New TMA (4,6,4′-Trimethyl angelicin) Analogues as Anti-Inflammatory Agents in the Treatment of Cystic Fibrosis Lung Disease

Abstract

A series of new-generation TMA (4,6,4′-trimethyl angelicin) analogues was projected and synthetized in order to ameliorate anti-inflammatory activity, with reduced or absent toxicity. Since the NF-κB transcription factor (TF) plays a critical role in the expression of IL-8 (Interluekin 8), a typical marker of lung inflammation in Cystic Fibrosis (CF), the use of agents able to interfere with the NF-κB pathway represents an interesting therapeutic strategy. Through preliminary EMSA experiments, we identified several new TMA derivatives able to inhibit the NF-κB/DNA complex. The selected active molecules were then analyzed to evaluate the anti-inflammatory effect using both Pseudomonas aeruginosa (PAO1) infection and TNF-alpha stimulus on the CF IB3-1 cell line. It was demonstrated that mainly two TMA analogues, GY971a mesylate salt (6-p-minophenyl-4,4′-dimethyl-angelicin) and GY964 (4-phenyl-6,4′-dimethyl-angelicin), were able to decrease the IL-8 gene expression. At the same time, these molecules were found to have no pro-apoptotic, mutagenic and phototoxic effects, facilitating our decision to test the efficacy in vivo by using a mouse model of acute P. aeruginosa lung infection. The anti-inflammatory effect of GY971a was confirmed in vivo; this derivative was able to deeply decrease the total number of inflammatory cells, the neutrophil count and the cytokine/chemokine profile in the P. aeruginosa acute infection model, without evident toxicity. Considering all the obtained and reported in vitro and in vivo pre-clinical results, GY971a seems to have interesting anti-inflammatory effects, modulating the NF-κB pathway, as well as the starting lead compound TMA, but without side effects.