Inhibitory effect of Pulicaria undulata extract on the aggregation and deposition of Aβ 1-42 Fibrils in Alzheimer’s Disease

Abstract

Abstract The accumulation of Amyloid β protein (Aβ) is believed to be the primary cause of neuritic plaque formation in Alzheimer's disease (AD). As a result, it is the main molecular factor responsible for the onset and progression of Alzheimer's disease. Aβ exists in two isoforms: Aβ40, Aβ42. In AD, the extracellular environment of neurons contains amyloid plaques primarily composed of Aβ1−40 and Aβ1−42. Aqueous extract of Pulicaria undulata has shown remarkable antioxidant, antimicrobial, anti-protein fibrillation, and anti-cancer activity. This study examined the effect of an aqueous extract of Pulicaria undulata on the aggregation and deposition of Aβ1−42 fibrils. The findings revealed that the concentration-dependent effect of Pulicaria undulata extract led to a decrease in the aggregation of Aβ1−42. This has been evidenced by analyzing the data obtained through various methods, including thioflavin T (ThT) binding assay, ANS-binding assay, circular dichroism spectroscopy, transmission electron microscopy (TEM), and SDS PAGE. The effect could be associated with the ability of P.undulata extract to form hydrophobic interactions and hydrogen bonds through its phenolic compounds, consequently preventing hydrophobic interactions and amyloid fibril formation. Our finding suggests that amyloid fibril formation can be prevented in degenerative diseases such as Alzheimer's by using P. undulata extract.