Effect of Uncaria tomentosa aqueous extract on the response to palmitate- induced lipotoxicity in cultured skeletal muscle cells

Abstract

Abstract Introduction: Type 2 diabetes mellitus (T2DM) is frequently associated with dyslipidemia, which corresponds to the increase in the triglycerides and fatty acid concentrations in tissues, such as the skeletal muscle. The use of herbal medicines as Uncaria tomentosa (Ut) has been proposed as an auxiliary treatment for patients with T2DM. In this study, it was evaluated the Ut aqueous extract effect on cell viability of skeletal myoblasts from C2C12 lineage exposed to the free fatty acid palmitate (PA), and on the reactive oxygen species (ROS) production, which consists a central event involved in T2DM pathogenesis. Methods: Cells were cultured in Dulbecco's modified Eagle's medium (DMEM), supplemented with 10% fetal bovine serum (FBS), at 37°C humidified atmosphere and 5% CO2. The cells were incubated with PA in different concentrations, in the presence or absence of 250 μg/ml Ut aqueous extract, for 2, 6 or 24 h. After these periods, oxidative stress was evaluated by fluorescence spectroscopy. Results: Incubation of cells with PA and Ut aqueous extract resulted in an increase of, at least, 50% in cell viability compared to control with only PA. The treatment of cells with Ut aqueous extract, for 6 h, followed by exposure to 500 μM PA, caused 38% less ROS formation than those incubated with only the free fatty acid. Conclusion: The Ut aqueous extract promoted a rise in cell viability, reduced cell death and attenuated ROS formation in cultures incubated with 500 μM PA, protecting cells from the fatty acid lipotoxicity.