Figure 3.

A – Scheme showing the metabolism of essential fatty acids, their role in inflammation and cytoprotection of endothelial cells. Note that corticosteroids block the activity of PLA2, desaturases, COX-2 and LOX and thus cause EFA/PUFA deficiency and inhibit the formation of PGE2, LTs and of LXA4/resolvins, protectins and maresins. Statins enhance the activities of desaturases and increase the formation of GLA, DGLA, AA and of LXA4/resolvins/protectin/maresins. TNF-α and IL-6 decrease the activity of desaturases and thus decrease the formation of GLA, DGLA and AA but enhance the activity of COX-2 and thus cause EFA/PUFA deficiency but increase the formation of PGE2. TNF-α and IL-6 stimulate PLA2 and thus increase the release of AA from the cell membrane lipid pool. Thus, both corticosteroids and TNF-α and IL-6 cause an EFA/PUFA deficiency state but have opposite actions on PLA2 and PGE2 formation B – Scheme showing the relationship among SARS-CoV-2 and other enveloped virus induced events on EFA metabolism, pro- and anti-inflammatory cytokines and their modulation by steroids and statins. For details see text. Modified from Das UN. J Inflammation Res 3: 143-70