Baicalein Reduces Liver Injury Induced by Myocardial Ischemia and Reperfusion

Baicalein is a component of the root of Scutellaria baicalensis Georgi, which has traditionally been used to treat liver disease in China. In the present study, we investigated baicalein' ability to reduce the liver injury induced by myocardial ischemia and reperfusion (I/R). Myocardial I/R was induced in this experiment by a 40min occlusion of the left anterior descending coronary artery and a 3h reperfusion in rats. The induced myocardial I/R significantly increased the serum levels of aspartate transaminase (AST) and alanine transaminase (ALT), indicating the presence of liver injury. Hepatic apoptosis was significantly increased. The serum levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) were significantly elevated, as was the TNF-α level in the liver. Intravenous pretreatment with baicalein (3, 10, or 30mg/kg) 10min before myocardial I/R significantly reduced the serum level increase of AST and ALT, apoptosis in the liver, and the elevation of TNF-α, IL-1β, and IL-6 levels. Moreover, baicalein increased Bcl-2 and decreased Bax in the liver. Phosphorylation of the prosurvival kinases, including Akt and extracellular signal-regulated kinases 1 and 2 (ERK1/2), was also increased. In conclusion, we found that baicalein can reduce the liver injury induced by myocardial I/R. The underlying mechanisms are likely related to the inhibition of the extrinsic and intrinsic apoptotic pathways, possibly via the inhibition of TNF-α production, the modulation of Bcl-2 and Bax, and the activation of Akt and ERK1/2. Our findings may provide a rationale for the application of baicalein or traditional Chinese medicine containing large amounts of baicalein to prevent liver injury in acute myocardial infarction and cardiac surgery.