Shrimp Oil Extracted from Shrimp Processing By-Product Is a Rich Source of Omega-3 Fatty Acids and Astaxanthin-Esters,and Reveals Potential Anti-Adipogenic Effects in 3T3-L1 Adipocytes

The province of Newfoundland and Labrador, Canada, generates tons of shrimp processing by-product every year. Shrimp contains omega (n)-3 polyunsaturated fatty acids (PUFA) and astaxanthin (Astx), a potent antioxidant that exists in either free or esterified form (Astx-E). In this study, shrimp oil (SO) was extracted from the shrimp processing by-product using the Soxhlet method (hexane:acetone 2:3). The extracted SO was rich in phospholipids, n-3 PUFA, and Astx-E. The 3T3-L1 preadipocytes were differentiated to mature adipocytes in the presence or absence of various treatments for 8 days. The effects of SO were then investigated on fat accumulation, and the mRNA expression of genes involved in adipogenesis and lipogenesis in 3T3-L1 cells. The effects of fish oil (FO), in combination with Astx-E, on fat accumulation, and the mRNA expression of genes involved in adipogenesis and lipogenesis were also investigated. The SO decreased fat accumulation, compared to untreated cells, which coincided with lower mRNA expression of adipogenic and lipogenic genes. However, FO and FO + Astx-E increased fat accumulation, along with increased mRNA expression of adipogenic and lipogenic genes, and glucose transporter type 4 (Glut-4), compared to untreated cells. These findings have demonstrated that the SO is a rich source of n-3 PUFA and Astx-E, and has the potential to elicit anti-adipogenic effects. Moreover, the SO and FO appear to regulate adipogenesis and lipogenesis via independent pathways in 3T3-L1 cells.     

Dietary Docosahexaenoic Acid and Eicosapentaenoic Acid Influence Liver Triacylglycerol and Insulin Resistance in Rats Fed a High-Fructose Diet

This study aimed to examine the benefits of different amounts of omega-3 (n-3) polyunsaturated fatty acids from fish oil (FO) on lipid metabolism, insulin resistance and gene expression in rats fed a high-fructose diet. Male Wistar rats were separated into two groups: Control (C, n = 6) and Fructose (Fr, n = 32), the latter receiving a diet containing 63% by weight fructose for 60 days. After this period, 24 animals from Fr group were allocated to three groups: FrFO2 (n = 8) receiving 63% fructose and 2% FO plus 5% soybean oil; FrFO5 (n = 8) receiving 63% fructose and 5% FO plus 2% soybean oil; and FrFO7 (n = 8) receiving 63% fructose and 7% FO. Animals were fed these diets for 30 days. Fructose led to an increase in liver weight, hepatic and serum triacylglycerol, serum alanine aminotransferase and HOMA1-IR index. These alterations were reversed by 5% and 7% FO. FO had a dose-dependent effect on expression of genes related to hepatic β-oxidation (increased) and hepatic lipogenesis (decreased). The group receiving the highest FO amount had increased markers of oxidative stress. It is concluded that n-3 fatty acids may be able to reverse the adverse metabolic effects induced by a high fructose diet.     

Fatty Acid Composition of Serum,Adipose Tissue,and Liver in Rats Fed Diets Containing Corn Oil or Cottonseed Oil

There have been few studies on the effect of cottonseed oil (CSO), one of the most commonly used vegetable oils in the United States, on indices of lipid status either in the rat or in any other species. Previous studies with rats have focused on the effect of CSO, versus that of other vegetable oils, on the concentration of cholesterol in serum and liver or on a limited number of fatty acids in serum, adipose tissue, or liver. The present study was designed to compare more fully than in previous studies the effect of CSO to that of corn oil (CO) on the fatty acid composition of serum, adipose tissue, and liver. Two groups of male rats (n=10 each) were used, each fed one of two purified diets containing 100 g/kg of either CO or CSO. Between-group differences included higher values (mol% total fatty acids) in adipose tissue for palmitic acid and stearic acid, but lower values in serum, adipose tissue, and liver for cis-vaccenic acid and oleic acid (C18:1n-9) for the CSO group than the CO. In addition, values in serum, adipose tissue, and liver for -linolenic acid (C18:3n-3) and its metabolite, docosahexaenoic acid (C22:6n-3), were lower for the CSO group than the CO. There was no effect of diet on serum or tissue levels of n-6 fatty acids (linoleic acid, dihomo--linolenic acid, and arachidonic acid). Differences in fatty acid compositions noted, e.g., those for C18:1n-9 and C22:6n-3, mainly reflected compositional differences between the two oils. Thus, use of CSO rather than CO affected serum and tissue concentrations of saturated, monounsaturated, and n-3 polyunsaturated fatty acids (PUFAs) but had no effect on n-6 PUFA status.     

The effect of algal protein diets on the regeneration of serum and liver proteins in protein depleted rats

The protein quality of algaeSpirulina platensis was evaluated biochemically in adult albino rats by serum protein regeneration studies. Rats depleted for 12 days were repleted for 15 days with diets containing 10% protein derived from algae, methionine supplemented algae, or casein. On protein depletion, the activity of the hepatic enzymes, succinic dehydrogenase and alanine aminotransferase, were lowered while the activity of alkaline phosphatase increased. Protein repletion with algal and casein diets resulted in an increased activity of succinic dehydrogenase and alanine amino transferase and a decrease in alkaline phosphatase activity. However, the levels of these three enzymes were lower with the algal than with the casein diets. Algal diets regenerated serum protein effectively though to a slightly lesser extent than casein.     

Influence of Dietary Lipids and Environmental Salinity on the n-3 Long-Chain Polyunsaturated Fatty Acids Biosynthesis Capacity of the Marine Teleost Solea senegalensis

Fish vary in their ability to biosynthesise long-chain polyunsaturated fatty acids (LC-PUFA) depending upon the complement and function of key enzymes commonly known as fatty acyl desaturases and elongases. It has been reported in Solea senegalensis the existence of a Δ4 desaturase, enabling the biosynthesis of docosahexaenoic acid (DHA) from eicosapentaenoic acid (EPA), which can be modulated by the diet. The present study aims to evaluate the combined effects of the partial replacement of fish oil (FO) with vegetable oils and reduced environmental salinity in the fatty acid composition of relevant body compartments (muscle, hepatocytes and enterocytes), the enzymatic activity over α-linolenic acid (ALA) to form n-3 LC-PUFA through the incubation of isolated hepatocytes and enterocytes with [1-¹⁴C] 18:3 n-3, and the regulation of the S. senegalensis fads2 and elovl5 in the liver and intestine. The presence of radiolabelled products, including 18:4n-3, 20:4n-3 and EPA, provided compelling evidence that a complete pathway enabling the biosynthesis of EPA from ALA, establishing S. senegalensis, has at least one Fads2 with ∆6 activity. Dietary composition prevailed over salinity in regulating the expression of fads2, while salinity did so over dietary composition for elovl5. FO replacement enhanced the proportion of DHA in S. senegalensis muscle and the combination with 20 ppt salinity increased the amount of n-3 LC-PUFA in hepatocytes.     

Biochemical response in rats to the addition of curry leaf (Murraya koenigii) and mustard seeds (Brassica juncea) to the diet

Three groups with 12 weanling male albino rats were group fed for 90 days on a standard laboratory rat diet plus 20% coconut oil either without a supplement or with the addition of 10% curry leaf or 10% mustard seeds. Feed was offered at a level of 10% body weight. At the end of the trial, measurements were made on the total serum cholesterol, high density lipoproteins, low density lipoproteins, and very low density lipoproteins fractions, release of lipoproteins into the circulation, lecithin cholesterol acyl transferase activity and lipoprotein lipase activity. Feed intake and mean body weight of the rats on each treatment was not significantly different. Both spices resulted in a reduction in total serum cholesterol and LDL+VLDL, an increase in the HDL, lower release of lipoproteins into the circulation and an increase in the LCAT activity.     

Nutrient composition and biological evaluation of mesta (Hibiscus sabdariffa) seeds

Two varieties of mesta (Hibiscus sabdariffa) seeds were analysed for their proximate composition. Their protein (18.8–22.3%), fat (19.1–22.8%) and dietary fiber (39.5–42.6%) contents were found to be high. The seeds were found to be a good source of minerals like phosphorus, magnesium and calcium. Their lysine and tryptophan contents were also high. Sulphur containing amino acids were limiting in this seed protein and the chemical score of mesta seed protein was 40 and 57 for AMV-2 and Bhimili-1 varieties respectively. Mesta seed oil is rich in unsaturated fatty acids (70%), of which linoleic acid constituted 44%. Weanling rats were fed with 10% mesta seed protein before and after cooking for 4 weeks. Food intake of animals receiving raw mesta seed diets was significantly lower than those receiving cooked mesta seed diets as well as the casein control diet. Protein and dry matter digestibilities of raw and cooked mesta seed diets were lower than that of casein control diet. Cooking improved the food intake, gain in body weight, dry matter and protein digestibility of mesta seed diets. PER and NPU of cooked mesta seed diets were significantly higher than the corresponding raw diets. These results indicate that cooked mesta seed protein is of relatively good quality.     

Fish Oil Increases Diet-Induced Thermogenesis in Mice

Increasing energy expenditure (EE) is beneficial for preventing obesity. Diet-induced thermogenesis (DIT) is one of the components of total EE. Therefore, increasing DIT is effective against obesity. We examined how much fish oil (FO) increased DIT by measuring absolute values of DIT in mice. C57BL/6J male mice were given diets of 30 energy% fat consisting of FO or safflower oil plus butter as control oil (Con). After administration for 9 days, respiration in mice was monitored, and then the data were used to calculate DIT and EE. DIT increased significantly by 1.2-fold in the FO-fed mice compared with the Con-fed mice. Body weight gain was significantly lower in the FO-fed mice. FO increased the levels of uncoupling protein 1 (Ucp1) mRNA and UCP1 protein in brown adipose tissue (BAT) by 1.5- and 1.2-fold, respectively. In subcutaneous white adipose tissue (subWAT), the levels of Ucp1 mRNA and UCP1 protein were increased by 6.3- and 2.7-fold, respectively, by FO administration. FO also significantly increased the expression of markers of browning in subWAT such as fibroblast growth factor 21 and cell death-inducing DNA fragmentation factor α-like effector a. Thus, dietary FO seems to increase DIT in mice via the increased expressions of Ucp1 in BAT and induced browning of subWAT. FO might be a promising dietary fat in the prevention of obesity by upregulation of energy metabolism.     

Redox Status and Neuro Inflammation Indexes in Cerebellum and Motor Cortex of Wistar Rats Supplemented with Natural Sources of Omega-3 Fatty Acids and Astaxanthin: Fish Oil,Krill Oil,and Algal Biomass

Health authorities worldwide have consistently recommended the regular consumption of marine fishes and seafood to preserve memory, sustain cognitive functions, and prevent neurodegenerative processes in humans. Shrimp, crabs, lobster, and salmon are of particular interest in the human diet due to their substantial provision of omega-3 fatty acids (n-3/PUFAs) and the antioxidant carotenoid astaxanthin (ASTA). However, the optimal ratio between these nutraceuticals in natural sources is apparently the key factor for maximum protection against most neuro-motor disorders. Therefore, we aimed here to investigate the effects of a long-term supplementation with (n-3)/PUFAs-rich fish oil, ASTA-rich algal biomass, the combination of them, or krill oil (a natural combination of both nutrients) on baseline redox balance and neuro-inflammation indexes in cerebellum and motor cortex of Wistar rats. Significant changes in redox metabolism were only observed upon ASTA supplementation, which reinforce its antioxidant properties with a putative mitochondrial-centered action in rat brain. Krill oil imposed mild astrocyte activation in motor cortex of Wistar rats, although no redox or inflammatory index was concomitantly altered. In summary, there is no experimental evidence that krill oil, fish oil, oralgal biomass (minor variation), drastically change the baseline oxidative conditions or the neuro-inflammatory scenario in neuromotor-associated rat brain regions.     

Characterization and Cytotoxicity Studies of the Rare 21:4 n-7 Acid and Other Polyunsaturated Fatty Acids from the Marine Opisthobranch Scaphander lignarius,Isolated Using Bioassay Guided Fractionation

The marine opisthobranch Scaphander lignarius has been analyzed in the systematic search for novel bioactive compounds in Arctic marine organisms using bioassay guided fractionation. A number of highly cytotoxic fractions were shown to contain mainly polyunsaturated fatty acids (PUFAs). Selected PUFAs were isolated and identified using both liquid chromatography-mass spectrometry (LC-MS) and nuclear magnetic resonance (NMR). It was shown that the opisthobranch contained unusual PUFAs such as several ω3 fatty acids and the ω7 heneicosa-5,8,11,14-tetraenoic acid (21:4 n-7) not isolated before. The organism was shown to be a very rich source of PUFAs and the activity of the isolated compounds against a range of human cancer cell lines (melanoma, colon carcinoma and breast carcinoma) is further reported. The ω7 PUFA was significantly more cytotoxic in comparison with reference ω6 arachidonic and ω3 eicosapentaenoic acid. A noteworthy non-selective cytotoxicity against normal lung fibroblasts was also established. The paper contains isolation protocols in addition to cytotoxicity data of the isolated compounds. The potential of marine mollusks as a source for rare PUFAs is also discussed.     

Growth,blood chemistry and histology of rats fed zincsupplemented rapeseed protein concentrates

Two rapeseed protein concentrates (RPC) supplemented with zinc oxide were fed to male and female rats at two levels providing approximately half or all of the protein in a purified basal diet containing 20% protein (N×6.25). Control groups were given either a purified basal diet with casein or a laboratory chow diet. After 16 weeks, there were no significant (P<0.05) differences in body weight except the male rats fed the casein control diet had higher body weights than did other male rats. No significant differences were observed in organ weights including thyroids, hematology, bone marrow differential counts, serum glucose, urea nitrogen, total protein, albumin/globulin ratio, cholesterol, transaminases or alkaline phosphatase. The levels of serum vitamins A and E of females fed some of the RPC diets were less than in those fed the caseincontrol diet, but equal to those in females fed laboratory chow diet. Females fed either RPC or casein in the semi-purified diets, which contained zinc oxide, exhibited kidney calcification.Bureau of Nutritional Sciences, No. 112; Food Research Institute, No. 420.     

Cassava-soy weaning food: Biological evaluation and effects on rat organs

Weaning food was formulated using a cassava product, `Tapioca' (TAP), supplemented with roasted – sproutedsoybeans (SS), with and without additional (10%)malted sorghum flour (MS). Biological evaluation wascarried out on the formulations using 4–5 week oldweanling albino rats, with Cerelac (a commercialmaize-milk weaning food) as the control diet. Therewere increases in growth rate of rats fed with boththe test and control diets. There were no significant(p > 0.05) differences between the test diets andcontrol diet in true digestibility values. Thebiological value (BV) and net protein utilization(NPU) values for the formulated diets were above therecommended minimum values. The weight of organs(small intestine, pancreas, liver and heart) of ratsfed TAP + SS and TAP + SS + MS based diets were nothigher than those of organs of rats fed Cerelac. Itwas concluded that cassava products could potentiallybe employed successfully in the preparation of weaningfoods of comparable quality to available commercialbrands.     

Bioavailability of tryptophan in selected foods by rat growth assay

Tryptophan bioavailabilities were estimated in 16 protein sources using 10 day rat growth assays with casein as the reference protein. Growth responses of rats fed test food diets were compared to growth responses of rats fed basal diets with graded levels of tryptophan ranging from 50 to 100 mg of tryptophan/100 g diet. Estimates of tryptophan availabilities were 85–100% for all products except whole wheat cereal (73%) and pinto beans (59%). Results of a previous study on lysine availability indicated that poor response to pinto beans was due either to poor digestibility or to the presence of some unidentified growth inhibitor.     

Hepatic Protection by Noni Fruit Juice Against CCl<Subscript>4</Subscript>-Induced Chronic Liver Damage in Female SD Rats

Morinda citrifolia L. (noni) has been used throughout the Pacific, Southeast Asia, Central America, and the Caribbean for a variety of health conditions, including heart and liver ailments. In this study, we examined the hepatoprotective effects of TAHITIAN NONI Juice (TNJ) against CCl(4)-induced chronic liver damage in female Sprague Dawley (SD) rats. Twelve female SD rats were divided into control, placebo and TNJ (6 mL/rat/day) groups. On day 15, animals in the placebo and TNJ groups received 0.25 mL/kg CCl(4) in corn oil once a week for 12 successive weeks. All animals were sacrificed at week 16. Blood and liver were collected for liver function, lipid panel tests, and histological observation. Histopathological examination revealed that liver sections from the TNJ + CCl(4) appeared similar to controls, whereas typical hepatic steatosis was observed in the placebo + CCl(4) group. Serum alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine transaminase (ALT), total cholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL), and very low-density lipoprotein (VLDL) levels were increased in the placebo group compared with the TNJ group. In contrast, high-density lipoprotein (HDL) was increased in the TNJ group and decreased in the placebo group. Thus, TNJ juice appears to protect the liver from chronic exogenous CCl(4) exposures. Such protective mechanisms are supportive evidence for the utility of noni in traditional medicine for liver ailments.     

Serum and liver lipids of rats fed rubber seed oil

Crude rubber seed oil (RSO) was incorporated at the 5% level in diets free of cholesterol or containing 1% cholesterol, respectively. These studies were initiated for the purpose of evaluating the palatability and potential toxicity of RSO. Corn oil was used as a control. A considerable amount of unsaponifiable matter was detected in RSO. In addition, RSO was found to possess a fatty acid profile which was fairly different from that of corn oil, primarily due to a much higher content of linolenic acid and a lower content of linoleic acid in RSO. No adverse effects on food intake and average daily gain were observed in rats fed RSO in both cholesterol-free and cholesterol diets. The presence of RSO in cholesterol-free diets results in lower (p<0.05) serum and liver total cholesterol levels than in control animals. A relative hypercholesterolemic effect compared to corn oil was observed however, when RSO was added to diets containing 1% cholesterol. In summary, the physicochemical properties of RSO as well as the presence of cholesterol in the diet are important factors in evaluating the cholesterolemic effect of RSO.     

Effect of varied fermentation periods on the diabetogenic potential of toasted cassava granules

The effects of exclusive gari diets prepared using varied fermentation periods on the fasting blood glucose levels (FBGL) and glucose tolerance (GT) of rats were studied. Thirty growing male albino rats divided randomly into 5 groups of 6 rats each were used. The 5 groups were each fed gari diets fermented for 0, 24, 48, 72 hours; and a standard rat diet, respectively, for 8 weeks. Data on the total cyanogen content and % crude protein of the diets; FBGL, GT, body weight, water:feed consumption ratio and clinical observations of the rats were collected. Results showed that the total cyanogen content and % crude protein of the diets were depleted as fermentation periods increased. The FBGL of all the gari-fed rats were significantly elevated and their GT significantly impaired with a significant variation between the groups. The elevated FBGL and impaired GT which were found to increase with increase in fermentation period were strongly inversely correlated to the % crude protein content of the diets (r = –0.92 and –0.96 respectively) suggesting that the diabetogenic potential of gari diets strongly depended on its % crude protein content. Shortened fermentation periods leading to production of gari with high total cyanogen content did not induce higher diabetogenicity.     

Effect of varied fermentation periods on the diabetogenic potential of toasted cassava granules.

The effects of exclusive gari diets prepared using varied fermentation periods on the fasting blood glucose levels (FBGL) and glucose tolerance (GT) of rats were studied. Thirty growing male albino rats divided randomly into 5 groups of 6 rats each were used. The 5 groups were each fed gari diets fermented for 0, 24, 48, 72 hours; and a standard rat diet, respectively, for 8 weeks. Data on the total cyanogen content and % crude protein of the diets; FBGL, GT, body weight, water:feed consumption ratio and clinical observations of the rats were collected. Results showed that the total cyanogen content and % crude protein of the diets were depleted as fermentation periods increased. The FBGL of all the gari-fed rats were significantly elevated and their GT significantly impaired with a significant variation between the groups. The elevated FBGL and impaired GT which were found to increase with increase in fermentation period were strongly inversely correlated to the % crude protein content of the diets (r = -0.92 and -0.96 respectively) suggesting that the diabetogenic potential of gari diets strongly depended on its % crude protein content. Shortened fermentation periods leading to production of gari with high total cyanogen content did not induce higher diabetogenicity.     

The USDA trypsin inhibitor study. IV. The chronic effects of soy flour and soy protein isolate on the pancreas in rats after two years

In two year feeding trials, histologic changes in the pancreas of the Wistar rat were evaluated after chronic dietary exposure to raw and heated, dehulled, defatted soy flour and soy protein isolates which provided a range of trypsin inhibitor (TI) concentrations from 93 to 1271 mg/100 g diet. Also investigated was the nutritional interaction of level of dietary protein with the development of pancreatic pathology. Graded levels of TI were achieved from mixtures of raw and heated soy flour or protein isolate. Dietary protein levels were 10%, 20%, and 30%; the two higher levels obtained in some diets through casein supplementation. A total of 26 diets, including casein controls, were fed to groups of 40 male rats. Growth rates with these diets were commensurate with protein quality and level. Mortality rates tended to be slightly greater in the higher protein diets, and rats fed only raw soy as a source of protein survived well.Two lesions, nodular hyperplasia (NH) and acinar adenoma (AA) constituted the major pathological findings in the pancreas, and the incidence rates of both were positively associated with the concentration of dietary TI. The incidences of pancreatic NH and AA compared to those of the corresponding casein control were significantly elevated in rats fed heated soy flour supplying 10% protein and the lowest level of TI investigated (93 mg/100 g diet). At low levels of TI (215 mg/100 g diet), supplementation by casein to raise the concentration of protein from 10% to 20% and 30% reduced the frequency of NH and AA. When the dose-response data for NH and AA was linearized by plotting the probit of percent incidence against log of TI concentration per gram of dietary protein, the response to soy flour and soy protein isolate was not significantly different. Numerous lesions commonly found in the aging rat were diagnosed, and modulation of their rate of occurrence by nutritional factors associated with the diets was apparent in some instances.Reference to a company and/or product named by the Department is only for purposes of information and does not imply approval or recommendation of the product to the exclusion of others which may also be suitable.     

Microalgae n-3 PUFAs Production and Use in Food and Feed Industries

N-3 polyunsaturated fatty acids (n-3 PUFAs), and especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are essential compounds for human health. They have been proven to act positively on a panel of diseases and have interesting anti-oxidative, anti-inflammatory or anti-cancer properties. For these reasons, they are receiving more and more attention in recent years, especially future food or feed development. EPA and DHA come mainly from marine sources like fish or seaweed. Unfortunately, due to global warming, these compounds are becoming scarce for humans because of overfishing and stock reduction. Although increasing in recent years, aquaculture appears insufficient to meet the increasing requirements of these healthy molecules for humans. One alternative resides in the cultivation of microalgae, the initial producers of EPA and DHA. They are also rich in biochemicals with interesting properties. After defining macro and microalgae, this review synthesizes the current knowledge on n-3 PUFAs regarding health benefits and the challenges surrounding their supply within the environmental context. Microalgae n-3 PUFA production is examined and its synthesis pathways are discussed. Finally, the use of EPA and DHA in food and feed is investigated. This work aims to define better the issues surrounding n-3 PUFA production and supply and the potential of microalgae as a sustainable source of compounds to enhance the food and feed of the future.     

Monocaprin Enhances Bioavailability of Fucoxanthin in Diabetic/Obese KK-Ay Mice

Fucoxanthin is a marine carotenoid found in brown seaweeds and several microalgae. It has been reported that fucoxanthin has health benefits such as anti-obesity and anti-diabetic effects. To facilitate fucoxanthin applications in the food industry, it is important to improve its low bioavailability. We attempted the combined feeding of fucoxanthin-containing seaweed oil (SO) and monocaprin in a powder diet and analyzed the fucoxanthin metabolite contents in the liver, small intestine and serum of diabetic/obese KK-A^y mice. After 4 weeks of feeding with the experimental diets, the serum fucoxanthinol concentrations of the mice fed 0.2% SO and 0.5% monocaprin were higher than those of the 0.2% SO-fed mice. Furthermore, fucoxanthinol accumulation in the liver and small intestine tended to increase in a combination diet of 0.2% SO and 0.125–0.5% monocaprin compared with a diet of 0.2% SO alone, although amarouciaxanthin A accumulation was not different among the 0.2% SO-fed groups. These results suggest that a combination of monocaprin with fucoxanthin-containing SO is an effective treatment for improving the bioavailability of fucoxanthin.