//5.a. Nature has provided medicines to treat disease for thousands of years Flashcards
How has medicine come from nature
- 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
Who was Hippocrates
- a Greek physician
- recorded more than 300 medicinal plants and herbs which he classified according to their physiological action
Importance of herbal medicine in 1673
- 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
How did morphine contribute to medicine
- 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
What are alkaloids
- a naturally occurring chemical compound
- the active ingredient in many medicinal drugs
What is glycoside
- a compound formed from sugar and another compound
- many medicines now are glycosides derived from plants e.g. asprin
Medicinal drugs derived from natural compounds: salicin- source
the bark of white willow and other willow species
Medicinal drugs derived from natural compounds: salicin- growing conditions
widespread on river bank, floodplains and wetland throughout the temperate zone
Medicinal drugs derived from natural compounds: salicin- medical usage
this is used for pain relief
Medicinal drugs derived from natural compounds: caffeine- source
tea, coffee, coca and other plants
Medicinal drugs derived from natural compounds: caffeine- growing conditions
tropical and sub tropical conditions, temperatures averaging 20 to 27 degrees celcius
Medicinal drugs derived from natural compounds: caffeine- medical usage
it is used as a stimulant for CNS, heart muscles and migraines
Medicinal drugs derived from natural compounds: nicotine- source
found in tobacco plant
Medicinal drugs derived from natural compounds: nicotine- growing conditions
optimal mean daily temperatures 20-30 degrees celcius, rainfall 600-800mm
Medicinal drugs derived from natural compounds: nicotine- medical usage
used as a main active ingredient in new drugs to treat wounds and depression
Medicinal drugs derived from natural compounds: morphine- source
it is from dried latex from seed pods of several species of opium poppy
Medicinal drugs derived from natural compounds: morphine- growing conditions
warm, humid conditions, 30-38 degrees celius temperatures
Medicinal drugs derived from natural compounds: morphine- medical usage
used as a pain reliever
Case study of one medicinal plant: the rosy periwinkle- what is it? Briefly describe it
- 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
Case study of one medicinal plant: the rosy periwinkle- what is it used for?
- it is used to treat wasp stings in India
- used to treat diabetes in China and the Philippines
Case study of one medicinal plant: the rosy periwinkle- what does it contain?
- 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
Case study of one medicinal plant: the rosy periwinkle- Why can’t scientists use the periwinkle
- 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
Mecicinal plants are mainly derived from wild populations and are at risk of extinction-what does this mean?
It means that reliance on medicine from wild plants is high in the developing world
Explain how supply and demand is a conservation issue arising from the international trade in medicinal plants
- 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
Explain how survival of wild medicinal plants is a conservation issue arising from the international trade in medicinal plants
- 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
Explain how protection of habitats and natural ecosystems is a conservation issue arising from the international trade in medicinal plants
- 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
