Upregulation of Nrf2 signaling and suppression of ferroptosis and NF-κB pathway by leonurine attenuate iron overload-induced hepatotoxicity

Hepatotoxicity is a major health concern that associates the iron overload diseases including hemochromatosis, sickle cell anemia, and thalassemia. Induction of ferroptosis, oxidative stress, and inflammation substantially mediates the iron-evoked hepatotoxicity. The current work investigated the potential protective effect of the natural alkaloid leonurine against the iron-induced hepatotoxicity and elucidated the underlining molecular mechanisms. Male Wistar rats were treated with iron only (30 mg/kg every other day over a ten-day period via intraperitoneal injection) or with iron and leonurine (leonurine: 100 mg/kg/day per oral via gastric gavage for 10 days) to establish the iron-overload model. Liver and blood specimens were then collected and subjected to molecular, biochemical, and histopathological investigations. The results revealed the ability of leonurine to suppress the iron-induced ferroptosis as reflected by modulation of the ferroptotic biomarkers glutathione peroxidase 4, cyclooxygenase-2, liver iron content, lipid hydroperoxides, and the leakage of the liver intracellular enzymes. Leonurine alleviated the iron-induced oxidative damage and inflammatory response in the liver tissues as indicated by decreased levels of DNA oxidation, lipid peroxidation, and the pro-inflammatory cytokines. In the same context, it improved the antioxidant potential of the liver tissues and ameliorated the iorn-induced histopathological abnormalities. Mechanistically, leonurine enhanced nuclear translocation of the antioxidant transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) and increased protein levels of its downstream targets NAD(P)H-quinone oxidoreductase 1 and heme oxygenase-1. Additionally, it suppressed the nuclear translocation of the inflammatory transcription factor nuclear factor kappa B (NF-κB) and downregulated its downstream pro-inflammatory cytokines tumor necrosis factor-alpha and interleukin-1 beta. The study highlights the hepatoprotective activity of leonurine against the iron-evoked hepatotoxicity that is potentially mediated through modulation of Nrf2 and NF-κB signaling.