Factors influencing the eicosanoids synthesis in vivo.

Abstract

External factors activate a sequence of reactions involving the reception, transduction, and transmission of signals to effector cells. There are two main phases of the body's reaction to harmful factors: the first aims to neutralize the harmful factor, while in the second the inflammatory process is reduced in size and resolved. Secondary messengers such as eicosanoids are active in both phases. The discovery of lipoxins and epi-lipoxins demonstrated that not all arachidonic acid (AA) derivatives have proinflammatory activity. It was also revealed that metabolites of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) such as resolvins, protectins, and maresins also take part in the resolution of inflammation. Knowledge of the above properties has stimulated several clinical trials on the influence of EPA and DHA supplementation on various diseases. However, the equivocal results of those trials prevent the formulation of guidelines on EPA and DHA supplementation. Prescription drugs are among the substances with the strongest influence on the profile and quantity of the synthesized eicosanoids. The lack of knowledge about their influence on the conversion of EPA and DHA into eicosanoids may lead to erroneous conclusions from clinical trials.