Exploring the Target and Mechanism of Radix Paeoniae Alba on Sjogren's Syndrome

Background: Radix Paeoniae Alba is a traditional Chinese herbal medicine. It can accelerate salivary secretion and alleviate the dry mouth of patients with Sjogren's syndrome (SS). Although it is widely used in clinical treatment, its target and mechanism remain unclear.

Objective: This study aims to analyze the main components of Radix Paeoniae Alba, explore the target genes, and propose the possible mechanism for Radix Paeoniae Alba's acceleration of salivary secretion.

Methods: The main active components and potential targets of Radix Paeoniae Alba were searched through the TCMSP database. Efforts were made to search for the related genes of Sjogren's syndrome in OMIM and GeneCards databases. Cytoscape v3.8.0 software was used to link target genes of active components and key genes of the disease. The software Autodock vina1.1.2. was adopted to simulate the interaction between active components and target genes. Human submandibular gland (HSG) cells were used in vitro experiments to verify the results of our analysis.

Results: β-Sitosterol, the main component of Radix Paeoniae Alba, may intervene in the disease through CHRM3. Molecular docking shows β-Sitosterol has a high affinity with CHRM3, and the interaction between CHRM3 and β-Sitosterol is the basis of biological activity. The in vitro experiments showed that β-Sitosterol could significantly up-regulate the mRNA and protein expression levels of both CHRM3 and secretion-related genes in HSG cells.

Conclusion: Our study shows that the chemical components of Radix Paeoniae Alba have a positive effect on the related mechanism of salivary secretion. We found that β-Sitosterol can promote the expression of CHRM3, stimulate salivary secretion, treat Sjogren's syndrome and potentially improve its prognosis.