👤 Shabana U Simjee

Alzheimer's disease (AD) is the most common type of dementia with a complex pathobiology. The clinically approved treatments against AD attempt to provide only symptomatic relief. Therefore, the current findings highlighted the neuroprotective effect and the potential signaling mechanism of quinic acid (1) and its amide derivatives (2-4) against phytohaemagglutinin (PHA)-induced neurotoxicity. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was conducted to assess the proliferative potential of 1-4 which were observed to increase the viability of SH-SY5Y cells. Microscopic examination of the cells induced with PHA and post treated with the respective test compound showed that 1 as well as its derivatives (2-4) improved morphology of the cells and subside the toxic effects of PHA. Evaluation of reactive oxygen species (ROS) production demonstrated that the test compounds except 4 decreased PHA-induced ROS in SH-SY5Y cells. The mRNA expression analysis of IL-1β, TNF-α, p38-α, p38-β and the disease associated ADAM10 and BACE1 genes revealed that 1 and its derivatives (2-4) reduced the PHA-induced elevated levels of inflammatory molecules whereas the compounds did not positively modulate the expression of proteolytic secretases. Moreover, the compounds reduced the disease specific increased expression of amyloid beta (Aβ), phosphorylated tau and activated p38 MAPK observed through fluorescence microscopy. Show less

Alzheimer's disease (AD) is a multifactorial,neurodegenerative disorder linked withextracellular amyloid beta (Aβ) plaques deposition and formation of intracellular neurofibrillary tangles (NFTs). Currently, no effective therapies are available to cure AD. Neuroinflammation isa well-known hallmark in the onset and advancement of AD and triggering receptor expressed on myeloid cells-2 (TREM-2), a microglial gene, is responsible for regulating inflammatory responses and clearance of cellular debris. Loss of TREM-2functionincreases neuroinflammation associated expression of pro-inflammatory markersthus resultingin reduced clearance of Aβ that further aid in disease progression.Therefore, targeting neuroinflammation is a good therapeutic approach for AD. This study aimed to determine the neuroprotective effect of nicotinic acid (NA) in vitro model of AD-like pathology induced in F-98 cell line using Phytohemagglutinin (PHA). MTT assay was employed for checking the cell viability as well as the proliferation of the cells following treatment with NA. PHA at the concentration of 10 μg/mL produces maximum plaques. The neuroprotective effect of NA was next evaluated against PHA-induced plaques and it was observed that NA reverses the damages induced by PHA i.e., by inhibiting the clustering of the cells and replacing the damaged cells with the new ones. Further, NA also increased the expression of TREM-2/DAP-12 with parallel decreased in the expression of IL-1β, TNF-α and iNOS. It also successfully altered disease associated ADAM-10 and BACE-1 compared to PHA control. These findings suggest that NA might be considered as a good therapeutic candidate for the treatment of neurodegenerative disorders like AD. Show less