Efficacy and mechanism of topical Chinese herbal formulation JieZe-1 on female lower genital tract co-infection with HSV-2 and Candida albicans via upregulating the cGAS/STING/IFN-I pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: JieZe-1 (JZ-1) originates from the classic Chinese gynecological formula Yi Huang Tang and demonstrates efficacy against lower female reproductive tract infections. However, its effects and mechanisms on herpes simplex virus type 2 (HSV-2) and Candida albicans (C. albicans) co-infection remain unclear.

AIM OF THE STUDY: This study aimed to investigate the effects and underlying mechanisms of JZ-1 against a co-infection model of HSV-2 and C. albicans.

MATERIALS AND

METHODS

The co-infection models were established in vitro (VK2, HaCaT) and in vivo (Balb/c mice). The levels of pathogen-related indicators and the expression of the cGAS/STING/IFN-I pathway were assayed via Gram staining, Western blot, qRT-PCR, immunofluorescence, and ELISA, respectively. Penciclovir and amphotericin B were employed as positive control drugs, and the effects of JZ-1 were evaluated via minimum inhibitory concentration assays, CCK8 assays, and transmission electron microscopy. Network pharmacology analysis was employed to explore the potential pathways and targets of JZ-1 in treating HSV-2 and C. albicans co-infection. By introducing siRNA and the STING inhibitor C-176, the mechanisms of JZ-1 against HSV-2 and C. albicans co-infection were explored.

RESULTS

In vitro, JZ-1 downregulated gD, ALS1, ALS3, and ECE1 expression, inhibited viral invasion, and reduced fungal adhesion. In vivo, JZ-1 suppressed fungal loading, alleviated genital herpes (GH) symptoms, reduced weight loss, and alleviated pathology in mouse vulvar and vaginal tissues. Network pharmacological analysis revealed 26 overlapping targets between JZ-1 and the co-infection disease, including IFNA1. Molecular docking revealed luteolin and berberine exhibited the strongest binding affinity to stimulator of interferon genes (STING). Mechanistically, JZ-1 upregulated STING, phospho-TANK-binding kinase 1 (P-TBK1), phospho-interferon regulatory factor 3 (P-IRF3), and promoted interferons (IFN) secretion along with the interferon-stimulated genes (ISGs) expression. Upon STING inhibition with siRNA or inhibitors, the efficacy of JZ-1 was diminished.

CONCLUSION

JZ-1 exerts effects against HSV-2 and C. albicans co-infection by upregulating the cGAS/STING/IFN-I pathway in a STING-dependent manner.