Identification of molecular changes in organs of obese rats following transcranial direct current stimulation (tDCS) - studies by FTIR microspectroscopy and chemometrics.

Due to increasing prevalence of obesity new safe and non-invasive therapies are sought to cope with the epidemic. Transcranial direct current stimulation (tDCS) is a neurostimulation technique that targets both the cortical and deeper brain structures. Both experimental studies and clinical research suggest the effectiveness of tDCS in suppressing appetite and reducing body mass. Therefore, to boost current knowledge on possible biochemical mechanisms underlying biological action of tDCS we determined the effects of tDCS on structural changes of lipids and proteins in key organs in obese rodents. For this purpose, Fourier transform infrared spectroscopy (FTIR) involving microscopic or horizontal attenuated total reflectance (HATR) sampling modes was applied. In order to complement the intergroup comparisons, principal component analysis (PCA) and receiver operator characteristics (ROC) analysis were utilized. Our study revealed that eight days of daily anodal tDCS (atDCS) induced immediate alterations in hepatic metabolism, but not in white adipose tissue (WAT). Furthermore, atDCS led to a significant reduction in lipid content in the renal medulla and renal pelvis. No substantial or interpretable changes were observed in cardiac and skeletal muscle tissues. These findings indicate that, based on the observed effects in these specific organs, atDCS may be a promising approach for restoring biomolecular parameters, particularly in the liver and kidney, and thus serves as a potential therapeutic method for addressing obesity-related conditions.