Antidepressant evaluation of polysaccharides from a Chinese herbal medicine Banxia‐houpu decoction

AbstractBanxia‐houpu decoction, a traditional Chinese medicine has been used in the treatment of depression. The present study confirmed that oral administration of polysaccharides from Banxia‐houpu decoction, exhibited a reduction in the immobility time in the tail suspension and in the forced swimming tests in mice in a time‐dependent manner. This effect at a dose of 320 mg/kg was more potent than that at a dose of 640 mg/kg. The polysaccharides from Banxia‐houpu decoction were active in animal models of depression with comparable effects to known antidepressants. The oral administration of the polysaccharides at a low dose for 4 weeks resulted in a significant increase in the monoamine neurotransmitter 5‐hydroxytryptamine (5‐HT) and dopamine (DA) levels in whole mouse brain, but produced no significant increase in 5‐hydroxyindoleacetic acid (5‐HIAA) and norepinephrine (NE) concentrations. The effect of polysaccharides on the brain neurotransmitter levels appeared to be quite different from the effect of fluoxetine, a serotonin specific reuptake inhibitor. The results indicate that the mode of action of polysaccharides from Banxia‐houpu decoction in depression might be related to both 5‐HT and DA systems. Copyright © 2004 John Wiley & Sons, Ltd.