Specific information and does not constitute a guarantee or warranty of the product by the U.S. Department of Agriculture and does not imply its approval to the exclusion of other products that may also be suitable.Author ContributionsConceived and designed the experiments: EDA. Performed the experiments: EDA RA. Analyzed the data: EDA RA. Contributed reagents/ 79831-76-8 site materials/SIS-3 analysis tools: RGS DGH. Wrote the paper: EDA RA RGS DGH.
Eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids are v-3 polyunsaturated fatty acids (PUFA), found primarily in marine lipids, that display many health benefits, such as the improvement of insulin sensitivity with beneficial effects against obesity and the prevention of cardiovascular diseases [1?]. The American Heart Association recommends eating fish rich in v-3 fatty acids. Despite numerous studies suggesting protective actions of EPA and DHA, the cellular and molecular rational for their intake remains of considerable interest. It is assumed that these beneficial effects are linked to the ability of both acids to inhibit the production of v-6 PUFA-derived prostaglandins and leukotrienes [5]. Additionally, recent studies have shown that a series of novel v-3 PUFA-derived compounds could be responsible for eliciting their beneficial effects [6?]. Resolvins and protectins have been shown for example to display potent anti-inflammatory and immunoregulatory actions [9, 10]. Among bioactive lipid mediators, prostaglandins (PG) exert a plethora of biological activities. PGs of the 2-series are formed by cyclooxygenase (COX)-1 and COX-2 from arachidonic acid (AA). COX converts AA (released from membrane phospholipids through the activity of several phospholipases, mainly phospho-lipases A2) to the unstable cyclic endoperoxide intermediates PGG2/H2 [11]. PGH2 is subsequently metabolized to several prostanoids, PGD2, PGE2, PGF2a, PGI2 and thromboxane A2 (TXA2) through the action of synthases (prostaglandin D synthase [PGDS], PGES, PGFS, PGIS and TXAS) [12,13]. In vitro, PGD2 spontaneously dehydrates to PGJ2 [14] which is converted to 15deoxy-d12,14-PGJ2 (15d-PGJ2) in the absence of albumin [15]. 15dPGJ2 has been detected in vivo [15,16] and has been shown to exhibit in vitro and in vivo anti-inflammatory and anti-proliferative effects [15,17]. The anti-inflammatory cyclopentenone PGs exert their effects, in part, by binding and activating the peroxisome proliferator-activated receptor-gamma (PPAR-c) [18,19]. EPA can also be enzymatically converted by cyclooxygenase into PGH3 which in turn is converted to the 3-series PGs, e.g., PGD3, PGE3, PGF3a and PGI3 [20?2]. The eicosanoids derived from EPA have less inflammatory activities compared with those produced from AA [23?5]. Another mechanism by which v-3 PUFA may exert beneficial effects is by modulating the secretion of adipocytokines [26, 27]. Adiponectin is one of the most abundant plasma protein adipocytokines that shows anti-inflammatory, anti-atherogenic and insulin-sensitizing properties [28, 29]. The potential mechanism by which v-3 PUFA modulate adiponectin secretion is notEPA-Derived Prostaglandin and Adiponectinfully understood, but may partially involve PPAR-c [30-33] which has been shown to play an important role in the transcriptional activation of the adiponectin gene [34]. A recent study showed the formation of J-series PGs from EPA [35]. The pathway by which 15d-PGJ3 could be generated is shown in Fig. 1. PGD3 would be first dehydrated to 15d-PGD3 a.Specific information and does not constitute a guarantee or warranty of the product by the U.S. Department of Agriculture and does not imply its approval to the exclusion of other products that may also be suitable.Author ContributionsConceived and designed the experiments: EDA. Performed the experiments: EDA RA. Analyzed the data: EDA RA. Contributed reagents/ materials/analysis tools: RGS DGH. Wrote the paper: EDA RA RGS DGH.
Eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids are v-3 polyunsaturated fatty acids (PUFA), found primarily in marine lipids, that display many health benefits, such as the improvement of insulin sensitivity with beneficial effects against obesity and the prevention of cardiovascular diseases [1?]. The American Heart Association recommends eating fish rich in v-3 fatty acids. Despite numerous studies suggesting protective actions of EPA and DHA, the cellular and molecular rational for their intake remains of considerable interest. It is assumed that these beneficial effects are linked to the ability of both acids to inhibit the production of v-6 PUFA-derived prostaglandins and leukotrienes [5]. Additionally, recent studies have shown that a series of novel v-3 PUFA-derived compounds could be responsible for eliciting their beneficial effects [6?]. Resolvins and protectins have been shown for example to display potent anti-inflammatory and immunoregulatory actions [9, 10]. Among bioactive lipid mediators, prostaglandins (PG) exert a plethora of biological activities. PGs of the 2-series are formed by cyclooxygenase (COX)-1 and COX-2 from arachidonic acid (AA). COX converts AA (released from membrane phospholipids through the activity of several phospholipases, mainly phospho-lipases A2) to the unstable cyclic endoperoxide intermediates PGG2/H2 [11]. PGH2 is subsequently metabolized to several prostanoids, PGD2, PGE2, PGF2a, PGI2 and thromboxane A2 (TXA2) through the action of synthases (prostaglandin D synthase [PGDS], PGES, PGFS, PGIS and TXAS) [12,13]. In vitro, PGD2 spontaneously dehydrates to PGJ2 [14] which is converted to 15deoxy-d12,14-PGJ2 (15d-PGJ2) in the absence of albumin [15]. 15dPGJ2 has been detected in vivo [15,16] and has been shown to exhibit in vitro and in vivo anti-inflammatory and anti-proliferative effects [15,17]. The anti-inflammatory cyclopentenone PGs exert their effects, in part, by binding and activating the peroxisome proliferator-activated receptor-gamma (PPAR-c) [18,19]. EPA can also be enzymatically converted by cyclooxygenase into PGH3 which in turn is converted to the 3-series PGs, e.g., PGD3, PGE3, PGF3a and PGI3 [20?2]. The eicosanoids derived from EPA have less inflammatory activities compared with those produced from AA [23?5]. Another mechanism by which v-3 PUFA may exert beneficial effects is by modulating the secretion of adipocytokines [26, 27]. Adiponectin is one of the most abundant plasma protein adipocytokines that shows anti-inflammatory, anti-atherogenic and insulin-sensitizing properties [28, 29]. The potential mechanism by which v-3 PUFA modulate adiponectin secretion is notEPA-Derived Prostaglandin and Adiponectinfully understood, but may partially involve PPAR-c [30-33] which has been shown to play an important role in the transcriptional activation of the adiponectin gene [34]. A recent study showed the formation of J-series PGs from EPA [35]. The pathway by which 15d-PGJ3 could be generated is shown in Fig. 1. PGD3 would be first dehydrated to 15d-PGD3 a.
