Arakidonihappoa

Arakidonihappoa, commonly known as arachidonic acid, is a polyunsaturated omega-6 fatty acid with 20 carbon atoms and four cis double bonds (typically designated at positions 5–6, 8–9, 11–12, and 14–15). Its molecular formula is C20H32O2. It is a structural component of membrane phospholipids in animal tissues and is enriched in liver and brain membranes.

Arakidonihappoa is stored in the esterified form within phospholipids and can be released by the action of phospholipase A2 in response to cellular stimuli such as stress, injury, or hormones. Once freed, it acts as a key precursor for a broad family of signaling molecules called eicosanoids, produced via cyclooxygenase (COX) and lipoxygenase (LOX) pathways. COX enzymes convert it into prostaglandins and thromboxanes, while LOX enzymes generate leukotrienes and other related compounds. These metabolites regulate inflammation, immune responses, blood flow, vascular tone, and platelet aggregation.

Physiological and clinical relevance includes its central role in inflammatory and allergic processes, pain and fever responses, and hemostasis. Pharmacological agents such as NSAIDs and corticosteroids influence arachidonic acid metabolism by inhibiting COX enzymes or related pathways, thereby modulating eicosanoid production.

Dietary aspects note that linoleic acid, an essential omega-6 fatty acid, can be converted in the body to arachidonic acid. Arachidonic acid is found in animal-derived foods (such as eggs, meat, and organ meats) and, to a lesser extent, in some fish oils, while plant-based sources are typically lower.