ABSTRACT
Radiofrequency electromagnetic field (RF-EMF) is used globally in conjunction with mobile communications. There are public concerns of the perceived deleterious biological consequences of RF-EMF exposure. This study assessed neuronal effects of RF-EMF on the cerebral cortex of the mouse brain as a proxy for cranial exposure during mobile phone use. C57BL/6 mice were exposed to 835 MHz RF-EMF at a specific absorption rate (SAR) of 4.0 W/kg for 5 hours/day during 12 weeks. The aim was to examine activation of autophagy pathway in the cerebral cortex, a brain region that is located relatively externally. Induction of autophagy genes and production of proteins including LC3B-II and Beclin1 were increased and accumulation of autolysosome was observed in neuronal cell bodies. However, proapoptotic factor Bax was down-regulted in the cerebral cortex. Importantly, we found that RF-EMF exposure led to myelin sheath damage and mice displayed hyperactivity-like behaviour. The data suggest that autophagy may act as a protective pathway for the neuronal cell bodies in the cerebral cortex during radiofrequency exposure. The observations that neuronal cell bodies remained structurally stable but demyelination was induced in cortical neurons following prolonged RF-EMF suggests a potential cause of neurological or neurobehavioural disorders.
Subject(s)
Autophagy/radiation effects , Cerebral Cortex/radiation effects , Hyperkinesis , Myelin Sheath/radiation effects , Neurons/radiation effects , Radio Waves , Animals , Beclin-1/metabolism , Beclin-1/radiation effects , Cerebral Cortex/metabolism , Cerebral Cortex/ultrastructure , Male , Mice, Inbred C57BL , Microtubule-Associated Proteins/metabolism , Microtubule-Associated Proteins/radiation effects , Neurons/metabolism , Neurons/ultrastructure , Proto-Oncogene Proteins c-bcl-2/metabolism , Proto-Oncogene Proteins c-bcl-2/radiation effects , bcl-2-Associated X Protein/metabolism , bcl-2-Associated X Protein/radiation effectsABSTRACT
Luteolin (LUT) is a flavone, which is universally present as a constituent of traditional Chinese herbs, and certain vegetables and spices, and has been demonstrated to exhibit potent radical scavenging and cytoprotective properties. Although LUT has various beneficial effects on health, the effects of LUT on the protection of skin remain to be fully elucidated. The present study investigated whether LUT can protect human skin fibroblasts (HSFs) from ultraviolet (UV) A irradiation. It was found that, following exposure to different doses of UVA irradiation, the HSFs exhibited autophagy, as observed by fluorescence and transmission electron microscopy, and reactive oxygen species (ROS) bursts, analyzed by flow cytometry, to differing degrees. Following incubation with micromolar concentrations of LUT, ROS production decreased and autophagy gradually declined. In addition, the expression of hypoxiainducible factor1α and the classical autophagyassociated proteins, LC3 and Beclin 1 were observed by western blotting. Western blot analysis showed that the expression levels of HIF1α, LC3II and Beclin 1 gradually decreased in the UVAirradiated HSFs following treatment with LUT. These data indicated that UVAinduced autophagy was mediated by ROS, suggesting the possibility of resistance against UV by certain natural antioxidants, including LUT.