Effect of Wedelia paludosa (Asteraceae) on Brain Neurotransmitters and Enzyme Monoamine Oxidase, Following Cold Immobilization Stress

 

Venkata Naveen Kasagana* and Swathi Sree Karumuri.

Dep. of Pharmaceutics, Sankaralingam Bhuvaneswari College of Pharmacy, Sivakasi-626130. Tamilnadu, India.

 

ABSTRACT:

Recently there has been a shift in universal trend from synthetic to herbal medicine, which we can say ‘Return to Nature’. In this regard India has a unique position in the world, where a number of recognized indigenous systems of medicine viz., Ayurveda, Siddha, Unani, Homeopathy, Yoga and Naturopathy are being utilized for the health care of people. Wedelia paludosa (Family Asteraceae), is a reputed medicinal aromatic plant used in traditional system of medicine. The herb is used as a tonic, in Hepatoprotective, Splenomegaly and in skin diseases. The other minor uses are the juice is administered in combination with aromatics for jaundice. The fresh plant is rubbed on the gums in tooth ache and applied with a little oil for headache. The leaves are considered as a tonic, alternative and useful in the cough, cephalgia skin diseases and alopecia. An infusion of the plant is given for swelling in the abdomen. In Assam the plant is used to prevent the effects of bad waters in hill tracts. The leaves are used in dyeing grey hair and in promoting the growth of hair. As a decoction, the plant is used in uterine haemorrhage and menorrhagia. The effect of aqueous extract of Wedelia paludosa leaves were evaluated on stress induced changes in brain neurotransmitters and enzyme monoamine oxidase levels in wistar rats. The extract was found to possess normalizing activity against cold immobilization stress induced changes in dopamine (DA), 5-hydroxy tryptamine (5-HT), norepinephrine (NE), 5-hydroxy indole acetic acid (5-HIAA), and enzyme monoamine oxidase (MAO). The results obtained provide biochemical evidence for anti-stress activity of Wedelia paludosa aqueous extract.

 

 

INTRODUCTION:

Stress is the phenomenon faced by every humans. Normal functioning of the body is dependent on optimum levels of stress. It is a necessary to keep the stress under control and normal functioning is not affected due to excess of stress ^[1]. Many marketed formulations deliberately claim to possess anti-stress action. In recent past there is great thrust on screening of herbs for their anti-stress activity. Wedelia paludosa are widely used in the Indian system of medicine. The said plant have free radical scavenging power and traditionally used as a tonic , considering this fact the present study has been carried out to assess the anti-stress activity of Wedelia paludosa  by studying its effect on brain norepinephrine (NE), dopamine (DA), 5-hydroxy tryptamine (5-HT), 5- hydroxy indole acetic acid (5-HIAA), and enzyme monoamine oxidase (MAO) levels.

 

MATERIALS AND METHODS:

Collection of plant material:

The plant, Wedelia paludosa was collected from the region of Thiruninravur, Thiruvallur Dist, Chennai, Tamil Nadu, India in the month of Feb.2010. The collected plant was authenticated by Prof. P. Jayaraman, Ph. D., Director, National Institute of Herbal Science (Retd, Professor, Presidency College, Chennai).

 

 

Preparation of Aqueous Extract:

The leaves were collected and dried under shade for 14 days and then made in to coarse powder with mechanical mixer, then passed with sieve no: 40 and stored in air tight container for further use. The dried powdered plant material of the plant (653gm) was first macerated (cold maceration) with Water: Chloroform solvent system (95:5) for 8 Days and extraction is done. The marc was again macerated with Water: Chloroform solvent system (95:5) for 3 Days and extraction is done. Both the extracts (2.950 lit and 2.865 lit respectively) were concentrated to (130ml) in water bath until a semi solid mass is obtained.

 

 

 

Table 1: Effect of aqueous extract of Wedelia paludosa on the brain Bio-amine and MAO levels following Cold Immobilizing Stress.

Treatment Group	Noradrenalin (ng/ml)	Dopamine (ng/ml)	5-Hydroxy tryptamine (ng/ml)	5-Hydroxy Indolic acetic Acid (ng/ml)	Monoamine Oxidase Units/mg
Normal Control	517.62±19.17	843.12±21.53	734.92±25.59	612.17±48.42	5.13±0.27
Restraint Control	471.74±23.75	771.79±59.85	836.35±56.75	827.54±20.67	4.89±0.23
AEWP (500 mg/kg)	607.12±48.42 ***	912.92±17.62 ***	496.37±24.63 ****	781.83±35.74 **	8.32±0.32

N=6, Values are expressed as mean ±SEM; **p<0.02; ***p<0.01; ****p<0.001, compared to restraint control.

AEWP= aqueous extract of Wedelia paludosa

 

Animals:

Six-weeks-old wistar rats (100–150 g) will be procured from animal house, Vel’s College of Pharmacy and acclimatized for 1 week. Rats will be caged in an atmosphere of filtered, pathogen-free air, provided with commercial rat chow and water and maintained at room temperature with a 12 h light/dark cycle and relative humidity of 50%. The animals were maintained as per the norms of CPCSEA and cleared by CPCSEA (290/CPCSEA/pharm-col-5/18810) and institutional ethical committee (Vel’s College of Pharmacy, Chennai).

 

Assessment of activity:

The rats were divided in to three groups of six rats in each. Group I served as control, Group II served as restraint control and Group III  served as Wedelia paludosa  treated respectively. The control animals received vehicle (1ml), and the treated group received the extract as a suspension at a dose of 500 mg/kg, b.w. once daily in the morning for 16 days through gastric intubation. One hour after completing the administration of the final dose, stress was induced by individually placing the animals in a restrainer for 3 h at 4°C ^[2]. Thereafter , the animals were sacrificed by cervical dislocation , whole brain was rapidly frozen at -5°C and brain NE,  DA, 5-HT, 5-HIAA were spectrofluorimetrically estimated by the methods of Ansell and Beeson ^[3] as modified by Cox and Perhach ^[4]. Brain MAO levels was estimated spectrometrically by McEween’s method ^[5].

 

Statistical analysis:

All observations are presented as mean ± SEM. The data was analyzed by student’s-t test. Differences were considered significant at 5% level.

 

RESULTS AND DISCUSSIONS:

A variety of stress induces a significant change in the metabolism and function of various neurotransmitters in the CNS as well as peripheral nervous system. Cold immobilization stress causes depletion of norepinephrine and dopamine levels in the brain ^[6]. It shows that norepinephrine is utilized during stress and dopamine levels in the brain increase as a compensatory mechanism, thus it acts as a precursor for the synthesis of more amount of  norepinephrine to cope up with demand. Drug treatment was found to prevent the stress induced depletion of norepinephrine and dopamine levels thus helping the organism to cope up better during the time of stress. Pre-treatment with plant extracts was found to significantly reduce the stress induced rise in brain 5-HT, 5-HIAA levels by preventing the reaction which elicits a significant rise in 5-HT and 5-HIAA levels ^[7] , thereby arresting the genesis of stress induced disorders. The enzyme MAO is mostly concern with the maintenance of the optimum level of biogenic amines within the brain ^[8] and it is postulated that the predominant function of MAO is to prevent the release of 5-HT ^[9]. Cold immobilization stress causes a marginal decrease in the activity of MAO, which in turns increases the 5-HT and 5-HIAA levels ^[10]. Pre-treatment with drug extract has resulted in the increase in MAO activity above normal levels(Table 1), thereby decreasing the elevated levels of 5-HT and 5-HIAA induced by stress. Thus the anti-stress activity of this plant could be attributed to the modulation of this enzymatic activity.

 

CONCLUSION:

The rapid industrial growth and the drastic increase in the world population has a direct impact on environment and society thus making the human being easily vulnerable to stress conditions. Global search is on, for the development of an effective anti-stress drug from natural source which can effectively tone up the disturbed physiological conditions of the human beings affected by such stress problem ^[11]. The aqueous extract of the leaves Wedelia paludosa offers protective effect against stress and can be a better alternative as anti -stress agent.

 

ACKNOWLEDGEMENT:

The authors are thankful to DR. J.Anbu, M.Pharm., Professor, Department of Pharmacology, Vel’s  College of Pharmacy, Chennai,  for his  endless help and guidance to carryout Pharmacological studies , we also thank Prof. P.Jayaraman ,Ph.D, Director, National Institute of Herbal Science (Retd,Professor,Presidency College,Chennai), for plant identification and its authentication.

 

REFERENCES:

1.        Seyle, H., Am. Sci. 1973, 61, 692-699.

2.        Padma, P., Khosa, R.L., Chansauria, J.P.N., Ray, A.K., J. Nat. Remed. 2001, 2 144-146.

3.        Ansell, G.B., Beeson, M.F., Anal. Biochem. 1968, 23, 196-200.

4.        Cox, R.H., Perhach, J.L., J. Neurochem. 1973, 20, 1777-1780.

5.        McEwen, C. M. Jr., Meth. Enzymol. 1971, 17, 686.

6.        Tache, J., Selye, H., Spielberger, J.G., Sarason. (Eds.), Stress and Anxiety, John Wiley and Sons, New York, 1978, pp.2.

7.        Joseph, M.A., Kennett, G.A., Brain Res, 1983, 270, 251-255

8.        Lefkowitz, R.J., Hoffman, B.B., Taylor, P., Goodman and Gilman’s- the Pharmacological Basis of Therapeutics,Pergamon Press, New York, 1991.

9.        Kuhm, D.M., Wolf, W.A., Youdium, M.B.H., J. Pharm. Pharmacol, 1984, 36, 46-51.

10.      Welch, B.L., Welch, A.S., Proceeding of Mario Negri Inst. For Pharmacol Res. Raveen Press New York 1970,pp.415.

11.      Kannur, D.M., Kulkarni, A.A., Paranjpe, M.P., Navangul, M.V., Phcog Rev, 2008, 3, 95- 101.

 

 

 

 

Received on 04.08.2011          Modified on 26.08.2011

Accepted on 04.09.2011         © RJPT All right reserved