Page 95 - Pharmacognosy 02-06203

Pharmaceutical preparations of Rauwolfia should be evaluated
biologically, because it contains a large number of alkaloids, with different
pharmacological activities, so the assay of total alkaloidal content is not a
true measure of the therapeutic activity, since only some of the alkaloids
have the desired action.

African Rauwolfia: R. vomitoria
A tree widely distributed in tropical Africa. It is important for the

preparation of reserpine alkaloid.

III- Root containing Terpene ester alkaloids
Aconite ‫درنة خانق الذئب‬

Aconite is the dried tuberous root of Aconitum napellus, family
Ranunculaceae.
In the past, it was used to relieve nerve and muscle pain, rheumatic and
arthritic complain in extremely small dose. However, the plant is deadly
p oisonous.

Constituents:
Aconite contains terpene ester alkaloids (0.3- 1.2 %); the most

important is aconitine. (30 % of total alkaloids consist of aconitine).

Pharmacological action of aconitine:
1- Aconitine causes stimulation followed by depression of both central &

peripheral nervous systems.
2- Aconitine causes depression of all heart functions, indirectly through its

effect on nervous system by stimulation of the Vagal peripheral nerve
endings.

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