RESUMEN
Hepatic ischemia/reperfusion (IR) injury is a complication that occurs during liver surgery, whereby hepatic tissue is injured by oxygen deficiency during ischemia, then further damaged by a cascade of inflammatory and oxidative insults when blood is resupplied during reperfusion. Antrodia camphorata is an indigenous fungus in Taiwan and an esteemed Chinese herbal medicine with various bioactivities. This study examined the effect of ergostatrien-3ß-ol (EK100), an active compound found in both the fruiting body and mycelia of A. camphorata, on IR injury pathologies in rats and cell models of oxidative and inflammatory stress. Male Sprague-Dawley rats were randomly assigned to receive a vehicle or 5 mg/kg EK100 prior to hepatic IR injury induced by 1 h ischemia followed by 24 h reperfusion, or a sham operation. RAW 264.7 murine macrophages and HepG2 hepatocytes were pretreated with EK100, then inflammation was induced with lipopolysaccharides in the former and oxidative stress was induced with hydrogen peroxide in the latter. EK100 decreased IR-induced elevation in serum levels of alanine aminotransferase and aspartate aminotransferase and lowered levels of the inflammatory cytokines tumor necrosis factor-α, interleukin (IL)-6, and IL-1ß. In addition, EK100 significantly reduced hepatic mRNA levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2, as well as nitrite production and iNOS gene expression in both hepatocyte and macrophage cell lines. We demonstrated that EK100 exhibits potent protec-tion against hepatic IR injury, which may be used to design strategies to ameliorate liver damage during liver surgery.
RESUMEN
A growing body of evidence demonstrates obesity-induced insulin resistance is associated with the development of metabolic diseases. This study was designed to investigate ethyl acetate fraction of Chinese olive fruit extract (CO-EtOAc)-mediated attenuation of obesity and hyperglycemia in a mouse model. About 60% HFD-fed mice were treated intragastrically with CO-EtOAc for last 6 weeks, and body weight, blood biochemical parameters as well as hepatic inflammation response were investigated. Our results showed that CO-EtOAc treatment significantly reduced the formation of hepatic lipid droplets, body weight gain, blood glucose, and improved serum biochemical parameters in HFD-induced obese and insulin resistant mice. We further explored the molecular mechanism underlying the blood glucose modulating effect of CO-EtOAc using L6 myotubes model. We conclude that CO-EtOAc effectively increases the glycogen content and glucose uptake by stimulating the membrane translocation of glucose transporter 4. In addition, CO-EtOAc depolarizes the mitochondrial membrane and decreases the mitochondrial oxygen consumption, which may result in AMPK activation and the consequent mitochondrial fission. This study shows that CO-EtOAc prevents the development of obesity in mice fed with HFD and is also capable of stimulating glucose uptake. The possible mechanism might be due to the effects of CO-EtOAc on activation of AMPK and promotion of mitochondrial fission.