Modificated Mahuang-Tang, a traditional herbal medicine suppresses inflammatory responses induced by cigarette smoke in human airway epithelial cell and mice

Abstract

Background: Cigarette smoke (CS) is a major contributor to the high incidence of chronic obstructive pulmonary disease (COPD) featured as chronic inflammation and airway obstruction. Mahuang-Tang is a traditional polyherbal mixture composed of four different herbs. It is widely used in Asia as a remedy for allergic reaction and inflammation.

Purpose: We investigated the effects of a modificated Mahuang-Tang water extract (MTWE) against airway inflammation caused by CS and lipopolysaccharide (LPS) in mice and cigarette smoke condensate (CSC)-stimulated NCI-H292 cells.

Methods: CS exposed to animals for 1 h per day from day 1 to day 7 and treated with LPS intranasally on day 4. One hour before CS exposure, animals were received MTWE (50 or 100 mg/kg) by oral gavage. Inflammatory cell count and cytokines levels were measured in the bronchoalveolar lavage fluid. Expression levels of matrix metalloprotease-9 (MMP-9) and extracellular signal-regulated kinase (Erk) were analyzed by western blotting.

Results: MTWE markedly decreased the neutrophil and other inflammatory cell counts in the bronchoalveolar lavage fluid and reduced proinflammatory mediators as evidenced by the decreases in inflammatory cell recruitment in lung tissue. Furthermore, MTWE meaningfully declined MMP-9 expression and reduced the Erk phosphorylation, caused by the CS and LPS exposure. In in vitro experiments, MTWE suppressed the elevated expression of proinflammatory cytokines induced by CSC treatment. MTWE reduced Erk phosphorylation and MMP-9 expression in CSC-stimulated H292 cells.

Conclusion: Overall, MTWE effectively inhibited the pulmonary inflammation and MMP-9 expression caused by the CS and LPS exposure, which was closely involved in suppression of Erk phosphorylation. These results suggest that MTWE possesses a potential for the treatment of COPD.

Keywords: Chronic obstructive pulmonary disease; Cigarette smoke; Extracellular signal-regulated kinase; Matrix metalloprotease-9; Modificated Mahuang-Tang water extract.