Rvs could be better analgesics than anti-inflammatory drugs
The identification of specialised pro-resolving lipid mediators (SPMs) changed our understanding of the inflammatory response process. It is no longer considered a passive but rather an active process involving resolving compounds, SPMs, of which there are a number of families: lipoxins (LX), derived from an omega-6 polyunsaturated fatty acid (n-6 PUFA), arachidonic acid (AA), and resolvins (Rv), protectins (PD) and maresins (MaR), derived from n-3 PUFAs (mainly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)). Many conditions associated with alleviating inflammatory signs and symptoms are related to SPMs, including inhibition of the traffic and excessive activation of neutrophils, stimulation of efferocytosis by macrophages and promotion of anti-angiogenic, antifibrotic and anti-infectious responses. The anti-inflammatory and pro-resolving actions of different SPMs are not equivalent. Each SPM has a unique structure and function and acts at a different moment in the resolution process.
The therapeutic treatment of inflammation usually involves inhibition of proinflammatory mediators, but in many cases this approach is ineffective. Recognising the proactive nature of inflammation resolution opens up alternative therapeutic paradigms based on resolving the acute phase of inflammation and preventing the onset of chronic inflammation.
Fonseca et al. have recently shown in murine inflammation and pain models that exogenous administration of RvE1 (derived from EPA) and RvD1 (derived from DHA), separately, have anti-inflammatory and analgesic effects (while protectin DX (PDX, a DHA-derived PD1 isomer) was shown to be inactive in the same situations). RvE1 and RvD1 have different activity profiles and E1 appears to be twice as potent as D1, while both tended to be better analgesics than the anti-inflammatory drugs to which they were compared (non-steroidal: indomethacin and celecoxib; steroids: dexamethasone).
Rvs could be better analgesics than the anti-inflammatory drugs commonly used to alleviate inflammation-related pain. Their therapeutic potential could be very useful and widely usable in numerous chronic inflammatory diseases.
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