Puerarin protects the retinal pigment epithelium (ARPE19) against hypoxia-induced blood-retinal barrier breakdown and Akt/Bcl2-dependent apoptosis

Abstract Background: Puerarin, an isoflavonoid, is a neuroprotectant against many ischemic brain injuries. The research purpose was to investigate whether puerarin treatment can inhibit hypoxia-induced apoptosis and barrier breakdown on human retinal pigment epithelium (ARPE-19) cells. Methods: Treatment with 100 µM of puerarin showed no ARPE-19 cytotoxicity. Treatments with 50 µM or 100 µM of puerarin significantly preserved cell viability under hypoxic conditions for 12 h (p < 0.05). Moreover, treatments with 50 µM and 100 µM of puerarin significantly reduced the proportion of Annexin V- and PI-positive ARPE cells under hypoxic conditions (p < 0.05). The TER analysis and junctional protein staining demonstrated that treatments with 50 µM or 100 µM of puerarin prevented the hypoxia-induced barrier disruption in APRE-19 cultures. In contrast to the untreated group, treatment with puerarin significantly increased the level of Bcl-2 and decreased the levels of p-Bad, Bax, and cleaved caspase 3 in RPE cell under hypoxic conditions (p < 0.05). Treatment with puerarin maintained Akt1 activation in the ARPE-19 cells under hypoxic conditions (p < 0.05), and inhibition of PR-induced Akt1 activation abolished the protective effect of puerarin in ARPE-19 cells under hypoxic conditions. Conclusion: Our results demonstrated that treatment with puerarin protected RPE cell against hypoxia-induced blood-retinal barrier breakdown and Akt-dependent apoptosis. These findings suggest that puerarin could be developed as an alternative treatment for ischemic and hypoxic retinal injuries.