Neuroprotective effects of photobiomodulation by hormesis on scopolamine induced neurodegenerative diseases of memory disorders in rats a paradigm shift.

The loss and progressive dysfunction of neurons are hallmarks of neurodegenerative diseases. The aim of the current study is to explore the effects of photobiomodulation at 460-660 nm (100-1000 lux units) on the progression of scopolamine-induced cognitive dysfunctions in Wistar male rats. Photobiomodulation (PBM) is defined as "the use of monochromatic or quasi-monochromatic light from a low-power laser or light-emitting diode (LED) source to modify or modulate biological functions." Neuroprotective activity was assessed by in vivo models such as the Morris water maze, the elevated plus maze (EPM), and the T-maze. After using scopolamine (1 mg/kg/day) as a dementia induction model for 21 days, the induction was primarily due to impairments in cholinergic transmission, oxidative stress, and inflammation. The in vitro determinations, including acetylcholinesterase (AChE), butyrylcholinesterase (BChE), reduced glutathione (GSH), malondialdehyde (MDA), superoxide dismutase (SOD), tumor necrosis factor-alpha (TNF-α), Interleukin 1 beta (IL-1β), and alkaline phosphatase (ALP), were assessed biochemicals and biomarkers. The structural and morphological integrity of the cortex and hippocampus was investigated through histopathology. In vivo studies of exteroceptive behavior models such as the Morris water maze, the EPM, and the T-maze revealed that administration of scopolamine resulted in enhanced escape latency time (ELT), transfer latency (TL), and decreased percentage alternation, respectively. The levels of AChE, BChE, reduced, GSH, SOD, TNF-α, IL-1β and ALP were increased, while MDA level was decreased. In contrast to normal and control groups with treatment groups, histopathology of the cortex and hippocampus examination revealed the maintenance of structural integrity and densities of CA1 and CA3 neuronal cells. However, network pharmacology predicted Ca modulation of various pathways, among the treatments with red LED light showed highly significant amelioration compared with normal and control groups. Photobiomodulation by hormesis, chromophores in cells, and tissues excitation can influence neuroprotective effect mainly by scavenging of ROS, variation in the level of GSH MDA and SOD mitochondrial electron transfer, the improved abscopal effects on improved in gut microbiome by resembles the of fecal ALP level correlation of intestinal microbiome, cholinergic neurotransmissions, anti-inflammatory, and antioxidant activities.