Shizhenqing granule stimulates the hypothalamic-pituitary-adrenal axis and reduces serum pro-inflammatory factors in a rat model with chronic eczema

Abstract

Objective: In this study, we examined the effects of Shizhenqing granule (SZQG) on hypothalamic-pituitary-adrenal (HPA) axis and serum inflammatory factors in a rat model of chronic eczema, in order to explore the mechanism of action of SZQG in treatment of this disease. Methods: Sixty Sprague–Dawley male rats were randomly divided into six groups (with 10 rats per group): blank group; model group; positive control group (prednisone); and the low-, medium-, and high-dose SZQG groups. Except for the blank group, rats in all other groups were treated with 2,4-dinitrochlorobenzene to induce chronic eczema. These rats were administered prednisone or SZQG for 7 consecutive days after successful establishment of the chronic eczema model, and samples were collected 12 h after the last administration. The degree of skin lesions and the changes in serum levels of corticotropin-releasing hormone (CRH), adrenocorticotropic hormone (ACTH), cortisol (CORT), interleukin (IL)-4, interferon (IFN)-γ, IL-25, and IL-31 among the groups were compared. Results: SZQG effectively increased the levels of CRH, ACTH, and CORT, which decreased in the serum of rats with chronic eczema, stimulated the function of the HPA axis, and promoted the expression of glucocorticoids. SZQG reduced the serum levels of inflammatory factors including IL-4, IL-25 and IL-31, which were overexpressed in rats with chronic eczema, and increased those of anti-inflammatory factor IFN-γ, thereby alleviating the inflammatory symptoms and itching, and ameliorating the clinical symptoms of chronic eczema. Conclusion: SZQG effectively alleviates skin lesions in the chronic eczema rat model by stimulating the function of the HPA axis.

Keywords

• Shizhenqing granule
• Chronic eczema
• Hypothalamic-pituitary-adrenal axis
• Inflammatory factors