Study on the anti-depressant and anxiolytic activities of the methanolic leaf extract of mitragyna speciosa korth and its effect on the level of some brain biogenic amines
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Date
1998
Authors
Abushwereb, Hanan Saaddin
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Mitragyna speciosa Korth (Family: Rubiaceae)
locally known as "Daun Biak", has· been shown to
have addictive properties and produce tolerance and
dependence. The methanolic leaf extract of
Mitragyna speciosa (MS) is known to contain several
alkaloids including mitragynine which has an indole
moiety. This moiety is also a feature of serotonin,
which is an important central neurotransmitter. In
view of the current strategy of designing
antidepressants in the form of
reuptake inhibitors (SSRis),
~selective serotonin
this study has
investigated whether the methanolic leaf extract of
Mitragyna speciosa possesses antidepressant-like
effect. Mitragyna speciosa has also been used as an
opium substitute probably to alleviate anxiety by
drug abusers when the drug itself is unavailable.
Therefore, this study has also investigated if the
methanolic leaf extract of Mi tragyna speciosa has
such anxiolytic-like effect. In order to elucidate
the possible mechanism of action of Mitragyna
speciosa, the level of neurotransmitters have also
been determined.
The Porsolt
antidepressants
swim
had
test
been
method
used
for
for
screening
the first
objective. Female mice were forced to swim for 6
minutes into a glass cylinder (height 27cm and
diameter 16.5cm) filled with 11cm water at 27°C.
This was followed 24h later with a second swim
session of 6 min. Drugs were administered (n=10)
orally 1, 5 and 24h after the first swim session to
record chronic effect. The oral administration of
Mitragyna speciosa methanolic leaf extract at doses
100, 200, 400 mg/kg, significantly reduced the
immobility time. The antidepressant-like effect of
the Mi tragyna speciosa methanolic leaf extract was
I'
compared to that of imipramine. The locomotor
activity of the methanolic leaf extract was
measured to confirm that the reduction in
immobility time was not due to the increase in
locomotion.
In addition, the plus-maze and open-field test of
exploratory behaviour were used for measuring the
anxiolytic-like effect of the extract. Chronic
administration of the Mitragyna speciosa methanolic
leaf extract 50, 100, 200 and 400 mg/kg, orally for
14 days on rats tested in the elevated plus-maze,
2 4 h after the last administration, was found to
produce an anxiolytic-like effect on their
exploratory behaviour at doses 100, 200 and 400
mg/kg. However, the effect of the methanolic leaf
extract on the general locomotor activity were not
found to be significantly changed. The effect of
this methanolic leaf extract were compared to that
of diazepam.
At
by
the time of
plus-maze
testing
and open
the anxiolytic
field, the
like-effect
levels of
different monoamines in four brain areas named; the
substantia nigra, the nucleus accumbens, the locus
coeruleus, and the raphe nuclei were also assayed
using high performance liquid chromatography
coupled with electrochemical detector (HPLC-EC).
The levels of serotonin were found to be
significantly higher in substantia nigra in doses
of 100 and 200 mg/kg of the methanolic leaf extract
of Mitragyna speciosa, while the serotonin
metabolite (5-hydroxyindoleacetic acid) was
increased in raphe nuclei and nucleus accumbens at
doses 100, 200 and 400 mg/kg of the Mitragyna
speciosa methanolic leaf extract.
An increase in noradrenaline levels in the four
tested regions; the locus coeruleus, nucleus
accumbens, substantia nigra and raphe nuclei was
also observed in doses of 100, 200 and 400 mg/kg.
The dopamine levels were increased in substantia
nigra and accumbens in doses of 100, 200 and 400
mg/kg. The results of the present study suggest
that the antidepressant- and anxiolytic-like effect
- of the Mitragyna speciosa extract, is probably
mediated mainly through the enhancement of central
neurotransmitter levels.
Description
Keywords
Anti-depressant , Methanolic leaf extract , Brain biogenic amines