Relieving effect of Lactobacillus crispatus RS08 on Candida albicans-induced vaginitis by regulating NF-κB signaling pathway.

Vaginitis is a common condition that adversely affects women's health, and maintaining a balanced vaginal microbiota is essential for its management. This study evaluated the therapeutic effects and anti-inflammatory mechanisms of Lactobacillus crispatus RS08 in a mouse model of experimental vaginitis. Therapeutic efficacy was assessed through vaginal appearance and histopathological analysis. Anti-inflammatory activity was evaluated by measuring myeloperoxidase (MPO) activity, serum levels of interleukin (IL)- 1β, IL-6, and IL-10, as well as mRNA expression of tumor necrosis factor-alpha (TNF-α), IL-1β, IL-6, interferon-gamma (IFN-γ), cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS). In addition, protein expression levels of nuclear factor-kappa B p65 (NF-κBp65) and inhibitor of NF-κB (IκB)-α in vaginal tissues were determined via Western blot. The results demonstrated that treatment with L. crispatus RS08 significantly improved both macroscopic and histological features of the vagina. It markedly reduced MPO activity and serum levels of the pro-inflammatory cytokines IL-1β and IL-6, while increasing the anti-inflammatory cytokine IL-10. Consistently, RS08 downregulated the mRNA expression of TNF-α, IL-1β, IL-6, IFN-γ, COX-2, and iNOS, and upregulated IL-10 expression. Western blot analysis further revealed that RS08 treatment suppressed the vaginitis-induced increase in NF-κBp65 protein expression and restored the decreased IκB-α protein expression, indicating modulation of the NF-κB signaling pathway. In conclusion, L. crispatus RS08 exhibits therapeutic potential against vaginitis by alleviating clinical symptoms and modulating inflammatory responses, likely through suppression of the NF-κB pathway. These findings support its potential application as a probiotic intervention for vaginitis management.