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The elucidation of the sources of n-3 fatty acids available for the humans in the Upper Palaeolithic and Neolithic is highly relevant in order to ascertain the availability of such nutrients in that time frame as well as to draw useful conclusions about healthy dietary habits for present-day humans. To this end, we have analysed fat from several frozen mammals found in the permafrost of Siberia (Russia). A total of 6 specimens were included in this study: 2 mammoths, i.e. baby female calf called “Lyuba” and a juvenile female called “Yuka”, both specimens approximately from the same time, i.e. Karginian Interstadial (41,000 and 34,000 years BP); two adult horses from the middle Holocene (4,600 and 4,400 years BP); and two bison very close to the Early Holocene (8,200 and 9,300 years BP). All samples were analysed by gas-liquid chromatography-mass spectrometry (GLC-MS) and GLC-flame ionization detector (GLC-FID). As demonstrated in this work, the fat of single-stomached mammals often consumed by Palaeolithic/Neolithic hunters contained suitable amounts of n-3 and n-6 fatty acids, possibly in quantities sufficient to meet the today's recommended daily intake for good health. Moreover, the results also suggest that mammoths and horses at that time were hibernators.

Two polyunsaturated fatty acids, docosahexaenoic acid (DHA) and arachidonic acid (ARA), as well as derivatives, such as eicosanoids, regulate different activities, affecting transcription factors and, therefore, DNA transcription, being a critical step for the functioning of fatty-acid-derived signaling. This work has attempted to determine the in vitro anticancer activities of these molecules linked to the gene transcription regulation of HT-29 colorectal cancer cells. We applied the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide test along with lactate dehydrogenase and caspase-3 assays; proteome changes were assessed by "sequential windowed acquisition of all theoretical mass spectra" quantitative proteomics, followed by pathway analysis, to determine the affected molecular mechanisms. In all assays, DHA inhibited cell proliferation of HT-29 cells to a higher extent than ARA and acted primarily by downregulating proteasome particles, while ARA presented a dramatic effect on all six DNA replication helicase particles. The results indicated that both DHA and ARA are potential chemopreventive agent candidates.

Colorectal cancer is one of the leading causes of death in Western countries; therefore, the implementation of healthy dietary habits in order to prevent its occurrence is a desirable action. We show here that both free fatty acids (FFAs) and some acylglycerols induce antitumoral actions in the colorectal cancer cell line HT-29. We tested several C18 polyunsaturated fatty acid-enriched oils (e.g., sunflower and Echium) as well as other oils, such as arachidonic acid-enriched (Arasco®) and docosahexaenoic acid-enriched (Marinol® and cod liver oil), in addition to coconut and olive oils. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide test indicated inhibitory effects on HT-29 cells viability for FFAs, and monoacylglycerol and diacylglycerol (DAG) species, while the lactate dehydrogenase test proved that FFAs were the more effective species to induce membrane injury. Conversely, all species did not exhibit actions on CCD-18 normal human colon cells viability. Furthermore, transmission electron microscopy showed the presence of necrosis and apoptosis, while the monoacylglycerol lipase (MAGL) inhibition test demonstrated high activity for 2-monoacylglycerols derived from Arasco and sunflower oils. However, different monoacylglycerols and DAGs have also the potential for MAGL inhibition. Therefore, checking for activity on colon cancer cells of specifically designed acylglycerol-derivative species would be a suitable way to design functional foods destined to avoid colorectal cancer initiation.

The aim of this work is to assess the fatty acid (FA) profiles, the lipid classes, and the positional distribution of FA within the triacylglycerol (TAG) structure of the lipids extracted from Lepidoptera larvae, compared with Diptera and Coleoptera ones. The major essential FA in most species was α‐linolenic acid (ALA), at 62.5 mol% of total FA in Caligo memnon. Oleic acid (OA) was found in high amounts in Galleria mellonella, at 44.8 mol% of total FA. The n‐6/n‐3 ratio was below 1 in 12 of the 15 species surveyed, reaching 14.8 in Oryctes nasicornis. As for lipid fractions, an increase in the amounts of stearic and linoleic acids in the phospholipids fraction was observed. Distribution of FA in the sn‐2 position of TAG is assessed through enzymatic hydrolysis reaction. Bombyx mori larvae contain ALA at 49.1 mol% of total FA at the sn‐2 position of TAG, while OA is the main FA in sn‐2 position in G. mellonella (88.5 mol% of total FA). Overall, Lepidoptera larvae constitute a rich source of specifically located at the sn‐2 position OA and ALA, and similar or better than current sources. Initial data on other insect orders also points in this direction. Practical Applications: The present study develops knowledge about the lipid classes of Lepidoptera larvae, as well as on their regiospecific FA profiles. The data from Lepidoptera species are compared to other ones obtained from samples belonging to Diptera and Coleoptera. Insects are rich in essential amino acids; therefore if they contain omega‐3 and omega‐9 FA, would be healthy alternatives to other commonly consumed animal foods, which tend to be rich in saturated and omega‐6 FA. Therefore, it is necessary to check different species to know their FA profile, as well as both the structure of their TAG and their lipid classes. Lepidoptera larvae constitute an alternative source of OA‐ and ALA‐rich oils, which can be devoted for food use, as well as for using in the food and pharmaceutical industries, with agronomic implications. The lipid classes and the regiospecific fatty acid profiles of several Lepidoptera larvae (Class Insecta) with different geographic origin and compared to that of Coleoptera and Diptera is achieved. Enzymatic hydrolysis reaction shows that oleic and α‐linolenic acids are preferably located at the sn‐2 position of triacylglycerols in most of the analyzed species. According to the results of this work, new functional oils extracted from various insect species can be obtained.

Docosahexaenoic acid (DHA) is a well-known dietary n-3 polyunsaturated fatty acid (PUFA) found in marine fish and organisms whose beneficial effects for human health are widely reported. However, the supply of food containing DHA is currently becoming critical due to the overexploitation of fisheries worldwide. Consequently, searching for alternative sources of DHA is a relevant issue nowadays. Viscera from cultured fishes is considered a by-product by the fishery industry and therefore discarded after fish processing. In this work, viscera from farmed marine fish (Sparus aurata and Dicentrarchus labrax) and also oil extracted from such by-products have been studied to assess their suitability as DHA sources by obtaining their fatty acid profiles. Viscera oil was used as a source for DHA purification by a simple and easily scalable chromatographic method. As a result, a highly purified DHA fraction (>99.0% DHA on total fatty acids) was obtained.Practical applications: This DHA concentrate obtained from viscera oil could be potentially used for alimentary or pharmaceutical purposes due to its lower cholesterol content compared with other known marine sources and also because only safe and legally allowed food-grade solvents have been used throughout the whole process. This way, by obtaining a high added-value product, a revaluation is given to fish by-products which are usually discarded. Abbreviations: DHA, docosahexaenoic acid; EE, ethyl ester; EPA, eicosapentaenoic acid; FA, fatty acid; FAME, fatty acid methyl ester; FID, flame ionization detector; MUFA, monounsaturated fatty acids; PCB, polychlorinated biphenyls; PUFA, polyunsaturated fatty acids; SFA, saturated fatty acids 724Eur.

The cytotoxic effects of extracts of the tomato variety "Racimo" have been evaluated through the use of the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay at several concentrations. Three extracts-ethanol-water, petroleum ether, and in vitro digested tomato-exhibited in vitro cytotoxicity against the proliferation of the cultured cancer cell line HT-29. The concentration that caused 50% inhibition of cancer cell growth occurred (GI(50)) of the different extracts for HT-29 cells was 62.5 μg/mL for the petroleum ether extract and 87.0 μg/mL for the digested tomato extract. For the ethanol-water extract, it was not possible to determine this parameter at the assayed extract concentrations. These results clearly indicate that after the digestion process, the less polar substances, such as carotenoids and sterols, are bioavailable as active species against cancer cells. The GI(50) levels for tomato extracts are similar to those values reported for medicinal plants. The results of the MTT assay on nonmutagenic CCD-18 cells showed a lack of negative effect on cell growth, which indicates that tomato extracts act selectively on HT-29 tumor cells. (1)H-Nuclear magnetic resonance spectra confirmed the presence of known compounds with accepted cytotoxic activity against tumor lines (lycopene and β-carotene). The high cytotoxicity for HT-29 cells showed by the petroleum ether extract might be due to the simultaneous presence in the extract of both carotenoids and glyceryl esters of fatty acids. The results of this work clearly indicate the importance of carotenoid consumption on colon tumor proliferation and prevention, and also the importance of the dietary fats in carotenoid bioavailability.