Ssanghwa-Tang, a traditional herbal formula, suppresses cigarette smoke-induced airway inflammation via inhibition of MMP-9 and Erk signaling

Abstract

We investigated the effects of Ssanghwa-Tang water extract (STWE), a traditional herbal medicine, on airway inflammation induced by cigarette smoke (CS) and lipopolysaccharide (LPS). Mice were exposed to CS for 1 h per day (8 cigarettes per day) from day 1 to day 7. On day 4, the mice were treated intranasally with LPS. STWE (50 or 100 mg/kg) was administered by oral gavage 1 h before the CS exposure. STWE markedly decreased the neutrophil and other inflammatory cell counts in bronchoalveolar lavage fluid, along with the reduction of proinflammatory mediators such as interleukin-1β (IL-1β), IL-6, and tumor necrosis factor-α. STWE significantly decreased inflammatory cell infiltration into lung tissue, induced by CS and LPS exposure. In addition, STWE reduced the expression level and activity of matrix metalloproteinase-9 (MMP-9) in the lung tissue, which was accompanied by a decrease in phosphorylation of extracellular signal-regulated kinase (Erk). STWE effectively inhibited the neutrophilic airway inflammation and MMP-9 expression induced by the CS and LPS exposure, which was closely related to the downregulation of Erk phosphorylation. These findings suggest that STWE has therapeutic potential for the treatment of airway inflammatory disorders such as chronic obstructive pulmonary disease.