Antimicrobial and anti-inflammatory effects of ethanol extract of Corylopsis coreana uyeki flos

Background: Corylopsis coreana Uyeki (Hamamelidaceae) is a medicinal plant cultivated in Northeast Asia. Previously, we have reported that an ethanol extract of Corylopsis coreana Uyeki flos (ECCF) contains four active compounds with antioxidant activity. Objective: The aim of this study was to investigate the antimicrobial spectrum against infectious bacteria and anti-inflammatory effect of ECCF in a mouse model of acute local inflammation. Materials and Methods: In vitro antimicrobial susceptibility was evaluated using standard plate assay technique. Antimicrobial activities (minimum inhibitory concentration, MIC; μg/mL) were determined with the serial dilution method. In vivo anti-inflammatory activity was studied using a mouse model of carrageenan-induced air pouch inflammation. Results: The ECCF showed antimicrobial activities against general bacteria and drug-resistant bacteria including Staphylococcus aureus, Micrococcus luteus ATCC 9341, Mycrobacterium smegmatis ATCC 9341, Mycrobacterium smegmatis ATCC 9341, Salmonella typhimrium KCTC 1925, and nine methicillin-resistant Staphylococcus aureus strains, with MIC values ranging from 250 to 1000 μg/mL. In in vivo mouse model, inflammatory morphologic changes observed in the air pouch membrane were restored to its normal condition by the ECCF treatment. Moreover, the ECCF significantly reduced exudate volumes, protein contents, inflammatory cell counts, and pro-inflammatory cytokine levels in the exudates recovered from air pouches of the mouse model. Flavonoids in the ECCF were found to contain bergenin, quercitrin, and quercetin with reported anti-inflammatory activity via suppressing tumor necrosis factor-α production. Conclusion: To the best of our knowledge, this is the first report to demonstrate the antimicrobial and anti-inflammatory activities of ECCF. Our results suggest that the ECCF might potentially serve as an alternative or complementary medicine for treating inflammatory diseases caused by microbial infection.