Gamma-linolenic acid (GLA)

Gamma-linolenic acid (GLA) is an 18-carbon omega-6 polyunsaturated fatty acid (18:3n-6) that plays a pivotal role in the regulation of inflammatory and metabolic processes. It is found naturally in human milk and in high concentrations within the seed oils of evening primrose, borage, and blackcurrant [1, 5, 13]. Although GLA is a lipid molecule rather than a traditional protein-based therapeutic target, it is clinically significant as a precursor to dihomo-gamma-linolenic acid (DGLA) and the anti-inflammatory mediator prostaglandin E1 (PGE1) [4, 13, 15]. GLA is utilized therapeutically to manage conditions such as diabetic neuropathy, rheumatoid arthritis, and atopic dermatitis, where endogenous production of GLA may be compromised [2, 6, 11]. Its biological effects are mediated through the modulation of eicosanoid signaling, weak antagonism of leukotriene B4 receptors, and activation of peroxisome proliferator-activated receptors (PPARs) [7, 10]. In the context of oncology, GLA has demonstrated the ability to enhance the efficacy of hormonal treatments like tamoxifen by modulating receptor expression and inducing apoptosis in certain cancer cell lines [10, 13]. Safety considerations primarily involve its potential to inhibit platelet aggregation, thereby increasing the risk of bleeding when combined with anticoagulant or antiplatelet medications [6, 11].

Other names

Gamolenic acid6,9,12-Octadecatrienoic acidcis-6,cis-9,cis-12-Octadecatrienoic acid18:3n-6all-cis-6,9,12-Octadecatrienoic acid

Gamma-linolenic acid (GLA) primarily functions as a metabolic precursor to dihomo-gamma-linolenic acid (DGLA), which is subsequently converted into the anti-inflammatory and vasodilatory prostaglandin E1 (PGE1) [1, 13, 15]. This pathway bypasses the rate-limiting delta-6 desaturase enzyme, which is often impaired in diseases like diabetes and atopic dermatitis [4, 12]. GLA also exhibits direct biological activity as a weak antagonist of the leukotriene B4 (LTB4) receptor [7] and as a natural agonist for peroxisome proliferator-activated receptors (PPARs), which regulate lipid metabolism and inflammation [10]. Furthermore, it can modulate the expression of genes involved in cell proliferation and apoptosis, such as down-regulating estrogen receptors in breast cancer cells when used in conjunction with tamoxifen [13].