OBJECTIVE

2

To optimize the extraction process and to primarily evaluate the anti-anxiety and anti-depression efficacy of polysaccharide from Baihe dihuang decoction.

METHODS

2

Based on Plackett-Burman experimental design， using the comprehensive score of yield and content of polysaccharide as indicators， with extraction time， water amount， alcohol precipitation concentration as factors， Box-Behnken response surface methodology was used to optimize the extraction process of polysaccharide from Baihe dihuang decoction； and the validation test was conducted. Forty ICR mice were divided into control group， venlafaxine group [positive control， 13.5 mg/（kg·d）]， Baihe dihuang polysaccharide high-dose and low-dose groups [5.28， 2.64 g/（kg·d），by raw material]， with 10 mice in each group （half male and half female）. Administration groups were given corresponding drug solution intragastrically， and control group was given water 10 mL/kg intragastrically， once a day， for 7 consecutive days. The elevated cross maze test， open field test， forced swimming test and tail suspension test were used to evaluate the effects of the extract prepared by the optimal process on the anxiety-like and depression-like behavior of mice； enzyme-linked immunosorbent assay was used to detect the effects of the extract on the levels of neurotransmitter in cerebral tissue of mice.

RESULTS

2

The optimal extraction process of Baihe dihuang decoction was： the water amount of 25 times， extract time of 1.5 hours， and alcohol precipitation concentration of 70%. In 3 times of validation test， the average yield and content of polysaccharide were 33.10% and 0.62 mg/mg， the relative deviations of which from the predicted values （36.14% and 0.65 mg/mg） were 8.40% and 4.62% respectively （RSD＜2%，

n

＝3）. The polysaccharide extract of Baihe dihuang decoction could effectively increase the percentages of open-arms entry， the percentages of open-arms time， the total distance of voluntary activities and the activity distance in central area， and significantly shortened the immobility time of forced swimming test and tail suspension test （

P

＜0.05 or

P

＜0.01）. The polysaccharide extract could significantly increase the levels of 5-hydroxytryptamine， norepinephrine （except for the Baihe dihuang polysaccharide low-dose group） and gamma-aminobutyric acid in cerebral tissue of mice， while significantly decrease the levels of glutamic acid （except for the Baihe dihuang polysaccharide low-dose group） （

P

＜0.05 or

P

＜0.01）.

CONCLUSIONS

2

The optimized extraction process of polysaccharide from Baihe dihuang decoction is stable and feasible， and the obtained polysaccharide extract has obvious anti-anxiety and anti-depression effect

in vivo

.