Table 2.

Overview of experimental trials on anti-depressant functions of officinal extracts.

Plant	Organisms	Dose	Tests	Parameters	Results	Reference
Ginkgo biloba	Male BALB/c mice	17-day dose of 5, 10, 20, 40 mg/kg	Forced swimming	Immobility period, locomotor activity, and monoamines	Mice exposed to 10 mg/kg/day of G. biloba extract showed a decline of 39% immobility time after forced swimming test. Reduced lipid peroxidation and radicals were associated with the extract.	[46]
Ginkgo biloba	136 Elderly humans with depression	Thrice 19.2 mg/day	Placebo-controlled trial	HAM-D * and serum S100B levels	Those exposed to G. biloba scored better on the HAM-D and showed lower expression of serum S100B, a brain injury marker.	[47]
Hypericum perforatum	20 Male mice (strain BlC57)	Single dose of 7, 35, 70 mg/kg	Forced swimming and tail suspension	Immobility period	Mice displayed a negative correlation between dose (7, 35, and 70 mg/kg b.m.) of St. John’s Wort extract and immobility time after forced swimming and tail suspension.	[48]
Curcuma longa	Male Sprague–Dawley rats	14-day dose of 2.5, 5, 10 mg/kg	Forced swimming, olfactory bulbectomy, open field, and passive avoidance test	Various levels of monoamines and metabolites, immobility, and behavioral abnormalities	Curcumin administration reversed neurotransmitter deficits induced by olfactory bulbectomy tests in rats. Behavior after olfactory bulbectomy and forced swimming tests was improved.	[41]
Valeriana officinalis	Albino Laca mice	Single- and 14-day admission of 10, 20, 40 mg/kg	Forced swimming	Immobility period, locomotor activity, norepinephrine and dopamine levels	Single administration of dichloromethane extracted from valerian significantly inhibited forced swimming-induced immobility in mice. Additionally, sustained administration decreased immobility and increased norepinephrine and dopamine levels.	[49]
Hibiscus tiliaceus	>40 Male Swiss albino mice	Single dose of 3, 10, 30 mg/kg	Forced swimming, tail suspension, and elevated plus-maze	Immobility, maze arm entry	Methanolic hibiscus flower extracts decreased the period of immobility times.	[50]
Paeonia lactiflora	80 Male ICR mice	80 and 160 mg/kg, 7 days	Forced swimming and tail suspension	Immobility period and MAO A and B activity	Peony extracts inhibited MAO A and B activity in mouse brains, significantly reduced inmobility times.	[51]
Piper methysticum	60 adult Humans	5 doses of 250 mg/day for 3 weeks	Placebo-controlled, double-blind, crossover trial	Hamilton Anxiety Scale, Beck Anxiety Inventory, and Montgomery–Asberg Depression Rating Scale	Aqueous kava extracts reduced all assessed parameters. Additionally, no clinical hepatotoxicity was observed, which has been reason for P. methysticum’s withdrawal in some countries.	[52]
Lavandula angustifolia	35 Wistar rats	Thrice administered 3428 mg/kg	Forced swimming	Immobility period	Aqueous lavender extracts significantly reduced immobility periods after forced swimming in rats, which was comparable to imipramine (30 mg/kg).	[53]
Passiflora foetida	30 Male Swiss albino mice	Single dosage of 100, 200, 300 mg/kg	Forced swimming, tail suspension, and open field	Immobility and locomotor activity	Methanolic passionflower extracts decreased immobility time in a dose-dependent manner in mice after tail suspension and forced swimming. Results were comparable to fluoxetine (20 mg/kg) and imipramine (15 mg/kg). No significant effects were observed on locomotor activity.	[54]

* HAM-D: Hamilton Depression Rating Scale.