Mayuri Lawar1, Varsha Shende1*, Suvarna Ingle2, Monali Sanghvi1, Naeem Hamdulay1
1Department of Pharmacology, Sinhgad College of Pharmacy, Post-Graduate Research Department, Off Sinhgad road, Vadgaon (Bk), Pune, Maharashtra, India.  
2Department of Pharmacology, Indira College of Pharmacy, New Pune Mumbai Highway, Tathwade, Pune, Maharashtra, India.

Depression and related mood disorders are among the world’s greatest public health problems. Mimosa pudica L. (MP), a creeping perennial herb exhibits analgesic, anxiolytic, diuretic, antiasthmatic, hepatoprotective activities. Although, previous study reveal antidepressant like effects of aqueous extract of MP at behavioral levels, but antidepressant like effects of hydroalcoholic extract of Mimosa pudica L. (HEMP) and its combinational effect with standard antidepressant drugs at behavioral and biochemical level is not scientifically evaluated. Hence, the present investigation evaluates the antidepressant activity of HEMP and its interaction with fluoxetine and imipramine in reserpine-induced behavioural despair in rats and the potential mechanism involved in HEMP action. HEMP at doses 50, 100 and 200 mg/kg p.o., fluoxetine at 5 & 20mg/kg p.o., imipramine at 5 & 15mg/kg p.o. and reserpine 6mg/kg i.p. were administered to different groups of rat (n=6). After reserpine treatment, rats were subjected to forced swimming test followed by assessment of locomotor activity. Rats were sacrificed after behavioural study for estimation of serotonin, monoamine oxidase (MAO) levels in rat brain. Results demonstrate that combination of subeffective doses of HEMP, fluoxetine and imipramine reduced the duration of immobility in forced swimming test, increased serotonin and decreased MAO-A and MAO-B enzyme levels in reserpine treated rats. These findings suggest that combination of HEMP with standard drugs in subeffective doses can exert potential antidepressant like effect through modulation of brain serotonergic system and MAO inhibition.


PharmaTutor (ISSN: 2347 - 7881)

Volume 2, Issue 9

Received On: 13/04/2014; Accepted On: 30/06/2014; Published On: 01/09/2014

How to cite this article: M Lawar, V Shende, S Ingle, M Sanghvi, N Hamdulay; Effect of Hydroalcoholic extract of Mimosa Pudica Linn. with Imipramine and Fluoxetine on Reserpine-induced Behavioural Despair in Rats; PharmaTutor; 2014; 2(9); 123-134

Depression is one of the most common psychiatric disorders, with a lifetime incidence of up to 20% in the general population, and associated with high morbidity and mortality rate despite major advances in treatment [1]. This has led to a continued search for effective treatments  including antidepressant drugs, herbal remedies, psychotherapy and electroconvulsive shock therapy. Recently, the interest in the use of herbal products and the focus on plant research has grown in the western world and developed countries [2]. The majority of currently available psychoactive drugs as herbal remedies are the reflection of such a situation. The demand of herbal remedies as psychotherapeutics is greater and has great growth potential in the global market [3, 4]. Various herbal plants have been used traditionally as antidepressant, amongst them one is MP, which is a well-known weed used as herbal remedy. MP is derived from the word “mimic” means to allude, to sensitivity of leaves and “pudica” means bashful, retiring or shrinking.

MP is a common sensitive, sprawling, and perennial plant and known as ‘Lajvanthi’ or ‘Chuimui’ in local Indian language, which usually grows about 15-45 cm high. Plant bears leaves with dark green colour, feathery, fern-like and divided into one or more pairs of segments near the end of the leaf stalk and flowers are pale pink in fluffy balls [5]. The leaves are bitter, sudorific and tonic and are used in hydrocele, haemorrhoids, fistula, scrofula, conjunctivitis, cuts and wounds and haemorrhages [6, 7]. As a member of family Fabaceae, the root system consists of a taproot and extensive fibrous roots with nodules [8]. The roots are bitter, astringent, acrid, alexipharmic, resolvent, diuretic, antispasmodic, emetic, constipating, and febrifuge and used in vitiated conditions of pitta, leucoderma, vaginopathy, metropathy, ulcers, dysentery, inflammations, burning sensation, haemorrhoids, jaundice, asthma, fistula, small pox, strangury, spasmodic, affections and fevers [6,9].

The flavonoids and tannins from MP are reported for their varied pharmacological activities like, wound healing[10], anti-anxiety[11], antidepressant[12], antiulcer[13], antifertility[14], antibacterial[15], hyperglycaemic[16], anticonvulsant[17] and antihypolipidemic [18]. But till date very few studies are reported on the role of MP in the functional regulation of neurotransmitters and their receptors and antidepressant activity of hydroalcoholic extract of MP (HEMP) is also not revealed yet. Thus in this study we reported the antidepressant effect of HEMP and its interaction with imipramine and fluoxetine on duration of immobility in forced swimming test, brain serotonin, Monoamine oxidase (MAO) enzymes level in reserpine treated rats.


Plant material:
HEMP was purchased from local supplier, Prist herbochem, Pune, along with its certificate of analysis and its standardisation was done using thin layer chromatography and preliminary phytochemical screening.

Preliminary phytochemical screening of plant extract:
Organoleptic characteristics, qualitative tests for alkaloids, flavonoids, saponins, steroids, triterpenoids and tannins were performed using standard procedure [19, 20] and quantitative tests were performed for total phenolic and total flavonoid content [21]. Standardisation of extract was done using thin layer chromatography (TLC).

Drugs and solutions:
Fluoxetine hydrochloride (Endoc Pharma, Rajkot), imipramine hydrochloride (Centurion laboratories, Vadodara), reserpine (Loba Cheime, India) and serotonin hydrochloride (Sigma Aldrich, USA). HEMP, Fluoxetine hydrochloride, Imipramine hydrochloride and serotonin hydrochloride were dissolved in distilled water. Reserpine was dissolved in 1% acetic acid solution v/v. All drug solutions were prepared fresh. All the other agents used were of analytical grade.

Experimental animals:
Sprague dawley rats (150- 200 gm) were procured from National Institute of Biosciences, Pune, India. The animals were maintained under standard laboratory conditions at temperature 23 ± 20°C, relative humidity 55 ± 10% and 12:12 h light / dark cycle maintained throughout the experiment. Animals had free access of water and standard laboratory feed ad libitum prior to the dietary manipulation. The animal studies were approved by the Institutional Animal Ethics Committee (Protocol no. SCOP/IAEC/Approval/2011-12/08), constituted for the purpose of control and supervision of experimental animals by Ministry of Environment and Forests, Government of India, New Delhi, India. Animals were naive to drug treatments and experimentation at the beginning of all studies. All tests were conducted between 08:00 and 14:00 h.

Rats were divided into different groups (n=6). Reserpine (6 mg/kg, i.p.) was administered to the rats 24 hrs before activity for induction of depression. Fluoxetine (20mg/kg p.o.), Imipramine (15mg/kg, p.o.) and HEMP (50, 100, 200mg/kg, p.o.) was given 24, 5 and 1 hrs before the behavioural study.

Forced swimming test:
The rats were placed individually in vertical Plexi glass cylinder  (50×20 cm) containing water  (25°C) at adepth of 30 cm for a 15-min period (pre-test session). At the end of this pretest  session, each rat was removed from the water, partially dried with a towel and placed in a warm enclosure, and afterwards returned back to their home cages. Twenty-four hours later, the animals were exposed to the same experimental conditions outlined above for only a 5-min period (test session) and their behavior was video taped with video recorder placed above the cylinder.  The total duration of immobility in each rat was measured during the test session. Immobility was assigned when no additional activity was observed other than that required to  keep the rat's head above the water. The behavioral assessments were performed by observers blind to experimental treatment. Reserpine and vehicle were administered 24 h before the test  session. Imipramine, fluoxetine and different doses of HEMP were administered 24, 5 and 1 h before the test session [22].

Biochemical estimation:
After behavioural test, rats were sacrificed and their brains were rapidly removed on dry ice at -20o C, washed with isotonic saline, weighed and were used for biochemical estimations.

Preparation of Brain tissue:
The brains were thawed, rinsed with isotonic saline, weighed again and homogenized (Homogenizer, REMI, India).The 10% homogenates were prepared in 10 volumes of cold phosphate buffer (10mM, pH 7.4), mingled at 4o C for 20 minutes. Serotonin estimation [23] in hypothalamus and MAO-A and MAO-B enzymes level in whole brain [24] were carried out using spectrophotometer.

Statistical analysis:
Results were expressed as mean ± S.E.M. The data were analyzed by one-way analysis of variance (ANOVA) followed by Tukey’s multiple comparison tests. Statistical significance was considered at P< 0.05 in all the cases.


Effects of fluoxetine on the immobility time in the forced swimming test and on the locomotor activity in the open-field test:
In the present study, one -way ANOVA revealed that fluoxetine  (5mg/kg and 20mg/kg p.o.) significantly reduced duration of  immobility in rats, when compared with the normal control group (P<0.0001; Fig 1A) and no significant difference was found in locomotor activity in normal control and fluoxetine treated group (Fig 1B).Further Post hoc test found that treatment with fluoxetine (5mg/kg and 20mg/kg p.o.) significantly reduced duration of  immobility in rats, when compared with the normal control group (P<0.05 & P<0.001 respectively) in a dose dependent manner.

Fig. 1A: Effects of Fluoxetine on duration of immobility in Forced swim test

n=6, values expressed in mean ± SEM,

***P<0.001 and *P<0.05 compared with normal control, [F (2, 15) =80.62, P<0.0001]

(One-way ANOVA followed by Tukey’s post hoc test).

Fig. 1B: Effects of Fluoxetine on locomotor activity in open field test

n=6, values expressed in mean ± SEM, no significance observed

[F (2, 15) =0.5812, P=0.5713] (One-way ANOVA followed by Tukey’s post hoc test).


SUBMIT YOUR ARTICLE/PROJECT AT articles@pharmatutor.org

Subscribe to Pharmatutor Alerts by Email