Traditional Medicine in Asia

Traditional Medicine in Asia
purified components can, after elution, be
tested for biological activity in an appropriate
test system. Thus, by such highly
sophisticated methodology it is possible to
proceed from “plant to drug”. 2
Drugs derived from plants as pure
chemicals have been in therapeutic use for
almost a century. Some of the plant constituents
have yielded novel chemical entities,
leading to their synthesis and the preparation
of their analogues or derivatives.
Some examples of such drugs derived from
plants are given in the following Table.
Table 3. Drugs derived from plants
Source Plant Active Constituent
Digitals lauata Digoxin
Ephedra vulgaris Ephedrine
Rauvolfia serpentina Reserpine
Cinchona bark Quinine
Artemesia annua Artemisinin
Commiphora mukul Guggulusterones
Asparagus racemosus Shatavarin
Picrorhiza kurroa Picroside
Adhatoda zeylanica Vasicine
Atropa belladona Atropine
Papaver somniferum Morphine
Plant Culture
This is a recent addition to bio-technology
in plant research. In vitro plant cultures
under varying experimental conditions result
in bioproducts with novel chemical
structures and biological activities.
Structure-based Designs
Having identified a chemical structure,
organic chemists are engaged in intensive
computerized drug design exercises. This
requires computer graphics, software for
molecular visualization, and docking
programmes to screen and find out which
262
compounds satisfy the appropriate stereostructure.
Computer modelling has already
yielded a number of compounds of herbal
origin with therapeutic possibilities.
Molecular Approach to Drug
Development
In recent years there have been tremendous
advances in understanding how drug
molecules modify cell functions. After Paul
Ehrlich postulated that drug molecules
interact with specific areas on cell membrane
or inside the cell called “receptors”,
such receptors have now been identified
and their stereo-chemistry studied. With
advances in genetic engineering the
receptors have even been cloned. It is now
possible to study drug receptor interactions
and their kinetics and therefore it is possible
to evaluate the therapeutic potential of
several naturally occurring phytochemicals
derived from higher plants.
While most investigators in this area of
drug development would prefer to work on
synthetic drugs, the potentials of herbal
medicines offering interesting chemical
entities are enormous. This type of development
can only be undertaken by the
pharmaceutical industry. Considering that
their annual turnover exceeds US$ 200
billion globally and the R&D inputs of some
dominant pharmaceutical companies is in
the vicinity of 10–15 per cent of their
turnover, it is possible for such frontline
industrial houses to invest in R&D on the
basis of leads provided by materia medica
and practices of traditional medicine.
Research on Quality Control
Methodology and
Standardization
Quality control and standardization are
essential to ensure safety and efficacy. Most