Nitro Fatty Acids (NO2-FAs): An Emerging Class of Bioactive Fatty Acids

Unsaturated nitro fatty acids (NO2-FAs) constitute a category of molecules that may be formed endogenously by the reaction of unsaturated fatty acids (UFAs) with secondary species of nitrogen monoxide and nitrite anions. The warhead of NO2-FAs is a nitroalkene moiety, which is a potent Michael acceptor and can undergo nucleophilic attack from thiol groups of biologically relevant proteins, showcasing the value of these molecules regarding their therapeutic potential against many diseases. In general, NO2-FAs inhibit nuclear factorκ-B (NF-κB), and simultaneously they activate nuclear factor (erythroid derived)-like 2 (Nrf2), which activates an antioxidant signaling pathway. NO2-FAs can be synthesized not only endogenously in the organism, but in a synthetic laboratory as well, either by a step-by-step synthesis or by a direct nitration of UFAs. The step-by-step synthesis requires specific precursor compounds and is in position to afford the desired NO2-FAs with a certain position of the nitro group. On the contrary, the direct nitration of UFAs is not a selective methodology; thus, it affords a mixture of all possible nitro isomers.

Role of Specialized Pro-Resolving Mediators in Modifying Host Defense and Decreasing Bacterial Virulence

Bacterial infection activates the innate immune system as part of the host’s defense against invading pathogens. Host response to bacterial pathogens includes leukocyte activation, inflammatory mediator release, phagocytosis, and killing of bacteria. An appropriate host response requires resolution. The resolution phase involves attenuation of neutrophil migration, neutrophil apoptosis, macrophage recruitment, increased phagocytosis, efferocytosis of apoptotic neutrophils, and tissue repair. Specialized Pro-resolving Mediators (SPMs) are bioactive fatty acids that were shown to be highly effective in promoting resolution of infectious inflammation and survival in several models of infection. In this review, we provide insight into the role of SPMs in active host defense mechanisms for bacterial clearance including a new mechanism of action in which an SPM acts directly to reduce bacterial virulence.

PSXV-25 Effects of multiple grass-fed and grain-fed beef systems on meat fatty acid composition

Retail sales of labeled fresh grass-fed beef in the U.S. have grown from $17 million in 2012 to $272 million in 2016. The objective of present study was to investigate the effect of four typical grass-fed and conventional beef systems raised in the western United States on beef fatty-acid composition. Treatments included: 1) steers stocked on pasture then finished in a feedyard (CON), 2) steers grass-fed for 20 months (GF20), 3) steers grass-fed for 20 months with a 45-day grain finish (GR45), and 4) steers grass-fed for 25 months (GF25). Fatty acids were analyzed with GC using a 100 m CPSil 88 capillary column. All statistical analyses were performed using a GLM procedure in R. Saturated fatty acid (SFA) concentrations were significantly different across treatments (P < 0.05) with GR45 having the lowest SFA of 43% and GF25 having the highest SFA at 46%. Cis-monounsaturated fatty acid (c-MUFA) particularly oleic acid, which is known as a heart healthy fatty acids, were highest for CON at 44% and lowest for GF20 at 37% (P < 0.05). Conjugated linoleic acids (CLA) were significantly lower for the grain-fed treatments (0.54 CON and 0.63 GR45; P < 0.05) compared to grass-fed treatments (0.93 GF20 and 0.86 GF25; P < 0.05). The grass-fed treatments were higher in n-3 PUFA (3.67 GF20 and 2.29 GF25) than CON (0.79; P < 0.05), however feeding grain for a short period of time did not decrease n-3 PUFA concentrations to the CON level (GF45 2.51; P < 0.05). In conclusion, our findings show that beef from grain-fed beef management systems is higher in c-MUFA, while grass-fed is significantly higher in bioactive fatty acids including CLA and branched chain fatty acids. Additional studies are needed to determine if fatty acid profiles between grass-fed and grain-fed beef would result in different health outcomes for the consumers.

The effect of supplemental bioactive fatty acids on growth performance and immune function of milk-fed Holstein dairy calves during heat stress

This study aimed to evaluate the effects of different supplemental fat sources [soybean oil (SBO) as a source of n-6 fatty acid and fish oil (FO) as a source of n-3 fatty acids] in the starter feed of milk-fed dairy calves during the hot season. Forty Holstein calves (3 d of age; 39.67 kg of body weight; ten calves per group) were randomly assigned to the experimental treatments as follows: (1) starter feed supplemented with no fat source (CON), (2) starter feed supplemented with 3% SBO (DM basis), (3) starter feed supplemented with 3% FO (DM basis), and (4) starter feed supplemented with an equal mixture of SBO and FO (1.5% each, DM basis). The milk feeding schedule was constant for treatments and all calves were weaned on d 65 of age. Results show that calves had greater starter intake, average daily gain, and body length when fed SBO compared to other treatments. However, feed efficiency was increased and inflammatory indicators (tumor necrosis factor-alpha, serum amyloid A and haptoglobin) concentrations were reduced in the calves fed FO compared to the other treatments. In summary, it was revealed that SBO rich in n-6 FA improved starter intake and growth performance, while FO rich in n-3 FA could improve the immune function of calves. Due to the current experimental condition, an equal mixture of SBO and FO (1.5% each, DM basis) can be recommended to have an optimum growth performance and immune function while the calves are reared under the heat conditions.

Potential favourable health effects of some dietary uncommon fatty acids

In addition to the major fatty acids widely studied, our diet contains many bioactive fatty acids less frequently investigated such as n-3 docosapentaenoic acid (n-3 DPA), natural trans fatty acids, conjugated fatty acids (CLAs), furan fatty acids (FuFAs), branched chain fatty acids (BCFAs) and fatty acid esters of hydroxyl fatty acids (FAHFAs). Many of them may have beneficial health effects, particularly in the prevention of cardiovascular diseases, inflammation and metabolic disorders such as diabetes. This review aims to give a brief overview of the current knowledge on these lipids. Thus, information about biosynthesis, food and tissue content, daily intake, biological and potential health effects of these fatty acids is provided.