Pharmacological Evaluation of Antidepressant Activity of Ethanolic Extract of Magnolia Officinalis in Mice

Abstract

Depression is the most common of the affective disorders (disorders of mood rather than disturbances of thought or cognition); it may range from a very mild condition, bordering on normality, to severe (psychotic) depression accompanied by hallucinations and delusions. There are two types and they are Unipolar and Bipolar Aim of the present study was to evaluate the antidepressant activity of Magnolia officinalis (MO) in experimental models of depression using mice. To study the effect of MO on behavior models of depression like forced swim test, tail suspension test. To study the effect of MO on mechanism based models of depression like 5-HTP induced head twitches, clonidine induced aggression and L-Dopa induced hyperactivity and aggressive behavior. To study the effect of MO on anti-oxidant levels of brain. The results from the present study confirm the antidepressant activity of magnolia officinalis, since it reduced the immobility in both FST and TST. In the present study, magnolia officinalis significantly increased the frequency of 5-HTP induced head twitches, Clonidine induced aggression and L-DOPA induced hyperactivity and aggressive behavior indicating its enhanced activity on serotonergic, noradrenergic and dopaminergic pathways respectively. Our results also confirm the involvement of serotonergic, noradrenergic and dopaminergic pathways in depression. Pretreatment with magnolia officinalis, also significantly increased the levels of SOD and Catalase with simultaneous decrease in LPO levels in mice brain, suggesting its strong antioxidant activity. Since oxidative stress is reported to play an important role in depression, the antioxidant activity of magnolia officinalis might be a part of the mechanism for its antidepressant activity. Results from behavioral experiments indicate that the antidepressant activity of magnolia officinalis, might be due to the facilitatory effect on serotonergic, noradrenergic and dopaminergic systems apart from the antioxidant activity.