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Print ISSN 2319-2003 | Online ISSN 2279-0780
doi: 10.5455/2319-2003.ijbcp20140817
IJBCP International Journal of Basic & Clinical Pharmacology
www.ijbcp.com International Journal of Basic & Clinical Pharmacology | July-August 2014 | Vol 3 | Issue 4 Page 656
Research Article
Evaluation of anti-depressant effect of lemon grass
(Cymbopogon citratus) in albino mice
Sujata Dudhgaonkar, Manali Mahajan*, Swapnil Deshmukh, Pallavi Admane, Huma Khan
INTRODUCTION
Depression and anxiety disorders are the most common
mental illnesses, each affecting in excess of 10-15% of
the population at some time in their lives. Both anxiety
and depressive disorders are amenable to pharmacological
treatments that have been developed since 1950s. The last
half century has seen notable advances in the discovery and
development of drugs for treating anxiety and depression.1
The current therapy includes monoamine oxidase inhibitors
(MAOI) (tranylcypromine, clorgyline, moclobemide)
tricyclics and related compounds (imipramine, amitryptyline,
desipramine, fluoxetine, and fluoxamine). However,
the typical anti-depressants are some of the most toxic
psychopharmacological agents.2 They produce unusual
side-effects such as MAOIs-insomnia, hypotension,
anorgasmia, weight gain, hypertensive crisis, and tyramine
cheese reaction. Tricyclic anti-depressants-anti-cholinergic
side-effects (dry mouth, tachycardia, constipation, urinary
retention, and blurred vision), sweating, tremor, postural
hypotension, cardiac conduction delay, sedation, weight
gain. Selective serotonin re-uptake inhibitors-headache,
nausea, other gastro intestinal effects, jitteriness, insomnia,
and sexual dysfunction.3
Since depressive disorders have a tremendous impact on
our lives, it is worth evaluating the alternative forms of
medicines which are better tolerated, more efcacious and
cost-effective like herbal products. Herbal medicine is a
major component in all indigenous peoples’ tradition, a
common element in ayurvedic, homeopathic, naturopathic,
traditional, oriental and native American Indian medicine.
Cymbopogon citratus, commonly known as lemon grass,
is a tropical plant from Southeast Asia, which is often sold
in stem form. It contains various active principles like
myrcene, citrondiol, citronellol, citronellal, and geraniol
ABSTRACT
Background: Depression is a common serious psychiatric disorder and the available
anti-depressant treatments are associated with many unwanted side-effects. Thus,
various herbal products have been tried. The advantages of herbal treatments would
include its complementary nature to the conventional treatment, thus making the latter
a safer and cheaper option for depressive disorders. The objective of the present study
was to evaluate the anti-depressant activity of lemon grass (Cymbopogon citratus)
in albino mice and compare it with Imipramine.
Methods: A total of 60 Swiss albino mice weighing around 20-40 g of either sex
were divided into 10 groups (n=6). They were orally administered with tween 80,
as a control, 20 mg/kg imipramine (standard), 5 mg/kg and 10 mg/kg C. citratus
(test drugs), and combination of imipramine (10 mg/kg) and C. citratus (10 mg/kg).
Duration of immobility was observed for last 4 mins of total 6 mins period in
groups 1-5 for forced swimming test (porsolt test) and groups 6-10 for tail suspension
test each on 1st, 8th and 15th day and recorded as mean±standard error of the
mean. Results were analyzed by one-way analysis of variance, followed by Tukey’s
post-hoc test.
Results: Lemon grass at the above doses signicantly reduced the immobility time
in both the tests compared with the control (<0.05). The reduction in the duration of
immobility at the dose of 10 mg/kg was comparable to imipramine.
Conclusions: The essential oil of lemon grass (C. citratus) has signicant anti-
depressant activity comparable to imipramine.
Keywords: Anti-depressant, Imipramine, Cymbopogon citratus
Department of Pharmacology,
IGGMC, Nagpur,
Maharashtra, India
Received: 23 May 2014
Accepted: 10 June 2014
*Correspondence to:
Dr. Manali M. Mahajan,
Email: manali1988_
mahajan@yahoo.com
© 2014 Dudhgaonkar S et al.
This is an open-access article
distributed under the terms
of the Creative Commons
Attribution Non-Commercial
License, which permits
unrestricted non-commercial
use, distribution, and
reproduction in any medium,
provided the original work is
properly cited.
Dudhgaonkar S et al. Int J Basic Clin Pharmacol. 2014 Aug;3(4):656-660
International Journal of Basic & Clinical Pharmacology | July-August 2014 | Vol 3 | Issue 4 Page 657
which impart various actions and benets, making the
plant multifunctional. Extracts of both leaves and stalks
are used as herbal medicine to treat nervous conditions and
inammation.4
Traditional Indian medicine employs lemon grass for fever,
infection and sedation (Lawless, 1995). It is also commonly
used as an antitusive, anti-rheumatic, anti-septic agent,
an insecticide and food flavoring agent (Julia, 1992).
In the Malay Peninsula, C. citratus is recommended in
folk medicine for common colds, pneumonia and gastric
problems (Carlini et al., 1986). In Brazil, it is used in
folk medicine for nervous conditions or gastro intestinal
disturbances (Carlini et al., 1986; Suzana et al., 2001).
In Thai, it is used in the treatment of fever, irregular
menstruation, diarrhea and digestive problems. It is also
used in Central and South America for nervous conditions
and helps to regulate blood pressure (Lawless et al., 1995;
Blumenthal, 1998).
Our study was aimed at studying the anti-depressant action
of C. citratus and to compare it with the conventional anti-
depressants available namely Imipramine. Studies proving
this use of C. citratus are lacking and needs attention since
depression is a growing problem of the modern world and
use of indigenous medicines is welcome in its treatment.
Aims and objectives
1. To evaluate the anti-depressant activity of C. citratus
in albino mice.
2. To compare the anti-depressant activity of C. citratus
and imipramine in albino mice.
3. To compare the anti-depressant activity of:
a. Combination of C. citratus and imipramine with
imipramine alone
b. Combination of C. citratus and imipramine with
C. citratus alone.
METHODS
This study was conducted over a period of 15 days in the
following manner.
Animals
Sixty Swiss albino mice of either sex weighing around
20-40 g were used. They were supplied from nearby
Government Medical College. They were maintained under
standard laboratory conditions (22±3°C, 12 hr light/dark
cycle) supplied with standard pellet food and water given
ad libitum in Government Medical college animal house.
The animals were cared in accordance with the guidelines
provided by the CPCSEA and the Institutional Ethics
Committee approved the entire study.
Plant extracts preparation
The plant was obtained from local ayurvedic college and
following processing was done in pharmacology Department
of Government Medical college.
The plant was dried and nely powdered. 100 g of this
powder was soaked in 500 ml distilled water for 72 hrs.
This mixture was ltered with sterile Whitman’s no 1 lter
paper. The ltrate obtained was stored in refrigerator at
4°C until required. This aqueous ltrate was freeze dried to
reconstitute the extract into powdered form.5
Imipramine hydrochloride is used as a standard in the dose of
20 mg/kg, administered by the oral route. Tween 80 is used
as the control in the dose of 0.1 ml/10 g (1%) administered
by oral route.
General procedure
The mice were divided into10 groups of six each as follows.
1. Group 1: Tween 80
2. Group 2: Imipramine 20 mg/kg
3. Group 3: C. citratus 5 mg/kg
4. Group 4: C. citratus 10 mg/kg
5. Group 5: Combination of C. citratus 10 mg/kg and
imipramine 10 mg/kg
6. Group 6: Tween 80
7. Group 7: Imipramine 20 mg/kg
8. Group 8: C. citratus 5 mg/kg
9. Group 9: C. citratus 10 mg/kg
10. Group 10: Combination of C. citratus 10 mg/kg and
Imipramine 10 mg/kg.
Drug or C. citratus extracts are orally administered to the
mice according to the group they belong to. After 1hr of oral
administration, they were subjected to the following tests:
• Group 1 to 5 were subjected to forced swimming test.
• Group 6 to 10 were subjected to tail suspension test.
Forced swimming test
The adult mice are forced to swim in a cylinder (40×18 cm)
with no escape. The mice become immobile after an initial
struggling phase. Duration of immobility was observed for
last 4 mins of total 6 mins period on day 1, 8 and 15.
Tail suspension test
Mice are rendered immobile by suspending from tail using
an adhesive tape which is applied at the point, which is three-
fourth of the distance from the base of the mouse’s tail. Its
nostril touches the water surface in a container. Initially the
animal tries to escape by making vigorous movements, but
is unable to escape and becomes immobile. The period of
immobility during the last 4 mins of total 6 mins period is
observed on day 1, 8 and 15.
Dudhgaonkar S et al. Int J Basic Clin Pharmacol. 2014 Aug;3(4):656-660
International Journal of Basic & Clinical Pharmacology | July-August 2014 | Vol 3 | Issue 4 Page 658
Statistical analysis
All data were subjected to one-way analysis of variance
using Statistical Package for the Social Sciences (SPSS)
18.0 software and in between groups were compared using
Tukey’s post-hoc test. p≤0.05 was considered as statistically
signicant.
RESULTS
Duration of immobility in the last 4 mins of the 6 mins
duration of both the tests are recorded as mean±standard
error of the mean on days 1, 8, and 15.
Forced swimming test (Table 1)
1) On day 1: There is no signicant reduction in the
duration of immobility in any group when compared
to the control.
2) On day 8: Signicant reduction (p≤0.05) in the duration
of immobility is observed in Groups 2 and 3 when
compared to 1. Highly signicant reduction (p≤0.01)
in duration of immobility seen in Groups 4 and 5.
3) On day 15: There is signicant reduction in duration
of immobility in all groups compared to 1. Group 2
reduces duration of immobility more than Group 3 and
Group 5, but less than Group 4. Group 3 is inferior to
Group 4 and 5. Group 4 is more effective than 5 in
reducing duration of immobility. Group 2, 4, and 5 are
comparable.
Tail suspension test (Table 2)
1. On day 1: No significant reduction in duration of
immobility in all the groups.
2. On day 8: No significant reduction in duration of
immobility in any group. Compared with day 1, day 8
showed reduction in duration of immobility in all groups
except group 6.
3. On day 15: Group 7 and 9 showed highly signicant
reduction in duration of immobility than Group 6.
Group 7 showed more reduction in the duration of
immobility than Group 8, but less than Group 9.
Reduction in duration of immobility was maximum on
day 15 compared to day 1 and 8.
DISCUSSION
Major depressive disorder is a mental disorder common in
psychiatric practice wherein a patient presents with at least
one of two major symptoms, constant sadness or anhedonia,
accompanied by at least ve secondary symptoms for at
least 2 weeks.5 The secondary symptoms include feelings
of worthlessness, difculty in concentrating, changes in diet
and sleep patterns. It is a relapsing, remitting illness having
>40% rate of recurrence over a 2 year period.6
Depression is multifactorial in origin. The various factors
include familial factors, early life events, neuro-endocrine
changes and genetics. The role of oxidative stress as a patho-
physiological mechanism in depression, can be explained by
the concept, sometimes referred to as the “oxygen paradox,”
that while oxygen is essential for aerobic life, excessive
amounts of its free radical metabolic by-products are toxic.7
These free radicals play integral roles in cellular signaling,
physiological immunogenic responses and mitosis. However,
being highly unstable molecules with unpaired electron they
have differential oxidative strengths and hence potential to
damage cellular proteins, lipids, carbohydrates and nucleic
acids.8
Table 1: Forced swimming test.
Day Group
1 (Tween 80) 2 (imipramine
20 mg/kg)
3 (C. citratus
5 mg/kg)
4 (C. citratus
10 mg/kg)
5 (imipramine 10 mg/kg+
C. citratus 10 mg/kg)
Day 1 140.37±3.79 134.5±3.79 137.33±3.79 134.83±3.79 136.0±3.79
Day 8 139.1±4.86 113.12±4.86* 116.5±4.86* 114.0±4.86** 110.5±4.86**
Day 15 130.67±3.89 85.57±3.89*** 97.33±3.89*** 83.5±3.89*** 86.5±3.89***
Least square mean ± standard error of mean. C. citratus: Cymbopogon citratus
Table 2: Tail suspension test.
Day Group
6 (Tween 80) 7 (imipramine
20 mg/kg)
8 (C. citratus
5 mg/kg)
9 (C. citratus
10 mg/kg)
10 (imipramine 10 mg/kg+
C. citratus 10 mg/kg)
Day 1 205.17±5.79 210.5±5.79 214.1±5.79 202.83±5.79 204.17±5.79
Day 8 196.5±7.11 170.67±7.11 185.83±7.11 171.83±7.11 184.33±7.11
Day 15 196.67±8.23 150.1±8.23** 163.17±8.23 149.33±8.23** 160.17±8.23
Least square mean ± standard error of mean, Not signicant: p > 0.05, Signicant: p ≤ 0.05*, Highly signicant: p ≤ 0.01**, Extremely
signicant: p ≤ 0.001***. C. citratus: Cymbopogon citratus
Dudhgaonkar S et al. Int J Basic Clin Pharmacol. 2014 Aug;3(4):656-660
International Journal of Basic & Clinical Pharmacology | July-August 2014 | Vol 3 | Issue 4 Page 659
Under physiological conditions, multiple tiers of defense
exist to protect against these free radicals, including the
restriction of their production through the maintenance of
a high oxygen gradient between the ambient and cellular
environments, their removal by non-enzymatic and
enzymatic anti-oxidants, and the reparation of oxidative
damages by structural repair and replacement mechanisms.9
Oxidative stress occurs when red-ox homeostasis is tipped
towards an overbalance of free radicals, due to either their
over production or deciencies in anti-oxidant defense.10 The
resultant cellular damage may range from cellular structural
damage to mitotic arrest, to apoptosis and cell necrosis,
depending on the level of oxidative stress severity.11 The
major classes of free radicals in living organisms are the
reactive oxygen species, reactive nitrogen species, which are
respective collective terms for oxygen and nitrogen derived
radicals, as well as some non-radicals that readily convert
into radicals.12 A possible mechanism of anti-depressant
action of lemon grass is the attenuation of this oxidative
stress by monoterpenes and polyphenols present in it.
The present study evaluated the anti-depressant activity
of aqueous extracts of C. citratus in two different animal
models, tail suspension test and forced swim test. Both the
models are widely used for screening anti-depressant drugs.
There is a signicant correlation between the potency of anti-
depressants in both the tests and clinical potency of the drugs.
C. citratus at doses of 5 mg/kg, 10 mg/kg and in combination
with Imipramine showed signicant reduction in the duration
of immobility in both the tests as compared to control, thus
proving that it has signicant anti-depressant activity.
C. citratus alone in the dose of 10 mg/kg is comparable to
imipramine 20 mg/kg and is more effective alone than it’s
combination with Imipramine 10 mg/kg.
Furthermore, there was no signicant reduction in duration
of immobility in all the groups on the rst day, but there
was signicant reduction on both days 8 and 15, more on
day 15 when compared to day 8. This implies that chronic
administration of C. citratus has anti-depressant activity.
Exact mechanisms underlying the anti-depressant action
cannot be concluded at the moment due to the presence
of a large number of phytochemicals in lemon grass oil.
C. citratus grass contains about 0.4 % of volatile oil and
that the oil contains 65-85% of citral and the concentration
of citral depend on the geographical area grown (Carbajal
et al., 1989). Apart from citral, lemon grass oil also contains
geraniol, myrcene, citronellal, citronellol, citronelyl,
limonene, linalool and dipentene (Torres, 1996). The leaves
also contain avones like luteolin and its 7-O-β–Glucoside
and 7-O-neohesperiodoside, iso-orientin and 2-O-rhamnosyl
iso-orientin, chlorogenic acid, caffeic acid p-coumaric
acid, fructose, sucrose, octacosanol and triacontanol
(De Matouschek, 1991). The gas chromatography-mass
spectrometry spectra of the essential oil separated by
Tognolini et al., (2006) from leaves of C. citratus by steam
distillation shows the occurrence of various compounds at
different percentages like methyl-5-hepten-2-one-0.43%,
myrcene - 15.48%, linalool - 1.28%, neral - 32.28%,
geraniol - 3.35%, geranial - 41.28%.
They have also observed that percentage composition of
non-oxygenated monoterpenes as 15.48%, oxygenated
monoterpenes as 78.19% and hydrocarbons as 0.43%. The
availability of avonoids like luteolin and 6-C-glucoside
has also been explained by Negrelle and Gomes, (2007).
It’s anti-depressant activity may be attributed to the presence
of 1,2 acetate of citronelyl. This action is mediated by
an interaction with the noradrenergic system. However,
interactions with other monoaminergic systems need to
be investigated to assess that this plant can be alternative
therapeutic approach in depression.13
Thus, C. citratus is multifunctional and the present
work, though of preliminary nature is concentrated on
its anti-depressant activity. Further elaborate research
work involving more numbers of animals and different
experimental models of anti-depressant activity are needed
to elucidate the exact molecular and biochemical mechanism
of action to develop more effective compound.
Funding: No funding sources
Conict of interest: None declared
Ethical approval: The study was approved by the Institutional
Animal Ethics Committee
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doi: 10.5455/2319-2003.ijbcp20140817
Cite this article as: Dudhgaonkar S, Mahajan M,
Deshmukh S, Admane P, Khan H. Evaluation of
antidepressant effect of lemon grass (Cymbopogon citratus)
in albino mice. Int J Basic Clin Pharmacol 2014;3:656-60.
