Encapsulation of Docosahexaenoic Acid Oil Substantially Improves the Oxylipin Profile of Rat Tissues

Abstract

Docosahexaenoic acid (DHA) is a major n-3 polyunsaturated fatty acid (PUFA) particularly involved in cognitive and cardiovascular functions. Due to the high unsaturation index, its dietary intake form has been considered to improve oxidation status and to favor bioaccessibility and bioavailability as well. This study aimed at investigating the effect of DHA encapsulated with natural whey protein. DHA was dietary provided as triacylglycerols to achieve 2.3% over total fatty acids. It was daily supplied to weanling rats for four weeks in omelet as food matrix, consecutively to a 6-hour fasting. First, when DHA oil was encapsulated, consumption of chow diet was enhanced leading to promote animal growth. Second, the brain exhibited a high accretion of 22.8% DHA, which was not improved by dietary supplementation of DHA. Encapsulation of DHA oil did not greatly affect the fatty acid proportions in tissues, but remarkably modified the profile of oxidized metabolites of fatty acids in plasma, heart, and even brain. Specific oxylipins derived from DHA were upgraded, such as Protectin Dx in heart and 14-HDoHE in brain, whereas those generated from n-6 PUFAs were mainly mitigated. This effect did not result from oxylipins measured in DHA oil since DHA and EPA derivatives were undetected after food processing. Collectively, these data suggested that dietary encapsulation of DHA oil triggered a more efficient absorption of DHA, the metabolism of which was enhanced more than its own accretion in our experimental conditions. Incorporating DHA oil in functional food may finally improve the global health status by generating precursors of protectins and maresins.

Role of encapsulation on the bioavailability of omega‐3 fatty acids

“…Additionally, PUFA‐rich oils might have their characteristic odor or taste, which reduces acceptability among the general public, specifically in the case of fish oils (Blanco‐Llamero et al., 2022). Nano‐based encapsulation systems offer a number of advantages, including the ability to hide unpleasant tastes, odors, and colors (Wang et al., 2022). Research studies noted higher consumer acceptability and improved quality of food products supplemented with nanoencapsulated fish oil than those fortified with free fish oil (Ghorbanzade et al., 2017).…”

“…Moreover, the formulation must keep the PUFA oil's biological properties following digestion to protect it from deteriorating GI conditions. Otherwise, harsh digestive juice and enzymes could harm the oil's structure and cause it to lose its biological usefulness (Blanco‐Llamero et al., 2022; Wang et al., 2022).…”

“…DHA improves neurological activity by promoting neurogenesis and synaptic plasticity as well as decreasing neuroinflammation, linking high DHA level in body with a reduced risk of myocardial infarction and CVD. The action of DHA is carried out chiefly through its derivatives, such as oxidized FA metabolites (oxylipins) or resolvins, maresins, and protectins; therefore, DHA's activity level is linked to the increase of its own derivatives and simultaneous decrease in derivatives of FA other than omega‐3 PUFA (Wang et al., 2022). DHA accumulates in cell membranes concurrently when omega‐6 FA, basically arachidonic acid (C20:4 ω − 6, ARA), is reduced or it is transformed back into EPA.…”

“…This disruption further reduces omega‐3 PUFA levels through free radical–dependent peroxidation processes (Valenzuela et al., 2017; Videla et al., 2022; Yang et al., 2022). The human body can convert around only 5% of the ingested ALA into long‐chain omega‐3 FA; hence, it is strongly advised to include long‐chain omega‐3‐rich oils (particularly EPA and DHA) from marine sources in recommended amounts within diets or as supplements because they have the added advantage of bypassing the conversion processes and being absorbed directly in the blood (Blanco‐Llamero et al., 2022; Saini et al., 2021; Wang et al., 2022).…”

“…There are various determinants of the bioavailability of omega‐3 PUFA in our body. Bioavailability can be affected by the structure and form of lipids, wherein it is found to decrease in the following order: PLs, TAG, and FFAs (Cholewski et al., 2018; Shahidi & Ambigaipalan, 2018; Wang et al., 2022). Moreover, it is observed that in the context of TAG and PL, the ω − 3 PUFA at the sn‐2 position are readily absorbed (Jin et al., 2020; Lee‐Chang et al., 2021).…”