Transcript Plants Used In Cancer Treatment

Plants Used In Cancer Treatment
Part - I
Cancer
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What is cancer?
US cancer statistics
Cancer costs
Most frequent cancers by organ effected
Cost of cancer per year in U.S.
Major types of cancers
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Over 200 types of cancer are known
grouped into major categories
 Carcinomas
 Sarcomas
 Melanomas
 Teratomas
 Leukemias
and Lymphomas
History of Cancer Therapy
Folk remedies
 NCI – 1955
 NCI-USDA – late 1950s
 NCI – 1985
 21st century
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Current Plant Based Therapies
Periwinkle
 Mayapple
 Yew
 Camptotheca
 Lapachol
 Others: Aspergillus fumigatus, Viscum
album
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Madagascar Periwinkle – Vinca alkaloids
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Catharanthus roseus is
known as the common or
Madagascar periwinkle,
Formerly classified as
Vinca rosea
Perennial evergreen herb
in Apocynaceae
Originally native to island
of Madagascar
Traditional uses of periwinkle
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Used to treat a wide assortment of diseases
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In Europe, folk remedy for diabetes for centuries
In India, juice from the leaves to treat wasp stings.
In Hawaii, boiled to make a poultice to stop bleeding.
In China, an astringent, diuretic and cough remedy.
In Central and South America, homemade cold remedy
to ease lung congestion and inflammation and sore
throats
Throughout the Caribbean, an flower extract to treat
eye irritation and infections
Interest in Periwinkle
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Two groups began independently working on
periwinkle in 1950s when they learned of a tea
Jamaicans were drinking to treat diabetes
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Univ of Western Ontario - Beer and Noble -interested
in plant as a possible “oral insulin” - they isolated
alkalod - vinblastin
Eli Lilly Pharmaceuticals - Svoboda
More alkaloids in periwinkle
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Overall 70 alkaloids have been identified in
periwinkle with various uses
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anticancer properties
lower blood sugar levels
hemostatics (arrest bleeding)
reserpine and serpentine - tranquilizers
Vincristine and vinblastine
Vincristine has been especially effective for
treating acute childhood leukemia, often
with 99% remission rates
 Vinblastine has been especially effective for
treating Hodgkin's disease - which had been
considered a fatal up to that point
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Mode of action of vinca alkaloids
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Vinblastine, vincristine, and two semi-synthetic
derivatives (vindesine and vinorelbine) all have
the same mode of action
Inhibit mitosis in metaphase by binding tubulin
Vinblastine
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Marketed as Velban
Half-life in the bloodstream of 24 hours
Vinblastine is mainly useful for treating Hodgkin's
disease, lymphocytic lymphoma, histiocytic
lymphoma, advanced testicular cancer, advanced
breast cancer, Kaposi's sarcoma
Another action: It also seems to fight cancer by
interfering with glutamic acid metabolism
Side effects of vinblastine
Side effects include hair loss, nausea,
lowered blood cell counts, headache,
stomach pain, numbness, constipation and
mouth sores
 Bone marrow damage is the typical doselimiting factor
 Caused severe birth defects in lab animals
so not used on pregnant patients
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Vincristine
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Marketed as Oncovin
Serum half-life of about 85 hours.
Used mainly to treat acute leukemia,
rhabdomyosarcoma, neuroblastoma, Hodgkin's
disease and other lymphomas
Also Wilms' tumor (80%) and Burkitt's lymphoma
(50%), when used in combination with other drugs
Neurotoxicity is the dose limiting factor (it can
cause damage to the peripheral nervous system)
Side effects of vincristine
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Same as those found with vinblastine
Nervous system problems such as sensory
impairment
Breathing problems or lung spasms shortly after
the drug is administered
Secondary cancers if they receive the drug along
with other anticancer drugs that are known to be
carcinogens
Severe birth defects in animal tests
Vindesine -semi synthetic
Marketed as Eldisine and Fildesin
 Serum half-life of about 24 hours
 Mainly to treat melanoma and lung cancers
(carcinomas) and, with other drugs, to treat
uterine cancers
 Toxicity and side effects are similar to those
of vinblastine
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Vinorelbine - semi-synthetic
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Marketed as Navelbine
Approved for non-small cell lung cancer and
breast cancer – usually in combination with other
drugs
Clinical trials on-going as a treatment for ovarian,
cervical, prostrate and other cancers
Seems to have a wider range of antitumor activity
than the other vinca alkaloids
Side effects include diarrhea, nausea, hair loss,
leukopenia