Novel Anti-Inflammatory Effects of Repaglinide in Rodent Models of Inflammation

Abstract

Background: Repaglinide is an FDA-approved treatment for type 2 diabetes mellitus. The anti-inflammatory effect of repaglinide in the absence of diabetes has not been reported previously. It is the objective of this set of studies to investigate the potential anti-inflammatory effects of repaglinide. Method: The in vivo anti-inflammatory effects of repaglinide were studied in two different models of delay type hyperreactivity (DTH) response induced by sheep red blood cells (sRBC) and 2,5′-dinitrofluorobenzene (DNFB), and in two different rodent models of lipopolysaccharide (LPS) challenge. Results: In mice systemically sensitized with sRBC, which subsequently received a local injection of sRBC in the footpad, local swelling occurred within 24 h after challenge. Repaglinide was efficacious in attenuating this response. In an orthogonal DTH model using DNFB as the antigen, the animals received topical sensitization with DNFB on their shaved backs, followed by topical challenge on the left ears. Repaglinide efficaciously downregulated the resulting ear swelling response. In mice challenged systemically or intratracheally with LPS, repaglinide significantly decreased serum tumor necrosis factor α level and bronchial alveolar lavage fluid MCP-1 levels, respectively. Conclusion: This set of data suggests novel anti-inflammatory effects of repaglinide in nondiabetic animals. However, the high dose required for an efficacious effect would make this application impractical in the clinic.