RESUMEN
OBJECTIVE: To explore the effects of Gymnadenia conopsea alcohol extract (GcAE) on the collagen synthesis in rat lungs exposed to silica and the influence on antioxidase activities, level of lipid peroxidation (LPO). METHODS: One hundred and twenty rats were randomly divided into control group, silica group, and GcAE-treated group. Silicotic animal models were established by direct tracheal instillation of silica into rat lungs surgically. From the second day of model establishment, rats in GcAE-treated group were orally given GcAE [8 g/(kg x d) corresponding to raw herb]. At 7, 14, 21, 28 and 60 days after establishment of the animal model, eight rats in each group were sacrificed, and samples were collected. The malondialdehyde (MDA) content, superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities in plasma were assayed by a spectrophotometer. Types I and III collagen were detected by Sirius red polarization and microscopy, and measuered by Image-Pro Plus Version 4.5 for Windows software. RESULTS: GcAE could reduce the lung/body weight ratio of rats exposed to silica, the synthesis of types I and III collagen of the lungs and the level of lipid peroxidation, increase the activities of SOD and GPx. CONCLUSION: GcAE can ameliorate the silica-induced pulmonary fibrosis by increasing the activities of antioxidase and alleviating the damage of lipid peroxidation to the lungs.