Abstract:The protective effect of polyphenols from Pinus sylvestris L. against hydrogen peroxide (H2O2)–induced oxidative stress in bovine pulmonary artery endothelial cells (BPAECs) was examined. An oxidative stress model was established by treating BPAECs with 100 μM H2O2. The BPAECs were divided into control group, H2O2 model group, and high-, medium-, and low-dose polyphenol groups (0.5, 0.1, and 0.05 mg/mL, respectively). Changes in the nuclear translocation of nuclear factor E2-related factor 2 (Nrf2) were detected by immunofluorescence, mRNA expression of Nrf2 was detected by reverse transcription-polymerase chain reaction (RT-PCR), and protein expression of Nrf2 was detected by western blotting. Various inhibitors were used to screen signaling pathways to determine the pathway that exerts the protective effect of polyphenols against oxidative stress. The polyphenols from P. sylvestris L. promoted the transfer of Nrf2 from the cytoplasm to the nucleus in BPAECs under hydrogen peroxide-induced oxidative stress. Compared with the control, the polyphenols from P. sylvestris L. significantly increased Nrf2 mRNA and protein levels (*p < 0.05, ** p < 0.01) in a dose-dependent manner (**p < 0.01). The polyphenol extract from P. sylvestris L. exerts a protective effect against hydrogen peroxide-induced damage in BPAECs, and likely activates Nrf2/ARE through COX-2, P38, and PI3K/AKT signaling pathways, but not the PKC pathway.
