Elucidating the anti-HSV-2 mechanism of Longdan Xiegan Decoction via the TLR9 signaling pathway: A multi-omics perspective.

Abstract

ETHNOPHARMACOLOGICAL RELEVANCE: Longdan Xiegan decoction (LDXGT), originally documented in the Secret Collection of the Orchid Chamber, is now widely used in clinical practice. While its clinical efficacy against genital herpes (GH) has been established, the underlying therapeutic mechanism remains incompletely understood. AIM OF THE STUDY: This study aims to investigate the mechanism of action of the LDXGT against HSV-2 using genomics, transcriptomics, and real-time quantitative polymerase chain reaction (RT-qPCR). MATERIALS AND METHODS: This study presents a UPLC-HRMS and network pharmacology framework for the initial exploration. The optimal potency concentration of LDXGT against HSV-2 infection was determined by cellular assay. Spinal cord neurons from mice model infected with HSV-2 before and after the LDXGT intervention were harvested for a viral genomics analysis. The SH-SY5Y cell model infected with HSV-2 before and after the LDXGT drug-containing serum intervention was obtained for a transcriptomic analysis. Establishing both in vitro and in vivo models with TLR9 overexpression (SH-H9) and knockdown (SH-L9) validated the pathway's role in the antiviral mechanism of LDXGT. RT-qPCR analysis quantified the expression levels of relevant genes. In addition, the LDXGT antiviral efficacy in the HSV-2-infected mouse model was evaluated in combination with the weight, skin lesion index symptom scores and ganglion virus load. RESULTS: Results demonstrated a significant anti-HSV-2 activity of LDXGT in vitro, effectively reducing virus-induced apoptosis. In vivo experiments revealed that LDXGT intervention markedly attenuated body weight loss, skin lesion severity, and decreased the incidence of hind-limb paralysis and mortality in HSV-2-infected mice. Genomics and transcriptomics predicted the anti-HSV-2 efficacy of LDXGT via the TLR9 signaling pathway, and these findings were substantiated by RT-qPCR results from both in vitro and in vivo experiments. CONCLUSIONS: The in vivo and in vitro experiments both demonstrated that the LDXGT had significant antiviral efficacy against HSV-2 infection. The present study provided relevant evidence that the LDXGT exerted antiviral efficacy through the TLR9 signaling pathway for HSV-2 infection treatment. This study provides an effective research strategy to further explore the mechanism of this traditional Chinese medicine (TCM) for preventing and treating diseases.