Fucoidan ameliorates steatohepatitis and insulin resistance by suppressing oxidative stress and inflammatory cytokines in experimental non-alcoholic fatty liver disease

Haloacetamides exacerbate non-alcoholic fatty liver disease induced by a high-fat diet in C57BL/6J mice

Obesity, a significant global health issue, heightens the risk of non-alcoholic fatty liver disease (NAFLD). Its interaction with environmental pollutants might exacerbate NAFLD's severity. Haloacetamides (HAcAms), a group of emerging nitrogenous disinfection byproducts (DBPs) and potent oxidative stressors, are found in chlorinated drinking water. Since oxidative stress is associated with HAcAms-DBP cytotoxicity and a key factor in NAFLD pathogenesis, we hypothesize that HAcAms-DBPs could exacerbate liver injury and NAFLD, particularly with high-fat diets. This study examined HAcAms-DBPs' impact on liver lipid metabolism in mice treated with 1 to 100 times the background drinking water level (13.05 µg/L) for up to 16 weeks of oral administration. Compared to a high-fat-only group, mice co-exposed to a high-fat diet and HAcAms-DBPs for 16 weeks had elevated serum alanine transaminase, aspartate transaminase, triglyceride, hepatic lipid aggregation, and inflammation response. Under high-fat conditions, background drinking water levels of HAcAms significantly upregulated liver Acetyl-CoA carboxylase 1, fatty acid synthase, peroxisome proliferator-activated receptor gamma (PPARγ), PPARγ coactivator-1α, glucose transporter 1 and 4 protein expression in C57BL/6J mice; 10 times background significantly increased expression of inflammatory marker tumor necrosis factor and liver fibrosis marker protein alpha-smooth muscle actin; 100 times further increased both liver damage and markers of early non-alcoholic steatohepatitis phenotypes like steatosis and lobular inflammation. HAcAms-DBPs plus high-fat conditions worsened liver damage. The possible health risks of NAFLD induced by HAcAms in obese individuals deserve further study.

Fucoidan ameliorates lipid accumulation, oxidative stress, and NF-κB-mediated inflammation by regulating the PI3K/AKT/Nrf2 signaling pathway in a free fatty acid-induced NAFLD spheroid model

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disease worldwide. Previous studies have reported that fucoidan can relieve obesity and hepatic steatosis in vivo, although the molecular mechanism remains unclear. This study aimed to explore the effect and potential molecular mechanism of fucoidan in NAFLD using the free fatty acid (FFA)-induced NAFLD spheroid model.

MATERIALS AND METHODS

The spheroids were constructed by fusing the HepG2 and LX-2 cells. Spheroids and HepG2 cells were stimulated with FFAs and fucoidan, then the intracellular lipid contents and the oxidative stress levels (ROS/MDA/GSH/GR/GPx/NQO1/GCLC/HO-1) were detected. Furthermore, the regulation of PI3K/AKT/Nrf2 pathway and the expression of inflammatory factors (TNF-α and IL-6) were measured.

RESULTS

Fucoidan markedly reduced FFA-induced intracellular lipid accumulation in spheroids and HepG2 cells. Notably, fucoidan relieved FFA-induced oxidative stress by reducing the levels of ROS and MDA, and elevating the levels of GSH, GR, and GPx. Furthermore, fucoidan reduced FFA-induced oxidative stress by activating the PI3K/AKT/Nrf2 signaling pathway and by inhibiting ROS-induced P65 NF-κB activation and inflammatory responses via Nrf2 pathway activation.

CONCLUSIONS

Our results demonstrated that fucoidan ameliorated FFA-induced lipid accumulation, oxidative stress, and NF-κB-mediated inflammation through the PI3K/AKT/Nrf2 signaling pathway in the spheroid and HepG2 cells model of NAFLD. These results provided new evidence for the clinical use of fucoidan in the treatment of NAFLD and its potential molecular mechanism of action.

Therapeutic Potential of Fucoidan in Alleviating Histamine-Induced Liver Injury: Insights from Mice Studies

Histamine, a bioactive component in certain foods such as Huangjiu has been associated with liver injury and disrupted intestinal balance. This study explored the potential therapeutic effects of fucoidan (FCD) in mitigating histamine-induced imbalances in mice. We found that FCD mitigated liver injury, reducing transaminases, oxidative stress, and inflammation. Histological improvements included decreased cell infiltration and necrosis. FCD restored tight junction proteins and suppressed inflammation-related genes. Western blot analysis revealed FCD's impact on TGF-β1, p-AKT, AKT, CYP2E1, Grp78, NLRP3, Cas-1, and GSDMD. Gut LPS levels decreased with FCD. Gut microbiota analysis showed FCD's modulation effect, reducing Firmicutes and increasing Bacteroides. FCD demonstrates potential in alleviating histamine-induced liver injury, regulating inflammation, and influencing gut microbiota. Further research exploring higher dosages and additional parameters is warranted.

Extracellular matrix turnover: phytochemicals target and modulate the dual role of matrix metalloproteinases (MMPs) in liver fibrosis

Extracellular matrix (ECM) resolution by matrix metalloproteinases (MMPs) is a well-documented mechanism. MMPs play a dual and complex role in modulating ECM degradation at different stages of liver fibrosis, depending on the timing and levels of their expression. Increased MMP-1 combats disease progression by cleaving the fibrillar ECM. Activated hepatic stellate cells (HSCs) increase expression of MMP-2, -9, and -13 in different chemicals-induced animal models, which may alleviate or worsen disease progression based on animal models and the stage of liver fibrosis. In the early stage, elevated expression of certain MMPs may damage surrounding tissue and activate HSCs, promoting fibrosis progression. At the later stage, downregulation of MMPs can facilitate ECM accumulation and disease progression. A number of phytochemicals modulate MMP activity and ECM turnover, alleviating disease progression. However, the effects of phytochemicals on the expression of different MMPs are variable and may depend on the disease models and stage, and the dosage, timing and duration of phytochemicals used in each study. Here, we review the most recent advances in the role of MMPs in the effects of phytochemicals on liver fibrogenesis, which indicates that further studies are warranted to confirm and define the potential clinical efficacy of these phytochemicals.

Marine algal polysaccharides as future potential constituents against non-alcoholic steatohepatitis

Non-alcoholic steatohepatitis (NASH) is one of the most chronic and incurable liver diseases triggered mainly by an inappropriate diet and hereditary factors which burden liver metabolic stress, and may result in liver fibrosis or even cancer. While the available drugs show adverse side effects. The non-toxic bioactive molecules derived from natural resources, particularly marine algal polysaccharides (MAPs), present significant potential for treating NASH. In this review, we summarized the protective effects of MAPs on NASH from multiple perspectives, including reducing oxidative stress, regulating lipid metabolism, enhancing immune function, preventing fibrosis, and providing cell protection. Furthermore, the mechanisms of MAPs in treating NASH were comprehensively described. Additionally, we highlight the influences of the special structures of MAPs on their bioactive differences. Through this comprehensive review, we aim to further elucidate the molecular mechanisms of MAPs in NASH and inspire insights for deeper research on the functional food and clinical applications of MAPs.

Uses of Papaya Leaf and Seaweed Supplementations for Controlling Glucose Homeostasis in Diabetes

Studies from laboratory animal models and complementary medical practices have implied that nutrients from special plants or herbs contain antidiabetic, antioxidant, anti-obese, anti-hypertensive, and anti-inflammatory properties. Seaweed and tropical papaya, which are widely available in Asian and Pacific countries, have been used as home remedies for centuries. The bioactive extracts from these plants contain vitamins A, C, B and E complexes, as well as polysaccharides, phenolic compounds, essential fatty acids, flavonoids, saponins, fucoidan, and phlorotannin. In this review, the authors examine the pathogenesis of diabetes characterized by hyperglycemia due to the dysregulation of glucose homeostasis, antidiabetic/antihyperglycemic seaweed or/and papaya derived bioactive phytochemicals and their proposed mechanisms of action in the management of Type 2 Diabetes Mellitus (T2DM). The authors also propose combining papaya and seaweed to enhance their antidiabetic effects, leveraging the advantages of herb-to-herb combination. Papaya and seaweed have demonstrated antidiabetic effects through in vitro assays, cellular models, and animal studies despite the limited clinical trials. Nutraceuticals with antidiabetic effects, such as secondary metabolites isolated from seaweed and papaya, could be combined for a synergistic effect on T2DM management. However, the application of these compounds in their purified or mixed forms require further scientific studies to evaluate their efficacy against diabetes-related complications, such as hyperlipidemia, elevated free radicals, pro-inflammatory molecules, insulin insensitivity, and the degeneration of pancreatic beta cells.

Research progress on the therapeutic effects of polysaccharides on non-alcoholic fatty liver diseases

Non-alcoholic fatty liver disease (NAFLD) has become the most common chronic liver disease and is a leading cause of cirrhosis and hepatocellular carcinoma. Due to its complex pathophysiology, there is currently no approved therapy. Polysaccharide, a kind of natural product, possesses a wide range of pharmacological activities. Numerous preclinical studies have confirmed that polysaccharides could interfere with the occurrence and development of NAFLD at multiple interrelated levels, such as improvement of glucose and lipid metabolism, antioxidation, anti-inflammation, and regulation of gut-liver axis, thus showing great potential as novel anti-NAFLD drugs. In this paper, we reviewed the polysaccharides with anti-NAFLD effect in recent years, and also systematically analyzed their possible pharmacological mechanisms.

Interleukin-22 alleviates alcohol-associated hepatic fibrosis, inhibits autophagy, and suppresses the PI3K/AKT/mTOR pathway in mice

BACKGROUND

Alcohol-associated hepatic fibrosis is a widespread liver disease with no effective treatment. Recent studies have indicated that interleukin-22 (IL-22) can ameliorate alcohol-associated liver disease. However, the mechanism underlying the role of IL-22 in alcohol-associated hepatic fibrosis remains unclear. Therefore, we investigated the effect of IL-22 in a mouse model of alcohol-associated hepatic fibrosis and its underlying mechanisms.

METHODS

Alcohol-associated hepatic fibrosis was induced by feeding male C57BL/6J mice with a Lieber-DeCarli liquid diet containing 4% ethyl alcohol for 8 weeks and injecting them with 5% tetrachloromethane (CCl₄ ) intraperitoneally for the last 4 weeks. During the last 4 weeks, IL-22 was also administered. We investigated the role of IL-22 in autophagy and the PI3K/AKT/mTOR signaling pathway using a 3-methyladenine intraperitoneal injection in the mice treated with IL-22. The effects of IL-22 on alcohol-associated hepatic fibrosis, autophagy-related gene expression, and PI3K/AKT/mTOR activity were assessed using histopathology, biochemical analysis, transmission electron microscopy, quantitative real-time PCR, immunohistochemistry, and western blotting.

RESULTS

Mice treated with ethanol and CCl₄ displayed distinct liver injuries, including hepatocyte necrosis, inflammatory cell infiltration, and hepatic fibrosis, which were substantially attenuated by IL-22 treatment. In addition, we found that IL-22 regulated the expression of autophagy-related genes and inhibited the PI3K/AKT/mTOR pathway, as evidenced by the reduction in p-PI3K, p-AKT, and p-mTOR expression after IL-22 treatment.

CONCLUSIONS

IL-22 exerts a marked protective effect against alcohol-associated hepatic fibrosis. Its effect may be partly related to the alteration of autophagy-related gene expression and inhibition of the PI3K/AKT/mTOR pathway in the liver.

Bioactive Compounds from Brown Algae Alleviate Nonalcoholic Fatty Liver Disease: An Extensive Review

Nonalcoholic fatty liver disease (NAFLD) is one of the most prevalent chronic liver diseases. The increasing NAFLD incidences are associated with unhealthy lifestyles. Currently, there are no effective therapeutic options for NAFLD. Thus, there is a need to develop safe, efficient, and economic treatment options for NAFLD. Brown algae, which are edible, contain abundant bioactive compounds, including polysaccharides and phlorotannins. They have been shown to ameliorate insulin resistance, as well as hepatic steatosis, and all of these biological functions can potentially alleviate NAFLD. Accumulating reports have shown that increasing dietary consumption of brown algae reduces the risk for NAFLD development. In this review, we summarized the animal experiments and clinical proof of brown algae and their bioactive compounds for NAFLD treatment within the past decade. Our findings show possible avenues for further research into the pathophysiology of NAFLD and brown algae therapy.

The anti-obesity and anti-diabetic effects of the edible seaweed Gloiopeltis furcata (Postels et Ruprecht) J. Agardh in mice fed a high-fat diet

Obesity and diabetes are serious, chronic medical conditions associated with a wide range of life-threatening conditions. The aim of this study was to investigate the effects of the edible red seaweed Gloiopeltis furcata (Postels et Ruprecht) J. Agardh (G. furcata) on the development of obesity, diabetes and related metabolic diseases in mice. Male C57BL/6J mice were fed a high-fat (HF) diet (60% energy as fat), or an HF diet containing 2% (w/w) or 6% powdered G. furcata for 13 weeks. Polysaccharides of G. furcata were isolated and their anti-inflammatory effects were evaluated in lipopolysaccharide-stimulated RAW264.7 cells. The HF diet group showed greater weight gain, lipid accumulation in the body and liver, and increased serum levels of glucose and cholesterol in comparison to the normal group fed a normal diet (10% energy as fat). The treatment of HF diet mice with G. furcata reduced these changes and stimulated the fecal excretion of fat. In addition, G. furcata suppressed the HF diet-induced elevation of inflammation and oxidative stress markers in the serum and liver. The isolated sulfated polysaccharide from G. furcata inhibited pancreatic lipase activity and decreased the production of nitric oxide and TNF-α in the murine macrophage cell line RAW264.7. These results show that G. furcata treatment can attenuate obesity, diabetes, hepatic steatosis, and dyslipidemia in mice fed an HF diet, which is associated with inhibited intestinal fat absorption and reduced inflammation and oxidative stress by a sulfated polysaccharide.

Tilapia-Head Chondroitin Sulfate Protects against Nonalcoholic Fatty Liver Disease via Modulating the Gut-Liver Axis in High-Fat-Diet-Fed C57BL/6 Mice

We isolated and characterized tilapia-head chondroitin sulfate (TH-CS) and explored its biological activity and mechanisms of action as an oral supplement for nonalcoholic fatty liver disease (NAFLD) induced by a high-fat diet (HFD) in mice. The results showed that treatment with TH-CS for 8 weeks alleviated the development of NAFLD, as evidenced by the notable improvement in liver damage, blood lipid accumulation and insulin resistance (IR). Meanwhile, TH-CS treatment reduced the expression of proinflammatory cytokines and normalized oxidative stress. Additionally, the analysis of 16S rDNA sequencing revealed that TH-CS could restore gut microbiota balance and increase the relative abundance of short-chain fatty acid (SCFA)-producing bacteria. Furthermore, SCFAs produced by related bacteria can further improve lipid metabolism and IR by regulating lipid synthesis signals. In conclusion, TH-CS is an effective dietary supplement for the prevention of NAFLD, and may serve as a potential supplementary treatment for lipid-related metabolic syndrome.

Seaweed Exhibits Therapeutic Properties against Chronic Diseases: An Overview

Seaweeds or marine macroalgae are known for producing potentially bioactive substances that exhibit a wide range of nutritional, therapeutic, and nutraceutical properties. These compounds can be applied to treat chronic diseases, such as cancer, cardiovascular disease, osteoporosis, neurodegenerative diseases, and diabetes mellitus. Several studies have shown that consumption of seaweeds in Asian countries, such as Japan and Korea, has been correlated with a lower incidence of chronic diseases. In this study, we conducted a review of published papers on seaweed consumption and chronic diseases. We used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) method for this study. We identified and screened research articles published between 2000 and 2021. We used PubMed and ScienceDirect databases and identified 107 articles. This systematic review discusses the potential use of bioactive compounds of seaweed to treat chronic diseases and identifies gaps where further research in this field is needed. In this review, the therapeutic and nutraceutical properties of seaweed for the treatment of chronic diseases such as neurodegenerative diseases, obesity, diabetes, cancer, liver disease, cardiovascular disease, osteoporosis, and arthritis were discussed. We concluded that further study on the identification of bioactive compounds of seaweed, and further study at a clinical level, are needed.

Antidiabetic potential of seaweed and their bioactive compounds: a review of developments in last decade

Diabetes Mellitus is a public health problem worldwide due to high morbidity and mortality rate associated with it. Diabetes can be managed by synthetic hypoglycemic drugs, although their persistent uses have several side effects. Hence, there is a paradigm shift toward the use of natural products having antidiabetic potential. Seaweeds, large marine benthic algae, are an affluent source of various bioactive compounds, including phytochemicals and antioxidants thus exhibiting various health promoting properties. Seaweed extracts and its bioactive compounds have antidiabetic potential as they inhibit carbohydrate hydrolyzing enzymes in vitro and exhibit blood glucose lowering effect in random and post prandial blood glucose tests in vivo. In addition, they have been associated with reduced weight gain in animals probably by decreasing mRNA expression of pro-inflammatory cytokines with concomitant increase in mRNA expression levels of anti-inflammatory cytokines. Their beneficial effect has been seen in serum and hepatic lipid profile and antioxidant enzymes indicating the protective role of seaweeds against free radicals mediated oxidative stress induced hyperglycemia and associated hyperlipidemia. However, the detailed and in-depth studies of seaweeds as whole, their bioactive isolates and their extracts need to be explored further for their health benefits and wide application in food, nutraceutical and pharmaceutical industries.

Anti-lung Cancer Marine Compounds: A Review

Lung cancer is one of the most common and lethal cancers in human beings. Lung cancer has been divided into two major types: small cell lung cancer (SCLC) and non-small cell lung carcinoma (NSCLC). Current drugs suffer from various side effects, and the insufficient efficacy of present treatments creates a desire for better more efficient new drugs. This review compares the diversity of marine-derived bioactive compounds from different marine species. Some of the natural products from marine resources are in different stages of clinical trials. By the way, most of them have been studied in vitro and in vivo. Additionally, in this review, the mechanisms of action of marine-derived anti-lung cancer components on lung cancer cell lines have been reviewed. In addition, considering growing rate and the high costs of cancer research, attention must be paid to some aspects of targeting and developing anti-lung cancer drug. In better words, like the other therapeutic strategies that have their particular challenges and weak points, several challenges about marine-derived anti-lung cancer components which exist for scientists for doing research are explained. Moreover, as the attentions in the field of cancer therapy are focused on designing and developing new anticancer strategies for the treatment of cancer in the future, the application of marine-derived anti-lung cancer components in the field of future cancer therapy and their role in future anticancer strategies are briefly discussed.

Brown-Algae Polysaccharides as Active Constituents against Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease is a metabolic disorder characterized by lipid overloading in hepatocytes that can progress pathogenically and even end in hepatocellular carcinoma. Nonalcoholic fatty liver disease pharmacological treatment is still limited by unwanted side effects, whereas the use of food components with therapeutic potential is advisable. The culinary use of marine algae is traditional for some populations and reviving worldwide, with promising health outcomes due to the large number of bioactive compounds found in seaweeds. The present review focuses on brown-algae polysaccharides, particularly fucoidan, alginate, and laminarin, and summarizes the experimental evidence of their potential effects against nonalcoholic fatty liver disease onset and progression. In vitro and in vivo studies demonstrate that brown-algae polysaccharides exert beneficial actions on satiety feeling, caloric intake, fat absorption, and modulation of the gut microbiota, which could account for indirect effects on energy and lipid homeostasis, thus diminishing the fat overload in the liver. Specific effects against nonalcoholic fatty liver disease pathogenesis and worsening are also described and sustained by the antioxidant, anti-inflammatory, and antisteatotic properties of brown-algae polysaccharides. Further studies are required to clarify the mechanism of action of brown-algae polysaccharides on liver cells, to determine the composition and bioavailability of brown-algae polysaccharides present in different algal sources and to probe the clinical availability of these compounds in the form of algal foods, food supplements, and regulated therapeutics.

Dietary fucoidan extracted from macroalgae Saccharina japonica alleviate the hepatic lipid accumulation of black seabream (Acanthopagrus schlegelii)

The use of an artificial diet often leads to the increase of risk factors for the development of liver diseases, such as hepatic lipid accumulation (HLA) in commercially cultured fish species. Our previous study showed that dietary Saccharina japonica could effectively alleviate HLA in black seabream (Acanthopagrus schlegelii), which may be linked predominantly to S. japonica fucoidan. Thus, a 56d nutritional trial was designed to investigate the effects of dietary fucoidan (CTRL, 0 g kg^-1; ASJ1, 0.75 g kg^-1; ASJ2, 3.00 g kg^-1) on growth performance, fillets nutritional values, and HLA of black seabream. Results showed that dietary fucoidan significantly improved the growth and the contents of n-3 polyunsaturated fatty acids (n-3PUFA) in fillets of black seabream. Moreover, dietary fucoidan improved HLA-related parameters, including reducing serum and liver lipid contents and the activity of aminotransferase. Meanwhile, histological analysis showed that dietary fucoidan reduced the area of hepatic lipid droplets in black seabream (P < 0.05). In addition, the transcriptomic analysis of differentially expressed gene (DEG) showed that all DEG in fatty acid metabolism, primary bile acid biosynthesis, and fatty acid biosynthesis were down-regulated, and all DEG in the regulation of autophagy were up-regulated in the ASJ1 group compared with CTRL group. Moreover, the metabolomic analysis of differentially expressed metabolite (DEM) found that lipid metabolism was the main type of KEGG pathway altered by fucoidan supplementation. Furthermore, the combined transcriptomic and metabolomic analysis found that dietary fucoidan mainly modified the lipid metabolic pathway of primary bile acid biosynthesis, glycerophospholipid metabolism, and arachidonic acid metabolism in the liver. In general, dietary fucoidan effectively alleviated HLA of black seabream, and the underlying mechanism may be ascribed to promoting the autophagy and inhibiting the synthesis of lipids and bile acids.

Fucoidan Modulated Oxidative Stress and Caspase-3 mRNA Expression Induced by Sulfoxaflor in the Brain of Mice

The current study aimed to investigate the role of fucoidan in the oxidative and apoptotic effects of sulfoxaflor, a neonicotinoid sulfoximine insecticide, in the brain of Swiss albino mice (Mus musculus). Sulfoxaflor and fucoidan were administered to mice at doses of 15 mg/kg/day (1/50 oral LD50) and 50 mg/kg/day, respectively, by oral gavage for 24 h or 7 days. The tGSH, TBARS and protein levels, and GPx, GR, and GST enzyme activities were determined by spectrophotometric methods. Caspase-3 gene expression level was determined by RT-PCR. Data analysis showed that brains of sulfoxaflor-treated mice exhibited higher TBARS levels; GPx, GR, and GST enzyme activities; and caspase-3 expression levels, as well as lower levels of tGSH. Co-administration of fucoidan and sulfoxaflor reduced the TBARS levels, increased tGSH levels, and increased GPx, GR, and GST enzyme activities. Fucoidan also decreased the sulfoxaflor-induced up-regulation of caspase-3 mRNA expression. Results of the present study showed that sulfoxaflor caused oxidative stress by inducing lipid peroxidation and altering GSH-dependent antioxidants in the brain of mice. In addition, sulfoxaflor may trigger apoptotic cell death shown by the up-regulation of caspase-3. Fucoidan treatment modulated all the aforementioned alterations in the brain of mice. It was concluded that fucoidan might have antioxidant effects that support the GSH-dependent antioxidant system and can play a modulator role in oxidative stress and caspase-3 expression in the brain of sulfoxaflor treated-mice.

Marine Sulfated Polysaccharides: Preventive and Therapeutic Effects on Metabolic Syndrome: A Review

Metabolic syndrome is the pathological basis of cardiovascular and cerebrovascular diseases and type 2 diabetes. With the prevalence of modern lifestyles, the incidence of metabolic syndrome has risen rapidly. In recent years, marine sulfate polysaccharides (MSPs) have shown positive effects in the prevention and treatment of metabolic syndrome, and they mainly come from seaweeds and marine animals. MSPs are rich in sulfate and have stronger biological activity compared with terrestrial polysaccharides. MSPs can alleviate metabolic syndrome by regulating glucose metabolism and lipid metabolism. In addition, MSPs prevent and treat metabolic syndrome by interacting with gut microbiota. MSPs can be degraded by gut microbes to produce metabolites such as short chain fatty acids (SCFAs) and free sulfate and affect the composition of gut microbiota. The difference between MSPs and other polysaccharides lies in the sulfation pattern and sulfate content, therefore, which is very important for anti-metabolic syndrome activity of MSPs. This review summarizes the latest findings on effects of MSPs on metabolic syndrome, mechanisms of MSPs in treatment/prevention of metabolic syndrome, interactions between MSPs and gut microbiota, and the role of sulfate group and sulfation pattern in MSPs activity. However, more clinical trials are needed to confirm the potential preventive and therapeutic effects on human body. It may be a better choice to develop new functional foods containing MSPs for dietary intervention in metabolic syndrome.

Sargassum fusiforme polysaccharide attenuates high-sugar-induced lipid accumulation in HepG2 cells and Drosophila melanogaster larvae

Lipid accumulation is a major factor in the development of non-alcoholic fatty liver disease (NAFLD). Currently, there is a lack of intervention or therapeutic drugs against NAFLD. In this study, we investigated the ability of Sargassum fusiforme polysaccharide (SFPS) to reduce lipid accumulation induced by high sugar in HepG2 cells and Drosophila melanogaster larvae. The results indicated that SFPS significantly (p < .01) decreased the accumulation of lipid droplets in high sugar-induced HepG2 cells. Furthermore, SFPS also suppressed the expression of Srebp and Fas (genes involved in lipogenesis) and increased the expression of PPARɑ and Cpt1 (genes that participated in fatty acid β-oxidation) in these cells. SFPS markedly reduced the content of triglyceride of the third instar larvae developed from D. melanogaster eggs reared on the high-sucrose diet. The expression of the Srebp and Fas genes in the larvae was also inhibited whereas the expression of two genes involved in the β-oxidation of fatty acids, Acox57D-d and Fabp, was increased in the larval fat body (a functional homolog of the human liver). We also found that SFPS ameliorated developmental abnormalities induced by the high-sucrose diet. These results of this study suggest that SFPS could potentially be used as a therapeutic agent for the prevention and treatment of NAFLD.

Sargassum fusiforme fucoidan alleviates diet-induced insulin resistance by inhibiting colon-derived ceramide biosynthesis

Sargassum fusiforme fucoidan (SFF) is a highly sulfated heteropolysaccharide with various biological activities. As one of the causative factors of type 2 diabetes mellitus (T2DM), insulin resistance has become a global health issue. In this study, we investigated the potential pharmacological mechanisms by which SFF ameliorates insulin resistance in high-fat diet (HFD)-fed mice. SFF significantly enhanced tauroursodeoxycholic acid (TUDCA, a conjugated bile acid) levels and inhibited the farnesoid X receptor (FXR) signaling in the colon. SFF administration reduced ceramide levels in both serum and colonic tissue of HFD-fed mice, as well as reduced expression of SPT and CerS genes, which encode enzymes crucial to the biosynthesis of ceramides regulated by FXR signaling. Pearson's analysis showed that the TUDCA level was positively correlated with the gut bacteria Clostridium, and this was further validated in pseudo-germfree mice. Taken together, the results suggested that SFF increased TUDCA levels by remodeling gut microbiota, and TUDCA, a natural FXR antagonist, inhibited the FXR/SHP signaling pathway to reduce colon-derived biosynthesis of ceramide, thereby improving insulin resistance in the diet-induced obese (DIO) mice. This study has provided new insights into the therapeutic potential of S. fusiforme fucoidan in metabolic diseases.

Pharmacological Activities of Sulfated Fucose-Rich Polysaccharides after Oral Administration: Perspectives for the Development of New Carbohydrate-Based Drugs

Marine organisms are a source of active biomolecules with immense therapeutic and nutraceutical potential. Sulfated fucose-rich polysaccharides are present in large quantities in these organisms with important pharmacological effects in several biological systems. These polysaccharides include sulfated fucan (as fucoidan) and fucosylated chondroitin sulfate. The development of these polysaccharides as new drugs involves several important steps, among them, demonstration of the effectiveness of these compounds after oral administration. The oral route is the more practical, comfortable and preferred by patients for long-term treatments. In the past 20 years, reports of various pharmacological effects of these polysaccharides orally administered in several animal experimental models and some trials in humans have sparked the possibility for the development of drugs based on sulfated polysaccharides and/or the use of these marine organisms as functional food. This review focuses on the main pharmacological effects of sulfated fucose-rich polysaccharides, with an emphasis on the antidislipidemic, immunomodulatory, antitumor, hypoglycemic and hemostatic effects.

Antioxidant and Signal-Modulating Effects of Brown Seaweed-Derived Compounds against Oxidative Stress-Associated Pathology

The biological and therapeutic properties of seaweeds have already been well known. Several studies showed that among the various natural marine sources of antioxidants, seaweeds have become a potential source of antioxidants because of their bioactive compounds. Most of the metabolic diseases are caused by oxidative stress. It is very well known that antioxidants have a pivotal role in the treatment of those diseases. Recent researches have revealed the potential activity of seaweeds as complementary medicine, which have therapeutic properties for health and disease management. Among the seaweeds, brown seaweeds (Phaeophyta) and their derived bioactive substances showed excellent antioxidant properties than other seaweeds. This review focuses on brown seaweeds and their derived major bioactive compounds such as sulfated polysaccharide, polyphenol, carotenoid, and sterol antioxidant effects and molecular mechanisms in the case of the oxidative stress-originated disease. Antioxidants have a potential role in the modification of stress-induced signaling pathways along with the activation of the oxidative defensive pathways. This review would help to provide the basis for further studies to researchers on the potential antioxidant role in the field of medical health care and future drug development.

In Vitro and In Vivo Study on the Toxic Effects of Propiconazole Fungicide in the Pathogenesis of Liver Fibrosis

Propiconazole (PCZ) is a hepatotoxic triazole fungicide. There are insufficient data on how PCZ induces liver fibrosis in humans. This study aimed to investigate the effect of PCZ on liver fibrosis and its underlying mechanisms. HepG2 cells and Sprague-Dawley rats were exposed to PCZ at doses of 0-160 μM (3-72 h) and 0.5-50 mg/kg body weight/day (28 days), respectively. PCZ-treated cells activated intracellular oxidative stress via cytochrome P450 and had higher mRNA levels of interleukin-1β, tumor necrosis factor-α, matrix metalloproteinase (MMP)-2, MMP-9, and transforming growth factor-β (TGF-β) than the control. PCZ treatment in cells induced a morphological transition with E-cadherin decrease and vimentin and Snail increase via the oxidative stress and TGF-β/Smad pathways. PCZ administration in rats induced liver fibrosis through pathological changes, epithelial-mesenchymal transition, and collagen deposition. Thus, our data suggest that exposure of PCZ to humans may be a risk factor for the functional integrity of the liver.

Effect of fucoidan on ethanol-induced liver injury and steatosis in mice and the underlying mechanism

BACKGROUND

Alcoholic liver disease is caused as a result of chronic alcohol consumption. In this study, we used an alcoholic liver injury mouse model to investigate the effect of fucoidan on ethanol-induced liver injury and steatosis and the underlying mechanisms.

METHODS

All mice were randomly divided into four groups: 1) control group, 2) model group, 3) diammonium glycyrrhizinate treatment group (200 mg/kg body weight), and 4) fucoidan treatment group (300 mg/kg body weight). Administration of ethanol for 8 weeks induced liver injury and steatosis in mice.

RESULTS

Fucoidan treatment decreased serum alanine aminotransferase activity, serum total cholesterol levels, and hepatic triglyceride levels, and improved the morphology of hepatic cells. Fucoidan treatment upregulated the expression of AMPKα1, SIRT1, and PGC-1α and inhibited the expression of ChREBP and HNF-1α. The levels of hepatic IL-6 and IL-18 were significantly decreased in the fucoidan group. Further, the levels of cytochrome P450-2E1 (CYP2E1), glucose-regulated protein (GRP) 78, and 3-nitrotyrosine (3-NT) in hepatic tissues were reduced in the fucoidan group as compared to the model group. Fucoidan significantly reversed the reduction of ileac Farnesoid X receptor (FXR) and fibroblast growth factor 15 (FGF15) levels induced by alcohol-feeding and reduced CYP7A1 (cholesterol 7α-hydroxylase) expression and total bile acid levels in the liver tissue. In addition, fucoidan regulated the structure of gut flora, with increased abundance of Prevotella and decreased abundance of Paraprevotella and Romboutsia as detected by 16S rDNA high-throughput sequencing.

CONCLUSION

Fucoidan inhibited alcohol-induced steatosis and disorders of bile acid metabolism in mice through the AMPKα1/SIRT1 pathway and the gut microbiota-bile acid-liver axis and protected against alcohol-induced liver injury in vivo.

Fucoidan and Fucoxanthin Attenuate Hepatic Steatosis and Inflammation of NAFLD through Modulation of Leptin/Adiponectin Axis

Non-alcoholic fatty liver disease (NAFLD) is the emerging cause of chronic liver disease globally and lack of approved therapies. Here, we investigated the feasibility of combinatorial effects of low molecular weight fucoidan and high stability fucoxanthin (LMF-HSFx) as a therapeutic approach against NAFLD. We evaluated the inhibitory effects of LMF-HSFx or placebo in 42 NAFLD patients for 24 weeks and related mechanism in high fat diet (HFD) mice model and HepaRG^TM cell line. We found that LMF-HSFx reduces the relative values of alanine aminotransferase, aspartate aminotransferase, total cholesterol, triglyceride, fasting blood glucose and hemoglobin A1c in NAFLD patients. For lipid metabolism, LMF-HSFx reduces the scores of controlled attenuation parameter (CAP) and increases adiponectin and leptin expression. Interestingly, it reduces liver fibrosis in NAFLD patients, either. The proinflammatory cytokines interleukin (IL)-6 and interferon-γ are reduced in LMF-HSFx group. In HFD mice, LMF-HSFx attenuates hepatic lipotoxicity and modulates adipogenesis. Additionally, LMF-HSFx modulates SIRI-PGC-1 pathway in HepaRG cells under palmitic acid-induced lipotoxicity environment. Here, we describe that LMF-HSFx ameliorated hepatic steatosis, inflammation, fibrosis and insulin resistance in NAFLD patients. LMF-HSFx may modulate leptin-adiponectin axis in adipocytes and hepatocytes, then regulate lipid and glycogen metabolism, decrease insulin resistance and is against NAFLD.

Sacran, a sulfated polysaccharide, suppresses the absorption of lipids and modulates the intestinal flora in non-alcoholic steatohepatitis model rats

AIMS

The objective of this study was to investigate the effects of administering sacran, a sulfated polysaccharide, on liver biology, gut microbiota, oxidative stress, and inflammation on stroke-prone spontaneously hypertensive (SHRSP5/Dmcr) rats that develop fibrotic steatohepatitis with histological similarities to that of non-alcoholic steatohepatitis (NASH).

MAIN METHODS

Four groups of 8-week-old SHRSP5/Dmcr rats were fed a high fat-cholesterol (HFC) diet for 4 and 8 weeks and administered either sacran (80 mg/kg/day) or a non-treatment, respectively. Liver function was evaluated by biochemical and histopathological analyses. Hepatic inflammatory markers were measured using mRNA expression. Fecal microbial profiles were determined via 16S rRNA sequencing. A triglyceride (TG) absorption test was administered to the 8-week-old Sprague-Dawley (SD) rats.

KEY FINDING

Sacran administration was observed to decrease the extent of oxidative stress and hepatic biochemical parameters in serum and hepatic injury with the levels of transforming growth factor-beta (TGF-β1) and tumor necrosis factor-alpha (TNF-α), being increased compared to those of the non-treatment group. At the genus level, sacran administration caused a significant decrease in the harmful Prevotella genus, and a significant increase in the useful Blautia genus was observed. Sacran administration also decreased the serum TG increase that was induced by administering corn oil to the SD rats.

SIGNIFICANCE

We conclude that sacran administration has the potential to reduce the absorption of lipids into blood and to improve several gut microbiotas, in the gastrointestinal tract, thereby inhibiting the subsequent development of oxidative stress and hepatic markers in the systematic circulation on NASH.

Current developments in the oral drug delivery of fucoidan

Fucoidan is well known to have various biological functions and is often investigated for pharmaceutical applications. Several studies have been conducted on clinical applications of fucoidan in recent years, especially regarding its oral drug delivery. Although fucoidan has shown promising results in various dosage forms, its potential applications as a dietary supplement have been demonstrated, and recent studies show that oral administration of fucoidan is preferred. However, the focus on the oral delivery of fucoidan in recent studies has caused its potency in therapy to be understudied. This review aims to provide results on the promising fucoidan activity by oral administration with in vivo studies. In addition to using it as an active ingredient, the utilization of fucoidan as an excipient in oral drug delivery systems will be discussed. An overview of fucoidan administration by oral delivery in recent promising studies will provide a direction for further investigations in clinical applications, particularly for fucoidan, which has a broad spectrum of bioactive properties.

Marine Algae as a Potential Source for Anti-diabetic Compounds - A Brief Review

BACKGROUND

Diabetes Mellitus (DM) is a major chronic metabolic disorder characterized by hyperglycemia that leads to several complications such as retinopathy, atherosclerosis, nephropathy, etc. In 2019, it was estimated that about 463 million people had diabetes, and it may increase up to 700 million in 2045. Marine macroalgae are the rich source of bioactive compounds for the treatment of diabetes mellitus.

OBJECTIVE

This review summarizes the recent epidemiology and possible use of marine macroalgae-derived bioactive compounds for the protection against chronic metabolic disease, diabetes mellitus and marine macroalgae as a nutraceutical supplement.

CONCLUSION

The present therapies available for diabetes treatment are oral medicines and insulin injections. But continuous use of synthetic medicines provides low therapeutic with many side effects. In continuing search of anti-diabetic drugs, marine macroalgae remain as a promising source with potent bioactivity. Among existing marine algae, red and brown algae are reported to show anti-diabetic activity. Hence, the present review focuses on the epidemiology, diabetes biomarkers and different secondary bioactive compounds present in marine macroalgae to treat diabetes mellitus.

Fucoidan: Biological Activity in Liver Diseases

Fucoidan is a type of polysaccharide rich in sulfuric acid groups and is mainly found in brown algae. Due to its extensive biological activities, such as anticoagulant, antitumor, antithrombotic, antiviral, anti-oxidant and enhancing immune function, fucoidan has gradually become a research hotspot. Under the scientific guidance of modern medical theory, fucoidan and its mechanism in oxidative stress, carbohydrate and lipid metabolism, inflammatory response, tumor proliferation, and metastasis have become a new research direction and an important basis as an effective liver protection drug. In this paper, we discuss the important role of fucoidan in viral hepatitis, liver fibrosis, liver cancer, nonalcoholic fatty liver and liver injury induced by drugs and ischemia and briefly discuss its underlying mechanism. We supplement the theoretical basis for its clinical application and provide effective targets for the development of follow-up dominant drugs.

Fucoidan attenuates hyperoxia-induced lung injury in newborn rats by mediating lung fibroblasts differentiate into myofibroblasts

Background

Hyperoxia-induced lung injury is one of the most common and frequent diseases in premature infants and may develop into bronchopulmonary dysplasia (BPD). Fucoidan, extracted from brown seaweed and brown algae, has anti-apoptosis, antioxidative and anti-fibrosis effects. This study aimed to explore whether fucoidan could alleviate hyperoxia-induced lung injury in newborn rats.

Methods

Lung wet-weight/dry-weight (W/D) ratio, total protein (TP) content, total cell counts, and lactate dehydrogenase (LDH) levels are used to evaluate lung injury. Masson staining is used to evaluate lung fibrotic. Tunnel assay and Hoechst 33258 assay were used to evaluate apoptosis. The levels of serum superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione (GSH) were measured using ELISA to assess oxidative stress. Western blot assay was used to detect apoptosis-related proteins Bcl-1, Bax, and myofibroblast proteins α-SMA.

Results

The data indicating fucoidan treatment remarkably reduces the lung W/D ratio and TP content, total cell counts, and LDH levels in bronchoalveolar lavage fluid (BALF). Also, fucoidan treatment significantly inhibited cell apoptosis with the elevated expression of Bcl-2/Bax in cultured lung fibroblasts. Moreover, treatment with fucoidan suppressed the levels of MDA significantly and elevated the level of SOD and GSH, showing that oxidative stress was restrained by fucoidan. Furthermore, the decreased expression levels of α-SMA and collagen I was detected in fibroblast treated with fucoidan.

Conclusions

These data suggest fucoidan may protect the lung from hyperoxia via suppressing cell apoptosis, mitigating oxidative stress, and inhibiting lung fibroblasts from differentiating into myofibroblasts.

Sargassum fusiforme Fucoidan Alleviates High-Fat Diet-Induced Obesity and Insulin Resistance Associated with the Improvement of Hepatic Oxidative Stress and Gut Microbiota Profile

Sargassum fusiforme fucoidan (SFF) exhibits diverse biological activities. Insulin resistance (IR) implicated in type 2 diabetes (T2D) has become an epidemic health issue worldwide. In this study, we investigated whether SFF can improve insulin sensitivity in high-fat diet (HFD)-fed mice. Our present data showed that SFF significantly reduced fasting blood glucose and IR index along with improved glucose tolerance. Impaired phosphorylation of Akt was also restored by SFF. Furthermore, SFF decreased the levels of MDA and 4-HNE-modified protein and increased GSH/GSSG ratio as well as elevated antioxidant enzymes and activated Nrf2 signaling. SFF also increased the abundance and diversity of gut microbiota in the obese mice, as well as improved intestinal integrity and inflammation. Our findings suggested that SFF ameliorated HFD-induced IR through activating the Nrf2 pathway, remodeling gut microbiota, and reducing intestinal inflammation, thus providing a novel perspective into the treatment strategy on metabolic disease.

Marine-Derived Surface Active Agents: Health-Promoting Properties and Blue Biotechnology-Based Applications

Surface active agents are characterized for their capacity to adsorb to fluid and solid-water interfaces. They can be classified as surfactants and emulsifiers based on their molecular weight (MW) and properties. Over the years, the chemical surfactant industry has been rapidly increasing to meet consumer demands. Consequently, such a boost has led to the search for more sustainable and biodegradable alternatives, as chemical surfactants are non-biodegradable, thus causing an adverse effect on the environment. To these ends, many microbial and/or marine-derived molecules have been shown to possess various biological properties that could allow manufacturers to make additional health-promoting claims for their products. Our aim, in this review article, is to provide up to date information of critical health-promoting properties of these molecules and their use in blue-based biotechnology (i.e., biotechnology using aquatic organisms) with a focus on food, cosmetic and pharmaceutical/biomedical applications.

Current Designs and Developments of Fucoidan-based Formulations for Cancer Therapy

BACKGROUND

Natural nanostructure materials have been involved in antitumor drug delivery systems due to their biocompatibility, biodegradation, and bioactive properties.

METHODS

These materials have contributed to advanced drug delivery systems in the roles of both bioactive compounds and delivery nanocarriers. Fucoidan, a valuable ocean material used in drug delivery systems, has been exploited in research on cancer and a variety of other diseases.

RESULTS

Although the uniqueness, structure, properties, and health benefits of fucoidan have been mentioned in various prominent reviews, current developments and designs of fucoidan-based formulations still need to be assessed to further develop an effective anticancer therapy. In this review, current important formulations using fucoidan as a functional material and as an anticancer agent will be discussed. This article will also provide a brief principle of the methods that incorporate functional nanostructure materials in formulations exploiting fucoidan.

CONCLUSION

Current research and future perspectives on the use of fucoidan in anticancer therapy will advance innovative and important products for clinical uses.

Catalpol Attenuates Hepatic Steatosis by Regulating Lipid Metabolism via AMP-Activated Protein Kinase Activation

The increased prevalence of nonalcoholic fatty liver disease (NAFLD), which develops from hepatic steatosis, represents a public health challenge. Catalpol, a natural component extracted from the roots of Radix Rehmanniae, has several pharmacological activities. The present study is aimed at examining whether catalpol prevents hepatic steatosis in cell and animal experiments and elucidating the possible mechanisms. HepG2 cells were treated with 300 μM palmitate (PA) and/or catalpol for 24 h in vitro, and male C57BL/6J mice fed a high-fat diet (HFD) were administered catalpol for 18 weeks in vivo. The results revealed that catalpol significantly decreased lipid accumulation in PA-treated HepG2 cells. Moreover, catalpol drastically reduced body weight and lipid accumulation in the liver, whereas it ameliorated hepatocyte steatosis in HFD-fed mice. Notably, catalpol remarkably promoted the phosphorylation of AMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase. Subsequently, catalpol repressed the expressions of lipogenesis-associated genes such as sterol regulatory element-binding protein 1c and fatty acid synthase but promoted the expressions of genes associated with fatty acid β-oxidation such as peroxisome proliferator-activated receptor α together with its target genes carnitine palmitoyltransferase 1 and acyl-CoA oxidase 1 (ACOX1). However, the preincubation of the HepG2 cells with compound C (10 μM), an AMPK inhibitor, prevented catalpol-mediated beneficial effects. These findings suggest that catalpol ameliorates hepatic steatosis by suppressing lipogenesis and enhancing fatty acid β-oxidation in an AMPK-dependent manner. Therefore, catalpol has potential as a novel agent in the treatment of NAFLD.

Combined treatments with metformin and phosphodiesterase inhibitors alleviate nonalcoholic fatty liver disease in high-fat diet fed rats: a comparative study

Nonalcoholic fatty liver disease (NAFLD) is an excessive accumulation of fats in the liver resulting in hepatic inflammation and fibrous tissue formation along with insulin resistance. This study was designed to investigate the possible protective effects of metformin alone and in combination with different phosphodiesterase inhibitors (PDEIs). Rats were fed a high-fat diet (HFD) for 16 weeks to induce NAFLD. Starting from week 12, rats received metformin alone or in combination with pentoxifylline, cilostazol, or sildenafil. HFD administration resulted in hepatic steatosis and inflammation in rats. In addition, liver index, body composition index, activities of liver enzymes, and serum lipids deviated from normal. Further, significant elevations were recorded compared to control in terms of serum glucose, insulin, and HOMA-IR (homeostasis model assessment index for insulin resistance), oxidative stress parameters, hepatic TNF-α and NF-κB gene expression, and iNOS protein expression. Rats treated with metformin showed a significant improvement in the aforementioned parameters. However, the addition of pentoxifylline to metformin treatment synergized its action and produced a fortified effect against HFD-induced NAFLD better than other PDEIs. Data from this study indicated that combined treatment of metformin and pentoxifylline had the most remarkable ameliorated effects against HFD-induced NAFLD; further clinical investigations are needed to approve PDEIs for NAFLD treatment.

Immune-modulating and anti-inflammatory marine compounds against cancer

The recent advances in cancer immunotherapy confirm the crucial role of the immune system in cancer progression and treatment. Chronic inflammation and reduced immune surveillance are both features of the tumor microenvironment. Strategies aimed at reverting pro-tumor inflammation and stimulating the antitumor immune components are being actively searched, and the anticancer effects of many candidate drugs have been linked to their ability to modulate the immune system. Marine organisms constitute a rich reservoir of new bioactive molecules; some of them have already been exploited for pharmaceutical use, whereas many others are undergoing clinical or preclinical investigations for the treatment of different diseases, including cancer. In this review, we will discuss the immune-modulatory properties of marine compounds for their potential use in cancer prevention and treatment and as possible tools in the context of cancer immunotherapy.

Fucoidan Ameliorates Oxidative Stress, Inflammation, DNA Damage, and Hepatorenal Injuries in Diabetic Rats Intoxicated with Aflatoxin B1

The current study was carried out to evaluate the ameliorative effect of fucoidan against aflatoxicosis-induced hepatorenal toxicity in streptozotocin-induced diabetic rats. Sixty-four Wister albino male rats were randomly assigned into eight groups (8 rats each) that received normal saline, fucoidan (FUC) at 100 mg/kg/day orally for 4 weeks, streptozotocin (STZ) at 50 mg/kg/i.p. single dose, STZ plus FUC, aflatoxin B₁ (AFB₁) at 50 μg/kg/i.p. after one month of the beginning of the experiment for 2 weeks, AFB₁ plus FUC, STZ plus AFB₁, or STZ plus AFB₁ and FUC. Injection of rats with STZ induced hyperglycemia. Rats with STZ-induced diabetes, with or without AFB₁ intoxication, had significantly elevated activities of serum aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase, and levels of serum urea, creatinine, cholesterol, 8-oxo-2′-deoxyguanosine, interleukin-1β, interleukin-6, and tumor necrosis factor-α. In addition, these rats exhibited increased lipid peroxidation and reduced glutathione concentration and activities of superoxide dismutase, catalase, and glutathione peroxidase enzymes in the hepatic and renal tissues. In contrast, administration of FUC to diabetic rats, with or without AFB₁ intoxication, ameliorated the altered serum parameters, reduced oxidative stress, DNA damage, and inflammatory biomarkers, and enhanced the antioxidant defense system in the hepatic and renal tissues. These results indicated that FUC ameliorated diabetes and AFB₁-induced hepatorenal injuries through alleviating oxidative stress, DNA damage, and inflammation.

Targeting of miR-96-5p by catalpol ameliorates oxidative stress and hepatic steatosis in LDLr-/- mice via p66shc/cytochrome C cascade

Hepatic steatosis and oxidative stress are considered to be the sequential steps in the development of non-alcoholic fatty liver disease (NAFLD). We previously found that catalpol, an iridoid glucoside extracted from the root of Romania glutinosa L, protected against diabetes-induced hepatic oxidative stress. Here, we found that the increased expression of p66shc was observed in NAFLD models and catalpol could inhibit p66shc expression to ameliorate NAFLD effectively. However, the underlying mechanisms remained unknown. The aim of the present study was to investigate the p66shc-targeting miRNAs in regulating oxidative stress and hepatic steatosis, also the mechanisms of catalpol inhibiting NAFLD. We found that the effects of catalpol inhibiting hepatic oxidative stress and steasis are dependent on inhibiting P66Shc expression. In addition, miR-96-5p was able to suppress p66shc/cytochrome C cascade via targeting p66shc mRNA 3’UTR, and catalpol could lead to suppression of NAFLD via upregulating miR-96-5p level. Thus, catalpol was effective in ameliorating NAFLD, and miR-96-5p/p66shc/cytochrome C cascade might be a potential target.

Seaweed-derived bioactives as potential energy regulators in obesity and type 2 diabetes

There is epidemiological evidence that dietary intake of seaweeds is associated with a lower prevalence of chronic diseases. While seaweeds are of high nutritious value, due to their high content of fiber, polyunsaturated fatty acids and minerals, they also contain an abundance of bioactive compounds. There is a growing body of scientific data that these bioactive moieties exert effects that could correct the metabolic dysregulation that is present in obesity and Type 2 diabetes (T2D). In this review we describe how the molecular mechanisms, specific to different tissues, that underly obesity and T2D are influenced by both seaweed extracts and seaweed-derived bioactive molecules. In obesity, modulation of antioxidant capacity and reduction of intracellular ROS levels within tissues, and regulation of signaling pathways involved in enhancing browning of white adipose tissue, have been highlighted as key mechanism and identified as a potential target for optimal energy metabolism. In T2D, management of post-prandial blood glucose by modulating α-glucosidase or α-amylase activities, modulation of the AMPK signaling pathway, and similarly to obesity, reduction of ROS and NO production with subsequent increased expression of antioxidant enzymes have been shown to play a key role in glucose metabolism and insulin signaling. Future studies aimed at discovering new therapeutic drugs from marine natural products should, therefore, focus on bioactive compounds from seaweed that exert antioxidant activity and regulate the expression of key signaling pathways involved in glucose homeostasis, mechanisms that are common to both obesity and T2D management. In addition, more data is required to provide evidence of clinical benefit.

The Antioxidant Activity of Polysaccharides Derived from Marine Organisms: An Overview

Marine-derived antioxidant polysaccharides have aroused extensive attention because of their potential nutritional and therapeutic benefits. However, the comprehensive comparison of identified marine-derived antioxidant polysaccharides is still inaccessible, which would facilitate the discovery of more efficient antioxidants from marine organisms. Thus, this review summarizes the sources, chemical composition, structural characteristics, and antioxidant capacity of marine antioxidant polysaccharides, as well as their protective in vivo effects mediated by antioxidative stress reported in the last few years (2013-2019), and especially highlights the dominant role of marine algae as antioxidant polysaccharide source. In addition, the relationships between the chemical composition and structural characteristics of marine antioxidant polysaccharides with their antioxidant capacity were also discussed. The antioxidant activity was found to be determined by multiple factors, including molecular weight, monosaccharide composition, sulfate position and its degree.

Fucoidan suppresses the gastric cancer cell malignant phenotype and production of TGF-β1 via CLEC-2

The sulfated polysaccharide fucoidan displays excellent anticancer properties with low toxicity in many kinds of cancers. However, its detailed pharmacological effect and mechanism of action in gastric carcinoma remains unclear. In this study, we found that fucoidan could suppress gastric cancer (GC) cell growth, as well as cell migration and invasion. A cytokine expression screen demonstrated that transforming growth factor beta 1 (TGF-β1) secretion was decreased in fucoidan-treated cells. Fucoidan has been reported to be a platelet agonist for the C-type lectin-like receptor 2 (CLEC-2), and our previous research found that upregulation of CLEC-2 inhibited GC progression. Here, we confirmed that fucoidan, combined with CLEC-2, significantly increased CLEC-2 expression in GC cells via the transcription factor caudal type homeobox transcription factor 2, an important regulator of gut homeostasis. In addition, the inhibitory effect of fucoidan on the GC cell malignant phenotype and TGF-β1 secretion could be restored by knocking down CLEC-2. Thus, our data suggest that fucoidan targets CLEC-2 to exert antitumorigenesis and antimetastatic activity, suggesting that fucoidan is a promising treatment for gastric carcinoma.

In vitro anticancer activity of fucoidan extracted from Sargassum cinereum against Caco-2 cells

Fucoidan is a marine sulfated polysaccharide, which is extracted from brown seaweed that has a wide range of bioactivities including anti-cancer properties. However, the underlying mechanism of fucoidan on its anti-cancer and apoptotic activity against colon cancer cell line Caco-2 remains to be elucidated. Hence, the present study evaluated the cytotoxicity, apoptotic and anti-cancer activity of fucoidan extracted from brown seaweed Sargassum cinereum against Caco-2 cell line. Cytotoxicity, morphological examination of nuclei, mitochondrial membrane potential, flow cytometry, reactive oxygen species (ROS) formation and detection of apoptotic efficacy of fucoidan were assessed by different assay protocols. Fucoidan inhibited growth of Caco-2 cells in a dose-dependent manner. IC50 concentration of fucoidan was found to be 250 μg/ml. AO/EB, Hoechst and Annexin V/PI staining confirmed the apoptosis induced by fucoidan in Caco-2 cells. Fucoidan was also found to increase ROS production and augment mitochondrial membrane permeability. The findings of the study suggest that fucoidan exerts potent anti-cancer and apoptotic effect on Caco-2 cells by enhancing ROS production. Thus, fucoidan may be used as a promising therapeutic regimen against various cancer cell types.

Resveratrol ameliorates maternal and post-weaning high-fat diet-induced nonalcoholic fatty liver disease via renin-angiotensin system

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) can develop in prenatal stages and can be exacerbated by exposure to a postnatal high-fat (HF) diet. We investigated the protective effects of resveratrol on prenatal and postnatal HF diet-induced NAFLD.

METHODS

Male Sprague-Dawley rat offspring were placed in five experimental groups (n = 10-12 per group): normal diet (VNF), maternal HF diet (ONF), postnatal HF diet (VHF), and maternal HF diet/postnatal HF diet (OHF). A therapeutic group with resveratrol for maternal HF diet/postnatal HF diet (OHFR) was used for comparison. Resveratrol (50 mg/kg/day) was dissolved in drinking water for offspring from post-weaning to postnatal day (PND) 120.

RESULTS

We found that HF/HF-induced NAFLD was prevented in adult offspring by the administration of resveratrol. Resveratrol administration mediated a protective effect on rats on HF/HF by regulating lipid metabolism, reducing oxidative stress and apoptosis, restoring nutrient-sensing pathways by increasing Sirt1 and leptin expression, and mediating the renin-angiotensin system (RAS) to decrease angiotensinogen, renin, ACE1, and AT1R levels and increased ACE2, AT2R and MAS1 levels compared to those in the OHF group.

CONCLUSION

Our results suggest that a maternal and post-weaning HF diet increases liver steatosis and apoptosis via the RAS. Resveratrol might serve as a therapeutic target by mediating protective actions against NAFLD in offspring exposed to a combination of maternal and postnatal HF diet.

Melatonin alleviates liver steatosis induced by prenatal dexamethasone exposure and postnatal high-fat diet

Prenatal exposure to glucocorticoids is associated with negative health consequences for the offspring that persist into adulthood, including liver steatosis. Melatonin has previously been demonstrated to suppress liver steatosis and oxidative stress in humans with non-alcoholic fatty liver disease and in animal models of obesity. The present study aimed to determine whether melatonin protects against liver steatosis induced by prenatal dexamethasone exposure followed by postnatal high-fat diet. Pregnant Sprague-Dawley rats at gestational days 14-21 were administered dexamethasone (0.1 mg/kg/day) or saline via intraperitoneal injection. The offspring were then divided into five groups, as follows: Vehicle, postnatal high-fat diet (VHF), prenatal dexamethasone exposure (DEX), prenatal dexamethasone exposure + postnatal high-fat diet (DHF), and prenatal dexamethasone exposure + postnatal high-fat diet + melatonin (DHFM) group. Following vehicle or dexamethasone exposure of the maternal rats, the offspring rats in the VHF, DHF and DHFM groups received a high-fat diet (58% fat) between weaning and 6 months of age. In the DHFM group, melatonin was administered to the mothers from gestational days 14-21 until weaning. The offspring continued to receive melatonin until they were sacrificed at 6 months old. Oil Red O staining demonstrated stronger intensity in the DHF group compared with that in the other four groups. Western blot analysis also revealed higher levels of cleaved caspase-3, tumor necrosis factor-α (TNF-α), suppressor of cytokine signaling 3 (SOCS3) and malondialdehyde (MDA), as well as reduced expression of manganese superoxide dismutase (MnSOD) and phosphoinositide 3-kinase (PI3K) in the DHF group compared with the vehicle and DHFM groups. In addition, melatonin reduced the Oil Red O staining intensity and the levels of cleaved caspase-3, TNF-α, SOCS3 and MDA, while it increased the MnSOD and PI3K levels, in the DHFM group compared with the DHF group. In conclusion, postnatal high-fat diet aggravated the prenatal dexamethasone-induced liver steatosis in adult rat offspring via inflammation, oxidative stress and cellular apoptosis, which may be ameliorated by prenatal melatonin therapy.

Combination Treatment of Deep Sea Water and Fucoidan Attenuates High Glucose-Induced Insulin-Resistance in HepG2 Hepatocytes

Insulin resistance (IR) plays a central role in the development of several metabolic diseases, which leads to increased morbidity and mortality rates, in addition to soaring health-care costs. Deep sea water (DSW) and fucoidans (FPS) have drawn much attention in recent years because of their potential medical and pharmaceutical applications. This study investigated the effects and mechanisms of combination treatment of DSW and FPS in improving IR in HepG2 hepatocytes induced by a high glucose concentration. The results elucidated that co-treatment with DSW and FPS could synergistically repress hepatic glucose production and increase the glycogen level in IR-HepG2 cells. In addition, they stimulated the phosphorylation levels of the components of the insulin signaling pathway, including tyrosine phosphorylation of IRS-1, and serine phosphorylation of Akt and GSK-3β. Furthermore, they increased the phosphorylation of AMPK and ACC, which in turn decreased the intracellular triglyceride level. Taken together, these results suggested that co-treatment with DSW and FPS had a greater improving effect than DSW or FPS alone on IR. They might attenuate IR by targeting Akt/GSK-3β and AMPK pathways. These results may have some implications in the treatment of metabolic diseases.