//5.a. Nature has provided medicines to treat disease for thousands of years

Question 1

How has medicine come from nature

Answer 1

• many modern medicines originate from natural compoumds found in wild plants and other natural sources such as microbes and anumaks (e.g. snak venom in drugs used to treat heart conditions)
• long before scientific medicine, plants were used for medicine e.g. woundowrt

Question 2

Who was Hippocrates

Answer 2

• a Greek physician

- recorded more than 300 medicinal plants and herbs which he classified according to their physiological action

Question 3

Importance of herbal medicine in 1673

Answer 3

• this was underlined in London in 1673 when the society of Apothecaries established the Chelsea Physic garden
• the healing qualities of many plants were known that their common names refelcted this e.g. lunghort

Question 4

How did morphine contribute to medicine

Answer 4

• it was the first naturally derived medicine
• 19th century
• morphine is extract from the latex produced in unripe seed pods of several poppy species
• end of 19th century-glycosides discovered

Question 5

What are alkaloids

Answer 5

• a naturally occurring chemical compound

- the active ingredient in many medicinal drugs

Question 6

What is glycoside

Answer 6

• a compound formed from sugar and another compound

- many medicines now are glycosides derived from plants e.g. asprin

Question 7

Medicinal drugs derived from natural compounds: salicin- source

Answer 7

the bark of white willow and other willow species

Question 8

Medicinal drugs derived from natural compounds: salicin- growing conditions

Answer 8

widespread on river bank, floodplains and wetland throughout the temperate zone

Question 9

Medicinal drugs derived from natural compounds: salicin- medical usage

Answer 9

this is used for pain relief

Question 10

Medicinal drugs derived from natural compounds: caffeine- source

Answer 10

tea, coffee, coca and other plants

Question 11

Medicinal drugs derived from natural compounds: caffeine- growing conditions

Answer 11

tropical and sub tropical conditions, temperatures averaging 20 to 27 degrees celcius

Question 12

Medicinal drugs derived from natural compounds: caffeine- medical usage

Answer 12

it is used as a stimulant for CNS, heart muscles and migraines

Question 13

Medicinal drugs derived from natural compounds: nicotine- source

Answer 13

found in tobacco plant

Question 14

Medicinal drugs derived from natural compounds: nicotine- growing conditions

Answer 14

optimal mean daily temperatures 20-30 degrees celcius, rainfall 600-800mm

Question 15

Medicinal drugs derived from natural compounds: nicotine- medical usage

Answer 15

used as a main active ingredient in new drugs to treat wounds and depression

Question 16

Medicinal drugs derived from natural compounds: morphine- source

Answer 16

it is from dried latex from seed pods of several species of opium poppy

Question 17

Medicinal drugs derived from natural compounds: morphine- growing conditions

Answer 17

warm, humid conditions, 30-38 degrees celius temperatures

Question 18

Medicinal drugs derived from natural compounds: morphine- medical usage

Answer 18

used as a pain reliever

Question 19

Case study of one medicinal plant: the rosy periwinkle- what is it? Briefly describe it

Answer 19

• it is a small evergreen shrub which is native to Madagascar although it is now common in many tropical and sub tropical regions
• the plant requires a warm tropical climate where soils are well drained but moisture retaining and slighltly acidic

Question 20

Case study of one medicinal plant: the rosy periwinkle- what is it used for?

Answer 20

• it is used to treat wasp stings in India

- used to treat diabetes in China and the Philippines

Question 21

Case study of one medicinal plant: the rosy periwinkle- what does it contain?

Answer 21

• it contains 70 know alkaloids, several of which have significant medical value
• two of these (vincristine and vinblastine) have been developed as powerful drugs in the treatment of various cancers
• vincristine is used in chemotherapy in childhood leukaemia- 90% survival rate
• vinblastine proved effective in treating Hodgkin’s lymphoma

Question 22

Case study of one medicinal plant: the rosy periwinkle- Why can’t scientists use the periwinkle

Answer 22

• they have been unable to synthesise the alkaloids and production of the drugs relies on commercial cultivation of the rosy periwinkle
• global scales of vincrisine/vinblastine are worth millions. Few of these profits are channelled back to Madagascar-this is exploitation of biological resources (biopiracy)
• biopiracy hinders economic hrowth and progress in tackling poverty and inequality

Question 23

Mecicinal plants are mainly derived from wild populations and are at risk of extinction-what does this mean?

Answer 23

It means that reliance on medicine from wild plants is high in the developing world

Question 24

Explain how supply and demand is a conservation issue arising from the international trade in medicinal plants

Answer 24

• most plants are sourced from natural supply-rosy periwinkle and foxglove are cultivated
• 80% of people in the developing world relu on traditional medicines-so demand is high
• species are under pressure because medicinal plants are sought

Question 25

Explain how survival of wild medicinal plants is a conservation issue arising from the international trade in medicinal plants

Answer 25

- traditional Chinese medicine and other tradtional practicies are unstainable - species that are threatened with extinction are slow growing or niche filling medicinal plants. 4000 medicinal plants are under threat-14 of these are criticallt threatejed r.g. honeysuckle from Nepal - TCM promotes wild supply over cultivated sources - over harvesting is widespread

Question 26

Explain how protection of habitats and natural ecosystems is a conservation issue arising from the international trade in medicinal plants

Answer 26

- habitat destruction, especially deforestation in the tropics, is a concern - tropical rainforests contain 70% of terrestrial plant species and only 1% has been screened for potential medicinal use-potential is hige - concerns over biopiracy-when medical drugs from wild environments are exploited by pharmaceutical companies with little or no benefit to idigenous people - one possible response is for pharmaceutical companies to work with local people, and for habitat and ecosystem conservation, company profits will be used to fund local community projects e.g. scheme in Samoa