Boronic Derivatization of Monoacylglycerol and Monitoring in Biofluids.

Monoacylglycerols (MAGs) are active mediators involved in multiple biological processes closely related to the pathological development of diabetes, obesity, and cancers. Sensitive and unambiguous detection of MAGs is thus essential; however, previous methods are both indirect and labor-intensive. Herein, we developed a straightforward approach by derivatization of MAGs with 3-nitrophenylboronic acid (3-NPB) for sensitive and selective analysis in cell lysates, tissues, and serums by mass spectrometry (MS). Reaction occurring between boronic acid and cis-diol moiety of MAGs blocked the formation of multiple adduct ions and tuned MAGs to negatively charged carrying species. In addition, the characteristic isotopic distribution of boron specialized the presence of modified MAGs in MS and led to distinctive identification. To eliminate endogenous interferences, we further introduced isotopic labeled d4-NPB equivalently premixed with d0-NPB to perform MAG derivatization, which resulted in rapid identification of modified MAGs in biofluids by displaying doublet peak characteristics. A comparative quantification approach was thereafter evoluted to reveal the amount variation of MAGs by d0-NPB and d4-NPB separately derivatized in different pathological tissue and serum samples. The presently developed NPB-based derivatization approach is expected to be essential in the metabolic study of MAG-related diseases.

Plasma concentrations of oleoylethanolamide in a primary care sample of depressed patients are increased in those treated with selective serotonin reuptake inhibitor-type antidepressants.

Oleoylethanolamide (OEA) is a non-cannabinoid acylethanolamide with multiple physiological roles that has been proposed to have antidepressant-like activity in preclinical models. OEA shares biosynthetic pathways with anandamide (AEA) a transmitter involved in affective disorders and anxiety in humans. However, although the participation of OEA in depression has been proposed, both, the contribution of OEA to the depressive phenotype and the effect of antidepressant therapy on circulating levels of this and related non-cannabinoid acylethanolamides in humans are basically unknown. The main objective of this study is to compare the plasma concentrations of OEA and related acylethanolamides in a sample of primary care patients with depression (n = 69) with those of healthy non-depressed patients (n = 47). At the time of admission to the study, 22 patients were under selective serotonin reuptake inhibitor (SSRI) antidepressant treatment and 47 patients were not receiving any type of intervention. In addition, plasma concentrations of the endocannabinoid 2-AG and two related monoacylglycerols were monitored. Plasma OEA concentrations were found to be elevated in depressed patients and to correlate with somatic symptoms of depression. Plasma concentrations of both, AEA and 2-AG, were found to be elevated also in depressed patients. Further analysis demonstrated that the elevation observed in the plasma concentrations of both, OEA and 2-AG, was associated to SSRI antidepressant therapy at the time of recruitment. Further clinical research is needed to understand whether SSRI-induced elevations in OEA levels contribute to the response to SSRI in depressed patients as described in preclinical models.

The bioavailability of eicosapentaenoic acid from reconstituted triglyceride fish oil is higher than that obtained from the triglyceride and monoglyceride forms.

Omega 3 fatty acids have healthcare benefits, but their absorption characteristics are not well defined, particularly for strategies to improve their bioavailability. We performed a double blind study comparing the bioavailability of 20% eicosapentaenoic acid in 4.5 grams of: natural triglyceride, reconstituted triglyceride, enzymatically synthesized triglyceride, monoglyceride and diglyceride. Seven healthy volunteers were given the supplements on five occasions while repeated measurements of eicosapentaenoic acid were taken to calculate the area under the curve for the next 24 hours. There was a significant difference between the mean of calculated area under the curve of eicosapentaenoic acid from reconstituted triglyceride (30.2) and that of the enzymatically synthesized triglyceride (11.9) and monoglyceride (13.4), z=-2.36 and -2.19, respectively, p<0.05. In summary, eicosapentaenoic acid bioavailability of chemically reconstituted triglycerides was better than that obtained from enzymatically synthesized triglyceride and monoglyceride.