Fabrízio dos Santos Cardoso
Rodrigo Álvaro Brandão Lopes Martins
Sérgio Gomes da Silva

Abstract Introduction: Alzheimer’s disease (AD) is characterized by the decline of cognitive functions such as learning and memory. Scientific society has proposed some non-pharmacological interventions, among which photobiomodulation has gained prominence for its beneficial effects. Therefore, we investigated, through systematic review, the therapeutic potential of photobiomodulation in AD.Methods: This systematic review was registered under the number CRD۴۲۰۱۹۱۲۸۴۱۶ in the International Prospective Record of Systematic Reviews (PROSPERO). A systematic search was conducted on the bibliographic databases (PubMed and ScienceDirect) with the keywords based on MeSH terms: “photobiomodulation therapy” or “low-level laser therapy” or “LLLT” or “light-emitting diode” and “amyloid” or “Alzheimer”. The data search was conducted from ۲۰۰۸ to ۲۰۱۹. We follow the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. The search strategy included experimental in vivo and in vitro studies in the English language and photobiomodulation as a non-pharmacological intervention. We included ۱۰ studies,being ۵ in vivo studies, ۴ in vitro studies, and ۱ study using in vivo and in vitro. To evaluate the quality of the studies, we used the Rob tool of the Systematic Review Center for Laboratory Animal Experimentation (SYRLE).Results: The studies showed that photobiomodulation is able to reduce the inflammatory response, oxidative stress, and apoptotic effects generated by amyloid-beta (Aβ) and restore mitochondrial function and cognitive behavior.Conclusion: Taken together, these results indicate that photobiomodulation may be a useful tool for treating AD. Keywords: Photobiomodulation therapy; Low-level laser therapy; LLLT; Light emitting diode; Amyloid; Alzheimer’s disease.