Astragalus polysaccharides mediated preventive effects on bronchopulmonary dysplasia in rats.

Bronchopulmonary dysplasia (BPD) is a multifactor chronic lung disease that mainly affects premature infants. In this study, we investigate the preventive effects of Astragalus polysaccharides (APS) on BPD, and explore its potential molecular mechanisms. Lung tissues of newborn Sprague-Dawley rats from the control group, the room air plus low-dose APS group, the room air plus high-dose APS group, the BPD model group, the low-dose APS group (20 mg/kg d), and the high-dose APS group (40 mg/kg d) were examined at the 4th, 10th, and 14th d of life. The pathomorphological change was evaluated by hematoxylin-eosin staining. The content levels of superoxide dismutase (SOD) and malondialdehyde (MDA) were measured by the assay kit. Moreover, the protein and/or mRNA expression levels of NF-κBp65, CD31, ICAM-1, and TNF-α were also detected by corresponding methods. APS decreased the inflammatory cells infiltrating compared with the BPD group. For the APS group, the activity of SOD was increased and the content of MDA was reduced compared with the BPD group at any time point. The protein and mRNA expression levels of NF-κBp65, ICAM-1, and TNF-α were all decreased, while the protein expression level of CD31 was increased in the APS-treated group, with the most significant difference of the high-dose group (P < 0.01) compared with the BPD group after birth on the 4th, 10th, and 14th d. APS can reduce airway remodeling and alveolar damage by its modulation of inflammatory mediators and antioxidation, suggesting some protective effects on BPD of neonatal rats.