Topic 8: Cancer, Immune System & Phytomedicines Flashcards
Colchicum autumnale (Overview)
- plant family: Colchicaeceae
- common name: crocus
- geography: europe to north africa
- habit/habitat: herb, gardens
- plant part used: corms
- ethnomedical uses: gout, arthritis, inflammation, pain
Colchicum autumnale (Chemistry)
-pharmaceuticals (alkaloids): colchicine, colchicum, colchiceine, amide, demecolcine
-mechanisms of action: causes a doubling of chromosomes by disorganizing the spindle mechanism at mitosis
-modern medical uses:
colchicine: gout, antitumor
colchiceine amide: antitumor
demecolcine: antitumor
Podophyllum peltatum and P. hexandrum (Overview)
- plant family: Berberidaceae
- common name: may apple
- geography: P. peltatum in eastern north america and P. hexandrum in himalays
- habit/habitat: perennial herb, forest
- plant parts: rhizome
Podophyllum peltatum and P. hexandrum (Chemistry)
-active components: podophyllum resin from rhizone and pdodphyllotoxin (podofilox)
-chemical derivatives: etoposide, teniposide
-mechanisms of action:
podophyllotoxin binds microtubule resulting in mitotic arrest in metaphase
teniposide and etopside block G1 phase of mitosis and S phase (DNA replication)
Catharanthus roseus (Overview)
- plant famiy: Apocynaceae
- common name: madagascar periwinkle, rosy periwinkle
- geography: native to madagascar, naturalized throughout the world
- habit/habitat: herb, open disturbed ground
- plant part used: all parts
Podophyllum peltatum and P. hexandrum (Uses)
-ethnomedical use: warts, laxative, cathartic, emetic, helminthic infectons, cancer
-therapeutic uses:
podophyllum resin: applied topically to tx condylomata acuminata (anogenital warts)
teniposide and etopside: testicalr carcinomas, small-cell lung carcinoma, Hodgkin;s and non-Hodgkin’s lymphoma, breast cancer, Karposi’s sarcoma, acute granulocytic leukemia
Catharanthus roseus (Chemistry)
- active components (alkaloids): vincristine and vinblastine
- mechanisms of action: bind to protein tublin to inhibit microtubule formation, prevents mitotic spindle formation, and arrests of cell division at metaphase
Cathaaranthus roseus (Uses)
- ethnomedical use: type 2 diabetes mellitus, Hodgekin’s disease
- therapeutic uses:
vincristine: acute childhood leukemia, Hodgekins deases, non-Hodgekin’s lymphoma, Wilm’s tumor, neuroblastoma, rhabdomyosarcoma, rapidly proliferating neoplasms
vinblastine: lymphoma, Hodgekin’s lymphoma, Karposi’s sarcoma, breat carcinoma, testicular carcinoma
Taxus brevifolia (Overview)
- plant family: Taxaceae
- common name: pacific yew
- geography: northern california up through pacific northwest
- habit/habitat: shrub, tree, forest
- plant part used: bark needles
Taxus brevifolia (Chemistry)
- ethnomedical use: skin cancer
- active compound: paclitaxel (taxol)
- chemical derivative: docetaxel (taxotere)
- mechanism of action: antimicrotubule and antimitotic
Taxus brevifolia (Uses)
paclitaxel (taxol) and decotaxel (taxotere)
-therapeutic uses: metastatic ovarian and breast cancer, potential use against carcinomas of the bladder, lung, head, neck, and espophagus
Camptotheca acuminata
-common name: cancer tree, happy tree, Xi Shu
-geography: china
-active molecule: camptothecin
-mechanism of action: camptothecin and its analog compounds can inhibit the nuclear DNA topoisomerase I enzyme
therapeutic uses: leukemia
Nerium oleander
- common name: oleander
- family: apocinaceae
- active molecules: oleandrin and oleandrigenin in plant extract preparation called anvirzel
- mechanism of action: stimulates tumor necrosis factor
- clinical use: experimental use to treat a variety of cancers
Viscum album
- plant family: loranthaceae
- common name: european mistletoe
- ecology: parasite on Quercus
- plant part used: bark extract
- cultural origins: europe
Viscum album (Uses)
- ethnomedical uses: joint inflammation, malignant tumors
- therapeutic uses: joint inflammation, malignant tumors, breast cancer
Anti-cancer Phytochemicals in Vegetables and Fruits
a diet rich in a spectrum of fruits and vegetables reduces the risk of developing cancer
Lycopene Carotenoid
- from Solanum (=Lycopersicum) esculenta (tomato)
- lycopene is a plant carotenoid found in tomato paste and also in watermons and grapefruits
- consumption of lycopene-rich foods work to reduce the likelihood of developing prostate cancer
Brassica oleracea
- contain anticancer molecules
- varieties: broccoli, cauliflower, kale, cabbage, brussel sprouts
- native to europe
- eaten as food
- sulfur rich active molecuels: isothiocyanates, glucosinolates
- reduce breast, prostate and ovarian cancers
Coffee arabica, C. robusta
-origin of coffee: northeastern africa
-plant parts used: seeds roasted, ground up, and brewed in hot water as a beverage
-active molecules: caffeine, anti-oxidant polyphenols
-studies conducted by the harvard school of public health have demonstrated the following:
reduces prostate cancer in men
reduces endometrial cancer in women
reduces breast cancer in women
reduces basal cell carcinoma of skin in men and women
Zingiber officinalis
- ginger
- origin: asia
- when meat is grilled, carcinogenic compounds are especially concentrated on the areas of the meat that are burned
- use of ginger containing sauces (e.g., teriyaki sauce) on the covering of the meat as it is grilled, significantly reduces the level of carcinogen formation in the grilled meat
Estrogen Receptor Binding
- bone estrogen receptors -> activates genes in bone -> low osteoporosis
- breast estrogen receptors -> activates genes in breasts -> high breast cancer
- uterine estrogen receptors -> activates genes in uterus -> high uterine cancer
Estradiol and Estrogen Derivatives Receptor Binding
- estradiol activates all three receptor types: low osteoporosis, high breast and uterine cancer
- tamoxifen activates bone and uterine receptors, but blocks breast receptors: low osteoporosis, and high uterine cancer
- raloxifene activates bone receptors and blocks both breast and uterine receptors: low osteoporosis
Beneficial Effects of Phytoestrogens From Soy and Other Plant-based Foods
- phytoestrogens have weak estrogenic effects which appear to be similar to the raloxifene
- isoflavones, lignins, and coumestrosis are all plant-derived phytoestrogens which may benefit post-menopausal disorders
Phytoestrogens (Effects)
dietary phytoestrogens may reduce:
- cardiovascular disease
- breast cancer
- ovarian cancer
- prostate cancer
- menopausal symptoms
- osteoporosis
Isoflavone Phytoestrogens
- in legumes (e.g., soybeans) fruits and vegetables
- formonoetin and biochanin A metabolized by bowel microflora to daidzein and genistein
- genistein may be further metabolized by p-ethyl phenol
Glycine max
- soybeans, in Fabaceae
- native to chian, consumed as whole bean, tofu, miso, soya sauce, flour
- highest amount of isoflavones of any known plant foods
- soybeans are 40% protein
- complete protein when combined with rice or wheat
- contain significant amounts of alpha-linolenic acid, genistein, and daidzein
Lignan Phytoestrogens
- flaxseed (Linum usitatissimum) in Linaceae
- lignin forms foundation of plant cell wall
- flaxseed highest known plant food source of lignans
- secoisolariciresinol and matieresinol are metabolized in humans to form the human lignans, enterolactone and enterodiol
- other rich sources of lignins: lentils, soy beans, triticale wheat, wheat bran, oat bran, kidney beans, navy beans,garlic, carrots, seeds, legumes, whole grains, fruits, and vegetables
Coumestan Phytoestrogens
coumestrol
- sources: sunflower seeds, legumes, and bean sprouts
- structure: similar to genistein and 17-beta esetradiol
- action: competitively binds to estrogen cytosol receptors
Phytoestrogens (Mechanisms of Action)
- bind to nuclear type II estrogen binding sites
- weaker estrogenic qualities than endogenous estrogens (e.g., estradiol)
- stimulate protein synthesis to a lesser degree than endogenous estrogens
- compete with stronger endogenous estrogens for receptors
- exert weak agonistic and antagonistic estrogenic activity
- inhibit growth of estrogen sensitive cancers (e.g., breast cancer)
Phytoestrogens (In Diet)
- 45 grams of soy protein a day for adults is recommended to reduce risk of cardiovascular disease, hormone dependent tumors (breast cancer), menopausal symptoms, and osteoporosis
- lower intakes of soy protein per day would likely also be beneficial
- isoflavins and lignans inhibit the proliferation of estrogen sensitive breast cancer cell lines
