Rosmarinic Acid as A Flavonoids Ameliorated Cytokines and Oxidative Stress Biomarkers in the Lung Lavage Fluid of Rats

Allergic asthma is a chronic respiratory condition characterized by pronounced inflammation, oxidative stress, and reversible airway obstruction. The objective of this study was to assess the effects of rosmarinic acid (RosA) on the mitigation of inflammation and oxidative stress in a rat model of asthma. Male Wistar rats were randomly assigned to six groups: (1) control group: administered normal saline via intraperitoneal (i.p.) and inhalation routes; (2) asthmatic group: exposed to ovalbumin (OVA) via i.p. and inhalation; (3) asthmatic rats treated with dexamethasone (1 mg/kg, orally); (4-6) three asthmatic groups receiving RosA at doses of 0.5, 1, and 2 mg/kg/day, orally. The levels of interleukin (IL-4 and IL-17A), interferon-gamma (IFN-γ), immunoglobulin E (IgE), nitrite (NO₂), superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA), and thiol (SH) were quantified in bronchoalveolar lavage fluid (BALF). Treatment with RosA significantly reduced the levels of IL-4, IL-17A, IgE, NO₂, and MDA, while it elevated the levels of SH and IFN-γ compared to the asthmatic group (<i>p</i> < 0.001). RosA dose-dependently significantly elevated SOD and CAT activities compared to sensitized rats (<i>p</i> < 0.001). Furthermore, medium and higher doses of RosA significantly increased SOD and CAT activities compared to its lower dose (<i>p</i> < 0.001). The therapeutic effects of RosA on oxidative stress and inflammatory mediators in asthmatic rats were found to be comparable to those achieved with dexamethasone treatment. These results indicate the potential of RosA to elicit beneficial effects in the reduction of asthma symptoms.