Vincristine immunosuppressive activity

Alkaloids such as vinblastine and vincristine are known to bind to the microtubules of the spindle apparatus. They are active agents that influence DNA synthesis and amino acid metabolism. They are also known to reduce mitosis at metaphase. Vinblastine and vincristine also have some immunosuppressive activity. There are many applications of these alkaloids. They have been used in the treatment of Hodgkin s disease, cancers and blood disorders. Vincristine is a basis for the development of clinic agents used to treat cerebral and pulmonary disorders. Vinblastine and vincristine are well-known anficancer agents. 

Cytotoxic agents which are used both for the treatment of cancer as for their immunosuppressive activity include cyclophosphamide, methotrexate, chlorambucil, vincristine, vinblastine and dactinomycin. 

The most important clinical use of dactinomycin is in the treatment of rhabdomyosarcoma and Wilms tumor in children, where it is curative in combination with primary surgery, radiotherapy, and other drugs, particularly vincristine and cyclophosphamide. Antineoplastic activity has been noted in Ewing s tumor, Kaposi s sarcoma, and soft-tissue sarcomas. Dactinomycin can be effective in women with advanced cases of choriocarcinoma in combination with methotrexate. Dactinomycin also has been used as an immunosuppressant in renal transplants. 

The list of commercial products from natural sources could fill volumes. It must be emphasized that their discoveries range from systematic searches, to tradition to chance favors the prepared mind. The latter is reemphasized in the discovery of the alkaloids from the periwinkle plant (vincristine and vinblastine) which were first screened for their hypoglycemic activity based on reports of their use by local groups in Madagascar. While the hypoglycemic response could not be confirmed under controlled laboratory conditions, an immunosuppressive effect due to... 

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