Resolving inflammation by using nutrition therapy: roles for specialized proresolving mediators

Abstract

Purpose of review: Inflammation is a unifying component of many of the diseases that afflict Western civilizations. Nutrition therapy and, in particular, essential fatty acid supplementation is one of the approaches that is currently in use for the treatment and management of many inflammatory conditions. The purpose of the present review is to discuss the recent literature in light of the discovery that essential fatty acids are converted by the body to a novel genus of lipid mediators, termed specialized proresolving mediators (SPMs).

Recent findings: The SPM genus is composed of four mediator families - the lipoxins, resolvins, protectins, and maresins. These molecules potently and stereoselectively promote the termination of inflammation, tissue repair, and regeneration. Recent studies indicate that in disease, SPM production becomes dysregulated giving rise to a status of failed resolution. Of note, several studies found that omega-3 fatty acid supplementation, at doses within the recommended daily allowance, led to increases in several SPM families that correlate with enhanced white blood cell responses in humans and reduced inflammation in mice.

Summary: Given the potent biological actions of SPM in organ protection and promoting bacterial clearance, nutritional therapies enriched in omega-3 fatty acids hold promise as a potential co-therapy approach when coupled with functional lipid mediator profiling.

Conflict of interest statement

Conflict of interest:The authors declare no conflict of interest.

Figures

Figure 1. SPM’s are produced in human organs and tissues.

This figure provides a non-exhaustive list of lipid mediator levels identified in inflamed and non-inflamed human tissues including brain (1), cerebrospinal fluid (2, 3), lymph nodes (4), adipose tissues (5), placenta (6), synovial fluids (–9), exhaled breath condensate (10), sputum (11), plasma (4, 12), serum (2, 4, 13), milk (14, 15), spleen (4) and urine (16), along with the ranges that these mediators were identified in each tissue or organ system. The biological actions for the identified mediators with human primary cells are in the femotmolar to nanomolar ranges.

Figure 2. Functional lipid mediator profiling provides a snapshot of the flux down of each of the major bioactive metabolomes.

This figure illustrates three of the four major lipid mediator bioactive metabolomes. Molecules illustrated here represent the flux down of each of the biosynthetic metabolomes from substrate to bioactive mediator to further metabolites, which may or may not retain function. Measuring the levels of these molecules in tissues provides a snapshot of the dynamic biochemical processes occurring at the site and therefore provide an insight into the inflammation-resolution status. Rv = Resolvin, LX = Lipoxin, MaR = Maresin, PD= Protectin, LT = Leukotriene, PG = Prostaglandin and Tx = Thromboxane.