The Inhibitory Effects of KRGE on Mixed Granulocytic Asthma due to Der p 38

Asthma is a chronic inflammatory airway disease triggered by allergens including house dust mite, food and environmental factors. Korean red ginseng extract (KRGE) has anti-inflammatory effects in asthma, atopic dermatitis and allergic rhinitis. This study aimed to evaluate the suppressive effects of KRGE on mixed-granulocytic asthma induced by Der p 38. In mixed granulocytic asthma-like the mice due to Der p 38, KRGE administration reduced the infiltration of neutrophils and eosinophils in the lungs. In addition, KRGE suppressed the levels of Th1, Th2 and Th17 cytokines in bronchoalveolar lavage fluid (BALF) and reduced serum IgE level. In BEAS-2B cells, Der p 38 increased the secretion of inflammatory cytokines such as interleukin (IL)-6, IL-8, and monocyte chemoattractant protein-1 (MCP-1), which was suppressed by pretreatment with KRGE. Neutrophil apoptosis was delayed by Der p 38 and it was inhibited by KRGE pretreatment. The pro-apoptotic effects of KRGE on neutrophils were closely associated with the activation of caspase 9 and caspase 3, and a decrease in the B-cell leukemia/lymphoma 2 protein (BCL-2)/BCL-2-associated X protein (BAX) expression ratio. These results suggest that KRGE has anti-inflammatory effect in asthma, especially mixed granulocytic asthma, and serves as a potential therapeutic alternative for alleviating mixed granulocytic asthma.