Phytochemicals perturb membranes and promiscuously alter protein function.

Area of Science:

• Biochemistry
• Molecular Biology
• Pharmacology

Background:

• Phytochemicals are consumed for health benefits, but their mechanisms are often unclear.
• Phenolic compounds frequently affect membrane protein function, hinting at a common pathway.
• The role of membrane bilayer perturbation in phytochemical activity requires further investigation.

Purpose of the Study:

• To investigate if lipid bilayer perturbation underlies the diverse biological activities of five common phenolic phytochemicals.
• To determine if these phytochemicals commonly affect membrane properties and protein functions.

Main Methods:

• Examined capsaicin, curcumin, EGCG, genistein, and resveratrol.
• Utilized molecular dynamics simulations to observe phytochemical localization and effects on lipid bilayers.
• Employed a gramicidin-based assay to assess bilayer-modifying propensity.
• Tested effects on four distinct membrane proteins: metalloproteases, mechanosensitive ion channels, and voltage-dependent potassium and sodium channels.

Main Results:

• All five tested phytochemicals altered lipid bilayer properties and membrane protein function.
• Molecular dynamics revealed phytochemicals localize at the bilayer/solution interface.
• Phytochemicals demonstrated indiscriminate modulation of diverse membrane proteins.
• Similar functional responses were observed across different proteins and phytochemicals, supporting a common mechanism.

Conclusions:

• The study provides evidence for a common, membrane bilayer-mediated mechanism of action for diverse phenolic phytochemicals.
• Observed effects are likely due to perturbations of the cell membrane rather than specific protein interactions.
• This finding offers a new perspective on the biological activities and health benefits of widely consumed phytochemicals.