Purpose: Obstructive sleep apnea (OSA) is associated with lung injury. As a novel pathophysiological hallmark of OSA, chronic intermittent hypoxia (CIH) enhances apoptosis. The present study aims to evaluate the effect of resveratrol (Res) on CIH-induced lung apoptosis and inflammation in a rat model of CIH.
Methods: Rats were randomly allocated to normoxia (control), CIH, and CIH + Res groups (n = 10 in each group). The CIH exposure duration was 12 weeks. Rats in the CIH + Res group were additionally administered Res (50 mg kg-1 d-1). Inflammatory cytokine levels were detected by enzyme-linked immunosorbent assays (ELISAs). A terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay was conducted to evaluate the apoptosis rate. Bax, cleaved caspase-3, Nrf2 and HO-1 protein levels were detected by western blotting.
Results: The IL-6 and TNF-α levels in the serum and alveolar lavage fluid in the CIH group were markedly higher than those in the control group. The percentage of apoptotic cells in the CIH group was higher than that in the control group. Bax and cleaved caspase-3 protein levels were increased in the CIH group compared with those in the control group. Nrf2 and HO-1 protein levels were decreased in the CIH group compared with those in the control group (p < 0.05). Compared with the CIH group, rats in the CIH + Res group had lower percentages of apoptotic cells, lower IL-6, TNF-α, Bax and cleaved caspase-3 protein levels, and higher Nrf2 and HO-1 protein levels (p < 0.05).
Conclusion: Res attenuates CIH-related inflammatory reactions and apoptosis in lung tissue by activating the Nrf2/ARE pathway.
Keywords: Apoptosis; Intermittent hypoxia; Lung injury; Nrf2; Resveratrol.