Phytol loaded PLGA nanoparticles ameliorate scopolamine-induced cognitive dysfunction by attenuating cholinesterase activity, oxidative stress and apoptosis in Wistar rat

OBJECTIVE

Alzheimer's disease (AD) is an acquired neurological disorder of cognitive and behavioral impairments, with a long and progressive route. Currently, efforts are being made to develop potent drugs that target multiple pathological mechanisms that drive the successful treatment of AD in human beings. The development of nano-drug delivery systems has recently emerged as an effective strategy to treat AD.

METHODS

In the present study, the protective effect of Phytol and Phytol loaded Poly Lactic-co-Glycolic Acid nanoparticles (Phytol-PLGANPs) were evaluated in Wistar rat scopolamine model of AD.

RESULTS AND DISCUSSION

The consumption of Phytol and Phytol-PLGANPs significantly ameliorated the cognitive deficits caused by scopolamine on spatial and short term memory. Phytol and Phytol-PLGANPs significantly enhanced the cholinergic effect by inhibiting both acetylcholinesterase and butyrylcholinesterase (AChE & BuChE), β-secretase 1 (BACE1) activity, attenuating macromolecular damage, reducing reactive oxygen species (ROS) and reactive nitrogen species (RNS) level by activating antioxidative defense system (Superoxide dismutase and catalase) and restoring glutathione metabolizing enzyme systems (Glutathione S-transferase) and also regulating the apoptotic mediated cell death. Moreover, in vivo toxicity study suggests that Phytol and Phytol-PLGANPs did not cause any adverse pathological alteration in rats treated with a higher concentration of Phytol-PLGANPs (200 mg/kg). Pharmacokinetic study revealed that Phytol-PLGANPs enhanced the biodistribution and sustained the release profile of phytol in the brain and plasma.

CONCLUSION

Overall, the outcome of the study suggests that Phytol and Phytol-PLGANPs act as a potent candidate with better anti-amnesic effects and multi-faceted neuroprotective potential against scopolamine-induced memory dysfunction in Wistar rats.

Phytol loaded PLGA nanoparticles regulate the expression of Alzheimer's related genes and neuronal apoptosis against amyloid-β induced toxicity in Neuro-2a cells and transgenic Caenorhabditis elegans

Amyloid β (Aβ) induced neurotoxicity has been postulated to initiate synaptic loss and subsequent neuronal degeneration in Alzheimer's disease (AD). The nanoparticles based drug carrier system is considered as a promising therapeutic strategy to combat this incurable disease. It was also found to inhibit cholinesterase activity and apoptosis mediated cell death in Neuro-2a cells. The in vivo study further revealed that the Phytol and Phytol-PLGA NPs (Poly Lactic-co-Glycolic Acid Nanoparticles) was found to increase the lifespan, chemotaxis behavior and decrease Aβ deposition & ROS (Reactive oxygen species) production in transgenic Caenorhabditis elegans models of AD (CL2006, CL4176). Phytol and Phytol-PLGA NPs treatment downregulated the expression of AD associated genes viz Aβ, ace-1 and hsp-4 and upregulated the gene involved in the longevity to nematodes (dnj-14) and it also reduced the expression of Aβ peptide at the protein level. Our results of in vitro and in vivo studies suggest that Phytol and Phytol-PLGA NPs hold promising neuroprotective efficacy and targets multiple neurotoxic mechanisms involved in the AD progression.