Kappaphycus alvarezii as a Food Supplement Prevents Diet-Induced Metabolic Syndrome in Rats

Differential Proneness to Obesity in Two Rat Strains with Diverse Immune Responses

Although obesity and metabolic syndrome (comprising at least three of the following traits-abdominal obesity, elevated blood pressure, triglycerides and glucose/insulin resistance, and reduced high-density lipoprotein cholesterol in serum) are known to impact immune system activity, these conditions are often not considered when immune response characteristics are investigated in various rodent strains. In this work, metabolic syndrome indices are compared in 3 month-old (young) and 6 month-old (adult) rats of Dark Agouti (DA) and Albino Oxford (AO) strains, while parameters of coagulation, inflammation and oxidative stress were determined in young animals. Study reveals that both young and adult AO rats are obese, intolerant to glucose with higher levels of triglycerides and lower levels of high-density lipoprotein cholesterol when compared to age-matched DA rats. Parameters of coagulation, inflammation and oxidative stress that may contribute to the worsening of metabolic syndrome during aging are also higher in young AO rats. Metabolic syndrome observed in young and intensified in adult AO rats should be taken into consideration when analyzing alterations in immune reactivity during aging in this rat strain.

Plant-Based Functional Foods from Borneo

Borneo, the third-largest island in the world, is shared between Malaysia (Sabah and Sarawak), Indonesia (Kalimantan) and Brunei. As a biodiversity hotspot, it is home to about 15,000 flowering plants and 3000 tree species, of which many are endemic to the region. Locally derived plant-based foods are gaining popularity due to their lower environmental impact, contribution to food sustainability and health benefits. The local fruits and vegetables of Borneo have been used traditionally by the indigenous community for medicinal purposes. This community knowledge can provide a valuable guide to their potential for use as functional foods. This review explores the contemporary foods from Borneo, including fruit, vegetables, seaweeds and plant-derived food products that are locally consumed. The findings show that the unique tropical food groups have a wide diversity of phytochemical compositions that possess a wide array of biological activities including anti-inflammatory, antioxidant, anti-microbial, anti-proliferative, anti-fungal, wound healing and expectorant properties. The wide range of plant-based foods in Borneo deserves further development for wider applications as functional foods.

A study on the impact of diet supplementation of fermented dried seaweed powder (Kappaphycus alvarezii) on healthy cat gut performance, skin and hair coat conditions, and behaviour

One of the key goals the feed industry emphasizes when exploring the incorporation of novel substances into animal diets is to enhance feed utilization efficiency, to bolster animal health and well-being. Fermented seaweed powder holds promise as a valuable and sustainable component of animal feed, owing to its rich nutrient profile and purported benefits for livestock and aquaculture species. This study provides some interesting and original preliminary data regarding the benefits of supplementing cats' diets with fermented dried seaweed. Using a broad investigative approach to measure and analyse multiple health benefits of feeding fermented dried macroalgae to cats as a nutritional supplement, the results of this 8-week study identified several positive health attributes related to body coat quality, nutrient digestibility, behavioural changes, a healthy gut microbiota ratio, and enhanced immunity. There were no adverse effects observed in the cats after supplementation with the fermented seaweed powder. The sample size in this study with cats should be increased, but this preliminary work showed that the seaweed-supplemented cats exhibited improvements in the measured health parameters over the control cats. As a result of this 8-week trial, key information has been provided regarding future research direction focusing on skin health application which is essential to the overall animal wellbeing.

Exploring carrageenan: From seaweed to biomedicine-A comprehensive review

Biomaterials are pivotal in the realms of tissue engineering, regenerative medicine, and drug delivery and serve as fundamental building blocks. Within this dynamic landscape, polymeric biomaterials emerge as the frontrunners, offering unparalleled versatility across physical, chemical, and biological domains. Natural polymers, in particular, captivate attention for their inherent bioactivity. Among these, carrageenan (CRG), extracted from red seaweeds, stands out as a naturally occurring polysaccharide with immense potential in various biomedical applications. CRG boasts a unique array of properties, encompassing antiviral, antibacterial, immunomodulatory, antihyperlipidemic, antioxidant, and antitumor attributes, positioning it as an attractive choice for cutting-edge research in drug delivery, wound healing, and tissue regeneration. This comprehensive review encapsulates the multifaceted properties of CRG, shedding light on the chemical modifications that it undergoes. Additionally, it spotlights pioneering research that harnesses the potential of CRG to craft scaffolds and drug delivery systems, offering high efficacy in the realms of tissue repair and disease intervention. In essence, this review celebrates the remarkable versatility of CRG and its transformative role in advancing biomedical solutions.

Effect of Gracilaria vermiculophylla Macroalga on Non-Alcoholic Fatty Liver Disease in Obese Rats

Marine algae are valuable sources of bioactive compounds that have the potential to be used in the management of various pathologies. Despite the increasing prevalence of NAFLD, the absence of an approved effective pharmacological treatment with demonstrable effectiveness persists. In this context, the aim of the present study is to assess the effect of Gracilaria vermiculophylla red seaweed dietary supplementation on hepatic lipid accumulation, as well as on oxidative stress, inflammation and fibrosis- related markers on obese fa/fa Zucker rats fed with a standard diet, supplemented or not with 2.5% or 5% dehydrated Gracilaria vermiculophylla. After a six-week supplementation with the macroalga, no significant reduction in hepatic total lipid content or hepatic triglyceride content was observed. However, both doses were able to diminish hepatic NEFA concentration by reducing de novo lipogenesis and increasing mitochondrial biogenesis. Moreover, supplementation with the dose of 2.5% improved some oxidative stress and inflammation-related markers. Supplementation with the dose of 5% did not exert these clear beneficial effects. Thus, this study demonstrates that while Gracilaria vermiculophylla may not mitigate hepatic steatosis, it could exert protective effects on the liver by reducing NEFA content and enhancing oxidative stress and inflammation parameters.

Biological activity of algal derived carrageenan: A comprehensive review in light of human health and disease

Carrageenans are a family of natural linear sulfated polysaccharides derived from red seaweeds and used as a common food additive. Carrageenan's properties, impact on health, and aesthetic benefits have all been studied for a long time; however, the mechanisms are still unclear. In pharmaceutical aspects, carrageenan displayed potential antioxidant and immunomodulatory properties in both in vivo and in vitro action. It also contributes to potential disease-preventive activities through dynamic modulation of important intracellular signaling pathways, regulation of ROS buildup, and preservation of major cell survival and death processes which leads to potential drug development. Furthermore, the chemical synthesis of the current bioactive medicine with confirmational rearrangement may increase availability and bioactivity needs diligent examination. In this review, we give an up-to-date overview of recent research on Carrageenan with reference to health and therapeutic advantages. In addition, we have focused on structural conformation and its primary strategic deployment in disease prevention, as well as the mechanistic investigation of how it functions to combat various disease-preventive employed for future therapeutic interventions. This review may get new insights into the possible novel role of carrageenan and open up a novel disease-preventive mechanism and enhance human health.

Skin Ageing: A Progressive, Multi-Factorial Condition Demanding an Integrated, Multilayer-Targeted Remedy

Of the human organs, skin is the most visible one that displays the manifestations of ageing. It has a very intricate microanatomical structure and performs several key physiological functions. The pathophysiology of cutaneous ageing is characterized by deterioration of structural stability and functional integrity, implying a continuous reduction in maximal function and reserve capacity, as a result of the accumulating damage due to both intrinsic and extrinsic factors. Elimination of unfavorable expressions associated with facial and cutaneous ageing is the key patient demand in aesthetic dermatology. Even though the progress has been made in nonsurgical therapies like fillers and lasers, non-invasive interventions by using skin care products designed for rejuvenation at an early stage are the most popular and accessible solution among people. In this review, we have scrutinized the ageing-associated cutaneous changes at molecular, cellular and tissue levels. To optimize the ageing process towards a healthy skin, we propose an integrated, multilayer-targeted intervention, which involves both topical application of anti-ageing formulations from outside and oral supplementation from inside. Additionally, several promising naturally derived ingredients are reviewed from an anti-aging perspective. Most of them possess various bioactivities and may contribute to the development of the mentioned anti-ageing remedy.

Freshwater Macroalgae, Oedogonium, Grown in Wastewater Reduce Diet-Induced Metabolic Syndrome in Rats

Macroalgae produce compounds with industrial, pharmaceutical and nutritional applications. In this study, biomass from the freshwater macroalgal genus Oedogonium was grown in either treated municipal wastewater (M) or ash dam water from a coal-fired power station (D). The biomass was investigated for its metabolic responses in high-carbohydrate, high-fat diet-fed rats, a model of human metabolic syndrome. The Oedogonium biomass cultured in M contained higher amounts of K, Mg, omega-3 polyunsaturated fatty acids (PUFA), insoluble fibre and β-carotene, while biomass grown in D contained higher amounts of Al, Fe, V, Zn, Mn and As. Biomass from M further increased body weight and inflammation in the heart and colon in high-carbohydrate, high-fat diet-fed rats. In contrast, biomass from D prevented changes in metabolic, cardiovascular and liver parameters without changing tissue histology. We suggest that increased intake of metals and metalloids through macroalgal biomass from D may decrease abdominal fat deposition while polysaccharides, PUFA and carotenoids from M may improve blood glucose responses in an obesogenic diet. Thus, macroalgal biomass grown in different wastewater sources could be acceptable for feed or food applications. This biomass could even provide potential health benefits in diet-induced metabolic syndrome.

Marine Bioactive Compounds Derived from Macroalgae as New Potential Players in Drug Delivery Systems: A Review

The marine algal ecosystem is characterized by a rich ecological biodiversity and can be considered as an unexploited resource for the discovery and isolation of novel bioactive compounds. In recent years, marine macroalgae have begun to be explored for their valuable composition in bioactive compounds and opportunity to obtain different nutraceuticals. In comparison with their terrestrial counterparts, Black Sea macroalgae are potentially good sources of bioactive compounds with specific and unique biological activities, insufficiently used. Macroalgae present in different marine environments contain several biologically active metabolites, including polysaccharides, oligosaccharides, polyunsaturated fatty acids, sterols, proteins polyphenols, carotenoids, vitamins, and minerals. As a result, they have received huge interest given their promising potentialities in supporting antitumoral, antimicrobial, anti-inflammatory, immunomodulatory, antiangiogenic, antidiabetic, and neuroprotective properties. An additional advantage of ulvans, fucoidans and carrageenans is the biocompatibility and limited or no toxicity. This therapeutic potential is a great natural treasure to be exploited for the development of novel drug delivery systems in both preventive and therapeutic approaches. This overview aims to provide an insight into current knowledge focused on specific bioactive compounds, which represent each class of macroalgae e.g., ulvans, fucoidans and carrageenans, respectively, as valuable potential players in the development of innovative drug delivery systems.

Traditional Knowledge and Modern Motivations for Consuming Seaweed (Limu) in Samoa

Seaweeds are a traditional food throughout the Pacific. In Samoa, the edible seaweeds limu fuafua (sea grapes, Caulerpa racemosa and C. chemnitzia) and limu a’au (red seaweed, Halymenia durvillei and Halymenia sp.) are hand-harvested and consumed fresh or cooked, respectively. However, there is limited scientific or traditional documentation of these commodities. Here, we assess the traditional use and cultural value of edible seaweeds and explore modern consumer preferences and perceived nutritional benefits. Structured enumerator-administered questionnaires were used to examine the relationship between consumption and demographics and subsequently to assess the key motivators for consumption, including perceived nutritional benefits. A total of 320 participants were surveyed across 20 village communities, with 95% reporting consumption of Caulerpa and 40% of Halymenia. Consumption was primarily on a weekly to monthly basis, and even once a day. Motivators and barriers for consumption were then assessed in 320 village participants with an additional 203 intercept interviews at fish markets. A content analysis of the open-ended questions revealed the key motivators for eating limu were health and taste (positive), whereas the key barriers were taste (negative) and availability. We identify opportunities to develop a nutrient evidence base for Samoan seaweeds to aid in marketing, especially for youth.

Large-Scale Characterization of the Soil Microbiome in Ancient Tea Plantations Using High-Throughput 16S rRNA and Internal Transcribed Spacer Amplicon Sequencing

There is a special interaction between the environment, soil microorganisms, and tea plants, which constitute the ecosystem of tea plantations. Influenced by environmental factors and human management, the changes in soil microbial community affected the growth, quality, and yield of tea plants. However, little is known about the composition and structure of soil bacterial and fungal communities in 100-year-old tea plantations and the mechanisms by which they are affected. In this regard, we characterized the microbiome of tea plantation soils by considering the bacterial and fungal communities in 448 soil samples from 101 ancient tea plantations in eight counties of Lincang city, which is one of the tea domestication centers in the world. 16S and Internal Transcribed Spacer (ITS) rRNA high-throughput amplicon sequencing techniques were applied in this study. The results showed that the abundance, diversity, and composition of the bacterial and fungal communities have different sensitivity with varying pH, altitude, and latitude. pH and altitude affect soil microbial communities, and bacterial communities are more sensitive than fungi in terms of abundance and diversity to pH. The highest α-diversity of bacterial communities is shown in the pH 4.50–5.00 and 2,200-m group, and fungi peaked in the pH 5.00–5.50 and 900-m group. Because of environmental and geographical factors, all microbes are similarly changing, and further correlations showed that the composition and structure of bacterial communities are more sensitive than fungal communities, which were affected by latitude and altitude. In conclusion, the interference of anthropogenic activities plays a more important role in governing fungal community selection than environmental or geographical factors, whereas for the bacterial community, it is more selective to environment adaptation than to adaptation to human activities.

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.

The effect of coffee consumption on glucose homeostasis and redox-inflammatory responses in high-fat diet-induced obese rats

Coffee effects on glucose homeostasis in obesity remain controversial. We investigated whether coffee mitigates the negative effects on glucose metabolism induced by a high-fat diet and the interrelationships with redox-inflammatory responses. Rats were treated with: control (CT-); coffee (CT+) 3.9 g of freeze-dried coffee/kg of diet; high-fat (HF-); or high-fat + coffee 3.9 g of freeze-dried coffee/kg of diet (HF+) diet. The high-fat diet increased weight gain, feed efficiency, HOMA β, muscle and hepatic glycogen, intestinal CAT and SOD activity, hepatic protein (CARB) and lipid oxidation (MDA), muscle Prkaa1 mRNA and IL6 levels, and decreased food intake, hepatic GR, GPX and SOD activities, intestinal CARB, intestinal Slc2a2 and Slc5a1 and hepatic Prkaa1 and Prkaa2 mRNA levels, hepatic glucose-6-phosphatase and muscle hexokinase (HK) activities, compared to the control diet. The high-fat diet with coffee increased hepatic GST activity and TNF and decreased IL6 and intestinal glucosidase activity compared with the high-fat diet. The coffee diet increased muscle glycogen, hepatic CARB and PEPCK activity, and decreased hepatic GR and SOD activities and intestinal CARB, compared with the control diet. Coffee increased insulin levels, HOMA IR/β, FRAP, muscle Prkaa1 mRNA levels and hepatic and muscle phosphofructokinase-1, and it decreased intestinal CAT, hepatic Slc2a2 mRNA levels and muscle HK activity, regardless of the diet type. In conclusion, chronic coffee consumption improves antioxidant and anti-inflammatory responses, but does not ameliorate glucose homeostasis in a high-fat diet-induced obesity model. In addition, coffee consumption increases insulin secretion and promotes muscle glycogen synthesis in rats maintained on a control diet.

Sun-Dried and Air-Dried Kappaphycus alvarezii Attenuates 5-Fluorouracil-Induced Intestinal Mucositis in Mice

5-fluorouracil (5-FU)-induced intestinal mucositis (IM) often makes chemotherapy patients suffer from physical and psychological suffering. Kappaphycus alvarezii (KA) is known for its potent multiple biological activities from decades. In the current study, we explored the effect of sun-dried and air-dried Kappaphycus alvarezii as a whole food supplement on 5-FU-induced IM. Diets supplemented with sun-dried Kappaphycus alvarezii (SKA, 3%), air-dried Kappaphycus alvarezii (AKA, 3%), and 5-aminosalicylic acid (0.005%) for consecutive14 days. While intraperitoneal injection of 5-FU (50 mg/kg) induced IM for last three consecutive days, and IM was assessed by the disease activity index (DAI) and inflammatory cytokine levels. Pretreatment of KA could alleviate phenotypic index, inhibit the increase of DAI, and reverse villus/crypt ratio. On the 14th day, AKA significantly increased the weight growth rate of the mice. The intervention of SKA significantly reduced the level of TNF-α and IL-1β (P < 0.01, P < 0.01), while the intervention of AKA significantly inhibited the level of TNF-α, IL-1β, and LT (P < 0.01, P < 0.01, P < 0.001). Therefore, these results showed that KA as a whole food supplement might be prevent the 5-FU-induced IM. For the first time suggest that the use of AKA might be more effective than SKA despite exact mechanism still needs further study.

Brown Seaweed Sargassum siliquosum as an Intervention for Diet-Induced Obesity in Male Wistar Rats

The therapeutic potential of Sargassum siliquosum grown in Australian tropical waters was tested in a rat model of metabolic syndrome. Forty-eight male Wistar rats were divided into four groups of 12 rats and each group was fed a different diet for 16 weeks: corn starch diet (C); high-carbohydrate, high-fat diet (H) containing fructose, sucrose, saturated and trans fats; and C or H diets with 5% S. siliquosum mixed into the food from weeks 9 to 16 (CS and HS). Obesity, hypertension, dyslipidaemia, impaired glucose tolerance, fatty liver and left ventricular fibrosis developed in H rats. In HS rats, S. siliquosum decreased body weight (H, 547 ± 14; HS, 490 ± 16 g), fat mass (H, 248 ± 27; HS, 193 ± 19 g), abdominal fat deposition and liver fat vacuole size but did not reverse cardiovascular and liver effects. H rats showed marked changes in gut microbiota compared to C rats, while S. siliquosum supplementation increased gut microbiota belonging to the family Muribaculaceae. This selective increase in gut microbiota likely complements the prebiotic actions of the alginates. Thus, S. siliquosum may be a useful dietary additive to decrease abdominal and liver fat deposition.

Molecular Mechanisms of the Anti-obesity Properties of Agardhiella subulata in Mice Fed a High-Fat Diet

The overweight and obese population has skyrocketed, resulting in a high incidence of metabolic disorders. Agardhiella subulata (AS) contains a variety of beneficial components, such as sulfur-containing polysaccharides (dietary fiber) and astaxanthin, which is considered to have anti-obesity potential. In this study, we investigated the effects and possible mechanisms of dietary AS on high-fat diet (HFD)-induced obesity in mice. AS supplementation significantly reduced HFD-induced weight gain (19%) and the visceral adiposity index (4.1%). In addition, the level of total cholesterol, triglyceride, and low-density lipoprotein was significantly decreased; adiponectin was significantly increased in serum and fecal triglyceride excretion was significantly higher in mice fed AS compared with mice on an HFD. Preadipocyte factor 1 and Sry-box transcription factor 9 that were significantly higher than the levels found for the HFD group lead to reduced adipogenesis. Moreover, accompanying the lipolysis and fatty acid β-oxidation that occur in the AS group, the concentration of non-esterified fatty acids was lowered to 0.4 ± 0.1 mEq/L. In addition, peroxisome proliferator-activated receptor γ and phosphorylation acetyl-CoA carboxylase increased 1.5- and 1-fold, thus increasing the expression of adiponectin and the activation of AMPK and ultimately resulting in lower blood glucose levels. The results of this study suggest that AS supplementation increases lipid excretion and improves energy metabolism to prevent obesity in mice fed a HFD.

Diagnostic Criteria for Metabolic Syndrome in Diet-Induced Rodent Models: A Systematic Review

BACKGROUND

Thousands of publications in recent years have addressed the induction of metabolic syndrome (MetS) in rodents. However, the criteria and the reference values for diagnosing this disease have not been defined.

OBJECTIVE

Our main objective was to carry out a systematic review to gather evidence about the criteria for biochemical and anthropometric parameters in which scientific studies have relied on to report that rats developed MetS from a previous dietary manipulation.

METHODS

We compiled characteristics and findings of diet-induced MetS with high-fat, high-carbohydrate, high-fat/high-carbohydrates, and cafeteria diet from PubMed and Science Direct databases published in the last 5 years.

RESULTS

The results on the principal determinants for the syndrome, published in the reviewed articles, were chosen to propose reference values in the rat models of food induction.

CONCLUSION

The values obtained will serve as reference cut-of points in the development of the disease; in addition, the compilation of data will be useful in planning and executing research protocols in animal models.

Caulerpa lentillifera (Sea Grapes) Improves Cardiovascular and Metabolic Health of Rats with Diet-Induced Metabolic Syndrome

Caulerpa lentillifera (sea grapes) is widely consumed in South-East Asia as a low-energy food with high contents of vitamins and minerals. This study investigated dried sea grapes containing 16.6% insoluble fibre commercially produced in Vietnam as an intervention. We hypothesised that insoluble fibre is the primary metabolite that will reverse diet-induced metabolic syndrome. Male Wistar rats (n = 48) were randomly allocated to four groups in a 16 week protocol. Two groups were fed either corn starch (C) or high-carbohydrate, high-fat (H) diets for the full 16 weeks. The other two groups received C and H diets for eight weeks and then received C. lentillifera added to these diets for the final eight weeks (CCL and HCL, respectively). High-carbohydrate, high-fat diet-fed rats developed obesity, hypertension, dyslipidaemia, fatty liver disease and increased left ventricular collagen deposition. C. lentillifera supplementation in HCL rats decreased body weight, systolic blood pressure, plasma concentrations of total cholesterol and non-esterified fatty acids, inflammatory cells in heart and liver, and visceral adiposity. The Firmicutes to Bacteroidetes ratio decreased in the gut microbiota of HCL rats. Therefore, C. lentillifera attenuated cardiovascular and metabolic symptoms of metabolic syndrome in rats, possibly by preventing infiltration of inflammatory cells together with modulating gut microbiota.

Carrageenan: Drug Delivery Systems and Other Biomedical Applications

Marine resources are today a renewable source of various compounds, such as polysaccharides, that are used in the pharmaceutical, medical, cosmetic, and food fields. In recent years, considerable attention has been focused on carrageenan-based biomaterials due to their multifunctional qualities, including biodegradability, biocompatibility, and non-toxicity, in addition to bioactive attributes, such as their antiviral, antibacterial, antihyperlipidemic, anticoagulant, antioxidant, antitumor, and immunomodulating properties. They have been applied in pharmaceutical formulations as both their bioactive and physicochemical properties make them suitable biomaterials for drug delivery, and recently for the development of tissue engineering. This article provides a review of recent research on the various types of carrageenan-based biomedical and pharmaceutical applications.

Bioactive Properties of Marine Phenolics

Phenolic compounds from marine organisms are far less studied than those from terrestrial sources since their structural diversity and variability require powerful analytical tools. However, both their biological relevance and potential properties make them an attractive group deserving increasing scientific interest. The use of efficient extraction and, in some cases, purification techniques can provide novel bioactives useful for food, nutraceutical, cosmeceutical and pharmaceutical applications. The bioactivity of marine phenolics is the consequence of their enzyme inhibitory effect and antimicrobial, antiviral, anticancer, antidiabetic, antioxidant, or anti-inflammatory activities. This review presents a survey of the major types of phenolic compounds found in marine sources, as well as their reputed effect in relation to the occurrence of dietary and lifestyle-related diseases, notably type 2 diabetes mellitus, obesity, metabolic syndrome, cancer and Alzheimer's disease. In addition, the influence of marine phenolics on gut microbiota and other pathologies is also addressed.

Anti-Obesity Effects of Macroalgae

Macroalgae have attracted great interest for their potential applications in nutraceutical and pharmaceutical industries as source of bioactive medicinal products and food ingredients. This review gathers data from in vitro and in vivo studies addressing the anti-obesity effects of macroalgae. Great consensus exists in all reported in vitro studies concerning the reduction induced by seaweed extracts in the expression of transcriptional factors controlling adipogenesis. In animals, macroalgae reduced body fat accumulation and prevented other obesity features, such as dyslipidemia, insulin resistance and fatty liver. These effects are not due to food intake reduction, since few studies have reported such event. Indeed, the effects on metabolic pathways in target tissues/organs seem to play a more relevant role. Macroalgae can reduce de novo lipogenesis, limiting fatty acid availability for triglyceride synthesis in white adipose tissue. This effect has been observed in both cell cultures and adipose tissue from animals treated with macroalgae extracts. In addition, increased fatty acid oxidation and thermogenic capacity, as well as a shift towards healthier gut microbiota composition may contribute to the body fat-lowering effect of macroalgae. Studies in humans are needed to determine whether macroalgae can represent a feasible tool to prevent and/or manage overweight and obesity.

Modulation of gut microbiota by spent coffee grounds attenuates diet-induced metabolic syndrome in rats

Coffee brewing produces spent coffee grounds as waste; few studies have investigated the health benefits of these grounds. This study investigated responses to spent coffee grounds in a diet-induced rat model of metabolic syndrome. Male Wistar rats aged 8-9 weeks were fed either corn starch-rich diet or high-carbohydrate, high-fat diet for 16 weeks, which were supplemented with 5% spent coffee grounds during the last 8 weeks. Rats fed non-supplemented diets were used as controls. High-carbohydrate, high-fat diet-fed rats developed metabolic syndrome including abdominal obesity, impaired glucose tolerance, dyslipidemia, and cardiovascular and liver damage. Body weight, abdominal fat, total body fat mass, systolic blood pressure, and concentrations of plasma triglycerides and non-esterified fatty acids were reduced by spent coffee grounds along with improved glucose tolerance and structure and function of heart and liver. Spent coffee grounds increased the diversity of the gut microbiota and decreased the ratio of Firmicutes to Bacteroidetes. Changes in gut microbiota correlated with the reduction in obesity and improvement in glucose tolerance and systolic blood pressure. These findings indicate that intervention with spent coffee grounds may be useful for managing obesity and metabolic syndrome by altering the gut microbiota, thus increasing the value of this food waste.

Carrageenans from the Red Seaweed Sarconema filiforme Attenuate Symptoms of Diet-Induced Metabolic Syndrome in Rats

Carrageenans are thickening and gelling agents that may provide health benefits. Iota (ι)-carrageenan, a linear sulfated polysaccharide, is produced by the red seaweed, Sarconema filiforme. This study investigated the potential of this seaweed as a functional food for the reversal of metabolic syndrome and possible mechanisms. Male Wistar rats were divided into four groups in a 16-week protocol: corn starch diet-fed rats (C); C rats supplemented with 5% S. filiforme for the last 8 weeks (CSF); high-carbohydrate, high-fat diet-fed rats (H); and H rats supplemented with 5% S. filiforme for the last 8 weeks (HSF). S. filiforme was produced in tank-based aquaculture yielding 27 g dry weight/day/m2 of culture area. H rats developed obesity, hypertension, dyslipidaemia, glucose intolerance, fatty liver and increased left ventricular collagen deposition. S. filiforme supplementation decreased body weight, abdominal and liver fat, systolic blood pressure, plasma total cholesterol concentrations, and plasma activities of alanine transaminase and aspartate transaminase. S. filiforme supplementation modulated gut microbiota without changing the Firmicutes to Bacteroidetes ratio. S. filiforme improved symptoms of high-carbohydrate, high-fat diet-induced metabolic syndrome in rats. Possible mechanisms include a reduced infiltration of inflammatory cells into organs as well as prebiotic actions in the gastrointestinal tract.

Health benefits and bioavailability of marine resources components that contribute to health - what's new?

The strict connection between nutritional intake and health leads to a necessity of understanding the beneficial and protective role of healthy nutrients and foods. The marine environment is a source of a plethora of many organisms with unique properties, extremely rich in bioactive compounds and with remarkable potential for medical, industrial and biotechnological applications. Marine organisms are an extreme valuable source of functional ingredients such as polysaccharides, vitamins, minerals, pigments, enzymes, proteins and peptides, polyunsaturated fatty acids (PUFA), phenolic compounds and other secondary metabolites that prevent or have the potential to treat several diseases given their cardiovascular protective, anti-inflammatory, anti-hypertensive, anti-oxidant, anti-coagulant, anti-proliferative and anti-diabetic activities. This review provides an overview on the current advances regarding health benefits of marine bioactive compounds on several diseases and on human gut microbiota. In addition, it is discussed a crucial factor that is related to the effectiveness of these compounds on human organism namely its real bioavailability.

Spinogenesis and Synaptogenesis Effects of the Red Seaweed Kappaphycus alvarezii and Its Isolated Cholesterol on Hippocampal Neuron Cultures

Neurotrophic factors promote the formation of spines and synapses in neuron development and maintenance. Synaptic connections enhance memory in the brain. In this study, the effects of Kappaphycus alvarezii ethanolic extract (EKA) and its isolated cholesterol (iCHOL) on spinogenesis and synaptogenesis of hippocampal neurons were evaluated. Compared with the vehicle, both EKA and iCHOL significantly promoted generation of dendritic filopodia (2.4- and 2.2-fold, respectively) and spine (1.7- and 1.4-fold) formations in spinogenesis; they also increased presynaptic (3.6- and 2.6-fold), postsynaptic (2.5- and 2.9-fold), and cocolonized (3.8- and 3.0-fold) puncta, which enhances synaptic function (P< 0.05). Further, EKA- and iCHOL-treated neurons showed significantly improved functional presynaptic plasticity (1.6- and 1.4-fold, respectively, at 17 days in vitro; P<0.05). These results indicate that K. alverezii facilitates neuronal development, and support its use as a functional food to reduce neurological disorders and prevent brain aging via helping to reconstruct partially damaged neural networks.

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.

Effect of carrageenans on some lipid metabolism components in vitro

The research described here focused on the effect of sulfated red algal polysaccharides (κ-, κ/β-, ι/κ-carrageenan) individually and in combination with lipopolysaccharide (LPS) on the synthesis of prostaglandin E₂ (PGE₂) and cytokines (interleukin [IL]-1β and IL-6) in whole blood model in vitro. The results demonstrated that, at high concentrations, carrageenans have substantial ability to modulate PGE₂ synthesis and stimulate IL-1β and IL-6 synthesis. A low degree of sulfate and high molecular weight were a prerequisite for the ability of carrageenans to modulate PGE₂ synthesis. Further, we investigated the ability of the carrageenans alone and in combination with casein to affect bile salt permeability through an artificial membrane imitating the gastrointestinal barrier. The least sulfated κ/β-carrageenan could retain bile salt permeation the most but less efficiently than cholestyramine. The polysaccharides did not affect pancreatic lipase activity. Our data confirm a possible mechanism of the cholesterol-reducing properties of carrageenan.

A dietary polysaccharide from Eucheuma cottonii downregulates proinflammatory cytokines and ameliorates osteoarthritis-associated cartilage degradation in obese rats

Osteoarthritis (OA) is a common form of arthritis, which is characterized by the degeneration of articular cartilage, leading to joint dysfunction. Oral drug therapy seems to ameliorate some signs and symptoms of OA, but may be accompanied by side effects and does not appear to be effective long-term. Seaweed has received much attention for pharmacological application due to its various biomedical properties, including the anti-inflammation, antitumor, and antioxidant effects. This study investigated the ameliorative effects of a dietary polysaccharide from Eucheuma cottonii extract (ECE) on an anterior cruciate ligament transection with partial medial meniscectomy surgery (ACLT+MMx) to induce OA in high-fat diet (HFD)-induced obese rats. Male Sprague-Dawley rats were fed an HFD for 12 weeks before ACLT+MMx surgery, after which they were administered a daily oral gavage of saline (Sham, OB Sham, and OBOA) and either low-dose ECE (100 mg per kg body weight), high-dose ECE (400 mg per kg body weight), or glucosamine sulfate as a positive control (OBOAGS; 200 mg per kg body weight) for 5 weeks. Treatment with ECE decreased the body weight, triglyceride and total cholesterol (TC) levels, and the TC/high-density lipoprotein (HDL)-C ratio in the obese rats. Additionally, ECE downregulated the expression of proinflammatory cytokines, including tumor necrosis factor-α, interleukin-1β, and leptin, and suppressed nuclear factor-kappa B and extracellular-signal-regulated kinase-1/2 expression, resulting in a decrease in the levels of matrix metalloproteinase (MMP)-1 and MMP-13 and prostaglandin-E₂ and attenuated cartilage degradation. These results demonstrate that the dietary polysaccharide from ECE can suppress OA development in obese rats, suggesting its potential efficacy as a promising candidate for OA treatment.

Low-Dose Curcumin Nanoparticles Normalise Blood Pressure in Male Wistar Rats with Diet-Induced Metabolic Syndrome

Nanoparticle formulations improve bioavailability and so may allow low-dose formulations of food-derived compounds such as curcumin to attenuate chronic systemic disease despite intrinsically low oral bioavailability. The current study induced metabolic syndrome in male Wistar rats aged eight–nine weeks using a high-carbohydrate, high-fat diet (H) with corn starch diet (C) as control. Using a reversal protocol, rats were given curcumin as either nanoparticles encapsulated in poly(lactic–co–glycolic acid) (5 mg/kg/day, HCNP) or as an unformulated low dose or high-dose suspension in water (low-dose, 5 mg/kg/day, HC5; high-dose, 100 mg/kg/day, HC100) or blank nanoparticles (HBNP) for the final eight weeks of the 16 week study. We analysed cardiovascular parameters including systolic blood pressure and left ventricular diastolic stiffness along with histopathology, liver parameters including plasma liver enzymes, histopathology and metabolic parameters, including glucose tolerance, blood lipid profile and body composition, and plasma curcumin concentrations. HC100 and HCNP but not HBNP normalised systolic blood pressure (C = 120 ± 4; H = 143 ± 5; HBNP = 141 ± 3; HC5 = 143 ± 4; HC100 = 126 ± 4; HCNP = 128 ± 4 mmHg), left ventricular diastolic stiffness and liver fat deposition. No other improvements were induced in HC100 or HCNP or other intervention groups (HC5 and HBNP). We conclude that 5 mg/kg/day curcumin nanoparticles in H rats showed similar improvements in cardiovascular function as 100 mg/kg/day unformulated curcumin correlating with similar plasma curcumin concentrations.

A Pilot Study on Anti-Obesity Mechanisms of Kappaphycus Alvarezii: The Role of Native κ-Carrageenan and the Leftover Sans-Carrageenan Fraction

Kappaphycus is a commercially important edible red alga widely cultivated for carrageenan production. Here, we aimed to investigate the anti-obesity mechanism of Kappaphycus alvarezii by comparing the effects of whole seaweed (T), extracted native κ-carrageenan (CGN), and the leftover fraction sans-carrageenan (SCGN) supplementations (5%, w/w) on diet-induced obese C57BL/6J mice. A high-fat diet induced both a raised body fat percentage and serum cholesterol level, increased adipocytes size, abnormal levels of adipocytokines, and promoted gut dysbiosis. Our results showed that, overall, both CGN and SCGN were more effective in reversing obesity and related metabolic syndromes to normal levels than T. Furthermore, these findings suggested that CGN- and SCGN-modulated gut dysbiosis induced by a high-fat diet, which may play an influencing role in adiponectin dysregulation. Our data also showed some evidence that CGN and SCGN have distinct effects on selected genes involved in lipid metabolism. In conclusion, both κ-carrageenan and SCGN have novel anti-obesity potential with possible different mechanisms of action.

Chlorogenic acid attenuates high-carbohydrate, high-fat diet-induced cardiovascular, liver, and metabolic changes in rats

Chlorogenic acid as a constituent of coffee is consumed regularly in the human diet. Chlorogenic acid intake has been associated with decreased risk of cardiovascular disease and type 2 diabetes. We hypothesized that chlorogenic acid would improve cardiovascular, liver, and metabolic responses in a rat model of metabolic syndrome induced by a high-carbohydrate, high-fat diet. Male Wistar rats (8-9 weeks old, 335 ± 2 g, n = 48) were divided into 4 groups and fed with corn starch diet (16 weeks); corn starch diet with chlorogenic acid in food for the last 8 weeks; high-carbohydrate, high-fat diet (16 weeks); or high-carbohydrate, high-fat diet with chlorogenic acid (~100 mg/kg/d) in food for the last 8 weeks. In high-carbohydrate, high-fat diet-fed rats, chlorogenic acid reduced energy intake and food efficiency to reduce visceral fat, especially retroperitoneal fat, and abdominal circumference; reversed the elevated systolic blood pressure; and attenuated left ventricular diastolic stiffness with reduced collagen deposition and infiltration of inflammatory cells in the left ventricle. Chlorogenic acid decreased inflammation and fat deposition in the liver along with reduced plasma liver enzyme activities of obese rats but did not change the plasma lipid profile. Chlorogenic acid increased diversity of gut microbiota, which may improve overall metabolism in the body. Thus, chronic dietary chlorogenic acid attenuated diet-induced inflammation as well as cardiovascular, liver, and metabolic changes, suggesting that chlorogenic acid has potential for further clinical evaluation.

Attenuation of Microbiotal Dysbiosis and Hypertension in a CRISPR/Cas9 Gene Ablation Rat Model of GPER1

G-protein-coupled estrogen receptor, Gper1, has been implicated in cardiovascular disease, but its mechanistic role in blood pressure control is poorly understood. Here, we demonstrate that genetically salt-sensitive hypertensive rats with complete genomic excision of Gper1 by a multiplexed guide RNA CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats)/Cas9 (CRISPR associated proteins) approach present with lower blood pressure, which was accompanied by altered microbiota, different levels of circulating short chain fatty acids, and improved vascular relaxation. Microbiotal transplantation from hypertensive Gper1+/+ rats reversed the cardiovascular protective effect exerted by the genomic deletion of Gper1. Thus, this study reveals a role for Gper1 in promoting microbiotal alterations that contribute to cardiovascular pathology. However, the exact mechanism by which Gper1 regulates blood pressure is still unknown. Our results indicate that the function of Gper1 is contextually dependent on the microbiome, whereby, contemplation of using Gper1 as a target for therapy of cardiovascular disease requires caution.

Neurotrophic Activity of the Carrageenophyte Kappaphycus alvarezii Cultivated at Different Depths and for Different Growth Periods in Various Areas of Indonesia

The carrageenophyte Kappaphycus alvarezii (Rhodophyta) has neurotrophic activity in primary hippocampal neurons. This seaweed is abundant and easily cultivated in tropical coastal areas. To determine the best growth conditions for neurotrophic activity, thalli were grown at different depths and for different periods in various areas of Indonesia. Neurotrophic activity was measured based on the number of primary neurites, the total length of the primary neurites, and the length of the longest neurite. K. alvarezii had higher neurotrophic activity than carrageenophytes K. striatum and Eucheuma denticulatum cultured under the same conditions. K. alvarezii grown at the surface for 45 days had higher (1.4- to 1.8-fold) neurotrophic activity than thalli grown at depth (2 m) or harvested sooner (15 days) (P < 0.05). Relatively high activities were detected in thalli cultured at Ternate and Garut, Indonesia. Therefore, from a commercial perspective, the culture conditions at the surface for 45 days were optimal for the production of both neurotrophic compounds and carrageenan. K. alvarezii produced neurotrophic compounds under various environmental conditions, although some conditions were optimal.

An improved rat model for chronic inflammatory bowel disease

BACKGROUND

Inflammatory bowel disease (IBD) is an important cause of chronic disability in humans.

METHODS

We characterized a model of chronic IBD in young male Wistar rats by administering dextran sodium sulfate (DSS: 0%, 0.25%, 0.5%, or 1% in drinking water) for six weeks, with 0.5% DSS for twelve weeks, following DSS cessation or together with treatment with sulfasalazine for the last 6 weeks. We measured gastrointestinal characteristics including stool consistency, blood in stools, small intestine and colon length, intestinal transit and permeability, and gut microbiota, as well as extra-intestinal parameters including oral glucose tolerance, systolic blood pressure, fat and lean mass, and left ventricular stiffness.

RESULTS

At 6 weeks, 0.25-1% DSS produced gastrointestinal changes as diarrhea and blood in stools. At 12 weeks, 0.5% DSS produced chronic and sustained gastrointestinal changes, with marked infiltration of inflammatory cells throughout the gastrointestinal tract and crypt distortion. Firmicutes increased and Bacteroidetes and Actinobacteria decreased in DSS-treated rats. Changes were reversed by DSS cessation or sulfasalazine treatment. Gastrointestinal permeability and extra-intestinal parameters did not change, so DSS changes were limited to the gastrointestinal tract.

CONCLUSION

Chronic 0.5% DSS produces selective and reversible gastrointestinal changes, providing an improved chronic model in rats that mimics human IBD for testing new interventions.

Dietary polysaccharide-rich extract from Eucheuma cottonii modulates the inflammatory response and suppresses colonic injury on dextran sulfate sodium-induced colitis in mice

Inflammatory bowel disease (IBD) is a known medical burden in most developed countries and a significant cause of morbidity. The IBD label includes Crohn's disease (CD) and ulcerative colitis (UC). Pharmacological and surgical intervention are the two main management approaches for IBD. Some drugs have been developed for IBD therapy, but accessibility is limited due to high costs. Furthermore, these agents have demonstrated inactivity over long-term treatment courses. Therefore, an urgent need is present for new treatment options that are safe, able to sustain clinical remission, and improve mucosal gut healing. Seaweed has received much attention in the pharmacological field owing to its various biomedical properties, including the prolongation of blood clotting time, as well as antitumor, anti-inflammation, and antioxidant effects. This study therefore aimed to examine the effects of a dietary polysaccharide-rich extract obtained from Eucheuma cottonii (EC) on a model of colitis. Colitis was induced in male BALB/c mice by the administration of 2.5% (w/v) dextran sulfate sodium (DSS) for 7 days. DSS-induced mice were treated with either one of three different doses of EC extracts (0.35, 0.70, and 1.75 g/kg body weight) or curcumin as a positive control (0.10 g/kg). Mice were sacrificed post-treatment and blood samples were collected. The disease activity index (DAI) and inflammatory cytokine levels (tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, IL-10) were measured. After treatment for 7 days, EC extract administration protected against weight loss and decreased the colon weight per length ratio. EC extract administration also decreased pro-inflammatory cytokine expression, increased IL-10 levels, and reduced colonic damage. Therefore, a dietary polysaccharide-rich extract from E. cottonii reduced DSS-induced bowel inflammation, thereby becoming a promising candidate for the treatment of colitis.