Low-level laser therapy ameliorates disease progression in a mouse model of multiple sclerosis

Abstract

Multiple sclerosis (MS) is an autoimmune demyelinating inflammatory disease characterized by recurrent episodes of T cell-mediated immune attack on central nervous system (CNS) myelin, leading to axon damage and progressive disability. The existing therapies for MS are only partially effective and are associated with undesirable side effects. Low-level laser therapy (LLLT) has been clinically used to treat inflammation, and to induce tissue healing and repair processes. However, there are no reports about the effects and mechanisms of LLLT in experimental autoimmune encephalomyelitis (EAE), an established model of MS. Here, we report the effects and underlying mechanisms of action of LLLT (AlGaInP, 660 nm and GaAs, 904 nm) irradiated on the spinal cord during EAE development. EAE was induced in female C57BL/6 mice by immunization with MOG35-55 peptide emulsified in complete Freund's adjuvant. Our results showed that LLLT consistently reduced the clinical score of EAE and delayed the disease onset, and also prevented weight loss induced by immunization. Furthermore, these beneficial effects of LLLT seem to be associated with the down-regulation of NO levels in the CNS, although the treatment with LLLT failed to inhibit lipid peroxidation and restore antioxidant defense during EAE. Finally, histological analysis showed that LLLT blocked neuroinflammation through a reduction of inflammatory cells in the CNS, especially lymphocytes, as well as preventing demyelination in the spinal cord after EAE induction. Together, our results suggest the use of LLLT as a therapeutic application during autoimmune neuroinflammatory responses, such as MS.

Low‐level light emitting diode (LED) therapy suppresses inflammasome‐mediated brain damage in experimental ischemic stroke

“…Several reports have demonstrated the anti‐inflammatory effects of light therapy in CNS diseases. When low‐level laser therapy (660 nm and 904 nm) was applied to experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis, the infiltration of mononuclear cells into the CNS was blocked . CNS demyelination was inhibited and the production of pro‐inflammatory cytokines such as IL‐17, IFN‐γ and IL‐1β was decreased .…”

“…When low‐level laser therapy (660 nm and 904 nm) was applied to experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis, the infiltration of mononuclear cells into the CNS was blocked . CNS demyelination was inhibited and the production of pro‐inflammatory cytokines such as IL‐17, IFN‐γ and IL‐1β was decreased . Low‐level laser therapy also reduced pro‐inflammatory cytokines IL‐1β, TNF‐α, TGF‐β and amyloid β plaques in a mouse model of Alzheimer's disease .…”

Laser Light Therapy in Inflammatory, Musculoskeletal, and Autoimmune Disease

“…LLLT has been studied in central nervous system disease as an adjunct therapy for diseases including Alzheimer's in mouse models, as well as neurologic deficits related to stroke and traumatic brain injury in rats and rabbits [78][79][80][81][82]. It has also shown promising anti-inflammatory effects in immune-mediated diseases as discussed above, making LLLT a potential therapy for MS. [83]. In this study, the two laser wavelengths tested (660 nm, 904 nm) reduced the NO influx seen in the spinal cord with EAE induction (p < 0.01) and markedly inhibited clinical signs of disease and EAE-associated weight loss, a clinical marker for disease severity and deterioration.…”

Effect of photobiomodulation treatment in the sublingual, radial artery region, and along the spinal column in individuals with multiple sclerosis

“…In vitro and in vivo studies have demonstrated that photobiomodulation is effective for inflammatory diseases, including MS. [ 15 ] This therapeutic modality has a broad range of benefits, such as the avoidance of cell and tissue death, the stimulation of healing and injury repair, reductions in pain, edema and inflammation, cell proliferation, and even apoptosis. [ 15 , 16 ] The outcomes of photobiomodulation include the regeneration of cells, the stimulation of the growth of Schwann cells, a reduction in spasticity, functional improvements, a reduction in nitric oxide levels, and the upregulation of the cytokine IL10, demonstrating that this therapeutic modality can offer neuroprotection. [ 15 , 17 ]…”

“…[ 15 , 16 ] The outcomes of photobiomodulation include the regeneration of cells, the stimulation of the growth of Schwann cells, a reduction in spasticity, functional improvements, a reduction in nitric oxide levels, and the upregulation of the cytokine IL10, demonstrating that this therapeutic modality can offer neuroprotection. [ 15 , 17 ]…”