Jiegeng decoction ameliorated acute pharyngitis through suppressing NF-κB and MAPK signaling pathways

Jiegeng decoction (JGD), consisting of Glycyrrhizae Radix et Rhizoma and Platycodonis Radix at the ratio of 2:1, is a classical Chinese medicine prescription firstly recorded in "Treatise on Febrile Diseases". JGD has been extensively utilized to treat sore throat and lung diseases for thousands of years in China. However, the pharmacological effect and mechanism of JGD on acute pharyngitis (AP) remain unclear.

Our research aimed to reveal the pharmacological effect of JGD on AP and its potential mechanisms.

The chemical components of JGD were analyzed based on the UPLC-MS analysis. The anti-inflammatory effect of JGD was evaluated by NO production using the Griess assay in RAW 264.7 cells. The mRNA expression of iNOS, IL-1β, IL-10, TNF-α, IL-6 and MCP-1 was determined by qRT-PCR in vitro. A 15% ammonia-induced AP model was established. The histopathology, the inflammatory cytokines IL-6 and MCP-1 in serum and the apoptosis-related genes caspease-8 and caspease-3 were determined by H&E staining, ELISA and qRT-PCR, respectively. The expression levels of p-p65, p65, p-JNK, JNK, p-p38, p38, p-ERK1/2, ERK1/2, and COX2 were measured through western blotting.

Nine compounds, including liquiritin, liquiritin apiosde, liquiritigenin, platycodin D, platycoside A, licorice saponin J2, licorice saponin G2, glycyrrhizic acid, and licochalcone A, were identified. JGD significantly inhibited NO production and regulated the mRNA expression levels of cytokines in LPS-stimulated RAW 264.7 cells. The results of in vivo experiments confirmed that JGD ameliorated AP through improving the pathological state of pharyngeal tissue, decreasing the serum levels of IL-6 and MCP-1 and preventing the tissue mRNA expression of caspease-8 and caspease-3. Furthermore, JGD also inhibited the NF-κB and MAPK pathways in the AP model.

This study suggested that JGD could alleviate AP through its anti-inflammation via NF-κB and MAPK pathways, which supported the traditional application of JGD for the treatment of throat diseases.