HDAC Downregulation of Xiaoqinglong Decoction in the Treatment of Allergic Rhinitis.

INTRODUCTION: As one of the most common allergic diseases, allergic rhinitis (AR) has attracted wide attention all over the world. More appropriate treatment of AR should be explored thoroughly. In recent years, traditional Chinese medicine has attracted more attention in AR treatment. As a classical Chinese medicine prescription, Xiaoqinglong decoction (XQLD) has been commonly used in treating AR. Even though its therapeutic effect on AR has been clinically confirmed, more molecular mechanism remains to be further investigated. Our research aimed to investigate the therapeutic mechanism of XQLD for AR management. METHODS: The study was evaluated in an ovalbumin sensitized mouse model and liquid chromatography-mass spectrometry was adopted to test the stability of XQLD's effective components. RESULTS: The results confirmed the stability and safety of the effective components of XQLD. XQLD significantly downregulated the expression of HDACs (HDAC1, HDAC3, and HDAC4) and Th2 inflammatory factors (IL4, IL5, and IL13) in AR mice. XQLD and the HDAC inhibitor JNJ-26481585 promoted the expression of epithelial tight junction proteins (claudin-1 and ZO-1) and decreased the expression of mucins (Muc5ac and Muc5b) in the nasal mucosa of AR mice. CONCLUSIONS: In conclusion, our findings present the beneficial effects of XQLD on AR and recovery of the nasal epithelium. We also identify the decreased HDAC as a potential target of XQLD for AR treatment. This study provides an important experimental proof for elucidating the therapeutic mechanism of XQLD.

Xiaoqinglong decoction mitigates nasal inflammation and modulates gut microbiota in allergic rhinitis mice.

Introduction: Allergic rhinitis (AR) is a respiratory immune system disorder characterized by dysregulation of immune responses. Within the context of AR, gut microbiota and its metabolites have been identified as contributors to immune modulation. These microorganisms intricately connect the respiratory and gut immune systems, forming what is commonly referred to as the gut-lung axis. Xiaoqinglong Decoction (XQLD), a traditional Chinese herbal remedy, is widely utilized in traditional Chinese medicine for the clinical treatment of AR. In this study, it is hypothesized that the restoration of symbiotic microbiota balance within the gut-lung axis plays a pivotal role in supporting the superior long-term efficacy of XQLD in AR therapy. Therefore, the primary objective of this research is to investigate the impact of XQLD on the composition and functionality of the gut microbiota in a murine model of AR. Methods: An ovalbumin-sensitized mouse model to simulate AR was utilized, the improvement of AR symptoms after medication was investigated, and high-throughput sequencing was employed to analyze the gut microbiota composition. Results: XQLD exhibited substantial therapeutic effects in AR mice, notably characterized by a significant reduction in allergic inflammatory responses, considerable alleviation of nasal symptoms, and the restoration of normal nasal function. Additionally, following XQLD treatment, the disrupted gut microbiota in AR mice displayed a tendency toward restoration, showing significant differences compared to the Western medicine (loratadine) group. Discussion: This results revealed that XQLD may enhance AR allergic inflammatory responses through the regulation of intestinal microbiota dysbiosis in mice, thus influencing the dynamics of the gut-lung axis. The proposal of this mechanism provides a foundation for future research in this area.