Plants and Cancer

Question 1

cancer

Answer 1

rapid and uncontrolled formation and growth of abnormal cells in the body

Question 2

examples of plants that contain carcinogens

Answer 2

• nicotine (tobacco leaves, tannins, etc)
• really highly acidic tea or coffee

Question 3

Podophyllum peltatum

Answer 3

• May apple
• root extract, long history among indigenous peoples of American Northeast in treating skin cancers

Question 4

Active Ingredients of the May Apple

Answer 4

• aliphatic alkaloids, podophyllins
• podophyllotoxin and alpha-peltatin (controls cancer by arresting cell division, inhibits DNA synthesis during S-phase)

Question 5

Podophyllotoxin mode of action

Answer 5

• stops replication cellular and viral DNA replication
• destabilizes microtubules to prevent cell division

Question 6

Podophyllotoxin uses in Modern Medicine

Answer 6

• used to treat HPV
• derivatives used to treat cancer

Question 7

side effect of Podophyllotoxin

Answer 7

• embryotoxic

Question 8

Colchicum autumnale

Answer 8

• Autumn Crocus
• extracts inhibit cell division
• contains the alkaloid colchicine
• disrupts spindle formation during mitosis

Question 9

Colchicine mode of action

Answer 9

• inhibits mitosis
• disrupts microtubules

Question 10

Colchicine uses in Modern Medicine

Answer 10

• used to treat gout
• derivatives used to treat cancer

Question 11

Side effects of Colchicine

Answer 11

• narrow therapeutic index results in OD
• damage bone marrow

Question 12

Trifolium pratense

Answer 12

• Red clover
• salve made from flowers
• isoflavone genistein as anti-oxidant
• suggested to be effective against breast cancer

Question 13

Where does Taxus brevifolia originate from

Answer 13

• Pacific Yew
• gymnosperm

Question 14

Yew tree and Taxol

Answer 14

• genus: Taxus
• evergreen trees/shrubs
• dioecious
• separate male/female plants
• contains taxine

Question 15

Taxine

Answer 15

a toxic alkaloid assemblage composed of more than seven alkaloids

Question 16

English Yew

Answer 16

• 1000 years old
• second oldest tree on planet
• economic uses: “the ice man”, long-bow (robin hood)

Question 17

Pacific Yew

Answer 17

• endemic to Pacific coastal rain forests of mountains of Western North America
• shade tree, very slow growing

Question 18

Where is the highest concentration of Taxol found?

Answer 18

• in the bark
• very low yield
• 0.007% on a bark dry weight basis

Question 19

Taxol Mode of Action

Answer 19

• worked out in 1979
• blocks cell replication
• M phase of the cell cycle (mitosis and cytokinesis) - prophase, microtubules assemble to form spindle
• late anaphase/telophase the spindle structure is lost

Question 20

Vincristine and vinblastine

Answer 20

• stop cell cycle by blocking microtubule assembly
• spindle formation inhibited

Question 21

Taxol Supply Problem

Answer 21

• course of treatment with taxol requires about 2 grams of taxol
• requires about 15 kg of bark
• national cancer institute set a goal of 12 000 patients a year