The different isoquinoline alkaloids, for example, berberine, palmitine, jatrorrhizine,
and sanguinarine, have clear differences in their pharmacological actions.
These are due to the differences in their functional groups, and to differences
in shape and energetics of the molecules.
Mechanism of action
One proposed mechanism of action of the different
isoquinoline alkaloids is that they bind
to specific sequences of DNA and RNA in the
cell. Small structural differences in the
different isoquinoloid molecules result in
significantly differing therapeutic results.
Designing new drugs
In an excellent summary, Bhandra K and Kumar
GS (2010) reviewed isolated isoquinoline
alkaloids with a view to future drug design.
They suggested that synthetic modifications
of these natural alkaloids might be designed
with superior DNA-binding effects, and
thus more powerful and more specific therapeutic
Advantages of the whole plant
However, the danger of side-effects from
the use of synthetic ‘improvements’ on
naturally occurring plant chemicals is
well known. A good example of this being
the addition of an acetyl group to salicylic
Also, the use of single isolated constituents
neglects the beneficial interactions between
the different constituents of a herb.
Synergy between herb constituents
For many herbs, not just one, but many constituents
contribute to the therapeutic actions of
the herb. For example, at least five chemical
types of constituent contribute to the actions
of Salvia species.
Synergy effects have been reported between
different groups of Salvia constituents.
For example, between different monoterpenoids,
and between salvionolic acids and tanshinones.
Click here to see research data on synergy
between Salvia constituents.
Synergy between herbs and drugs
Research reports of positive synergy effects
between herbs or herb constituents and drugs
are increasing. This knowledge can be incorporated
into new herb combinations.
Click here to see Bereberis research data
on synergy between berberine and different