One of the most common plants grown in gardens or in pots to bring colour to the surroundings is the simple periwinkle plant which is know botanically as the Catharanthus roseus. It grows easily, and is generally, pink or white in colour.
This plant has been the source of two of the most effective treatments for leukaemia which is often termed cancer of the blood. The two drugs which come from the rather unpretentious plant are vinblastine and vincristine which are used all over the world for the treatment of leukaemia. The active ingredients are present in the leaves of the plants.
Professor Noble and his colleague Dr Beer, at the University of Western Ontario in Canada, had heard that this plant had been used for the treatment of diabetes in Jamaica. They therefore administered this plant to rabbits in 1958, to see Whether the blood sugar level in these rabbits would e reduced – this would be a sign that the plant could be used in controlling diabetes. The scientists found that there was practically no change in the blood sugar level but there was a reduction in the white blood cells. This finding aroused
the interests of the scientist who then carried out chemical studies with the leaves of this plant. They isolated two alkaloids – vinblastine and vincristine. These two alkaloids were tested first on animals where it reduced the white blood cells and then clinically evaluated in patients with leukaemia where the rate of production of white blood cells is very high. The two alkaloids were effective in reducing the white blood cells. The alkaloids became the mainstay of treatment of the leukaemia and of Hodgkins disease. Although the early studies of the Catharanthus roseus were carried out at Western Ontario, the sophisticated chemistry work and the technology which was needed to convert a finding in the laboratory into a drug was carried out at the Eli Lilly laboratories at Indianapolis in USA. This study was conducted by a group of scientists under the leadership of G.H. Sveboda. They type of relationship needed between the scientists working in the university setting and scientists working in the industry, which is essential for drug development, is an excellent example in this work, culminating in the discovery of the two most exciting anti-cancer drugs.
With more international industries coming into the country, in the wake of liberalisation, to carry out research in India and with Indian laboratories not having adequate resources to develop new drugs, ways should be found to stimulate suck activity. Eli Lily is one of the pharmacetucials which has taken a decision to enter India and carry out collaborative research in this country with an Indian pharmacetucial house.
Cultivation of the vinca, as the plant is popularly called, is carried out in South India. Readers may perhaps indentify the plant by its Hindi name, “sada bahar”. Although India gains much foreign exchance by exporting this plant, Indians have to purchase vinblistine and vincristine, prepared by Eli
lilly, at high prices. The process of extraction of the alkaloids is not easy and that is one reason why Eli Lilly still manufactures the drug. The writer recently visited the laboratory of the Central Insitute of Medicinal and Aromatic Plants Organisation at Bangalore, Where Dr Dimri showed the work going on in trying to develop newer strains of Catharanthus roseus, which would be more resistant to diseases. One such strain has already been developed which is called W.H.40.
During experimental studies carried out with the plant Semecarpus anacardium, the writer along with Dr V S Mathur and colleagues at chandigarh, discovered by accident that the extract of this nut also reduced the white blood cells in rats and rabbits. Perhaps this plant could also yield anti leukaemia drugs if this important lead of the 1970s is followed up.
Showing posts with label effective leukemia treatment. Show all posts
Showing posts with label effective leukemia treatment. Show all posts
