Physicochemical Properties of the Soluble Dietary Fiber from Laminaria japonica and Its Role in the Regulation of Type 2 Diabetes Mice

Laminaria japonica is a large marine brown alga that is annually highly productive. However, due to its underutilization, its potential value is substantially wasted. For example, a lot of Laminaria japonica cellulose remains unused during production of algin. The soluble dietary fiber (SDF) was prepared from the byproducts of Laminaria japonica, and its physicochemical properties were explored. SDF exhibits good water-holding, oil-holding, water-absorbing swelling, glucose and cholesterol absorption capacity, and inhibitory activity of α-amylase and α-glucosidase. In addition, the beneficial effects of SDF in diabetic mice include reduced body weight, lower blood glucose, and relieved insulin resistance. Finally, the intestinal flora and metabolomic products were analyzed from feces using 16S amplicon and LC-MS/MS, respectively. SDF not only significantly changed the composition and structure of intestinal flora and intestinal metabolites, but also significantly increased the abundance of beneficial bacteria Akkermansia, Odoribacter and Bacteroides, decreased the abundance of harmful bacteria Staphylococcus, and increased the content of bioactive substances in intestinal tract, such as harmine, magnolol, arachidonic acid, prostaglandin E2, urimorelin and azelaic acid. Taken together, these findings suggest that dietary intake of SDF alleviates type 2 diabetes mellitus disease, and provides an important theoretical basis for SDF to be used as a functional food.

Anti-Inflammatory Activity of Fucoidan Extracts In Vitro

Fucoidans are sulfated, complex, fucose-rich polymers found in brown seaweeds. Fucoidans have been shown to have multiple bioactivities, including anti-inflammatory effects, and are known to inhibit inflammatory processes via a number of pathways such as selectin blockade and enzyme inhibition, and have demonstrated inhibition of inflammatory pathologies in vivo. In this current investigation, fucoidan extracts from Undaria pinnatifida, Fucus vesiculosus, Macrocystis pyrifera, Ascophyllum nodosum, and Laminaria japonica were assessed for modulation of pro-inflammatory cytokine production (TNF-α, IL-1β, and IL-6) by human peripheral blood mononuclear cells (PBMCs) and in a human macrophage line (THP-1). Fucoidan extracts exhibited no signs of cytotoxicity in THP-1 cells after incubation of 48 h. Additionally, all fucoidan extracts reduced cytokine production in LPS stimulated PBMCs and human THP-1 cells in a dose-dependent fashion. Notably, the 5–30 kDa subfraction from Macrocystis pyrifera was a highly effective inhibitor at lower concentrations. Fucoidan extracts from all species had significant anti-inflammatory effects, but the lowest molecular weight subfractions had maximal effects at low concentrations. These observations on various fucoidan extracts offer insight into strategies that improve their efficacy against inflammation-related pathology. Further studies should be conducted to elucidate the mechanism of action of these extracts.

Substantiation of the method of primary processing of Japanese kelp for food production

Химический состав и свойства морских водорослей позволяют с успехом применять их для профилактических и лечебных целей, для приготовления различных пищевых продуктов. В Японском море найдено более 310 представителей зеленых, бурых и красных водорослей. Из бурых водорослей преобладают многочисленные виды ламинариевых (Laminariaceae), наиболее ценной в промысловом отношении является ламинария японская (Laminaria japonica). Первичная обработка свежих водорослей предусматривает их тщательную мойку и вымачивание, но и после этого ее ткани содержат все еще высокие концентрации минеральных веществ, не позволяющие ее дальнейшее использование без дополнительной обработки. Поэтому при обработке ламинарии предусматривают ее варку, которая позволяет улучшить вкус, запах, цвет и консистенцию, а также повысить усвояемость водоросли организмом. Однако при варке в отвар переходит значительное количество водорастворимых солей и органических веществ. Поэтому выбор правильных режимов первичной обработки водорослей, при которых происходят минимальные потери физиологически ценных компонентов и обеспечиваются высокие органолептические показатели, будет способствовать производству широкого ассортимента пищевой продукции на их основе. Целью научно-исследовательской работы является обоснование способа первичной обработки ламинарии для производства пищевой продукции. Предложен способ обработки ламинарии, включающий в себя предварительную выдержку ламинарии в воде при температуре 10…15 °С в соотношении ламинария:вода - 1:2 в течение 20 мин и двукратную варку при температуре 40…50 °С при соотношении ламинария:вода 1:2 в течение 15-20 мин. Установлено, что внесение органических кислот на первом этапе варки способствует улучшению органолептических показателей водорослей. Исчезают специфические вкус и аромат водорослей, консистенция становится менее жесткой. Определены концентрации органических кислот в составе варочных вод: уксусной кислоты 1-3 %, лимонной кислоты 1-2 %. Полученный полуфабрикат при обработке ламинарии предложенным способом можно использовать при производстве разных видов пищевой продукции (сушеной, кулинарии, пресервов и др.). The chemical composition and properties of seaweed make it possible to successfully use them for prophylactic and therapeutic purposes, for the preparation of various food products. More than 310 representatives of green, brown and red algae have been found in the Sea of Japan. Numerous species of kelp (Laminariceae) prevail among brown algae, the most valuable commercially is Japanese kelp (Laminaria japonica). The primary processing of fresh algae involves their thorough washing and soaking, but even after that, its tissues still contain high concentrations of minerals, which do not allow its further use without additional processing. Therefore, when processing kelp, boil it is provided, which allows you to improve the taste, smell, color and consistency, as well as increase the digestibility of the algae by the body. However, during cooking, a significant amount of water-soluble salts and organic matter passes into the broth. Therefore, the choice of the correct modes of primary processing of algae, in which minimal losses of physiologically valuable components occur and high organoleptic characteristics are provided, will contribute to the production of a wide range of food products based on them. The purpose of the research work is to substantiate the method of primary processing of kelp for the production of food products. A method for processing kelp is proposed, which includes preliminary exposure of kelp in water at a temperature of 10…15 °C in a kelp: water ratio of 1:2 for 20 minutes and double cooking at a temperature of 40…50 °C at a kelp: water ratio of 1:2 within 15-20 minutes. It was found that the introduction of organic acids at the first stage of cooking contributes to the improvement of the organoleptic characteristics of algae. The specific taste and aroma of algae disappears, the consistency becomes less rigid. The concentration of organic acids in the composition of the cooking water has been determined: acetic acid 1-3 %; citric acid 1-2 %. The resulting semi-finished product when processing kelp by the proposed method can be used in the production of various types of food products (dried, cookery, preserves, etc.).

Soluble Polysaccharide Derived from Laminaria japonica Attenuates Obesity-Related Nonalcoholic Fatty Liver Disease Associated with Gut Microbiota Regulation

In this study, the effects of a polysaccharide derived from Laminaria japonica (LJP) on obesity were investigated in mice fed a high-fat diet (HFD). LJP significantly attenuated obesity-related features, lowering serum triglycerides, glucose, total cholesterol and low-density lipoprotein cholesterol levels. HFD-induced liver steatosis and hepatocellular ballooning were significantly attenuated by LJP. Additionally, LJP was found to significantly modulate hepatic gene expressions of AMPK and HMGCR, which are key regulators of lipid and cholesterol metabolism. We further found that LJP ameliorated HFD-induced gut microbiota (GM) dysbiosis by significantly reducing the obesity-related Firmicutes to Bacteroidetes ratio, meanwhile promoting the growth of Verrucomicrobia at the phylum level. At the genus level, propionate-producing bacteria Bacteroides and Akkermansia were elevated by LJP, which might explain the result that LJP elevated fecal propionate concentration. Taken together, these findings suggest that dietary intake of LJP modulates hepatic energy homeostasis to alleviate obesity-related nonalcoholic fatty liver disease associated with GM regulation.

Effects of Lactobacillus plantarum FZU3013-Fermented Laminaria japonica on Lipid Metabolism and Gut Microbiota in Hyperlipidaemic Rats

In this study, we explored the effect of Lactobacillus plantarum FZU3013-fermented Laminaria japonica (LPLJ) supplementation to prevent hyperlipidaemia in rats fed with a high-fat diet (HFD). The results indicate that LPLJ supplementation improved serum and hepatic biochemical indicators (p < 0.05), elevated short-chain fatty acid levels, reduced HFD-induced accumulation of lipid droplets in the liver, modulated the relative abundance of some microbial phylotypes, and reduced hyperlipidaemia in HFD-fed rats by adjusting the aminoacyl-tRNA, phenylalanine, tyrosine, and tryptophan biosynthetic pathways, as well as the phenylalanine, D-glutamine and D-glutamate, and glutathione metabolic pathways. Additionally, hepatic mRNA levels of the genes involved in lipid metabolism and bile acid homeostasis were significantly reduced by LPLJ intervention (p < 0.05). These results suggest that LPLJ has a positive effect on modulating lipid metabolism and has the potential to be a functional food that can help prevent hyperlipidaemia.

Protection against Oxidative Stress-Induced Apoptosis by Fermented Sea Tangle (Laminaria japonica Aresch) in Osteoblastic MC3T3-E1 Cells through Activation of Nrf2 Signaling Pathway

The purpose of the present study was to explore the efficacy of fermented extract of sea tangle (Laminaria japonica Aresch, FST) with Lactobacillus brevis on DNA damage and apoptosis in hydrogen peroxide (H2O2)-stimulated osteoblastic MC3T3-E1 cells and clarify related signaling pathways. Our results showed that exposure to FST significantly improved cell viability, inhibited apoptosis, and suppressed the generation of reactive oxygen species (ROS) in H2O2-stimulated cells. In addition, H2O2 triggered DNA damage in MC3T3-E1 cells was markedly attenuated by FST pretreatment. Moreover, H2O2-induced mitochondrial dysfunctions associated with apoptotic events, including loss of mitochondrial membrane potential (MMP), decreased Bcl-2/Bcl-2 associated x-protein (Bax) ratio, and cytosolic release of cytochrome c, were reduced in the presence of FST. FST also diminished H2O2-induced activation of caspase-3, which was associated with the ability of FST to protect the degradation of poly (ADP-ribose) polymerase. Furthermore, FST notably enhanced nuclear translocation and phosphorylation of nuclear factor erythroid 2-related factor 2 (Nrf2) in the presence of H2O2 with concomitant upregulation of heme oxygenase-1 (HO-1) expression. However, artificial blockade of this pathway by the HO-1 inhibitor, zinc protoporphyrin IX, greatly abolished the protective effect of FST against H2O2-induced MC3T3-E1 cell injury. Taken together, these results demonstrate that FST could protect MC3T3-E1 cells from H2O2-induced damage by maintaining mitochondrial function while eliminating ROS along with activation of the Nrf2/HO-1 antioxidant pathway.