Exploring the immunomodulatory activities ofextract against lipopolysaccharide-induced allergic inflammation in mice through suppression of innate pro-inflammatory cytokines, COX-2 and iNOS signalling pathways.

Abstract

OBJECTIVES: This study sought to evaluate the biological effects of the hydroethanolic extract of(SDE) on some innate immune responses that are implicated in inflammatory respiratory diseases, using the lipopolysaccharide-induced mice model. METHODS: Lipopolysaccharide (LPS, 0.5&#x202f;mg/kg) was dissolved in 2&#x202f;mL phosphate buffered saline and injected (IP) into mice 1&#x202f;h after drug administration to induce inflammation and systemic immune responses. Mice were pre-treated with either 10&#x202f;mg/kg prednisolone or SDE (50, 100, 250&#x202f;mg/kg,..). The expressions of TNF-&#x3b1;, IL-1&#x3b2;, IL-6, stem cell factor (SCF), nitric oxide (NO), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 enzymes (COX-2) were evaluated by a real-time PCR technique. Furthermore, histopathological examinations were performed on the lung tissues. RESULTS: Pre-treatment with SDE significantly suppressed (p<0.001) the expressions of TNF-&#x3b1;, SCF, IL-1&#x3b2;, IL-6, and COX-2, as well as iNOS enzymes in the mRNAs of LPS-induced mice, and it also reduced NO levels and endotoxin-induced lung damage. CONCLUSIONS: SDE exhibited strong immunomodulatory activities and thus, would have potential benefits in immune-inflammatory disease management.