Naringenin Inhibits Ferroptosis in Renal Tubular Epithelial Cells of Diabetic Nephropathy Through SIRT1/FOXO3a Signaling Pathway

Abstract

Naringenin has the potential to regulate ferroptosis and mitigate renal damage in diabetic nephropathy (DN). However, it remains unclear whether the naringenin's effects in DN are linked to its ability to regulate ferroptosis. This study investigated the potential anti-ferroptosis properties of naringenin in high glucose (HG)-induced renal tubular epithelial cell models. HK-2 cells were cultured in HG medium to establish the DN cell model. HK-2 cells were treated with different doses of naringenin to explore the effect of naringenin. The CCK-8 results show that 50 μM ~ 200 μM of naringenin do not affect the viability of HK-2 cells and the viability of HG-induced HK-2 cells increase in a dose-dependent manner with naringenin treatment. Additionally, naringenin increased the levels of IL-10 while decreasing the levels of IL-1β, TNF-α, IL-6, and ROS in HG-induced HK-2 cells. Naringenin also reduced the levels of Fe²⁺, oxidized lipid ROS, MDA, 4-HNE, ACSL4, and TFR1 in HG-induced HK-2 cells, while increasing the levels of non-oxidized lipid ROS, SOD, GSH-Px, SLC7A11, and GPX4. Meanwhile, naringenin restored the levels of MMP, ATP and MPTP opening, reduced OCR in HG-induced HK-2 cells. Furthermore, naringenin reversed the decreased expression of SIRT1, p-FOXO3a, Nrf2 and Nuclear Nrf2 caused by HG. SIRT1 inhibitor EX527 and Nrf2 inhibitor ML385 attenuated the effects of naringenin on ferroptosis in HG-induced HK-2 cells, with EX527 demonstrating a stronger reversal effect on ferroptosis than ML385. These results suggest that naringenin inhibits ferroptosis in HG-induced HK-2 cells mainly through SIRT1/FOXO3a signaling pathway. This finding further enhanced our understanding of the mechanism behind naringenin's protective effect on DN.