Lipidomic Analysis of Plasma from Healthy Men and Women Shows Phospholipid Class and Molecular Species Differences between Sexes

The phospholipid composition of lipoproteins is determined by the specificity of hepatic phospholipid biosynthesis. Plasma phospholipid 20:4n-6 and 22:6n-3 concentrations are higher in women than in men. We used this sex difference in a lipidomics analysis of the impact of endocrine factors on the phospholipid class and molecular species composition of fasting plasma from young men and women. Diester species predominated in all lipid classes measured. 20/54 Phosphatidylcholine (PtdCho) species were alkyl ester, 15/48 phosphatidylethanolamine (PtdEtn) species were alkyl ester, and 12/48 PtdEtn species were alkenyl ester. There were no significant differences between sexes in the proportions of alkyl PtdCho species. The proportion of alkyl ester PtdEtn species was greater in women than men, while the proportion of alkenyl ester PtdEtn species was greater in men than women. None of the phosphatidylinositol (PtdIns) or phosphatidylserine (PtdSer) molecular species contained ether-linked fatty acids. The proportion of PtdCho16:0_22:6, and the proportions of PtdEtn O-16:0_20:4 and PtdEtn O-18:2_20:4 were greater in women than men. There were no sex differences in PtdIns and PtdSer molecular species compositions. These findings show that plasma phospholipids can be modified by sex. Such differences in lipoprotein phospholipid composition could contribute to sexual dimorphism in patterns of health and disease.     

Differential Impact of Sex on Seasonal Changes in Mantle and Tentacle Phospholipids and Triacylglycerols in Sepia officinalis

The aim of the present work was to study the effect of season on phospholipids and triacylglycerols (TAG) of mantle and tentacles of female and male wild Sepia officinalis. The identified phospholipids were phosphatidylethanolamine (PtdEtn), phosphatidylcholine (PtdCho), phosphatidylserine (PtdSer), and phosphatidylinositol (PtdIns), and PtdEtn was the major fraction. Results showed apparent seasonal variation of phospholipid content, particularly with female samples. Fatty acid composition of phospholipid classes showed a differentiation much more in the proportions than in the diversity of fatty acids. Results showed that the major saturated fatty acids were 16:0 and 18:0, the major monounsaturated fatty acids were 18:1 and 20:l, and the major polyunsaturated fatty acids were docosahexaenoic acid (22:6n-3) (DHA) and eicosapentaenoic acid (20:5n-3) (EPA). The results relative to TAG demonstrated significant variations. Principal component analysis confirmed the seasonal and sexual effects. This study could be appropriate for the improvement of consistent monitoring of phospholipid and TAG accumulation in cephalopod, which might be important for both physiological studies and food industries.     

N‐Stearoylethanolamine Restores Pancreas Lipid Composition in Obesity‐Induced Insulin Resistant Rats

This study investigates the protective effect of N‐stearoylethanolamine (NSE), a bioactive N‐acylethanolamine , on the lipid profile distribution in the pancreas of obesity‐induced insulin resistant (IR) rats fed with prolonged high fat diet (58 % of fat for 6 months). The phospholipid composition was determined using 2D thin‐layer chromatography. The level of individual phospholipids was estimated by measuring inorganic phosphorus content. The fatty acid (FA) composition and cholesterol level were investigated by gas–liquid chromatography. Compared to controls, plasma levels of triglycerides and insulin were significantly increased in IR rats. The pancreas lipid composition indicated a significant reduction of the free cholesterol level and some phospholipids such as phosphatidylcholine (PtdCho), phosphatidylethanolamine (PtdEtn), phosphatidylinositol (PtdIns), phosphatidylserine (PtdSer) compared to controls. Moreover, the FA composition of pancreas showed a significant redistribution of the main FA (18:1n‐9, 18:2n‐6, 18:3n‐6 and 20:4n‐6) levels between phospholipid, free FA, triglyceride fractions under IR conditions that was accompanied by a change in the estimated activities of Δ9‐, Δ6‐, Δ5‐desaturase. Administration of N‐stearoylethanolamine (NSE, 50 mg/kg daily per os for 2 weeks) IR rats triggered an increase in the content of free cholesterol, PtdCho and normalization of PtdEtn, PtdSer level. Furthermore, the NSE modulated the activity of desaturases, thus influenced FA composition and restored the FA ratios in the lipid fractions. These NSE‐induced changes were associated with a normalization of plasma triglyceride content, considerable decrease of insulin and index HOMA‐IR level in rats under IR conditions.     

Incorporation and distribution of saturated and unsaturated fatty acids into nuclear lipids of hepatic cells

Liver nuclear incorporation of stearic (18∶0), linoleic (18∶2n−6), and arachidonic (20∶4n−6) acids was studied by incubation in vitro of the [1-¹⁴C] fatty acids with nuclei, with or without the cytosol fraction at different times. The [1-¹⁴C] fatty acids were incorporated into the nuclei as free fatty acids in the following order: 18∶0>20∶4n−6≫18∶2n−6, and esterified into nuclear lipids by an acyl-CoA pathway. All [1-¹⁴C] fatty acids were esterified mainly to phospholipids and triacylglycerols and in a minor proportion to diacylglycerols. Only [1-¹⁴C] 18∶2n−6-CoA was incorporated into cholesterol esters. The incorporation was not modified by cytosol addition. The incorporation of 20∶4n−6 into nuclear phosphatidylcholine (PC) pools was also studied by incubation of liver nuclei in vitro with [1-¹⁴C]20∶4n−6-CoA, and nuclear labeled PC molecular species were determined. From the 15 PC nuclear molecular species determined, five were labeled with [1-¹⁴C]20∶4n−6-CoA: 18∶0–20∶4, 16∶0–20∶4, 18∶1–20∶4, 18∶2–20∶4, and 20∶4–20∶4. The highest specific radioactivity was found in 20∶4–20∶4 PC, which is a minor species. In conclusion, liver cell nuclei possess the necessary enzymes to incorporate exogenous saturated and unsaturated fatty acids into lipids by an acyl-CoA pathway, showing specificity for each fatty acid. Liver cell nuclei also utilize exogenous 20∶4n−6-CoA to synthesize the major molecular species of PC with 20∶4n−6 at the sn-2 position. However, the most actively synthesized is 20∶4–20∶4 PC, which is a quantitatively minor component. The labeling pattern of 20∶4–20∶4 PC would indicate that this molecular species is synthesized mainly by the de novo pathway.     

Erucic Acid is Differentially Taken up and Metabolized in Rat Liver and Heart

Because X-linked adrenoleukodystrophy is treated using erucic acid (22:1n-9), we assessed its metabolism in rat liver and heart following infusion of [14-¹⁴C]22:1n-9 (170 Ci/kg) under steady-state-like conditions. In liver, 2.3-fold more tracer was taken up as compared to heart, accounted entirely by increased incorporation into the organic fraction (4.2-fold). The amount of tracer entering the aqueous fraction, which represents β-oxidation, was not different between groups; however a significantly elevated proportion of tracer was in the heart aqueous fraction. In both tissues, 76% of the radioactivity found in the organic fraction was esterified in neutral lipids, while only about 10% was found esterified into phospholipids. In liver, 56% of lipid radioactivity was found in cholesteryl esters, whereas in heart 64% was found in triacylglycerols. Because 22:1n-9 can be chain shortened, we assessed tracer metabolism using phenacyl fatty acid derivatives esterified from saponified esterified neutral lipid (triacylglycerol/cholesteryl ester) and phospholipid fractions. In heart esterified neutral lipids, 75% of tracer was recovered as 22:1n-9 and only 10% as oleic acid (18:1n-9), while in liver only 25% of the tracer was recovered as 22:1n-9, while 50% was found as stearic acid (18:0) and 10% as 18:1n-9. In liver and heart phospholipids, the tracer was distributed amongst the n-9 fatty acid family. Thus, 22:1n-9 under went tissue selective metabolism, with conversion to 18:0 the dominant pathway in the liver presumably for export in the neutral lipids, while in heart it was found primarily as 22:1n-9 in neutral lipids and used for β-oxidation.     

High Arachidonic Acid Levels in the Tissues of Herbivorous Fish Species (<Emphasis Type="Italic">Siganus fuscescens,Calotomus japonicus</Emphasis> and <Emphasis Type="Italic">Kyphosus bigibbus</Emphasis>)

The lipid and fatty acid compositions in the various organs (muscle, liver, other viscera) and stomach contents of three common herbivorous fish species in Japan, Siganus fuscescens, Calotomus japonicus and Kyphosus bigibbus, were examined to explore the stable 20:4n-6 (arachidonic acid, ARA) sources. Triacylglycerol (TAG), phosphatidylethanolamine (PtdEtn), and phosphatidylcholine (PtdCho) were the dominant lipid classes, while the major FA contents were 16:0, 18:1n-9, 16:1n-7, 14:0, 18:0, 18:1n-7, and some PUFA, including ARA, 20:5n-3 (eicosapentaenoic acid, EPA), 22:5n-3 (docosapentaenoic acid, DPA), and 22:6n-3 (docosahexaenoic acid, DHA). The amounts of these fatty acids were varied among species and their lipid classes. Phospholipids contained higher levels of PUFA than TAG. However, ARA in both phospholipids and TAG was markedly present in the muscle and viscera of all specimens, particularly in C. japonicus and K. bigibbus. Moreover, their ARA levels were higher than the levels of DHA and EPA. The observed high ARA level is unusual in marine fish and might be characteristic of herbivorous fish. Furthermore, ARA was the dominant PUFA in the stomach contents of the three species, suggesting that the high ARA level originated from their food sources. The above indicates that these three herbivorous fishes are ARA-rich marine foods and have potential utilization as stable ARA resources.     

Dietary arachidonic acid and hepatic desaturation of fatty acids in obese zucker rats

The effect of low levels of dietary arachidonic acid (20:4n-6) on Δ6 desaturation of linoleic acid (18:2n-6) and α-linolenic acid (18:3n-3), and on Δ5 desaturation of dihomo-γ-linolenic acid (20:3n-6) were studied in liver microsomes of obese Zucker rats, in comparison with their lean littermates. Fatty acid composition of serum total lipids and of phospholipids from liver microsomes and from total heart and kidney was determined to see whether modifications of desaturation rate, if any, were reflected in the tissue fatty acid profiles. Animals fed for 12 wk on a balanced diet, containing 20:4n-6 and 18:2n-6, were compared to those fed 18:2n-6 only. The low amount of dietary 20:4n-6 greatly inhibited Δ6 desaturation of 18:2n-6 and Δ5 desaturation of 20:3n-6, whereas Δ6 desaturation of 18:3n-3 was slightly increased in obese rats. Inhibition of the biosynthesis of long-chain n-6 fatty acids by dietary arachidonic acid was only slightly reflected in the 20:4n-6 content of liver microsome phospholipids. On the contrary, the enrichment of serum total lipids and heart and kidney phospholipids in this fatty acid was pronounced, more in obese than in lean animals. Our results show that, although the desaturation rate of the n-6 fatty acids in liver microsomes was greatly decreased by the presence of arachidonic acid in the diet, the tissue phospholipid content in arachidonic acid was not depressed. The potentiality of synthesis of eicosanoids of the 2 family from this fatty acid is consequently not lower, especially in obese rats, in which certain tissues are deficient in arachidonic acid, in comparison with their lean littermates.     

Development of a Fish Cell Culture Model to Investigate the Impact of Fish Oil Replacement on Lipid Peroxidation

Fish oils are rich in omega-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFA), predominantly 20:5n-3 and 22:6n-3, whereas vegetable oils contain abundant C₁₈-PUFA, predominantly 18:3n-3 or 18:2n-6. We hypothesized that replacement of fish oils with vegetable oils would increase the oxidative stability of fish lipids. Here we have used the long established and easily cultivated FHM cell line derived from the freshwater fish species fathead minnow (Pimephales promelas) to test this hypothesis. The FHM cells were readily able to synthesize 20:5n-3 and 24:6n-3 from 18:3n-3 but 22:6n-3 synthesis was negligible. Also, they were readily able to synthesize 20:3n-6 from 18:2n-6 but 20:4n-6 synthesis was negligible. Mitochondrial β-oxidation was greatest for 18:3n-3 and 20:5n-3 and the rates for 16:0, 18:2n-6, 22:6n-3 and 18:1n-9 were significantly lower. Fatty acid incorporation was predominantly into phospholipids (79–97%) with very little incorporation into neutral lipids. Increasing the fatty acid concentration in the growth medium substantially increased the concentrations of 18:3n-3 and 18:2n-6 in the cell phospholipids but this was not the case for 20:5n-3 or 22:6n-3. When they were subjected to oxidative stress, the FHM cells supplemented with either 20:5n-3 or 22:6n-3 (as compared with 18:3n-3 or saturated fatty acids) exhibited significantly higher levels of thiobarbituric reactive substances (TBARS) indicating higher levels of lipid peroxidation. The results are discussed in relation to the effects of fatty acid unsaturation on the oxidative stability of cellular lipids and the implications for sustainable aquaculture.     

Methylmercury Increases and Eicosapentaenoic Acid Decreases the Relative Amounts of Arachidonic Acid-Containing Phospholipids in Mouse Brain

The membrane phospholipid composition in mammalian brain can be modified either by nutrients such as dietary fatty acids, or by certain toxic substances such as methylmercury (MeHg), leading to various biological and toxic effects. The present study evaluated the effects of eicosapentaenoic acid (EPA) and MeHg on the composition of the two most abundant membrane phospholipid classes, i.e., phosphatidylcholines (PtdCho) and phosphatidylethanolamines (PtdEtn), in mouse brain by using a two‐level factorial design. The intact membrane PtdCho and PtdEtn species were analyzed by liquid chromatography–mass spectrometry. The effects of EPA and MeHg on the PtdCho and PtdEtn composition were evaluated by principal component analysis and ANOVA. The results showed that EPA and MeHg had different effects on the composition of membrane PtdCho and PtdEtn species in brain, where EPA showed strongest impact. EPA led to large reductions in the levels of arachidonic acid (ARA)‐containing PtdCho and PtdEtn species in brain, while MeHg tended to elevate the levels of ARA‐containing PtdCho and PtdEtn species. EPA also significantly increased the levels of PtdCho and PtdEtn species with n‐3 fatty acids. Our results indicate that EPA may to some degree counteract the alterations of the PtdCho and PtdEtn pattern induced by MeHg, and thus alleviate the MeHg neurotoxicity in mouse brain through the inhibition of ARA‐derived pro‐inflammatory factors. These results may assist in the understanding of the interaction between MeHg, EPA and phospholipids, as well as the risk and benefits of a fish diet.     

Characteristics of Fatty Acid Composition of the Deep-Sea Vent Crab, <Emphasis Type="Italic">Shinkaia crosnieri</Emphasis> Baba and Williams

The neutral and polar lipids of the Galatheidae vent crab, Shinkaia crosnieri, with its eggs were studied to assess its lipid physiology and trophic relationship at hydrothermal vents. The vent crab obtained many of its lipids from Bathymodiolus mussels and chemosynthetic microorganisms which live on a mat of long, silky setae on the crab body as exosymbionts. In all lipid classes, the major monounsaturated fatty acids were 16:1n-7 and 18:1n-7, which originate from bacteria. The major polyunsaturated fatty acids (PUFA) in the triacylglycerols were 16:2n-4, 18:2n-4, 18:2n-7, 18:3n-4,7,10, and 16:2n-3, while those of the crab polar lipids were 16:2n-4, 18:2n-4, 18:3n-4,7,10, 20:4n-6 (arachidonic acid), 20:5n-3 (icosapentaenoic acid), and 22:6n-3 (docosahexaenoic acid) in the phosphatidylethanolamine, and 16:2n-4, 18:2n-4, and 18:3n-4,7,10, with noticeable levels of 20:4n-6, 20:5n-3, and 22:6n-3 in the phosphatidylcholine. In the crab and its eggs, TAG and phospholipid PUFA consisted primarily of n-4 family (n-4 and n-7) methylene-interrupted PUFA with n-3 and n-6 PUFA. The unique fatty acid composition mix of n-3, n-4, and n-6 PUFA in S. crosnieri lipids suggests the vent crab utilizing chemosynthetic bacteria, which produce both unusual n-4 and normal n-3 and n-6 PUFA. Such unique fatty acid composition differs from that reported for other common marine animals, which depend on organic matter derived from phytoplankton lipids.     

Nonessential fatty acids in formula fat blends influence essential fatty acid metabolism and composition in plasma and organ lipid classes in piglets

The n-6 and n-3 fatty acid status of developing organs is the cumulative result of the diet lipid composition and many complex events of lipid metabolism. Little information is available, however, on the potential effects of the saturated fatty acid chain length (8:0–16:0) or oleic acid (18:1) content of the diet on the subsequent metabolism of the essential fatty acids 18:2n-6 and 18:3n-3 and their elongated/desaturated products. The effects of feeding piglets formulas with fat blends containing either coconut oil (12:0±14:0) or medium chain triglycerides (MCT, 8:0±10:0) but similar levels of 18:1, 18:2n-6 and 18:3n-3, or MCT with high or low 18:1 but constant 18:2n-6 and 18:3n-3 on the fatty acid composition of plasma, liver and kidney triglycerides, phospholipids and cholesteryl esters, and of brain total lipid, were studied. Diet-induced changes in the fatty acid composition of lipid classes were generally similar for plasma, liver and kidney. Dietary 18:1 content was reflected in tissue lipids and was inversely associated with levels of 18:2n-6. Lower percentage of 18:2n-6, however, was not associated with lower levels of its elongated/desaturated product 20:4n-6 but was associated with higher levels of 22:6n-3. Feeding coconut oilvs. MCT resulted in lower 18:1 levels in all lipids, and higher percentages of 20:4n-6 in tissue phospholipid. Increasing the dietary n-6/n-3 ratio from 5 to 8 significantly increased tissue percentage of 18:2n-6 and decreased phospholipid 22:6n-3. In contrast to plasma, liver and kidney, brain lipid fatty acid composition was not influenced by the formula saturated fatty acid chain length, content of 18:1, or n-6/n-3 ratio. In summary, the studies show that the dietary requirement for n-6 and n-3 fatty acids may be influenced by the nonessential saturated and monounsaturated fatty acids fed concurrently.     

Composition of muscle tissue lipids of silver carp and bighead carp

Lipids have a complex role in the nutritional value of food. Some polyunsaturated fatty acids, characterized as essential, are extremely important for human health. This is primarily related to α-linolenic acid (18:3n-3), eicosapentaenoic acid (20:5n-3) and docosahexaenoic acid (22:6n-3). Content of polyunsaturated n-3 fatty acids is usually much higher in lipids of marine fish than in freshwater fish. Previous investigations have shown that muscle tissue of silver carp and bighead carp from fish farms may be a rich source of essential fatty acids. Because of that, the objective of this work was to examine contents and composition of fatty acids and total lipids in the muscle tissue of silver and bighead carp, with the aim to find out whether there are significant differences in this respect between the two species and to what extent the harvest season can influence the composition of lipids in these freshwater fish. This study showed that there is no significant difference either in the content of polyunsaturated n-3 and n-6 fatty acids, or in the n-6/n-3 fatty acid ratio in these two fish species. The lipids of both the silver and bighead carp from the spring harvest have significantly higher contents of the n-3 acids and a significantly lower n-6/n-3 ratio than fish from the autumn harvest.     

Effects of Cigarette Smoke on Cell Viability,Linoleic Acid Metabolism and Cholesterol Synthesis,in THP−1 Cells

Cigarette smoke (CS) contains thousands of substances, mainly free radicals that have as a target the polyunsaturated fatty acids (PUFA). Long chain PUFA are produced through elongation and desaturation reactions from their precursors; the desaturation reactions are catalyzed by different enzymes: the conversion of 18:2n-6 (linoleic acid, LA) to 18:3n-6 by Delta6 desaturase, while that of 20:3n-6 to 20:4n-6 by Delta5 desaturase. The aim of this work is to evaluate the effect of serum exposed to cigarette smoke (SE-FBS) on (1) cell viability and proliferation, (2) [1-(14)C] LA conversion and desaturase activities in THP-1 cells, a monocytic cell line. In THP-1, CS inhibits cell proliferation dose-dependently, by producing a modification in the cell cycle with a reduced number of cells in synthesis and mitosis phases at higher concentrations. CS also decreases [1-(14)C] LA conversion to its derivatives in a concentration-dependent manner, inhibiting the activities of Delta6 and mainly Delta5 desaturase. In addition, CS does not modify the incorporation of LA into various lipid classes but it reduces cholesterol synthesis from radiolabelled acetate, and increases free fatty acid, TG and CE levels. In conclusion, CS affects lipid metabolism, inhibiting LA conversion and desaturase activities. CS also shifts the "de novo" lipid synthesis from free cholesterol to TG and CE, where LA is preferentially esterified.     

Retroconversion of Docosapentaenoic Acid (n-6): an Alternative Pathway for Biosynthesis of Arachidonic Acid in Daphnia magna

The aim of this study was to assess metabolic pathways for arachidonic acid (20:4n-6) biosynthesis in Daphnia magna. Neonates of D. magna were maintained on [¹³C] enriched Scenedesmus obliquus and supplemented with liposomes that contained separate treatments of unlabeled docosapentaenoic acid (22:5n-6), 20:4n-6, linoleic acid (18:2n-6) or oleic acid (18:1n-9). Daphnia in the control treatment, without any supplementary fatty acids (FA) containing only trace amounts of 20:4n-6 (~0.3 % of all FA). As expected, the highest proportion of 20:4n-6 (~6.3 %) was detected in Daphnia that received liposomes supplemented with this FA. Higher availability of 18:2n-6 in the diet increased the proportion of 18:2n-6 in Daphnia, but the proportion of 20:4n-6 was not affected. Daphnia supplemented with 22:5n-6 contained ~3.5 % 20:4n-6 in the lipids and FA specific stable isotope analyses validated that the increase in the proportion of 20:4n-6 was due to retroconversion of unlabeled 22:5n-6. These results suggest that chain shortening of 22:5n-6 is a more efficient pathway to synthesize 20:4n-6 in D. magna than elongation and desaturation of 18:2n-6. These results may at least partially explain the discrepancies noticed between phytoplankton FA composition and the expected FA composition in freshwater cladocerans. Finally, retroconversion of dietary 22:5n-6 to 20:4n-6 indicates Daphnia efficiently retain long chain n-6 FA in lake food webs, which might be important for the nutritional ecology of fish.     

Metabolic Syndrome Affects Fatty Acid Composition of Plasma Lipids in Obese Prepubertal Children

The aim of the present study was to assess the plasma fatty acid composition of the total plasma lipids and lipid fractions in obese prepubertal children with and without metabolic syndrome (MS). Thirty-four obese prepubertal children were recruited: 17 who met MS criteria and 17 who did not; and twenty prepubertal children of normal weight. MS characteristics, insulin resistance (by homeostasis model assessment [HOMA-IR]), and plasma adiponectin (by radioimmunoassay) were recorded. Separation of lipid fractions was performed by liquid chromatography and the concentration of fatty acids in total plasma lipids and fractions was determined by gas-liquid chromatography. Concentrations of 16:1n-7, 16:1n-9, 18:3n-3, 22:6n-3, and n-3 PUFA in total plasma lipids (P < 0.05) and of 16:0, 16:1n-7, 18:1n-9, 18:2n-6, and n-6 PUFA in triacylglycerols (TG) (P < 0.05) were significantly higher in obese MS versus normal-weight children. Increased risk of MS was positively associated with plasma concentration of 16:1n-7 and negatively associated with proportion of 20:4n-6 (OR 2.76; P = 0.004; OR 0.56, P = 0.030, respectively). Saturated FA in TG were associated with HOMA-IR (R = 0.349, P = 0.017) and 22:5n-6 with adiponectin (R = 0.336, P = 0.05). In conclusion, increased concentrations of 16:1n-7 and decreased proportions of 20:4n-6 and 22:5n-6 in plasma lipids appear to be early markers of MS in children at prepubertal age.     

The Composition of the Cuticular and Internal Free Fatty Acids and Alcohols from <Emphasis Type="Italic">Lucilia sericata</Emphasis> Males and Females

GC, GC-MS, and HPLC-LLSD analyses were used to identify and quantify cuticular and internal lipids in males and females of the blow-fly (Lucilia sericata). Sixteen free fatty acids, seven alcohols and cholesterol were identified and quantitatively determined in the cuticular lipids of L. sericata. Cuticular fatty acids ranged from C(6) to C(20) and included unsaturated entities such as 16:1n-9, 18:1n-9, 20:4n-3 and 20:5n-3. Cuticular alcohols (only saturated and even-numbered) ranged from C(12) to C(20) in males and C(10) to C(22) in females. Only one sterol was found in the cuticular lipids of both males and females. 23 free fatty acids, five alcohols and cholesterol were identified in the internal lipids. Internal fatty acids were present in large amounts-7.4 mg/g (female) and 10.1 mg/g (male). Only traces of internal alcohols (from C(14) to C(26) in males, from C(14) to C(22) in females) were found in L. sericata. Large amounts of internal cholesterol were identified in L. sericata males and females (0.49 and 0.97 mg/g of the insect body, respectively).     

Lipid Profiles of Five Essential Phospholipid Preparations for the Treatment of Nonalcoholic Fatty Liver Disease: A Comparative Study

Nonalcoholic fatty liver disease (NAFLD) is associated with an imbalance in fatty acid composition and can progress from simple steatosis to steatohepatitis, liver cirrhosis, and hepatocellular carcinoma. Essential phospholipids (EPL), which contain high levels of 1,2-dilinoleoylphosphatidylcholine, can be used to treat NAFLD. Polyenylphosphatidylcholine (PPC) preparations are external, commercially available EPL products. The lipid composition of five commercially available PPC preparations, including Essentiale Forte, Fortifikat, Hepatoprotect Regenerator, Fortifikat Forte, and Esentin Forte were compared, the outcome of which may impact physician choice in the treatment of NAFLD. Following lipid extraction, a comparative analysis of key lipid content was performed using a QTRAP6500+ triple quadruple ion trap hybrid mass spectrometer (Sciex) in nanoelectrospray ionization mode. The glycerophospholipid composition of each PPC was determined, including levels of phosphatidylcholine (PtdCho), and phosphatidylethanolamine (PtdEtn) species, as well as PtdCho:PtdEtn ratio. Of the five preparations analyzed, Essentiale Forte contained the highest PtdCho levels (61.9 mol%) and lowest PtdEtn levels (4.9 mol%). PtdCho 36:4 levels, a polyunsaturated species of PtdCho, were highest in Esentin Forte (39.3 mol%) and Essentiale Forte (38.3 mol%) compared with other PPCs (28.7–35.8 mol%). Levels of lysophosphatidylcholine, phosphatidylinositol, phosphatidic acid, and phosphatidylglycerol were low in all five preparations. Lipid composition was consistent between the preparations. The high PtdCho:PtdEtn ratio composition of Essentiale Forte compared with the other PPC analyzed, as well as the presence of polyunsaturated fatty acids, suggest it could be the most clinically beneficial commercially available hepatoprotective product in the treatment of NAFLD.     

Lipase G-Catalyzed synthesis of monoglycerides in organic solvent and analysis by HPLC

Monoglycerides were synthesized with Lipase G fromPenicillium sp. as biocatalyst. This enzyme successfully catalyzed the esterification of glycerol with oleic acid (18:1 n-9) or eicosapentaenoic acid, EPA (20:5 n-3) in hexane. Esterification at 40°C for 24 hr resulted in 86.3 mol% and 64.3 mol% incorporation of 18:1 n-9 and 20:5 n-3, respectively. Lipase GC fromGeotrichum candidum was not effective in esterifying the fatty acids under the present experimental conditions. Lipase G was able to incorporate 98.5 mol% and 98.1 mol% of 18:1 n-9 onto glycerol in 24 hr or less at 25°C and 37°C, respectively, in the absence of molecular sieve 4A. The product formed was analyzed by high performance liquid chromatography (HPLC) with a combined evaporative light scattering mass detector (ELSD) and ultraviolet detection at 206 nm. The result of this study demonstrates that Lipase G is capable of incorporating long-chain fatty acids of potential health benefit onto glycerol.