Inhibition of oxidative stress and autophagy by arbutin in lipopolysaccharide-induced myocardial injury

Background: Sepsis is a syndrome characterized by a systemic inflammatory response. Arbutin (Ar) is an active natural product known for its bactericidal and anti-inflammatory effects. Many studies have reported the diverse pharmacological actions of Ar, but there is no relevant research on the effect of Ar on lipopolysaccharide (LPS)-induced myocardial injury. Objective: The purpose of this study was to investigate the effect of Ar on LPS-induced myocardial injury and its underlying mechanisms. Materials and Methods: The levels of tumor necrosis factor alpha, interleukin 6, cardiac troponin-I, and procalcitonin were detected by ELISA. The levels of phosphorylated c-Jun N-terminal kinase (p-JNK), phosphorylated extracellular regulated protein kinase (p-ERK), and phosphorylated p38 (p-p38) proteins were detected by flow cytometry using Cytometric Bead Array. Western blot was used to detect the expression of autophagy-related and estrogen receptor (ER)-associated proteins. Levels of the oxidative stress-related markers were detected by the cuvette assay. Results: The levels of the inflammatory factors, LC3B, malondialdehyde, p-JNK, and p-p38 were increased in LPS-treated rats, while the ERK, total superoxide dismutase, glutathione peroxidase, p62, and ER-associated proteins were decreased. These effects could be effectively reversed by Ar, which could be blocked by ER antagonist ICI182780. Our previous study found Ar to possess an estrogen-like activity. Conclusion: Ar inhibits the oxidative stress and autophagy and offers protection from the LPS-induced myocardial injury via the ER pathway.