Betaine Attenuates High‐Fat‐Diet‐Induced Metabolism‐Associated Steatotic Liver Disease via the Inhibition of Ferroptosis Through the Nrf2/GPX4 Axis

Metabolism-associated steatotic liver disease (MASLD) encompasses a broad spectrum of liver disorders characterized by systemic metabolic imbalance, and its prevalence is increasing. Current therapeutic strategies are limited, highlighting the need for novel interventions. Ferroptosis has emerged as a significant factor in MASLD pathogenesis, suggesting a potential target for therapeutic development. A MASLD model was established in mice via a high-fat diet. The mice in the betaine-supplemented group were fed a diet containing 0.3% (w/w) betaine from the start of the intervention. Metabolic indicators, liver histology, and ferroptosis markers, such as lipid peroxidation and iron homeostasis, were evaluated. In vitro, AML12 cells were cultured with palmitic acid to mimic a high-fat environment, and the preventive effects of betaine on ferroptosis markers were assessed. To further validate the antiferroptotic actions of betaine, erastin was used in both in vivo and in vitro models. In this study, betaine attenuated HFD-induced hepatic steatosis, effectively reducing lipid peroxidation and iron accumulation both in vivo and in vitro. Furthermore, betaine also counteracted erastin-induced hepatocyte ferroptosis. Mechanistic investigations revealed the activation of the Nrf2/GPX4 axis by betaine, elucidating its antiferroptotic mechanism. This study provides preliminary evidence that, in an early-stage, preventive murine model, betaine could ameliorate hepatic steatosis by limiting ferroptosis, in association with Nrf2 pathway activation. These findings suggest the ferroptosis-Nrf2 axis as a potential target for preventive strategies and warrant further evaluation in advanced disease models and clinical settings.