Oxidative stress can induce lung damage and aggravate airway inflammation in asthma. Previously, we reported that rosmarinic acid (RA) exerted strong anti-inflammatory effects in a mouse allergic asthma model. Therefore, we hypothesized that RA might also have antioxidative effects in a superimposed asthma mouse model with oxidative lung damage challenged with ovalbumin (Ova) and hydrogen peroxide (H2O2). We evaluated the antioxidative and anti-asthmatic activity of RA and explored its possible mechanisms of action. Mice sensitized to Ova and challenged with Ova and H2O2 were treated with RA 1 h after challenge. RA treatment greatly diminished the number of inflammatory cells; decreased IL-4, IL-5, and IL-13 production; increased IFN-γ secretion; significantly downregulated ROS production; and markedly upregulated the activities of SOD, GPx, and CAT. Furthermore, RA treatment resulted in a significant increase in the expression of Cu/Zn SOD and a notable reduction in NOX-2 and NOX-4 expression in lung tissues. These findings suggest that RA may effectively alleviate oxidative lung damage and airway inflammation in asthma.
Keywords: antioxidation; asthma; oxidative lung damage; rosmarinic acid.