A pilot study on the effects of DHA/EPA-enriched phospholipids on aerobic and anaerobic exercises in mice

DHA/EPA-PL andl-carnitine had significant effects on aerobic exercise, while astaxanthin improved anaerobic exercise. The possible mechanism involved carbohydrate and lipid metabolism, mitochondrial respiratory chain and tricarboxylic acid cycle.

Soy β-Conglycinin Peptide Attenuates Obesity and Lipid Abnormalities in Obese Model OLETF Rats

We previously reported that soy β-conglycinin (βCG) improves obesity-induced metabolic abnormalities, but not obesity, in obese model Otsuka Long-Evans Tokushima fatty (OLETF) rats. In the present study, we aimed to investigate the effects of βCG-derived peptide consumption on obesity and lipid abnormality in OLETF rats. To this end, wild-type Long-Evans Tokushima Otsuka and OLETF rats were provided a normal diet containing 20% casein for four weeks as a control. In addition, we prepared βCG peptide by enzymatic hydrolysis, and OLETF rats were fed a diet in which half of the casein was replaced by βCG peptide (βCG peptide group). Consequently, rats in the βCG peptide group showed decreased abdominal white adipose tissue weight and lipid content (serum and liver triglycerides, and serum and liver cholesterol) compared to control OLETF rats. Further analysis demonstrated that βCG peptide consumption decreased lipogenic enzyme activity and increased lipolytic enzyme activity in the liver of OLETF rats. In addition, suppressive effects on both synthesis and absorption of cholesterol were observed in βCG peptide-fed OLETF rats. These findings suggest that peptidization of βCG enhanced the anti-obese and hypolipidemic effects of βCG.

The rapid effects of eicosapentaenoic acid (EPA) enriched phospholipids on alleviating exercise fatigue in mice

It has been reported that docosahexaenoic acid/eicosapentaenoic acid (DHA/EPA) and phospholipids (PLs) play an important role in alleviating exercise fatigue. However, the difference of DHA and EPA in ameliorating exercise fatigue is still unclear. Furthermore, the comparative study about DHA/EPA-PLs and nonpolar DHA/EPA on exercise fatigue has not been reported. In the present study, the effects of DHA and EPA on exercise fatigue was firstly compared by conducting an exhaustion test, and the results showed that triglyceride (TG) with high ratio of EPA had a more significant effect on alleviating exercise fatigue than TG with a low ratio of EPA in mice. Therefore, eicosapentaenoic acid–ethyl ester (EPA–EE) and EPA–PL were then selected to compare the rapid effects of polar and nonpolar DHA/EPA on exercise fatigue in mice by a weight-loaded swimming exhaustion test. A single intake of EPA–PL but not EPA–EE significantly alleviated exercise fatigue in mice by increasing the lactic acid recycling rate as well as inhibiting glycogen consumption and muscle injury, suggesting that EPA–PL exhibited a rapid effect on alleviating exercise fatigue. The study might represent a potential novel candidate or targeted dietary pattern for alleviating exercise fatigue.

EPA-PL has rapid effects on alleviating exercise fatigue by inhibiting lactic acid accumulation, glycogen consumption and muscle injury.

Koji glycosylceramide commonly contained in Japanese traditional fermented foods alters cholesterol metabolism in obese mice

Koji, which is manufactured by proliferating non-pathogenic fungus Aspergillus oryzae on steamed rice, is the base for Japanese traditional fermented foods. We have revealed that koji and related Japanese fermented foods and drinks such as amazake, shio-koji, unfiltered sake and miso contain abundant glycosylceramide. Here, we report that feeding of koji glycosylceramide to obese mice alters the cholesterol metabolism . Liver cholesterol was significantly decreased in obese mice fed with koji glycosylceramide. We hypothesized that their liver cholesterol was decreased because it was converted to bile acids. Consistent with the hypothesis, many bile acids were increased in the cecum and feces of obese mice fed with koji glycosylceramide. Expressions of CYP7A1 and ABCG8 involved in the metabolism of cholesterol were significantly increased in the liver of mice fed with koji glycosylceramide. Therefore, it was considered that koji glycosylceramide affects the cholesterol metabolism in obese mice.

Trimethylamine-N-oxide (TMAO)-induced atherosclerosis is associated with bile acid metabolism

BACKGROUND

Recently, trimethylamine-N-oxide (TMAO) plasma levels have been proved to be associated with atherosclerosis development. Among the targets aimed to ameliorating atherosclerotic lesions, inducing bile acid synthesis to eliminate excess cholesterol in body is an effective way. Individual bile acid as endogenous ligands for the nuclear receptor has differential effects on regulating bile acid metabolism. It is unclear whether bile acid profiles are mechanistically linked to TMAO-induced development of atherosclerosis.

METHODS

Male apoE^-/- mice were fed with control diet containing 0.3% TMAO for 8 weeks. Aortic lesion development and serum lipid profiles were determined. Bile acid profiles in bile, liver and serum were measured by liquid chromatographic separation and mass spectrometric detection (LC-MS). Real-time PCRs were performed to analyze mRNA expression of genes related to hepatic bile acid metabolism.

RESULTS

The total plaque areas in the aortas strongly increased 2-fold (P < 0.001) in TMAO administration mice. The levels of triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-c) in TMAO group were also significantly increased by 25.5% (P = 0.044), 31.2% (P = 0.006), 28.3% (P = 0.032), respectively. TMAO notably changed bile acid profiles, especially in serum, the most prominent inductions were tauromuricholic acid (TMCA), deoxycholic acid (DCA) and cholic acid (CA). Mechanically, TMAO inhibited hepatic bile acid synthesis by specifically repressing the classical bile acid synthesis pathway, which might be mediated by activation of small heterodimer partner (SHP) and farnesoid X receptor (FXR).

CONCLUSIONS

These findings suggested that TMAO accelerated aortic lesion formation in apoE^-/- mice by altering bile acid profiles, further activating nuclear receptor FXR and SHP to inhibit bile acid synthesis by reducing Cyp7a1 expression.

The contribution of cholesterol and epigenetic changes to the pathophysiology of breast cancer

Breast cancer​ is one of the most commonly diagnosed cancers in women. Accumulating evidence suggests that cholesterol plays an important role in the development of breast cancer. Even though the mechanistic link between these two factors is not well understood, one possibility is that dysregulated cholesterol metabolism may affect lipid raft and membrane fluidity and can promote tumor development. Current studies have shown oxysterol 27-hydroxycholesterol (27-HC) as a critical regulator of cholesterol and breast cancer pathogenesis. This is supported by the significantly higher expression of CYP27A1 (cytochrome P450, family 27, subfamily A, polypeptide 1) in breast cancers. This enzyme is responsible for 27-HC synthesis from cholesterol. It has been shown that 27-HC can not only increase the proliferation of estrogen receptor (ER)-positive breast cancer cells but also stimulate tumor growth and metastasis in several breast cancer models. This phenomenon is surprising since 27-HC and other oxysterols generally reduce intracellular cholesterol levels by activating the liver X receptors (LXRs). Resolving this paradox will elucidate molecular pathways by which cholesterol, ER, and LXR are connected to breast cancer. These findings will also provide the rationale for evaluating pharmaceutical approaches that manipulate cholesterol or 27-HC synthesis in order to mitigate the impact of cholesterol on breast cancer pathophysiology. In addition to cholesterol, epigenetic changes including non-coding RNAs, and microRNAs, DNA methylation, and histone modifications, have all been shown to control tumorigenesis. The purpose of this review is to discuss the link between altered cholesterol metabolism and epigenetic modification during breast cancer progression.

Effects of Astaxanthin and Docosahexaenoic-Acid-Acylated Astaxanthin on Alzheimer's Disease in APP/PS1 Double-Transgenic Mice

Alzheimer's disease (AD) is a progressive neurodegenerative disorder with the characteristics of senile plaques, neuroinflammation, neurofibrillary tangles, and destruction of synapse structure stability. Previous studies have verified the protective effects of astaxanthin (AST). However, whether synthesized docosahexaenoic-acid-acylated AST diesters (AST-DHA) could delay AD pathogenesis remains unclear. In the present study, APP/PSEN1 (APP/PS1) double-transgenic mice were administrated with AST and AST-DHA for 2 months. The results of radial 8-arm maze and Morris water maze tests showed that AST-DHA exerted more significant effects than AST in enhancing learning and memory levels of APP/PS1 mice. Further mechanical studies suggested that AST-DHA was superior to AST in regulating the parameters of oxidative stress, reducing tau hyperphosphorylation, suppressing neuroinflammation, and regulating inflammasome expression and activation in APP/PS1 mice. The findings suggested that AST-DHA attenuated cognitive disorders by reducing pathological features in APP/PS1 mice, suggesting that AST-DHA might be a potential therapeutic agent for AD.

Comparative Analysis of EPA/DHA-PL Forage and Liposomes in Orotic Acid-Induced Nonalcoholic Fatty Liver Rats and Their Related Mechanisms

Nonalcoholic fatty liver disease (NAFLD) has become one predictive factor of death from various illnesses. The present study was to comparatively investigate the effects of eicosapentaenoic acid-enriched and docosahexaenoic acid-enriched phospholipids forage (EPA-PL and DHA-PL) and liposomes (lipo-EPA and lipo-DHA) on NAFLD and demonstrate the possible protective mechanisms involved. The additive doses of EPA-PL and DHA-PL in all treatment groups were 1% of total diets, respectively. The results showed that Lipo-EPA could significantly improve hepatic function by down-regulating orotic acid-induced serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels by 55.6% and 34.2%, respectively (p < 0.01). Moreover, lipo-EPA exhibited excellent inhibition on the mRNA expression of SREBP-1c and FAS at the values of 0.454 ± 0.09 (p < 0.01) and 0.523 ± 0.08 (p < 0.01), respectively, thus ameliorating OA-induced NAFLD. Meanwhile, lipo-EPA could significantly suppress the SREBP-2 and HMGR levels (31.4% and 66.7%, p < 0.05, respectively). In addition, EPA-PL and lipo-DHA could also significantly suppress hepatic lipid accumulation mainly by enhancement of hepatic lipolysis and cholesterol efflux. Furthermore, DHA-PL played a certain role in inhibiting hepatic lipogenesis and accelerating cholesterol efflux. The results obtained in this work might contribute to the understanding of the biological activities of EPA/DHA-PL and liposomes and further investigation on its potential application values for food supplements.

The Protective Effect of Antarctic Krill Oil on Cognitive Function by Inhibiting Oxidative Stress in the Brain of Senescence-Accelerated Prone Mouse Strain 8 (SAMP8) Mice

Alzheimer's disease (AD) is a common neurodegenerative disorder, and oxidative stress plays a vital role in its progression. Antarctic krill oil (AKO) is rich in polyunsaturated fatty acids, which has various biological activities, such as improving insulin sensitivity, alleviating inflammation and ameliorating oxidative stress. In this study, the protective effect of AKO against AD were investigated in senescence-accelerated prone mouse strain 8 (SAMP8) mice. Results showed that treatment with AKO could effectively ameliorate learning and memory deficits and ease the anxiety in SAMP8 mice by Morris water maze, Barnes maze test and open-field test. Further analysis indicated that AKO might reduce β-amyloid (Aβ) accumulation in hippocampus through decreasing the contents of malondialdehyde (MDA) and 7,8-dihydro-8-oxoguanine (8-oxo-G), increasing the superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities in the brain of SAMP8 mice.

PRACTICAL APPLICATION

The results of Morris water maze, Barnes maze test and open-field test indicated that Antarctic krill oil (AKO) improved the cognitive function and anxiety of SAMP8 mice. AKO reduced the Aβ₄₂ level in hippocampus of SAMP8 mice. AKO ameliorated oxidative stress in brain rather than in serum and liver of SAMP8 mice.

Comparative study of the effects of phosphatidylcholine rich in DHA and EPA on Alzheimer's disease and the possible mechanisms in CHO-APP/PS1 cells and SAMP8 mice

The beneficial effects of DHA-PC and EPA-PC on AD and the possible underlying molecular mechanisms.

A comparative study of EPA-enriched ethanolamine plasmalogen and EPA-enriched phosphatidylethanolamine on Aβ42 induced cognitive deficiency in a rat model of Alzheimer's disease

The possible molecular mechanism of EPA-pPE and EPA-PE on AD.

Sea cucumber saponin liposomes ameliorate obesity-induced inflammation and insulin resistance in high-fat-diet-fed mice

Liposomes proved to be a good form for the intake of sea cucumber saponins, which exhibited better bioactivity in preventing diseases related to metabolic syndrome.

Comparative analyses of DHA-Phosphatidylcholine and recombination of DHA-Triglyceride with Egg-Phosphatidylcholine or Glycerylphosphorylcholine on DHA repletion in n-3 deficient mice

Background

Docosahexaenoic acid (DHA) is important for optimal neurodevelopment and brain function during the childhood when the brain is still under development.

Methods

The effects of DHA-Phosphatidylcholine (DHA-PC) and the recombination of DHA-Triglyceride with egg PC (DHA-TG + PC) or α-Glycerylphosphorylcholine (DHA-TG + α-GPC) were comparatively analyzed on DHA recovery and the DHA accumulation kinetics in tissues including cerebral cortex, erythrocyte, liver, and testis were evaluated in the weaning n-3 deficient mice.

Results

The concentration of DHA in weaning n-3 deficient mice could be recovered rapidly by dietary DHA supplementation, in which DHA-PC exhibited the better efficacy than the recombination of DHA-Triglyceride with egg PC or α-GPC. Interestingly, DHA-TG + α-GPC exhibited the greater effect on DHA accumulation than DHA-TG + PC in cerebral cortex and erythrocyte (p < 0.05), which was similar to DHA-PC. Meanwhile, DHA-TG + PC showed a similar effect to DHA-PC on DHA repletion in testis, which was better than that of DHA-TG + α-GPC (p < 0.05).

Conclusion

We concluded that different forms of DHA supplements could be applied targetedly based on the DHA recovery in different tissues, although the supplemental effects of the recombination of DHA-Triglyceride with egg PC or α-GPC were not completely equivalent to that of DHA-PC, which could provide some references to develop functional foods to support brain development and function.

Pterostilbene, a dimethylated analog of resveratrol, promotes energy metabolism in obese rats

Pterostilbene (trans-3,5-dimethoxy-4-hydroxystilbene) is a dimethylated analog of resveratrol and has been reported to exert various pharmacological effects. In this study, we evaluated the effect of pterostilbene on the pathogenesis of obesity and energy metabolism in obese rats. Pterostilbene significantly activates silent mating type information regulation 2 homolog-1 and peroxisome proliferator-activated receptor-alpha in vitro. At 4 weeks a 0.5% pterostilbene diet markedly suppressed the abdominal white adipose tissue (WAT) accumulation in obese rats. The oxygen consumption and energy expenditure were significantly higher in the pterostilbene group, and pterostilbene increased the fat metabolism rather than the carbohydrate metabolism in obese rats. The mRNA level of uncoupling protein, a thermogenic regulator, was increased and the mRNA levels of fatty acid synthase and leptin, which are involved in lipogenesis and fat storage, were markedly decreased in WAT after the pterostilbene feeding. These results suggest that pterostilbene prevents WAT accumulation through the enhancement of energy metabolism and partly the suppression of lipogenesis in obese OLETF rats.

Soy Protein Isolate Suppresses Lipodystrophy-induced Hepatic Lipid Accumulation in Model Mice

Lipodystrophies are acquired and genetic disorders characterized by the complete or partial absence of body fat with a line of metabolic disorders, including hepatic steatosis. Because soy protein isolate (SPI) has been reported to reduce cholesterol and triglyceride levels in animals and humans, we explored the effect of SPI on the pathophysiology of hepatic lipid accumutaion in a diet-induced lipodystrophy model mice. Four weeks of the lipodystrophy model diet induced hepatic lipid accumulation concomitant with marked deficiencies of adipose tissue and serum adipocytokines in mice. However, supplementing the lipodystrophy model diet with SPI could alleviate the hepatic lipid acculation without affecting the lipoatrophic effect of the diet. Enhanced lipogenesis is the principal mechanism of hepatic steatosis in this model, but SPI supplementation significantly attenuated the increase in enzyme activity and/or mRNA expression. Additionally, SPI supplementation upregulated the hepatic mRNA expression of an enzyme involved in cholesterol catabolism. In conclusion, our results indicate the possibility of dietary SPI to attenuate lipodystorophy-induced hepatic steatosis through the direct reduction of hepatic lipogenesis without affecting adipocytokine production.

Serum pharmacokinetics of choline, trimethylamine, and trimethylamine-N-oxide after oral gavage of phosphatidylcholines with different fatty acid compositions in mice

Little is known about the pharmacokinetics of phosphatidylcholine (PC)-derived choline, trimethylamine (TMA), and trimethylamine-N-oxide (TMAO). We therefore aim to investigate serum choline, TMA, and TMAO pharmacokinetics following different PCs gavage and compare the difference between PC emulsions and liposomes (SOL). Serum choline, TMA, and TMAO levels were measured after orally gavaged egg yolk PC emulsion (EGE), squid PC emulsion (SQE), soybean PC emulsion (SOE), and SOL in fasted mice. Time to reach peak concentration (Tmax) and productions for TMA and TMAO were more slow and less in SQE group compared with EGE and SOE groups. Tmax for choline, TMA, and TMAO prolonged, and the productions of them were significantly declined in SOL group compared to SOE group. These findings indicated that marine source squid PC could counter-regulate the potential risks of TMAO generation, and the use of liposome as the form of PC supplementary may eliminate TMAO production.

Effects of different fatty acids composition of phosphatidylcholine on brain function of dementia mice induced by scopolamine

BACKGROUND

Phosphatidylcholine (PC), the major source of dietary choline, has been demonstrated to improve the capability of learning and memory in rodent and the amelioration of long-chain n-3 polyunsaturated fatty acids (PUFA) on anti-aging and anti-oxidation is widely known as well. In this study, three kinds of PC were chose to demonstrate the role of different fatty acids composition on glycerol backbone in improving the brain function of mice induced by scopolamine which was used to impair cholinergic system and cause oxidative stress.

METHODS

Male BALB/c mice were randomly divided into 5 groups: model (M) group, control (Con) group, egg yolk lecithin (EL) group, squid PC (SQ-PC) group and sea cucumber PC (SC-PC) group. The intraperitoneal injection of scopolamine hydrobromide (5 mg/kg) was carried out on the 8(th) of group feeding and sustained daily until the end of test. Morris water maze test was used to evaluate the improvement of cognitive decline and the activity of acetylcholinesterase (AchE), superoxide dismutase (SOD) and monoamine oxidase (MAO) and malondialdehyde (MDA) content in brain were measured to assess the physiological changes.

RESULTS

In behavior test, the latency of PC groups was significantly reduced, while number of crossing the platform and time in target quadrant were increased in comparison with M group and the improvements of SQ-PC and SC-PC were better than that of EL (P < 0.05). Similar trend was observed in physiological changes. The AchE activity was effectively decreased and the SOD activity increased in hippocampus, cortex and white matter when comparing PC groups with M group. SQ-PC, SC-PC and EL respectively showed 22.82, 28.80 and 11.81 % decrease in MDA level in brain compared with M group. The MAO activity in white matter of SQ-PC, SC-PC and EL group separately depressed 33.05, 33.64 and 19.73 % in comparison with M group. No significance between SQ-PC and SC-PC was found in these indicators except the SOD activity in hippocampus and white matter. SQ-PC group had a higher SOD activity in hippocampus (103.68U/mg · prot.) and lower in white matter (120.57 U/mg · prot.) than SC-PC group (95.53 U/mg · prot. in hippocampus, 134.49 U/mg · prot. in white matter). PC rich in n-3 PUFA acted more ameliorative effects than that barely contained on the indicators above.

CONCLUSIONS

Different fatty acids composition of PC all could diminish the cognitive decline and biological damage and protect the brain. EPA and DHA partly enhaced to the advantageous effects.

Japanese traditional dietary fungus koji Aspergillus oryzae functions as a prebiotic for Blautia coccoides through glycosylceramide: Japanese dietary fungus koji is a new prebiotic

Background

The Japanese traditional cuisine, Washoku, considered to be responsible for increased longevity among the Japanese, comprises various foods fermented with the non-pathogenic fungus Aspergillus oryzae (koji). We have recently revealed that koji contains an abundant amount of glycosylceramide. Intestinal microbes have significant effect on health. However, the effects of koji glycosylceramide on intestinal microbes have not been studied.

Materials and methods

Glycosylceramide was extracted and purified from koji. C57BL/6N mice were fed a diet containing 1 % purified koji glycosylceramide for 1 week. Nutritional parameters and faecal lipid constituents were analyzed. The intestinal microbial flora of mice on this diet was investigated.

Results

Ingested koji glycosylceramide was neither digested by intestinal enzymes nor was it detected in the faeces, suggesting that koji glycosylceramide was digested by the intestinal microbial flora. Intestinal microbial flora that digested koji glycosylceramide had an increased ratio of Blautia coccoides. Stimulation of B. coccoides growth by pure koji glycosylceramide was confirmed in vitro.

Conclusions

Koji functions as a prebiotic for B. coccoides through glycosylceramide. Since there are many reports of the effects of B. coccoides on health, an increase in intestinal B. coccoides by koji glycosylceramide might be the connection between Japanese cuisine, intestinal microbial flora, and longevity.

Long-term fatty liver-induced insulin resistance in orotic acid-induced nonalcoholic fatty liver rats

We investigated whether fatty liver preceded insulin resistance or vice versa using a long-term orotic acid (OA)-induced nonalcoholic fatty liver disease (NAFLD) model without the confounding effects of obesity and hyperlipidemia and explored the role of the liver in insulin resistance. Male Wistar rats were fed with or without OA supplementation for 30, 60, and 90 days. The NAFLD group showed increased liver lipid at 30, 60, and 90 days; glucose intolerance was noted at 60 and 90 days. Furthermore, partial liver proteins and gene expressions related to upstream signaling of insulin were decreased. However, the liver glycogen content was elevated, and gluconeogenesis genes expressions were obviously decreased at 90 days. The occurrence of fatty liver preceded insulin resistance in OA-induced NAFLD without the interference of obesity and hyperlipidemia, and hepatic insulin resistance may not play a conclusive role in insulin resistance in this model.