OBJECTIVE To explore the mechanism of Taohong Siwutang Jiawei in regulating T helper cell 1(Th1)/Th2 balance and ovarian estradiol(E2) secretion to intervene in psoriasis in mice.

METHODS Seventy-two SPF female BALB/c mice were randomly divided into blank group, model group, positive control group, and low, medium, and high-dose groups of Taohong Siwutang Jiawei. A mouse psoriasis-like skin lesion model was induced by applying 5% imiquimod cream to the back of the mice, and drug intervention was given simultaneously during modeling. After administration, the psoriasis area and severity index(PASI) score was performed on the skin lesions on the back of the mice; HE staining was used to observe the histopathological changes of skin lesions and ovarian tissues in mice; TUNEL method was used to detect the apoptosis of granulosa cells in the mouse ovarian tissue; IHC was used to detect the expression of proliferation antigen Ki-67 in the skin lesions on the back of the mice; ELISA was used to detect the levels of interferon-γ(IFN-γ), tumor necrosis factor-α(TNF-α), interleukin(IL)-4, IL-10 in the serum, skin lesions, and ovarian tissue of the mice, the levels of E2 in the serum and ovarian tissue, and the levels of cytochrome P450 cholesterol side chain lyase(P450scc), 3β-hydroxysteroid dehydrogenase(3β-HSD), and 17β-HSD in the ovarian tissue; Western blotting and Real-time PCR were used to detect the protein and gene expression levels of IFN-γ, IL-4, estrogen receptor α(ERα), and ERβ in the peripheral blood of the mice; flow cytometry was used to detect the proportion of Th1/Th2 cells in the peripheral blood of the mice.

RESULTS Compared with the blank group, the PASI score, Baker score, Ki-67 positive expression level, and the percentage of ovarian granulosa cell apoptosis in the model group were significantly increased, the concentrations of IFN-γ and TNF-α in the serum, skin lesions, and ovarian tissue were significantly increased, the concentrations of IL-4 and IL-10 were significantly decreased, the concentrations of E2 in the serum and ovarian tissue were significantly decreased, the concentrations of P450scc, 3β-HSD, and 17β-HSD in the ovarian tissue were significantly decreased, the protein and gene expression levels of IFN-γ in the peripheral blood and the positive rate of Th1⁺ cells were significantly increased, the protein and gene expression levels of IL-4, ERα, and ERβ and the positive rate of Th2⁺ cells were significantly decreased, and the Th1/Th2 cell ratio was significantly increased. Compared with the model group, the PASI score, Baker score, Ki-67 positive expression level, and the percentage of ovarian granulosa cell apoptosis in each drug administration group were significantly decreased, the concentrations of IFN-γ and TNF-α in the serum, skin lesions, and ovarian tissue were significantly decreased, the concentrations of IL-4 and IL-10 were significantly increased, the concentrations of E2 in the serum and ovarian tissue were significantly increased, the concentrations of P450scc, 3β-HSD, and 17β-HSD in the ovarian tissue were significantly increased, the protein and gene expression levels of IFN-γ in the peripheral blood and the positive rate of Th1⁺ cells were significantly decreased, the protein and gene expression levels of IL-4, ERα, and ERβ and the positive rate of Th2⁺ cells were significantly increased, and the Th1/Th2 cell ratio was significantly decreased.

CONCLUSION Taohong Siwutang Jiawei can significantly reduce the expression of Th1 cell differentiation factors and increase the expression of Th2 cell differentiation factors in the serum, skin lesions, and ovarian tissue of psoriasis mice, regulate the Th1/Th2 immune balance, improve the apoptosis of ovarian granulosa cells, promote the secretion of E2 and the expression of its receptors ERα and ERβ, and reduce the degree of inflammatory cell infiltration and epidermal thickening, thus playing a role in the treatment of psoriasis.