OBJECTIVE  To investigate the protective effect proanthocyanidin B2(PC-B2) on oxidative damage and apoptosis of mouse astrocytes(AS) induced by hydrogen peroxide(H₂O₂) and its mechanism.

METHODS  AS were isolated and cultured from neonatal C57BL/6 mice(1−3 d). The optimal concentration of H₂O₂ and PC-B2 was divided into four groups: normal group, normal+PC-B2 group(100 μg·mL^‒1 PC-B2 treated for 24 h), H₂O₂ model group(200 μmol·L^‒1 H₂O₂ treated for 24 h), PC-B2 group(200 μmol·L^‒1 H₂O₂ and 100 μg·mL^‒1 PC-B2 treated for 24 h). The cell viability of each group was detected by CCK-8 method. Cytotoxicity was detected by LDH method. The antioxidant capacity was detected by ABTS and DPPH. The content of MDA and the activity of SOD, CAT and GSH-Px were detected by ELISA kit. Detection of apoptosis in each group was done by TUNEL staining. The mRNA and protein expression levels of Bax, Bcl-2, Caspase-3, Akt/Stat3, p-Akt, p-Stat3 and Nrf2/HO-1 in AS were detected by RT-PCR and Western blotting, respectively.

RESULTS  PC-B2 could significantly enhance cell viability and inhibit AS apoptosis. Compared with the H₂O₂ model group, PC-B2 intervention could significantly reduce the content of LDH and MDA in AS, and increase the activity of SOD, CAT and GSH-Px. PC-B2 intervention could inhibit the mRNA and protein expression of Bax and Caspase-3, and up-regulate the mRNA and protein expression of Akt/Stat3, Bcl-2, Nrf2/HO-1.

CONCLUSION  PC-B2 can enhance the antioxidant capacity of AS through Akt/Stat3 and Nrf2/HO-1 pathways, therefore reduce H₂O₂-induced AS oxidative damage and apoptosis.