Antidepressant Effect of Plectranthus amboinicus on Chronic Unpredictable Mild Stress Induced Rats

Plectranthus amboinicus contains flavonoids, alkaloid and terpenoids as its major component. The purpose of the study is to explore the antidepressant activity of hydroethanolic extract of Plectranthus amboinicus leaf in rats. Chronic unpredictable mild stress (CUMS) was employed to induce stress in rats. Plectranthus amboinicus (200mg/kg, body weight) and Fluoxetine (20mg/kg, body weight) were administered during the 28 day stress exposure period. Antidepressant activity of ethanolic extract of leaf of Plectranthus amboinicus was investigated by using forced swim test (FST). Enzymatic antioxidants such as SOD, GPx, GSH and non enzymatic antioxidants such as vitamin C and lipid peroxidation show the significant increase and improved scavenging activity in treated rats when compared to depressed rats. So, it was concluded that Plectranthus amboinicus possesses potential antidepressant which may be due to its antioxidant effect. 1 Victor Arokia Doss. D, ǂ Nithyanand. P and *ǂ Sowndarya. R 1 Associate Professor, 1ǂ Department of Biochemistry, PSG College of Arts & Science, Coimbatore, Tamil Nadu, India. Submission: 10 May 2016 Accepted: 15 May 2016 Published: 25 May 2016 www.ijppr. humanjournals.com Citation: Sowndarya. R et al. Ijppr.Human, 2016; Vol. 6 (2): 377-382. 378 INTRODUCTION Depression is a chronic illness that affects mental stability, personal and social relations. Herbal drugs possess least side effects compared to synthetic medicines. It interferes with daily life and normal functions. According to WHO estimated, 121 million people suffer from clinical depression. The high relevance of suicide in depressed patients (up to 15%) and the other complications arising from stress and its effects on the cardiovascular system has suggested that it will be the second leading cause of death by the year 2020. Prevalence rate for all mental disorders in India was observed to be 65.4/1000 population. Out of which prevalence rate for affective disorders is estimated to be 31.2/1000 population [1] . Symptoms of depression include biological and emotional components. In biological symptoms include retardation of action and thoughts, sleep disturbance etc., emotional symptoms include pessimism, ugliness, loss of motivation and loss of self system. It occurs usually in the early adult life of patients with depression have more symptoms include decrease in monoamine neurotransmitters particularly and dopamine [2] . Numerous antidepressant compounds are now available presumably acting via different mechanism including serotonergic, noradrenergic and dopaminergic system. Medical plants therapies may be effective alternatives in the treatment of depression and has progressed significantly in the past decade [3] . Herbal drugs possess least side effects compared to synthetic medicines. Medicinal plants became an important source for novel antidepressant drugs. The analyses of Plectranthus amboinicus leaves revealed the presence of alkaloids, carbohydrates, glycosides, proteins, amino acids, flavonoids, quinine, tannins, phenolic compounds and terpenoids. Alkaloids have pronounced physiological effect particularly on the nervous system. MATERIALS AND METHODS Collection of Plant Material The young leaves of Plectranthus amboinicus were collected from Coimbatore and authenticated by Botanical Survey of India, Coimbatore, Tamilnadu, India. A voucher specimen has been deposited in the laboratory for future reference (BSI/SRC/5/23/2015 /Tech). The specimen was later shade dried, powdered and stored in an airtight container for further use. www.ijppr. humanjournals.com Citation: Sowndarya. R et al. Ijppr.Human, 2016; Vol. 6 (2): 377-382. 379 The powdered material was used for pharmacological investigation while for phytochemical screening, the powder was extracted with different solvents in their increasing order of polarities such as petroleum ether, chloroform, 50% ethanol, water and ethanol. The crude extracted were collected and stored in bottles. Preparation of Extract Solution The hydroethanolic extract of Plectranthus amboinicus was prepared at large scale (100g leaf extract powder in 500ml water and 500ml ethanol). It was filtered and the filtrate was then evaporated to dryness using rotatory evaporator and crystals were obtained. The crystals obtained were weighed and dissolved in sufficient quantity of water. This solution was administrated orally to the experimental animal for the treatment of depression.