Changes of local vaginal immune regulation in rats infected with vulvovaginal candidiasis

Abstract

Objective: To study the disease process of vulvovaginal candidiasis (VVC) infection in rat model of VVC, and to study the immuno-repairing effect of different treatments on vaginal epithelium and the ultra-structural changes of vaginal epithelial cells. Methods: The VVC model of female rats were established. After successful modeling, the rats were treated with no treatment (model control group), nystatin and Kangfu Xiaoyan suppository. The vaginal epithelium was observed by transmission electron microscopy and immunohistochemical staining. The ultra-structural changes of epithelial cells and the expression of cytokines interferon γ (IFN-γ), interleukin (IL) 4, IL-17 and IgG in epithelial cells were observed and analyzed statistically. Results: The negative conversion rate of model control group was 0, and that of nystatin group was 6/6, and that of Kangfu Xiaoyan suppository group was 5/6; significant difference existed between nystatin, Kangfu Xiaoyan suppository group and model control group (P<0.05). The ultrastructures of vaginal epithelial cells were damaged obviously after VVC infection, and the ultrastructures were repaired by nystatin and Kangfu Xiaoyan suppository under transmission electron microscope. Immunohistochemical staining showed, the expressions of IFN-γ and IgG in the four cytokines which played a protective role increased after Kangfu Xiaoyan suppository treatment, significantly different from that of model control group (P<0.05), but there were no significant differences of the IFN-γ and IgG expression between Kangfu Xiaoyan suppository group and those of nystatin group (P>0.05); the expression of IL-17 was increased after nystatin treatment, but decreased after Kangfu Xiaoyan suppository treatment, and the difference between the two groups had statistical significance (P<0.05). Conclusions: The ultrastructure of vaginal epithelial cells after VVC infection could be damaged obviously, the local immune state is disordered, and the antifungal drug nystatin has a good therapeutic effect on VVC, it could significantly repair the damaged vaginal epithelium structure after VVC infection and strengthen the protective immune function of vaginal epithelium. Kangfu Xiaoyan suppository, one of Chinese medicine, has similar therapeutic effect with nystatin.