Agriculture Reference
In-Depth Information
of the stems bear five prominent longitudinal ridges.
Cytisus
is a perennial herb with a bitter taste.
The flowering tops are the plant part used medicinally.
Habitat and Distribution —
Broom is a European herb that has been introduced to the semi-
tropical regions of the continent. It is cultivated in South Africa as a garden plant.
Ethnomedicinal Uses —
It is employed as a diuretic and in the treatment of mild hypertension.
A decoction of the leaves is used with lime for chest complaints.
Constituents —
Cytisus
contains quinolizidine alkaloids, flavonoids, phenylethylamines,
lectins, and monoterpenes. The major compounds isolated from the plant include the alkaloids
sparteine, lupanine, isosparteine, ammoderine, and related derivatives;
506,507
tyramine, epinine,
salsolidine, and related phenylethylamines;
507
genistein, quercetin, and their glycosides;
123,508
and
caffeic and
p-
coumaric acids.
509
The seeds contain lectins,
510
and the volatile oil yields eugenol,
phenol, cresols, isovaleric acid, benzoic acid, and benzylalcohol, as well as
cis-
3-hexen-1-ol and
1-octen-3-ol.
509
Pharmacological Studies —
Cytisus
exerts a plethora of pharmacological activity due to its
several constituents. It has a slowing effect on pathologically accelerated stimuli arising in the
atrium, reduces increased irritability in the conduction system, and regulates the heart rhythm,
simultaneously improving venous return.
511
It does not have any activity on the failing myocardium
and therefore is not considered a digitaloid.
One of the active principles, sparteine, has a curare-like effect on peripheral nerves, which
depresses respiration; it reduces the conductivity of cardiac muscle, and it is oxytocic.
512
Oxytyramine,
a phenylethylamine found in the plant, has been shown to be a vasoconstrictor.
511
Broom is a diuretic and cathartic and has been used for the treatment of tumors.
508
Other alka-
loids present in
Cytisus
, especially sarothamine and genistein, also inhibit conduction. The fla-
vonoids, which co-occur with these alkaloids, have been reported to have a beneficial effect on
myocardial function and the initiation of cardiac impulses.
512
Sparteine exhibits genetic polymorphism in its
in vivo
oxidation profile, and care must be taken
to determine the appropriate dose for people from differing backgrounds. Sparteine polymorphism
has been observed among the various racial groups.
513 -515
The drug is effectively inhibited by quini-
dine administration.
515
Clinical Properties —
Oral preparations of
Cytisus
are used in the treatment of persistent
arrhythmias or extrasystoles. It is indicated for long-term treatment of persistent postinfectious myo-
carditis with arrhythmia and to prevent a tendency for extrasystoles. The drug is also not effective for
the treatment of absolute arrhythmia or paroxysmal tachycardia.
511
The plant has also been used as
an antioxidant and as a hepatoprotective agent. The extract inhibited the toxicity of CCl
4
in rats in a
dose-dependent manner, and the activity of the extract at a dose of 500 mg/kg was comparable to the
standard drug silymarin (25 mg/kg) in the protection of the liver from oxidative stress.
512
Toxicity and Adverse Effects —
Cytisus,
when taken in low doses, is relatively nontoxic, but at
higher doses the drug causes drowsiness, visual disturbances, and congestion in the head. Sparteine
intoxication produces marked bradycardia. Another member of the genus
Cytisus, C. laburnum
(actu-
ally belonging to the genus
Laburnum
), is very toxic and should not be used for the preparation of drugs.
DATURA
The
Datura
species
D. stramonium
,
D. metel,
and
D. fastuosa
are widely distributed in Africa.
For medicinal purposes, the distinction between the three species is not considered important since
they all yield the pharmacologically important tropane alkaloids hyoscine, atropine, and hyoscamine.
In some topics,
D. metel
is considered synonymous with
D. fastuosa
and
D. innoxia.
As indicated in
the following discussions, only the variety alba of
D. fastuosa
is synonymous with
D. metel;
the black
variety of the former appears to be a distinct species and is often confused with
Vernonia amygdalina.
