18 research outputs found
The Anti-amyloidogenic effect of natural product extracts on amyloid-like fibril formation of trypsin in aqueous organic solvents
The formation of amyloid fibrils has been associated with several human diseases. The
appearance of amyloid aggregation is an indicator of different central nervous system neurological
disorders and neurodevelopmental diseases, which affect the brain and peripheral tissues. The
misfolding and aggregation of proteins cause a large number of different neurodegenerative
diseases. Amyloid is a generic structural form of the polypeptide chain and most proteins can form
amyloid-like fibrils under proper conditions.
Natural product extracts contain important bioactive compounds without undesirable side
effects, which are necessary for the prevention and cure of various diseases. 52 phenolic
compounds were identified in culinary herbs and spices. The aromatic rings of polyphenols may
competitively interact with aromatic residues in amyloidogenic proteins, prevent the π-π
interaction and block the self-assembly process.
The phenolic hydroxyls of polyphenols may inhibit amyloid fibril formation via binding
the hydrophobic residues in amyloidogenic proteins. Here we report the inhibitory effect of some
natural product extracts on the formation of amyloid fibrils using trypsin as a model protein in
aqueous ethanol. Inhibition of aggregation and fibrillation of trypsin was determined based on
turbidity measurement, aggregation kinetics assay, amyloid specific dye Congo red (CR), fouriertransformed infrared (FTIR) spectroscopy, electronic circular dicroism (ECD) and transmission
electron microscopy (TEM). The experiments revealed that great anti-fibrillation activity was
exerted by chili extract, P. ginseng extract, grapefruit seed extract, peppermint extract, Eduscho
coffee extract, and Egri bikavér red wine. It was found that the amount of fibril formation was greatly reduced with increasing concentration of extracts and the inhibitory effect is dose-dependent
Among Commercially Available Fruit Juices, Pomegranate Is the Most Effective Inhibitor of PMS-Trypsin Amyloid-Like Fibrils Formation
Inhibition of the formation of amyloid-like fibrils with spices, especially cloves
During the study of inhibition of amyloid fibril formation, α-chymotrypsin protein was developed in 55% ethanol at pH 7.0. We investigated the inhibitory effect of different spices on amyloid fibril formation using turbidity measurements and Congo red binding assays. We found that all spices except the black pepper and caraway seed prevented fibril formation. The highest inhibition was measured with the clove, which reduced the amount of aggregates by 90%. We studied the inhibitory effect of the cloves at different concentrations on aggregation, it was found that the inhibitory activity of clove is dependent on concentration. We have measured the total phenolic content of the spice extracts too. Based on all these findings we have come to the following conclusion: Our results indicate that spices can contain other compounds too – not only phenolic compounds – which influence the formation of amyloid fibrils, and the effectiveness of various phenolic compounds are different
Eduscho coffee extract effectively inhibits the formation of amyloid-like fibrils by trypsin in aqueous ethanol
Inhibition of the formation of amyloid-like fibrils using herbal extracts
We tested the amyloid fibril formation inhibitory effect of seven teas diluted in 55% ethanol at pH 7.0 at a protein concentration of 0.15 mg/ml α-chymotrypsin. In the experiments we investigated the formation and inhibition of amyloid fibrils by turbidity measurements, aggregation kinetics experiments and Congo red binding assay. The results suggest that the different teas effectively inhibit the formation of amyloidlike fibrils. The two most potent inhibitors were peppermint and melilot, extracts which almost completely inhibited the formation of aggregates in 5-fold dilution. The inhibitory effect on the aggregation formation of melilot and peppermint extracts was concentration dependant. The extent of inhibition was found to be proportional with the total concentration of phenolic compounds
Grapefruit Seed Extract Inhibits the Formation of Amyloid-like Fibrils by Trypsin in Aqueous Ethanol
Several natural compounds deriving from plants are known to be efficient anti-amyloid aggregation agents. In this study, anti-aggregation activity of grapefruit seed extract was investigated using trypsin as a model protein in aqueous ethanol at pH 7.0. Using turbidity measurement, Congo red (CR) binding assay, electronic circular dichroism (ECD) and transmission electron microscopy (TEM), we found that grapefruit seed extract has ability to inhibit trypsin amyloidlike fibril formation in vitro, and effectiveness increases with growing concentration of grapefruit seed extract. The total phenolic content of it was determined. The results showed that in addition to the polyphenolic compounds some other compounds are also responsible for the fibril formation inhibitory effect. We indicated it for the first time that limonin has anti-fibrillation effect