Danzhi Xiaoyao Powder Reduced the Scratching Behavior Exaggerated by Chronic Psychological Stress in Mice

Abstract Objective: To explore the efficacy and possible mechanism of Danzhi Xiaoyao Powder in the treatment of scratching behavior worsened by psychological factors. Methods: Male BALB/c mice were divided into control group (CON group), chronic WAS group(WAS group) and chronic WAS + Danzhi Xiaoyao Powder group(DZX group). All mice excluded control group were exposed to 1 h water avoidance stress (WAS) for ten consecutive days. DZX group were given Danzhi Xiaoyao Powder solution by intragastric administration every day, and the other two groups were given the same amount of saline. Twenty-four hours after the last stress session, the mice were injected into the back of the neck with a condensation product of N-methyl-p- methoxyphenethylamine with formaldehyde (compound 48/80), and their scratching behavior was then observed for 120 min. The scratching number was recorded, th histamine levels in the plasma were examined, and the behavioral changes of depression in mice before and after treatment were observed by open field test and forced swimming test. Results: The scratching number was significantly higher in the WAS group than in the DZX group, which still higher than in the CON group. The peak histamine in the plasma after the compound 48/80 injection were also significantly higher in the WAS group in comparison to the DZX group. In terms of depression behavior, the number of standing in the DZX group was more than that in the WAS group and less than that in the CON group, and the immobility time in the forced swimming test was less than that in the WAS group and more than that in the CON group. Conclusion: Danzhi Xiaoyao Powder can relieve the scratching behavior of mice under the influence of WAS, and its possible mechanism is to control the release of histamine and improve the depressive state of mice.