Punarnavine, an alkaloid isolated from ethanolic extract of Boerhaavia diffusa Linn. reverses depression-like behaviour in mice subjected to chronic unpredictable mild stress.

Punarnavine (20 and 40 mg/kg) and fluoxetine (20 mg/kg) per se administered orally for 14 successive days significantly decreased immobility periods of both unstressed and stressed mice in forced swim test. These drugs also significantly decreased sucrose preference in both stressed and unstressed mice as compared to their respective controls, indicating significant antidepressant-like activity. The drugs did not show any significant effect on locomotor activity of mice. The alkaloid also significantly decreased monoamine oxidase (MAO-A) activity, malondialdehyde levels in both unstressed and stressed mice; and significantly reversed the stress-induced decrease in reduced glutathione and catalase activity. It also significantly attenuated the stress-induced increase in plasma nitrite and corticosterone levels. Thus, punarnavine showed antidepressant-like activity in unstressed and stressed mice probably through inhibition of brain MAO-A activity, decrease in plasma nitrite levels and due to its antioxidant activity. In addition, punarnavine also showed antidepressant-like activity in stressed mice possibly through decrease in plasma corticosterone levels.

Antidepressant-like Activity of Celastrus paniculatus Seed Oil in Mice Subjected to Chronic Unpredictable Mild Stress.

Aims: The present study was done to evaluate the antidepressant-like effect of Celastrus paniculatus seed oil in Swiss young albino mice subjected to chronic unpredictable mild stress. Study Design: Prospective. Place and Duration of Study: Department of Pharmaceutical Sciences, Guru Jambheshwar University of Science and Technology, Hisar, Haryana, India, between August 2012 to February 2013. Methodology: The behavioral models such as forced swim test (FST) and sucrose preference test were used to evaluate the effect of seed oil on depression in mice. The oil (50, 100 and 200 mg/kg, p.o.) and fluoxetine (20 mg/kg, p.o.) per se were administered for 14 successive days to unstressed and stressed mice. The effect of oil on locomotor activity of mice was also evaluated. In addition, the effects of oil on brain monoamine oxidase-A, malondialdehyde levels, reduced glutathione and catalase activities; and plasma corticosterone and nitrite levels were also assessed. Results: The oil significantly decreased immobility period of both unstressed and stressed mice in FST as compared to the control. The oil also prevented the stressinduced decrease in sucrose preference, indicating significant antidepressant-like activity There was no significant effect on locomotor activity of mice by the oil. Antidepressant-like activity of the oil was comparable to the standard drug, fluoxetine. The oil also significantly decreased monoamine oxidase-A (MAO-A) activity, malondialdehyde levels in both unstressed and stressed mice; and significantly prevented stress-induced decrease in reduced glutathione and catalase activities. It also significantly attenuated stress inducedincrease in plasma nitrite and corticosterone levels. Conclusion: Celastrus paniculatus seed oil showed significant antidepressant-like activity in both unstressed and chronic unpredictable mild stressed mice probably due to inhibition of MAO-A activity, decrease in plasma nitrite levels; and through scavenging of free radicals. In addition, the oil also showed antidepressant-like activity in stressed mice probably through decrease in plasma corticosterone levels.

Behavioural and neuroendocrine effects of aqueous extract of Boerhaavia diffusa Linn. in mice using tail suspension and forced swim tests – A preliminary study.

The present study was done to evaluate the effect of aqueous extract of B. diffusa on depression in mice using behavioral models such as tail suspension test (TST) and forced swim test (FST). The extract (50, 100 and 200 mg/kg, po) was administered for 14 successive days to Swiss young albino mice. On 14th day, 60 min after administration, mice were subjected to TST and FST. The administration of aqueous extract of B. diffusa (50, 100 and 200 mg/kg, po) significantly decreased immobility period in both TST and FST, indicating significant antidepressant-like activity. The lowest dose (50 mg/kg) of the extract decreased the immobility period most significantly in FST, showing most potent antidepressant-like action. The efficacy of the extract (50 mg/kg) was comparable to fluoxetine (20 mg/kg). The extract did not show any significant effect on locomotor activity. The extract showed significant monoamine oxidase -A inhibitory activity. There was no significant effect of the extract on plasma corticosterone levels. Prazosin (α1-adrenoceptor antagonist), sulpiride (selective D2-receptor antagonist), baclofen (GABAB agonist), and p-CPA (tryptophan hydroxylase inhibitor) significantly attenuated the extract-induced antidepressant-like effect, when tested in TST. The extract might produce antidepressant-like effect by interaction with α1-adrenoceptors, dopamine-D2 receptors, serotonergic, and GABAB receptors. Thus, aqueous extract of B. diffusa showed significant antidepressant-like activity in mice probably through involvement of monoaminergic and GABAergic systems.

Evaluation of antidepressant-like activity of aqueous and ethanolic extracts of Terminalia bellirica Roxb. fruits in mice.

The present study was undertaken to investigate the effect of aqueous and ethanolic extracts of T. bellirica on depression in mice using forced swim test (FST) and tail suspension test (TST). The extracts were administered orally for 10 successive days in separate groups of Swiss young male albino mice. Aqueous extract (50, 100 and 200 mg/kg) in a dose-dependent manner and ethanolic extract (100 mg/kg) significantly reduced the immobility time of mice in both FST and TST. The extracts were without any significant effect on locomotor activity of mice. The efficacies of aqueous extract (200 mg/kg) and ethanolic extract (100 mg/kg) were found to be similar to that of imipramine (15 mg/kg, po) and fluoxetine (20 mg/kg, po) administered for 10 successive days. Both extracts reversed reserpine-induced extension of immobility period of mice in FST and TST. Prazosin (62.5 microg/kg, ip; an alpha1-adrenoceptor antagonist), sulpiride (50 mg/kg, ip; a selective D2 receptor antagonist) and p-chlorophenylalanine (100 mg/kg, ip; an inhibitor of serotonin synthesis) significantly attenuated the aqueous and ethanolic extract-induced antidepressant-like effect in TST. Thus, both the aqueous and ethanolic extracts of T. bellirica elicited a significant antidepressant-like effect in mice by interaction with adrenergic, dopaminergic and serotonergic systems.