Taxus chinensis(Yew),an ancient tree species left behind after the Quaternary glacier,has been listed as the world’s rare and endangered plants and the world’s top ten endangered species.It is a national first-class protected tree species and is known as the”plant giant panda”.
So,
As a”living fossil of plants”,what are the effects and applications of yew extract?
Yew,is a Taxus plant of Taxaceae.There are 11 species of yew in the world,distributed in temperate to tropical regions of the northern hemisphere.There are 4 species and 1 variety in China,namely,Chinese yew,northeast yew,Yunnan yew,South yew and Tibet yew,which are distributed in Northeast,South China and southwest China.Paclitaxel extracted from the bark and leaves of yew has outstanding curative effect on a variety of advanced cancers and is known as”the last line of defense for the treatment of cancer”.
Development history of paclitaxel:
In 1963,American chemists M.C.Wani and monre E.wall first isolated the crude extract of paclitaxel from the bark and wood of Pacific yew,which grows in the forests of the western United States.In the screening experiment of Taxus chinensis,Wani and wall found that the crude extract of paclitaxel had high activity on mouse tumor cells in vitro,and began to isolate this active component.Due to the extremely low content of the active ingredient in plants,it was not until 1971 that they cooperated with Andre t.McPhail,a chemistry professor at Duke University to determine the chemical structure of the active ingredient-a tetracyclic diterpene compound,and named it taxol.
What is paclitaxel?
Paclitaxel is a monomer diterpenoid extracted from the bark of Natural Plant Taxus.It is a complex secondary metabolite.It is also the only drug known to promote microtubule polymerization and stabilize polymerized microtubules.Isotope tracing showed that paclitaxel was only bound to polymerized microtubules and did not react with unpolymerized tubulin dimers.After contacting paclitaxel,cells will accumulate a large number of microtubules in cells.The accumulation of these microtubules interferes with various functions of cells,especially stops cell division in the mitotic stage and blocks normal cell division.
Application of paclitaxel:
1.Anticancer
Paclitaxel is the first line drug for ovarian cancer and advanced breast cancer.The National Cancer administration began human clinical trials as early as 1983 to test its toxicity and anticancer activity.
Paclitaxel is mainly used in ovarian cancer and breast cancer through the second-and third clinical study.It also has some effect on lung cancer,colorectal cancer,melanoma,head and neck cancer,lymphoma and brain tumor.
2.Antitumor
Paclitaxel is the first choice of anti-tumor drugs in hospitals all over the world.It can promote the assembly of microtubules by promoting the polymerization of spindle tubulin subunits.It is an anti-microtubule antitumor drug.
3.Treatment of rheumatic arthritis
Studies have shown that taxol has been approved by FDA for rheumatoid arthritis,and paclitaxel gel is a topical preparation for paclitaxel in rheumatoid arthritis.
Post time: Apr-21-2022