Membrane Interactivity of Non-steroidal Anti-inflammatory Drugs: A Literature Review

Background: Although the mode of action of non-steroidal anti-inflammatory drugs (NSAIDs) has been exclusively referred to as inhibition of cyclooxygenase, their broad pharmacological and toxicological spectra are not necessarily interpreted by the direct interaction with such enzyme proteins.

Aims: Since NSAIDs have the common amphiphilic structure, they have the possibility of acting on membrane-constituting lipids. In order to gain insights into the additional mechanism of NSAIDs, we reviewed their membrane interactivity to modify the physicochemical properties of membranes.

Methodology: We retrieved scientific articles from PubMed/MEDLINE, Google Scholar and ACS Publications by searching databases from 1990 to 2019. Research papers published in English in the internationally recognized journals and on-line journals were cited with preference to more recent publications. Collected articles were reviewed by title, abstract and text for relevance.

Results: Results of the literature search indicated that NSAIDs structure-specifically cause the in vitro and in vivo interactions with artificial and biological membranes to change membrane fluidity, lipid phase transition and permeability. The features and potencies of their membrane interactivity vary depending on drug concentration, medium pH and membrane lipid composition. In addition to membrane proteins, NSAIDs act on membrane lipids to exhibit the anti-inflammatory and anti-tumor activity by interacting with lipid bilayer membranes at relatively low concentrations to decrease membrane fluidity and thereby affect the enzymatic activity of membrane-associated proteins and to exhibit the gastrointestinal and cardiovascular toxicity by interacting with membranous phospholipids at relatively high concentrations to increase membrane fluidity and thereby impair the membrane-relevant biofunctions. Other diverse effects of NSAIDs may also be related to their membrane interactions.

Conclusion: NSAIDs share the membrane interactivity common to them as one of possible pharmacological and toxicological mechanisms.