Gleditsiae sinensis fructus Pills combined with Jujubae fructus attenuate chronic bronchitis via regulation of AGE-RAGE signaling pathway

Gleditsiae sinensis fructus Pills (GF) is a famous classical prescription, that is regularly combined with Jujubae fructus (JF) for the treatment of chronic bronchitis (CB) in the clinic. While the clinical efficacy of this combination prescription is clearly established, the active ingredients and molecular mechanisms remain unclear.To elucidate the mechanisms of action of Gleditsiae sinensis fructus Pills combined with Jujubae fructus (GF&JF) against CB based on network pharmacology and experimental verification.The potential targets of GF&JF involved in therapeutic activity against CB were predicted based on network pharmacology and an "ingredients-targets" network constructed. The Metascape database was used for Module, GO functional and KEGG signaling pathway enrichment analyses of potential targets. Molecular docking was applied to simulate the binding activities of key candidate active ingredients to core targets. For experimental verification, a CB model was established through smoking and nasal cavity drip of lipopolysaccharide. Related inflammatory factors, including TNF-α, TGF-β, IL-6 and IL-8 in serum, and IL-4 IL-8, IFN-γ and IL-10 in bronchoalveolar lavage fluid (BALF), were detected using ELISA. Hematoxylin and eosin (H&E) and Masson staining were performed to observe pathological changes in lung and tracheal tissue. The expression of related proteins and mRNAs in the lung tissue were detected using immunohistochemistry (IHC), quantitative real-time PCR, and western blot.In network pharmacology, 36 common targets of GF&JF for CB were screened and the key targets and main signaling pathways identified. The active ingredients quercetin and stigmasterol in GF&JF had more targets for CB, which displayed good binding activity to IL-6, VEGFA, and EGFR, as established from molecular docking results. In vivo, GF&JF effectively inhibit the inflammatory response in CB mice and improved pathological changes in lung and tracheal tissue. In terms of the key proteins of the AGE-RAGE signaling pathway, GF&JF induced significant down-regulation of IL-6, ICAM-1, VCAM-1, EGFR, CASPASE-3, AGEs and RAGE proteins in lung tissue as well as mRNA expression of IL-6, ICAM-1, VCAM-1, EGFR, AGEs and RAGE.The GF&JF combination exerts a good therapeutic effect in CB model mice, which may be attributed to inhibition of the inflammatory response as well as regulation on the expression of AGE-RAGE signaling pathway. In addition, quercetin and stigmasterol appear to be the main active ingredients of GF&JF in the treatment of CB.