Effects of arbutin on glucose uptake by glucose transporter 4 (GLUT4) and its cytoprotective properties in L6 skeletal muscle cell line.

ABSTRACT

It has been well known that oxidative stress and increased intracellular reactive oxygen species (ROS) have a pivotal role in disrupting the insulin signaling pathways leading to cellular insulin resistance. In this study, we evaluated arbutin's effects on glucose uptake by GLUT4 and cytoprotective properties in the L6 skeletal muscle cell line. The effect of arbutin and tertiary butyl hydrogen peroxide (t-BHP) on glucose uptake in cultured L6 cells was investigated by flow cytometry. We also evaluated gene expression levels of GLUT1 and GLUT4 in the L6 cells by quantitative real-time polymerase chain reaction analysis. The results from the study demonstrated that the optimum ROS generation occurred 3 h after 100 µM t-BHP treatment and pretreatment with arbutin (500 and 1000 µM) significantly inhibited the t-BHP induced ROS generation (p < .05). Our result indicated that 3 h pretreatment of L6 cells with 1000 µM of arbutin before 50 µM t-BHP significantly increased glucose uptake than the 50 µM t-BHP alone group (p < .05). Our findings may suggest that an increase in the uptake of 2-NBDG by L6 cells with arbutin pretreatment can be associated with increased expression of GLUT4 and GLUT1 under oxidative stress.