Transcript Plant-derived compounds in clinical trials (Saklani and

‘Plant-derived compounds in clinical
trials’ (Saklani and Kutty, 2008)
Frances Watkins
29 November 2010
Market Share
• Global market valued at $18 billion in 2005
and estimated to be >$26 billion by 2011
• A review of 91 plant-derived compounds in
clinical trials in Sep 2007
• 26 plant based drugs approved/launched
between 2000-2006 including Artemotil,
Galanthamine and Abraxane
Plant-based anticancer drugs
• 56 plant based
anticancer drugs in
clinical trials
• Most promising
analogues from
Paclitaxel/Taxol,
Camptothecin,
Combrestatin,
Podophyllotoxin and
Vinca alkaloids
Structure of Taxol
Medicinal Plants
• 50% of prescription drugs in last 25 years have
been derived from chemicals first identified in
plants (Newman and Cragg, 2007)
• Ever increasing need to develop new treatments
for modern disease and more efficient
medications for established health complaints
• A growing interest in developing mixtures of
natural products from traditional medicines
(Harvey, 2008)
Health Applications
• Infectious and parasitic
disease
• Pain and neurological
disease
• Cardiovascular and
metabolic disease
• Inflammatory disease
• Oncological disease
Traditional Use
• Silybum marianum (Asteraceae) used for liver
and biliary tract disease – standardised
extract in Phase II
• Lobelia inflata - an emetic and respiratory
stimulant; aid to cease smoking – Lobeline
has been used for methamphetamine
addiction and hyperactivity disorder (ADHD)
• Xiao Chai Hu Tang (Minor Bupleurum
Decoction) TCM herbal formulas used for
hepatitis, liver cancer and nephritis
Plant Compounds
Galanthus nivalis
• The greatest contribution to
medicine - the alkaloid group:
quinine (isolated in 1820),
codeine (1832), morphine
(1806) and galanthamine
(1950s)
• Found in 15-30% of all
flowering plants in the roots,
rhizomes, leaves, bark, fruit or
seeds
• >40 alkaloids found in Vinca
major
Other Metabolites
• Catechins found in green
tea, grapes, black tea,
chocolate and wine
• Many lignans i.e.
flaxseed are converted
by intestinal bacteria and
become active
metabolites which are
then readily absorbed
• Essential oils
Linum usitatissimum
Ethical Issues
Hoodia gordonii
• Plants facing threat
through excessive
harvesting: Hoodia
species, Yew, Echinacea
and Magnolia
• Impact on local
communities and
environment
• Generate sustainable
cash crops for biomass –
2 x 108Kg = 7.5 106
bushels
Future Perspectives
• Encouraging number of plant-based drugs in
clinical trials although a 30% drop compared
to pre 2000 (Harvey, 2008)
• Modern techniques combined with traditional
knowledge will offer a quicker route to drug
discovery
• Pharmaceutical industry recognising
traditional medicinal systems are valuable
leads to drug discovery (Verpoorte, 2009)
Thank you
• Any questions?
References
Harvey, A. (2008) ‘Natural products in drug discovery’. Drug
Discovery Today. 13, (19/20), pp.894-901.
Newman, DJ and Cragg, GM (2007) ‘Natural products as
sources for new drugs over the last 25 years’. Journal Natural
Products. 70, pp.461-477.
Saklani, A. and Kutty, S.K. (2008) ‘Plant-derived compounds in
clinical trials’. Drug Discovery Today. 13, (3/4), pp.161-171.
Verpoorte, R. (2009) ‘A systems view on the future of medicine:
Inspiration from Chinese medicine?’. Journal of
Ethnopharmacology. 121, pp.479-481.