In 1963, the short leaf from the Pacific Northwest yew bark is found on many tumor cytotoxicity of natural substances. 1971, the active ingredients extracted paclitaxel, screening with anti-tumor effect. U.S. National Cancer Institute in 1979, thousands of plant species on natural anti-tumor activity of extracts were screened and found that Taxol is one of the most anti-tumor activity of the material, and has a unique mechanism of action.
Experimental study of paclitaxel, further studies have shown that the mechanism of paclitaxel is different from other anti-microtubule drugs (such as colchicine and vinca alkaloids), which is mainly to promote microtubule disassembly and leads to microtubule breakdown, paclitaxel could be specifically bind to Lu-bit on the small tube, resulting in microtubule polymerization into clumps and bundles and make it stable, these effects can inhibit the normal microtubule network reorganization. In vitro experiments showed that paclitaxel has significant radiosensitization, cell activity may be to stop the radiation in the most sensitive of horses and M phase. In addition, paclitaxel can induce tumor necrosis factor- gene expression.
Experimental study of paclitaxel and paclitaxel on mice leukemia L1210 and P1S34, BI6 melanoma anti-tumor activity. And other similar anti-microtubule drugs, paclitaxel combined with a wide range of plasma protein (twenty-three 98%). Latest data show that compared with the 24h, 3h leukopenia induced by administration of the program less. Leukocyte reduction of the concentration of the drug with more than wide (possibly 0.051mal / L) exposure time is related. Mainly in the liver metabolism of paclitaxel, with the bile into the intestine, the feces excreted, and only a small amount of the prototype from the urine. Cleared by the renal clearance accounted for only 1% – 8%, renal dysfunction, generally do not affect the use of paclitaxel.
Experimental Study of Taxol, the drug interaction studies have shown that the first will increase with the DDP major toxicity of paclitaxel, may be due to DDP cytochrome P450 enzymes on the regulation, resulting in decreased plasma clearance of paclitaxel. In vitro, after the first use of paclitaxel with DDP, low toxicity, tumor cell killing effect on the larger.