The Effect of Polyphenols on Protein Degradation Pathways: Implications for Neuroprotection

Abstract

Human neurodegenerative diseases are accompanied by accumulation of heavily oxidized and aggregated proteins. However, the exact molecular reason is not fully elucidated yet. Insufficient cellular protein quality control is thought to play an important role in accumulating covalently oxidized misfolded proteins. Pharmacologically active polyphenols and their derivatives exhibit potential for preventive and therapeutic purposes against protein aggregation during neurodegeneration. Although these compounds act on various biochemical pathways, their role in stabilizing the protein degradation machinery at different stages may be an attractive therapeutical strategy to halt the accumulation of misfolded proteins. This review evaluates and discusses the existing scientific literature on the effect of polyphenols on three major protein degradation pathways: chaperone-mediated autophagy, the proteasome and macroautophagy. The results of these studies demonstrate that phenolic compounds are able to influence the major protein degradation pathways at different levels.

Positive correlation between proteasome activity and polyphenols in the telencephalon of adult female mice

“…Contradictory data about age-related proteasome compromise are revised by Dantuma and Bott in accordance with different experimental conditions 20 . The neuroprotective activity of polyphenols depends on their capacity to stabilise degradation machinery and promote quality control of proteins with subsequent increase of lifespan 21 . Accordingly, polyphenols are neurotropic compounds 11 , which showed a positive relation with proteasome in the current work.…”

An Overview of Crucial Dietary Substances and Their Modes of Action for Prevention of Neurodegenerative Diseases

“…Potential toxicities of polyphenols are likely to arise from: (i) pro-oxidant effects connected to their radical-scavenging properties; (ii) excessive biotransformation in the liver; and (3) increased acute stress responses. The pro-oxidant activities of polyphenols can be attributed to the catechol's structure; catechols can generate superoxide anions, which can lead to formation of the quinone counterparts [175].…”

Structure and Functional Properties of Antioxidant Nanoemulsions Prepared with Tea Polyphenols and Soybean Protein Isolate

“…With the increased TP concentration, the ability to reduce DPPH increased and then decreased. The results of a study on the antioxidant capacity of tea polyphenols combined with proteins is presented by Hajieva et al 16 . When the TP concentration was between 0.05 and 0.10 g/100 mL, the DPPH scavenging ability was not significantly changed p 0.05 .…”