Inhibition of Amyloid-like Fibril Formation of Trypsin by Red Wines

Abstract

Abstract:The aim of the present study was to examine the potential role and applicability of dietary supplements in reducing the risk of development of amyloid diseases associated with the gastrointestinal tract, such as type II diabetes. Trypsin, a well-known serine protease was used as a model protein in our experiments. The effect of various red wines on the formation of amyloid-like fibrils of trypsin was studied in vitro, in aqueous ethanol, at pH 7.0. Turbidity measurements, aggregation kinetics experiments, Congo red binding assays and electronic circular dichroism spectroscopic measurements were used to follow the aggregation process in the presence or absence of various red wines. The results suggest that red wines effectively inhibit the formation of amyloid-like fibrils of trypsin and the inhibitory effect is dose-dependent. The extent of inhibition was found to be proportional to the total concentration of phenolic compounds.

Inhibition of the formation of amyloid-like fibrils using herbal extracts

“…Although the sensitivity of the turbidity method is low, it can be a good tool when larger aggregates are formed [21,26]. Fuentes et al also showed results in which peppermint proved to be a good islet amyloid polypeptide amyloid inhibitor [9].…”

“…CR is a well-known amyloid specific dye, which upon binding with the amyloid exhibits increase in absorption with a characteristic red shift [2]. CR specifically binds against β-pleated sheet conformation, and does not bind to the proteins with shorter β-pleated structures [21]. If the fibrils are present in the sample, and CR dye is added, the absorption maximum is displaced from 490 nm to 510 nm.…”

Grapefruit Seed Extract Inhibits the Formation of Amyloid-like Fibrils by Trypsin in Aqueous Ethanol

“…The total phenolic content of the grapefruit seed extract was determined, and it was 495.5 mg GAE/l. Compared to other inhibitory agents the efficiency of inhibition of amyloid formation did not change proportionally with the total phenolic content in the presence of the grapefruit seed extract [24]. It is probable that polyphenolic compounds are not the only responsible factors for the fibril formation inhibitory effect, but also other compounds are involved.…”

Among Commercially Available Fruit Juices, Pomegranate Is the Most Effective Inhibitor of PMS-Trypsin Amyloid-Like Fibrils Formation

“…32,33 An increase in the absorption at 350 nm indicates a greater degree of aggregation. 34 The sample without fruit juice showed maximum absorption whereas in the presence of different juices it was significantly reduced. All the juices we used inhibited aggregation, but their levels of effectiveness were different.…”