Abstract
Inflammation is an essential protective response against injury or infection. Physiological inflammation eliminates the pathogen, promotes tissue repair and healing. An exaggerated, out of control inflammation, however, can become pathological. Inflammation can generate secondary cell damage, inflame the vessels (endothelitis), activate coagulation processes. Among these pathogenetic factors (cell damage, inflammation, endothelitis, coagulopathies), self-amplification mechanisms can be created, spreading beyond the initial site, up to Multiple Organ Failure (MOF) and host death. If the inflammation does not resolve in a physiological way, the remodeling of the tissues can be maladaptive and lead to the onset of chronic inflammatory degenerative diseases. Diseases such as sepsis, burns, polytrauma, severe forms of influenza or COVID-19, are characterized by a condition of hyperinflammation, associated with a condition of immunosuppression. The initial events triggered by the pathogen (cell damage, interferon response in the case of viruses) ignite the inflammation by activating the inflammasome, the transcription factor NFkB, the release of pro-inflammatory eicosanoids (Prostaglandins, Leukotrienes, Thromboxanes) by neutrophils and macrophages. Hence, the cells of the innate immune system produce pro-inflammatory cytokines. Indeed, the ‘’eicosanoid storm’’ precedes the ‘’cytokine storm’’. Eicosanoids are a group of potent endogenous lipid mediators derived from omega-6 fatty acids Arachidonic Acid (AA). Eicosanoids include a group of molecules with pro-inflammatory (Prostaglandins, Leukotriens) and pro-coagulant (Thromboxanes) action. In addition, Arachidonic Acid (AA) is the source of Lipoxins (LXs). Lipoxins belong to a group of molecules collectively referred to as specialized pro-solving mediators (SPMs) which also include molecules derived from w-3 eicosapentaenoic acid (EPA): Resolvins (ReV-E sieres) and w-3 docohexanoic (DHA): Resolvins D-series (ReV D-series); Protectins (PTs); Maresins (MaRs). SPMs are important for the resolution phase of inflammation to take place properly. Their deficiency could be involved in both acute uncontrolled inflammation and chronic inflammation. The active regulation of the acute inflammatory process, integrating the precursors of Specialized Pro-resolving Mediators (SPMs), such as ⍵-6 and ⍵-3 in balanced ratio, or the SPMs themselves, could be a complementary therapeutic approach useful for taming the "storm of cytokines '' which characterizes exaggerated forms of inflammation. ⍵-3 and ⍵-6 are part of already widely used, readily available, inexpensive and safe supplements. Resolvins have already been included in clinical trials for various other inflammatory diseases (eye diseases, periodontal diseases).