Effect of some local plant extracts on fatty acid composition of fish (Alestes baremoze) during smoking and sun drying in the Far-North region of Cameroon.

The objective of this study was to assess the antioxidant activities of three plant extracts (Moringa oleifera leaves, Xylopia aethiopica fruits, and Allium cepa leaves) and to evaluate their effects on the preservation of fish polyunsaturated fatty acids (PUFAs) during smoking and sun-drying processes. PUFAs are highly prone to oxidation during fish processing. The plant extracts were analyzed for their polyphenol contents and were evaluated for their total antiradical capacity. The polyphenol components of each plant were characterized. The hydroethanolic and aqueous extracts were added to the fish at concentrations of 3, 6, 9, and 12 g/L and 10, 20, 30, and 40 g/L, respectively. Butylated hydroxytoluene (BHT) was used as a positive control at a concentration of 2 g/L to compare the antioxidant effects of the plant extracts. The treated fish was subjected to smoking or sun drying and the fatty acid composition of the fish lipid extract was assessed. The results showed that the total polyphenolic, flavonoid, and tannin contents varied significantly from one plant extract to the other (p < .05). The radical scavenging and FRAP increased significantly with the concentration of the plant extracts (p < .05). An HPLC analysis of the extracts led to the preliminary identification of four hydroxycinnamic acids in M. oleifera and X. aethiopica, one anthocyanin and one flavone glycoside in M. oleifera, and four flavan-3-ols in X. aethiopica. Moreover, eight flavonols were preliminarily identified in the three plants. Compared to the control product, these plant extracts significantly protected fish PUFAs from oxidation (p < .05). The aqueous extract of A. cepa at 40 g/L better preserved omega-3 in fish during smoking and sun drying than the control product. Incorporating the three plant extracts during smoking and sun-drying processes can effectively preserve the PUFAs in fish. Therefore, these plants are viable sources of natural antioxidants in the preservation of fish products.

Rapid assessment of fatty acyls chains of phospholipids and plasmalogens by atmospheric pressure chemical ionization in positive mode and high-resolution mass spectrometry using in-source generated monoacylglycerol like fragments intensities.

We recently published a new concept using monoacylglycerol-like fragments [MG+H-H2O]+ (ions B) produced in-source by atmospheric pressure photoionization in positive mode and high-resolution mass spectrometry for the determination of the fatty acyl (FA) composition of triacylglycerols (TGs) from plant oils. This study extends the concept to the phospholipids (PLs) category and shows that the APCI+ source can also be used. Moreover, the coupling with NP-LC allows to simultaneously analyze different PLs classes in the same sample. We compared the relative intensities of the ions B produced in-source to the % composition of FAs determined by GC-FID. In the case of PLs from natural extracts composed exclusively of diacyl-PLs, the relative intensities of ions B are close to the % of the FAs obtained by GC-FID. This approach is not directly useable for extracts containing plasmalogens (P-PLs). For these PLs, acidic hydrolysis by HCl fumes allows hydrolyzing selectively vinyl ether functions to form lyso-PLs. The analysis of hydrolyzed extracts makes it possible to obtain the composition of P-PLs FAs thanks to the lyso-PLs thus formed, while the diacyl-PLs composition remains unchanged. Unlike GC-FID FAs determination, this approach allows a distinction between the diacyl-PLs and P-PLs FAs composition. We also found that the ion B intensities were consistent among the PL classes (PG, PE, PA, PI, CL, PS and PC) and lyso- forms (LPE and LPC). In the case of the diacyl-PLs extracts analyzed, no statistically significant differences were found between the PLs FAs compositions calculated from ion B intensities and the corresponding GC-FID data. A weighting coefficient was applied to correct ion B intensities issued from polyunsaturated FAs with three or more double bonds. The fatty alkenyls composition of P-PLs could also be calculated from the % intensities of specific ions.

Modeling the fragmentation patterns of triacylglycerides in mass spectrometry allows the quantification of the regioisomers with a minimal number of standards.

Mass spectrometry allows the relative quantification of the regioisomers of triacylglycerides by the calibration of their fragmentation patterns. However, due to the plethora of regioisomers of triacylglycerides, calibration with every standard is not feasible. An analytical challenge in the field is the prediction of the fragmentation patterns of triacylglycerides to quantify their regioisomers. Thus, we aimed to model these fragmentation patterns to quantify the regioisomeric composition, even for those without commercially available standards. In a first step, we modeled the fragmentation patterns of the regioisomers of triacylglycerides obtained from different published datasets. We found the same qualitative trends of fragmentation beyond differences in the type of adduct in these datasets (both [M+NH4]+ and [M+H]+), and the type of instrument (orbitrap, Q-ToF, ion-trap, single quadrupole, and triple quadrupole). However, the quantitative trends of fragmentation were adduct and instrument specific. From these observations, we modeled quantitatively the common trends of fragmentation of triacylglycerides in every dataset. In a second step, we applied this methodology on a Synapt G2S Q-ToF to quantify the regioisomers of triacylglycerides in sunflower and olive oils. The results of our quantification were in good agreement with previous published quantifications of triacylglycerides, even for regioisomers that were not present in the training dataset. The species with more than two highly unsaturated fatty acids (arachidonic, eicosapentaenoic, and docosahexaenoic acids) showed a complex behavior and lower predictability of their fragmentation patterns. However, this framework presents the capacity to model this behavior when more data are available. It would be also applicable to standardize the quantification of the regioisomers of triacylglycerides in an inter-laboratory ring study.

Maternal supplementation with n-3 long chain polyunsaturated fatty acids during perinatal period alleviates the metabolic syndrome disturbances in adult hamster pups fed a high-fat diet after weaning.

Perinatal nutrition is thought to affect the long-term risk of the adult to develop metabolic syndrome. We hypothesized that maternal supplementation with eicosapentaenoic acid and docosahexaenoic acid during pregnancy and lactation would protect offspring fed a high-fat diet from developing metabolic disturbances. Thus, two groups of female hamsters were fed a low-fat control diet, either alone (LC) or enriched with n-3 long chain polyunsaturated fatty acids (LC-PUFA) (LO), through the gestational and lactation periods. After weaning, male pups were randomized to separate groups that received either a control low-fat diet (LC) or a high-fat diet (HC) for 16 weeks. Four groups of pups were defined (LC-LC, LC-HC, LO-LC and LO-HC), based on the combinations of maternal and weaned diets. Maternal n-3 LC-PUFA supplementation was associated with reduced levels of basal plasma glucose, hepatic triglycerides secretion and postprandial lipemia in the LO-HC group compared to the LC-HC group. Respiratory parameters were not affected by maternal supplementation. In contrast, n-3 LC-PUFA supplementation significantly enhanced the activities of citrate synthase, isocitrate dehydrogenase and α-ketoglutarate dehydrogenase compared to the offspring of unsupplemented mothers. Sterol regulatory element binding protein-1c, diacylglycerol O-acyltransferase 2, fatty acid synthase, stearoyl CoA desaturase 1 and tumor necrosis factor α expression levels were not affected by n-3 LC-PUFA supplementation. These results provide evidence for a beneficial effect of n-3 LC-PUFA maternal supplementation in hamsters on the subsequent risk of metabolic syndrome. Underlying mechanisms may include improved lipid metabolism and activation of the mitochondrial oxidative pathway.

n-3 PUFA added to high-fat diets affect differently adiposity and inflammation when carried by phospholipids or triacylglycerols in mice.

BACKGROUND: Dietary intake of n-3 polyunsaturated fatty acids (PUFA) is primarily recognized to protect against cardiovascular diseases, cognitive dysfunctions and the onset of obesity and associated metabolic disorders. However, some of their properties such as bioavailability can depend on their chemical carriers. The objective of our study was to test the hypothesis that the nature of n-3 PUFA carrier results in different metabolic effects related to adiposity, oxidative stress and inflammation. METHODS: 4 groups of C57BL/6 mice were fed for 8 weeks low fat (LF) diet or high-fat (HF, 20%) diets. Two groups of high-fat diets were supplemented with long-chain n-3 PUFA either incorporated in the form of phospholipids (HF-ω3PL) or triacylglycerols (HF-ω3TG). RESULTS: Both HF-ω3PL and HF-ω3TG diets reduced the plasma concentrations of (i) inflammatory markers such as monocyte chemoattractant protein-1 (MCP-1) and interleukin 6 (IL-6), (ii) leptin and (iii) 4-hydroxy-2-nonenal (4-HNE), a marker of n-6 PUFA-derived oxidative stress compared with the control HF diet. Moreover, in both HF-ω3PL and HF-ω3TG groups, MCP-1 and IL-6 gene expressions were decreased in epididymal adipose tissue and the mRNA level of gastrointestinal glutathione peroxidase GPx2, an antioxidant enzyme, was decreased in the jejunum compared with the control HF diet. The type of n-3 PUFA carrier affected other outcomes. The phospholipid form of n-3 PUFA increased the level of tocopherols in epididymal adipose tissue compared with HF-ω3TG and resulted in smaller adipocytes than the two others HF groups. Adipocytes in the HF-ω3PL and LF groups were similar in size distribution. CONCLUSION: Supplementation of mice diet with long-chain n-3 PUFA during long-term consumption of high-fat diets had the same lowering effects on inflammation regardless of triacyglycerol or phospholipid carrier, whereas the location of these fatty acids on a PL carrier had a major effect on decreasing the size of adipocytes that was not observed with the triacyglycerol carrier. Altogether, these results would support the development functional foods containing LC n-3 PUFA in the form of PL in order to prevent some deleterious outcomes associated with the development of obesity.

Gastric conditions control both the evolution of the organization of protein-stabilized emulsions and the kinetic of lipolysis during in vitro digestion.

During digestion, lipids undergo modifications of their colloidal and molecular structures, which depend on the digestive conditions and the composition of the digestive juices. The aim of this work was to evaluate whether gastric pH and pepsin modulate the colloidal evolution and the bioacessibility of fatty acids of an oil-in-water emulsion stabilized by a protein during in vitro digestion. The fate of BSA-stabilized rapeseed oil-in-water emulsion during gastric phase at pH 2.5 or 4.0 with or without pepsin and its consequences on intestinal lipolysis was measured in the simulated gastric and duodenal conditions. The pH had limited impact but pepsin favoured flocculation and coalescence of the droplets, modulating the early stage of lipolysis but not its final extent.

Dietary oxidized n-3 PUFA induce oxidative stress and inflammation: role of intestinal absorption of 4-HHE and reactivity in intestinal cells.

Dietary intake of long-chain n-3 PUFA is now widely advised for public health and in medical practice. However, PUFA are highly prone to oxidation, producing potentially deleterious 4-hydroxy-2-alkenals. Even so, the impact of consuming oxidized n-3 PUFA on metabolic oxidative stress and inflammation is poorly described. We therefore studied such effects and hypothesized the involvement of the intestinal absorption of 4-hydroxy-2-hexenal (4-HHE), an oxidized n-3 PUFA end-product. In vivo, four groups of mice were fed for 8 weeks high-fat diets containing moderately oxidized or unoxidized n-3 PUFA. Other mice were orally administered 4-HHE and euthanized postprandially versus baseline mice. In vitro, human intestinal Caco-2/TC7 cells were incubated with 4-hydroxy-2-alkenals. Oxidized diets increased 4-HHE plasma levels in mice (up to 5-fold, P < 0.01) compared with unoxidized diets. Oxidized diets enhanced plasma inflammatory markers and activation of nuclear factor kappaB (NF-κB) in the small intestine along with decreasing Paneth cell number (up to -19% in the duodenum). Both in vivo and in vitro, intestinal absorption of 4-HHE was associated with formation of 4-HHE-protein adducts and increased expression of glutathione peroxidase 2 (GPx2) and glucose-regulated protein 78 (GRP78). Consumption of oxidized n-3 PUFA results in 4-HHE accumulation in blood after its intestinal absorption and triggers oxidative stress and inflammation in the upper intestine.

n-3 PUFA prevent metabolic disturbances associated with obesity and improve endothelial function in golden Syrian hamsters fed with a high-fat diet.

Glucose intolerance and dyslipidaemia are independent risk factors for endothelium dysfunction and CVD. The aim of the present study was to analyse the preventive effect of n-3 PUFA (EPA and DHA) on lipid and carbohydrate disturbances and endothelial dysfunction. Three groups of adult hamsters were studied for 20 weeks: (1) control diet (Control); (2) high-fat diet (HF); (3) high-fat diet enriched with n-3 PUFA (HFn-3) groups. The increase in body weight and fat mass in the HF compared to the Control group (P < 0.05) was not found in the HFn-3 group. Muscle TAG content was similar in the Control and HF groups, but significantly lower in the HFn-3 group (P = 0.008). Glucose tolerance was impaired in the HF compared to the Control group, but this impairment was prevented by n-3 PUFA in the HFn-3 group (P < 0.001). Plasma TAG and cholesterol were higher in the HF group compared to the Control group (P < 0.001), but lower in the HFn-3 group compared to the HF group (P < 0.001). HDL-cholesterol was lower in the HFn-3 group compared to the Control and HF groups (P < 0.0005). Hepatic secretion of TAG was lower in the HFn-3 group compared to the HF group (P < 0.005), but did not differ from the Control group. Hepatic gene expression of sterol regulatory element-binding protein-1c, diacylglycerol O-acyltransferase 2 and stearyl CoA desaturase 1 was lower in the HFn-3 group, whereas carnitine palmitoyl transferase 1 and scavenger receptor class B type 1 expression was higher (P < 0.05). In adipocytes and adipose macrophages, PPARγ and TNFα expression was higher in the HF and HFn-3 groups compared to the Control group. Endothelium relaxation was higher in the HFn-3 (P < 0.001) than in the HF and Control groups, and was correlated with glucose intolerance (P = 0.03) and cholesterol (P = 0.0003). In conclusion, n-3 PUFA prevent some metabolic disturbances induced by high-fat diet and improve endothelial function in hamsters.