Astragalus polysaccharides exert protective effects in newborn rats with bronchopulmonary dysplasia by upregulating the expression of EGFL7 in lung tissue.

The aim of this study was to explore the effects of Astragalus polysaccharides (APS) on the mRNA expression of epidermal growth factor-like domain 7 (EGFL7) in lung tissue in newborn rats with bronchopulmonary dysplasia (BPD). For this purpose, a total of 96 newborn SD rats were randomly divided into 4 groups (n=24): the control group, air room plus APS group, BPD group and the APS group (20 mg/kg/day). Lung tissues were obtained on days 4, 10 and 14 after birth. Morphological changes were observed and the protein and mRNA expression levels of EGFL7, Bax and Bcl-2 were determined. The rats in the BPD group (BPD induced by hyperoxia) presented with an arrest in alveolar and vascular development and low mRNA and protein expression levels of of EGFL7, Bcl-2 and high levels of Bax compared with the rats in the control group. However, lung damage in the APS intervention group was attenuated compared with the BPD group. The protein and mRNA expression levels of EGFL7 and Bcl-2 were also increased and the level of Bax was decreased in the APS intervention group (P<0.01) compared with the BPD model group after birth on days 4, 10 and 14. Our data demonstrate that APS reduce airway remodeling and alveolar damage by upregulating the expression of EGFL7 and exert protective effects against BPD in neonatal rats. Thus, APS may have potential for use as a therapeutic strategy for BPD.