Protective effects of luteolin on high glucose-induced ferroptosis in müller cells

This study aims to investigate the protective effects of luteolin on Müller cells under high glucose conditions and to elucidate its potential mechanisms of action.

Firstly, Primary rat retinal Müller cells were divided into three groups: a control group (Control), a high glucose group (HG), and a high glucose plus luteolin group (HG + luteolin). To confirm that ferroptosis is indeed involved in cell death, cells were divided into another three groups: Control, HG), and high-glucose + Ferrostatin-1 (HG + Fer-1). Additionally, to further establish ferroptosis as the specific target of luteolin treatment, cells were divided into another three groups: Control, ferroptosis activator (RSL3), and RSL3 + luteolin group (RSL3 + luteolin). Cell apoptosis was assessed using flow cytometry and TUNEL staining. Intracellular levels of reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione (GSH) were quantified with biochemical assay kits. Mitochondrial morphology was examined via transmission electron microscopy. The expression of ferroptosis-related factors xCT and GPX4 was evaluated through quantitative polymerase chain reaction and Western blotting.

The HG group showed increased apoptosis, ROS, MDA, mitochondrial damage and reduced levels of SOD, GSH, xCT and GPX14 compared to the control group. The HG + luteolin group reversed these effects, reducing apoptosis and oxidative stress while restoring mitochondrial health and increasing protective gene expression. Fer-1 inhibits high glucose-induced apoptosis and promotes cellular xCT and GPX4 protein expression. Luteolin inhibited RSL3-induced cellular iron apoptosis and promoted cellular xCT and GPX4 protein expression.

The results demonstrate that high glucose levels induce ferroptosis in Müller cells. Conversely, luteolin intervention has been shown to alleviate high glucose-induced Müller cell damage by inhibiting cellular ferroptosis.