Determination of selenium and its compounds in marine organisms

In this study, we investigate the type and quantity of selenium compounds in fish and marine organisms, using ion-pair reversed phase LC–ICP-MS, developed and applied for the analysis of Atlantic cod, Atlantic salmon, Greenland halibut, Atlantic herring, blue mussel, common crab, scallop, calanus, and Euphasia super. Of the samples examined, the lowest level of selenium was found in farmed Atlantic salmon (0.17 mg Se kg⁻¹ dm). The total selenium extraction efficiency by phosphate buffer was 2.5 times higher in sea plankton and shellfish samples than in fish samples. Analysis of Se species in each hydrolysate obtained by proteolysis showed the presence of selenomethionine, which constituted 41.5% of the selenium compounds detected in hydrolysates of Atlantic herring and 98.4% of those in extracts of Atlantic salmon. Inorganic compounds, such as selenates and selenites, were detected mainly in sea plankton and shellfish samples (<0.13 mg Se kg⁻¹ wm), although no correlation was found between the presence of inorganic compounds and total selenium concentration. The accuracy of the total selenium determination was validated using a certified reference material (oyster tissue (NIST 1566b)). A lyophilised powder of cod (Gadus morhua) was used to validate speciation analysis, enzymatic hydrolysis of lyophilised powder of cod recovered 54 ± 6% of total selenium, and SeMet constituted 83.5 ± 5.28% of selenium detected in hydrolysates. The chromatographic detection limits were, respectively, 0.30 ng mL⁻¹, 0.43 ng mL⁻¹, 0.54 ng mL⁻¹, 0.55 ng mL⁻¹, 0.57 ng mL⁻¹ and 0.72 ng mL⁻¹ for selenate, selenomethionine, selenite, Se-methyl-selenocysteine, selenocystine and selenomethionine selenoxide.The data on selenium concentrations and speciation presented here could be useful in estimating levels of selenium intake by seafood consumption.     

The development of functional foods: lessons from the gut

Functional foods have resulted from the gradual recognition that healthy diets result from eating nutritious foods and from the identification of the mechanisms by which foods modulate metabolism and health. After initial successes with foods that reduce blood cholesterol level, probiotic bacteria and prebiotic carbohydrates have now also demonstrated added health benefits. As ingredients become more complex, the need to stabilize such ingredients in foods become increasingly important to the success of functional foods. Modern biotechnologies such as genomics, genetic expression and biomarkers of health and performance will be applied to this increasingly visible portion of human diets.     

基于菌群调控下的天然植物活性成分与全食态健康效用评价

肠道菌群与人体共同协作,菌群在帮助宿主对食物中的营养成分进行深入消化与利用的同时,也一同分享宿主为其提供的生存空间与营养物质,这是微生物与宿主之间形成的一种互利共生的特殊共存方式。这样的精妙结合,不仅使得微生物在人体中形成了固有的菌群结构,得到赖以生存的生物基位,也通过自身的功能代谢以及群体信号,为宿主在免疫、营养等方面提供所必需的调节与支撑。围绕药食同源天然植物的健康作用研究,目前大多着眼于对其功能组分的分离提取与活性评价。如植物多糖、多酚与黄酮等活性功能成分。然而在传统中医药中,植物多以全食态进行复配应用。目前在菌群水平研究中发现,对于影响人体健康水平的菌群模式并非固定且依赖于某一单菌种变化,微生物之间的生态竞争与代谢调控均以群体的方式与宿主持续进行共进化。药食同源天然植物,对菌群的调节作用主要还是依靠其全食态,这也从菌群这个微观生态环境的角度为传统中医学理论中对于中药食材即天然植物全食状态下的药效提供了重要佐证。因此,对于药食同源天然植物的开发与利用,应当结合菌群整体的调控进行分析,并对其全食状态与活性功能组分有充分的认识与评价。     

Recombinant Balsamin induces apoptosis in liver and breast cancer cells via cell cycle arrest and regulation of apoptotic pathways

Recombinant balsamin (rBalsamin), a type I ribosome inactivating protein classified as RNA N-glycosidase, is known to possess antibacterial and DNase like activity. However, its anticancer properties have not yet been examined. In this study, we aimed to investigate the potential cytotoxicity of rBalsamin on hepatocellular (HepG2 and H4IIE) and breast (MCF-7 and BT549) carcinoma cells and the related mechanism. rBalsamin arrested cell cycle at G or S phase and increased the level of caspase-3/8. The expression of Bax, Bid, Bad and p53 increased and that of Bcl-2 and BCL-xl decreased in liver and breast cancer cells with rBalsamin treatment. We found that rBalsamin inhibited cell viability of liver and breast cancer cells in a concentration and time dependent manner with IC₅₀ ranging between 18.92 to > 200 μg/mL. These findings suggest that rBalsamin induced apoptosis in liver and breast cancer cells via death receptor and mitochondrial associated apoptotic pathways, could prove beneficial in the field of cancer therapeutics, highlighting its potential as a functional food ingredient.     

Health benefits of fermented foods: microbiota and beyond

Consumption of fermented foods is associated with numerous health benefits stemming from viable microorganisms and fermentation-associated modifications to food constituents. FM, fermented milk product; FDP, fermented dairy products; FSP, fermented soy products; LFODMAP, low-fermentable oligosaccharides, disaccharides, monosaccharides, polyols; IBS, irritable bowel syndrome.

     

Immunomodulatory effects of polysaccharides isolated from Hericium erinaceus on dendritic cells

Hericium erinaceus (H. erinaceus; HE) polysaccharides (HE-PS) have been shown to have immunomodulatory activity. We found that the bioactive components of β-glucan derivatives consisted of 20% in HE-PS. We used an analytic platform for investigating the effects of HE-PS on the maturation of rat dendritic cells (DCs), which are derived from rat bone marrow hematopoietic cells (BMHCs). The results showed that treatment with 50 μg/mL HE-PS changed the morphology of the DCs to an active form in parallel with a significant two fold increase in MHC class II and CD80/86 surface antigens compared to the control. Furthermore, endocytosis by the DCs was significantly reduced at the same dosage. IL-12, IFN-γ and IL-10 cytokine secretion was significantly increased by 2.7, 1.5 and 1.6-fold, respectively, compared to the control after treatment with 50 μg/mL of HE-PS. This study used a powered analysis platform to show that HE-PS induces DCs activation and modulates the T_H1 immune response. Thus, HE-PS has potential as an immunopotentiating agent that could be further developed in the health food industry.     

Health benefits of chromones: common ingredients of our daily diet

Phytochemistry Reviews - Chromones are naturally occurring phenolic compounds that are universally present in a healthy human diet. To date, thousands of chromone derivatives, including chromone...     

组方食品对2型糖尿病小鼠血糖及 肠道菌群的影响

目的研究含有浒苔等植物的功能性食品对糖尿病小鼠血糖浓度的影响,并应用PCR-DGGE技术评价其对昆明小鼠肠道菌群稳态的影响。方法采用高脂饲料喂养昆明小鼠加腹腔注射链脲佐菌素(STZ)的方法建立糖尿病小鼠模型;将实验动物随机分为正常对照组、自然恢复组和功能性食品喂养组,连续给药4周,尾静脉采血测量血糖水平。收集小鼠新鲜粪便,提取粪便细菌基因组DNA,通过PCR-DGGE获得细菌群落指纹图谱,并进行相关软件分析,同时切离差异显著条带进行序列分析。结果本实验采用的功能性食品对糖尿病小鼠有降糖作用,并使血糖值稳定地维持在较低水平。4周后,功能性食品喂养的糖尿病小鼠血糖水平相对普通饲料喂养的糖尿病小鼠血糖发生显著性下降(t=4.19,P0.01);给2型糖尿病小鼠提供普通饲料时,其肠道菌群种类和数目相对较少;而提供功能性食品时,肠道菌群种类和数目相对增多,特别是双歧杆菌、Prevotella oryzae、Barnesiella intestinihominis、Culturomica和Parabacteroides distasonis明显增多,但是Muribaculum较少。结论高脂饲料结合STZ诱导的2型糖尿病小鼠肠道菌群发生显著改变,组方食品通过扶持肠道菌群,降低血糖水平。     

Production of antihypertensive and antioxidant activities by enzymatic hydrolysis of protein concentrates recovered by ultrafiltration from cuttlefish processing wastewaters

This work focuses on the production of antihypertensive and antioxidant activities using enzymatic hydrolysis of protein concentrates recovered by ultrafiltration of different wastewaters from the industrial processing of cuttlefish (Illex argentinus). The effluents were produced in the processes of thawing (E1), softening (E2), boiling (E3) and gelation (E4). Our results showed that membranes with cut-off at 100, 30 and 10 kDa were an effective resource to protein concentration of E2 and E3 but limited for E1 and E4. In addition, E2 and E3 retentates led to remarkable antihypertensive and antioxidant activities, further improved by enzymatic hydrolysis. Also sequential ultrafiltration revealed the enrichment of these protein concentrates in peptides with high angiotensin-converting enzyme (ACE)-inhibitory activity. Thereby, UF-fractionation followed by proteolysis of protein concentrates from cuttlefish wastewaters offers new opportunities for the development of bioactive hydrolysates with application in the food industry. In addition, this approach contributes to an improved depuration of industrial wastewaters, reducing the treatment costs and leading to a decrease in its contaminating effect.     

Selenium and Mercury in Pelagic Fish in the Central North Pacific Near Hawaii

Protective effects of selenium against mercury toxicity have been demonstrated in all animal models evaluated. As interactions between selenium and mercury and their molar ratios in seafood are essential factors in evaluating risks associated with dietary mercury exposure, considering mercury content alone is inadequate. In this study, the absolute and molar concentrations of mercury and selenium were determined in edible portions from 420 individual fish representing 15 species of pelagic fish collected from the central North Pacific Ocean near Hawaii. Selenium was in molar excess of mercury in almost all fish species evaluated. The rank order of mean Se/Hg molar ratios was striped marlin (17.6) > yellowfin tuna (14.1) > mahimahi (13.1) > skipjack tuna (12.8) > spearfish (11.4) > wahoo (10.8) > sickle pomfret (6.7) > albacore tuna (5.3) > bigeye tuna (5.2) > blue marlin (4.1) > escolar (2.4) > opah (2.3) > thresher shark (1.5) > swordfish (1.2) > mako shark (0.5). With a Se/Hg molar ratio of less than 1, mako shark was the only fish containing a net molar excess of mercury. A selenium health benefit value based on the absolute amounts and relative proportions of selenium and mercury in seafood is proposed as a more comprehensive seafood safety criterion.     

Direct comparison of metabolic health effects of the flavonoids quercetin,hesperetin, epicatechin,apigenin and anthocyanins in high-fat-diet-fed mice

Dietary flavonoid intake is associated with reduced risk of cardiovascular diseases, possibly by affecting metabolic health. The relative potency of different flavonoids in causing beneficial effects on energy and lipid metabolism has not been investigated. Effects of quercetin, hesperetin, epicatechin, apigenin and anthocyanins in mice fed a high-fat diet (HF) for 12 weeks were compared, relative to normal-fat diet. HF-induced body weight gain was significantly lowered by all flavonoids (17–29 %), but most by quercetin. Quercetin significantly lowered HF-induced hepatic lipid accumulation (71 %). Mesenteric adipose tissue weight and serum leptin levels were significantly lowered by quercetin, hesperetin and anthocyanins. Adipocyte cell size and adipose tissue inflammation were not affected. The effect on body weight and composition could not be explained by individual significant effects on energy intake, energy expenditure or activity. Lipid metabolism was not changed as measured by indirect calorimetry or expression of known lipid metabolic genes in liver and white adipose tissue. Hepatic expression of Cyp2b9 was strongly downregulated by all flavonoids. In conclusion, all flavonoids lowered parameters of HF-induced adiposity, with quercetin being most effective.

Electronic supplementary material

The online version of this article (doi:10.1007/s12263-015-0469-z) contains supplementary material, which is available to authorized users.     

Phytochemical characterization of potential nutraceutical ingredients from Evening Primrose oil (Oenothera biennis L.)

Evening Primrose oil (EPO) is a natural product extracted by cold-pressed from Oenothera biennis L. seeds. EPO is widely used as a dietary supplement from which beneficial effects have been reported in rheumatic and arthritic conditions, atopic dermatitis, psoriasis, premenstrual and menopausal syndrome, and diabetic neuropathy. The beneficial effects of EPO are thought to be due to its γ-linolenic acid content; in contrast, little effort has been expended to characterize the non-triglyceridic constituents of EPO. In order to evaluate its potential as source of functional food ingredients our aim in this work has been identified and quantified the different components of EPO by different techniques (GC–MS and HPLC). The lipid profile showed that oleic (7%), linoleic (74%) and γ-linolenic (9%) were the most abundance fatty acids. Unsaponifiable matter and subfractions were obtained by CEE/2568/91. Separation of the compounds under study was achieved giving a reasonable analysis time and good resolution. A yield (1.82–1.95%) of unsaponifiable matter was obtained and levels of saturated hydrocarbons (0.291.97 ± 14.85 mg) were noticed. β-Sitosterol (7952.00 ± 342.25 mg/kg oil) and campesterol (883.32 ± 0.45 mg/kg oil) were predominant in phytosterol fraction (9573 mg/kg oil), while tetracosanol (236.93 ± 2.32 mg/kg oil) and hexacosanol (289.92 ± 3.41 mg/kg oil) in linear aliphatic alcohol fraction (798.04 ± 5.66 mg/kg oil). In the phenolic fraction (55.49 ± 2.76 mg/kg oil), ferulic acid (25.23 ± 2.64 mg/kg oil) was the major component. From the results obtained, it can be suggested that the Evening Primrose oil can be considered an interesting alimentary source of substances of nutraceutical value.     

左旋肉碱在医疗、保健食品领域的研究应用新进展

左旋肉碱是一种广泛存在于机体组织的特殊氨基酸,其主要生理功能是氧化脂肪,为机体提供能量.本文综述了左旋肉碱近年来在我国临床治疗领域／功能性保健食品添加剂等方面的新的试验结果。     

The costs and benefits of resource sharing: reciprocity requires resource heterogeneity

The evolution of resource sharing requires that the fitness benefits to the recipients be much higher than the costs to the giver, which requires heterogeneity among individuals in the fitness value of acquiring additional resources. We develop four models of the evolution of resource sharing by either direct or indirect reciprocity, with equal or unequal partners. Evolution of resource sharing by reciprocity requires differences between interacting individuals in the fitness value of the resource, and these differences must reverse although previous acts of giving are remembered and both participants survive. Moreover, inequality in the expected reproductive value of the interacting individuals makes reciprocity more difficult to evolve, but may still allow evolution of sharing by kin selection. These constraints suggest that resource sharing should evolve much more frequently by kin selection than by reciprocity, a prediction that is well supported by observations in the natural world.     

Conflict between direct and indirect benefits of female choice in desert Drosophila

Identifying the factors that contribute to the adaptive significance of mating preferences is one major goal of evolutionary research and is largely unresolved. Both direct and indirect benefits can contribute to mate choice evolution. Failure to consider the interaction between individual consequences of mate choice may obscure the opposing effects of individual costs and benefits. We investigate direct and indirect fitness effects of female choice in a desert fly (Drosophila mojavensis), a species where mating confers resistance to desiccation stress. Females prefer males that provide a direct benefit: greater resistance to desiccation stress. Mating preferences also appear to have indirect consequences: daughters of preferred males have lower reproductive success than daughters of unpreferred males, although additional experimentation will be needed to determine if the indirect consequences of female preferences actually arise from 'sexually antagonistic' variation. Nevertheless, the results are intriguing and are consistent with the hypothesis that an interaction between direct and indirect benefits maintains sexually antagonistic variation in these desert flies: increased desiccation resistance conferred by mating might offset the cost of producing low-fecundity daughters.     

Pharmaceutically active secondary metabolites of marine actinobacteria

Marine actinobacteria are one of the most efficient groups of secondary metabolite producers and are very important from an industrial point of view. Many representatives of the order Actinomycetales are prolific producers of thousands of biologically active secondary metabolites. Actinobacteria from terrestrial sources have been studied and screened since the 1950s, for many important antibiotics, anticancer, antitumor and immunosuppressive agents. However, frequent rediscovery of the same compounds from the terrestrial actinobacteria has made them less attractive for screening programs in the recent years. At the same time, actinobacteria isolated from the marine environment have currently received considerable attention due to the structural diversity and unique biological activities of their secondary metabolites. They are efficient producers of new secondary metabolites that show a range of biological activities including antibacterial, antifungal, anticancer, antitumor, cytotoxic, cytostatic, anti-inflammatory, anti-parasitic, anti-malaria, antiviral, antioxidant, anti-angiogenesis, etc. In this review, an evaluation is made on the current status of research on marine actinobacteria yielding pharmaceutically active secondary metabolites. Bioactive compounds from marine actinobacteria possess distinct chemical structures that may form the basis for synthesis of new drugs that could be used to combat resistant pathogens. With the increasing advancement in science and technology, there would be a greater demand for new bioactive compounds synthesized by actinobacteria from various marine sources in future.     

Beneficial microbiota. Probiotics and pharmaceutical products in functional nutrition and medicine

The article is mainly devoted to such representatives of gut microbiota as lactic acid bacteria and bifidobacteria, with minor accent on less frequently used or new probiotic microorganisms. Positive effects in treatment and prevention of diseases by different microbial groups, their metabolites and mechanisms of action, management and market of probiotic products are considered.     

内蒙古磴口县林业生态建设工程综合效益评价

林业生态建设工程具有重要的经济、生态和社会效益。内蒙古磴口县是林业生态建设工程实施的重点地区,对该区域林业生态建设工程的综合效益进行评价,具有代表性意义。依据评价指标体系构建原则、相关文献资料和当地实际情况,构建磴口县林业生态建设工程综合评价体系;在此基础上,通过时间序列分析,完成1991—2015年磴口县的林业生态建设工程综合效益量化评价。结果表明:在林业生态建设工程评价体系中,经济、生态和社会3个方面所占比重不同,其中,国内生产总值、造林面积、吸收二氧化硫年增加价值、削减粉尘年增加价值及农民人均纯收入五项指标在综合效益评价中权重比例较大;近年来磴口县林业生态建设工程综合效益较1990—1999年期间有所提高,但波动幅度较大,而近年来研究区综合效益趋于稳定并略有上升。磴口县林业生态建设工程在改善区域生态环境、遏制沙化土地扩展等方面的成效相对显著,有效促进了地区经济发展。     

Functional and safety aspects of enterococci in dairy foods

The genus Enterococcus like other LAB has also been featured in dairy industry for decades due to its specific biochemical traits such as lipolysis, proteolysis, and citrate breakdown, hence contributing typical taste and flavor to the dairy foods. Furthermore, the production of bacteriocins by enterococci (enterocins) is well documented. These technological applications have led to propose enterococci as adjunct starters or protective cultures in fermented foods. Moreover, enterococci are nowadays promoted as probiotics, which are claimed for the maintenance of normal intestinal microflora, stimulation of the immune system and improvement of nutritional value of foods. At the same time, enterococci present an emerging pool of opportunistic pathogens for humans as they cause disease, possess agents for antibiotic resistance, and are frequently armed with potential virulence factors. Because of this “dualistic” nature, the use of enterococci remains a debatable issue. However, based on a long history of safe association of particular enterococci with some traditional food fermentations, the use of such strains appears to bear no particular risk for human health. Abundance of knowledge as well as progress in molecular techniques has, however, enabled exact characterization and safety assessment of strains. Therefore, a balanced evaluation of both, beneficial and undesirable nature of enterococci is required. A clear understanding of their status may, therefore, allow their safe use as a starter, or a probiotic strain. The present review describes the broader insight of the benefits and risks of enterococci in dairy foods and their safety assessment.