Effects of Schisandra chinensis Baillon (Schizandraceae) on lipopolysaccharide induced lung inflammation in mice

Schisandra chinensis Baillon (Sc), an anti-inflammatory herb that has been used in traditional Chinese medicine for thousands of years, is frequently used to treat upper respiratory tract infections. This study was conducted to evaluate the ability of a water extract of Sc to prevent airway inflammation both in vitro and in vivo. Human lung alveolar epithelial-derived A549 cells were stimulated with to interleukin-1β, tumor necrosis factor-α, and interferon-γ (IL-1β, TNF-α, and INF-γ; cytokine mixture; CM) and treated with Sc extracts. They were then evaluated using nitric oxide (NO), IL-8 and monocyte chemotactic protein-1 (MCP-1) secretions. In the in vivo study, BALB/c mice were challenged with lipopolysaccharide (LPS) to induce acute airway inflammation. After this challenge, the mice were treated with Sc extracts (10, 50 and 100mg/kg) by oral administration, and inflammatory cells in the bronchoalveolar lavage (BAL) fluid were counted. IL-6 and TNF-α secretions were measured using an enzyme-linked immunosorbent assay. Lung tissues of the LPS treated mice were prepared and stained with hematoxylin and eosin (HE) for histological examination. In the A549 cells, Sc extracts dose-dependently and significantly inhibited CM-induced NO production and reduced IL-8 and MCP-1 secretions. Sc extracts efficiently suppressed neutrophil and macrophage infiltrations of lung tissues and increased IL-6 and TNF-α levels in BAL fluid in LPS-instilled BALB/c mice. In addition, Sc extracts treatment inhibited pathologic progress in the lung tissues, as confirmed by H&E staining. These findings indicate that Sc extracts could be potentially useful for the treatment of acute lung inflammation and acute lung injury. [Display omitted]