca alkaloid family but unlike all the other vinca alkaloids. Vinorelbine inhibits tubulin polymerization and blocks mitosis at G₂-M, causing cell death in interphase or at the following mitosis.