Effect of Low-Frequency, Low-Energy Pulsed Electromagnetic Fields in Injured Neuronal and Microglial Models of Alzheimer's Disease

Abstract: Alzheimer's disease (AD) is a neurodegenerative pathology covering about 70% of all cases of dementia. This pathology is associated with neuroinflammation and neuronal cell death, which are involved in disease progression. A lack of effective therapies exists and halting this process represents a therapeutic challenge. Literature data suggest several neuroprotective effects of low-frequency, low-energy pulsed electromagnetic fields (PEMFs) on biological systems and clinical studies report that PEMFs stimulation is safe and well tolerated. The aim of this work is to investigate the effects of PEMFs exposure in in vitro injured cellular models of neurons and microglia on oxidative stress and cell death. SH-SY5Y cells were stimulated by H2O2 or amyloid beta (Aβ) peptide and N9 microglial cells were activated with LPS or Aβ peptide. Reactive oxygen production, mitochondrial integrity and cell death modulation were investigated through H2DCFDA and JC1 biochemical assays, fluorescence and MTS experiments. Cells were exposed to PEMFs which produced a pulsed signal with the following parameters: pulse duration of 1.3 ms and frequency of 75 Hz. The outcomes demonstrated that PEMFs defended SH-SY5Y cells against Aβ peptide or H2O2-induced oxidative stress, mitochondrial damage, and cell death. Furthermore, in microglia activated by LPS or Aβ peptide, they reverted the reduction of mitochondrial potential, oxidative damage and cell death. Overall, these findings imply that PEMFs influence the redox state of the cells by significantly boosting antioxidant levels in both AD microglia and neuronal in vitro models.