Caulerpa okamurae extract inhibits adipogenesis in 3T3-L1 adipocytes and prevents high-fat diet–induced obesity in C57BL/6 mice

Structural characteristics of sulfated xylogalactomannan isolated from Caulerpa okamurae and its anticoagulant activity

Due to wonderful taste, rich nutrition and biological functions, many marine green algae in the genus Caulerpa have been recently developed as candidates for green caviar. A novel water-soluble sulfated xylogalactomannan CO-0-1 was obtained from the green algae Caulerpa okamurae. CO-0-1 was mainly composed of mannose (Man), galactose (Gal), and xylose (Xyl) at the ratio of 4.4:4.0:1.4 with the molecular weight at 470 kDa and the sulfate content at 12.78 %. The sulfated xylogalactomannan had Man at the backbone with →4)-β-D-Manp-(1→ and →2)-β-D-Manp-(1→ as the main chain and branches at O-3 position. The side chains contained →3)-β-D-Galp-(1→ and minor →2)-β-D-Xylp(1→. The sulfate groups only distributed at the side chains and at O-6 position of →3)-β-D-Galp-(1→ and O-4 position of (1→2)-β-D-Xylp. The anticoagulant activity indicated that CO-0-1 displayed intrinsic anticoagulant and specific anti-thrombin activities. The investigation expanded the utilization and development scene and scope of the green algae Caulerpa okamurae.

Buddleja officinalis Maxim.: A review of its botany, ethnopharmacology, phytochemistry, pharmacology, and therapeutic potential for ophthalmic diseases

ETHNOPHARMACOLOGICAL RELEVANCE

Buddleja officinalis Maxim. (B. officinalis), commonly known as "Menghua" "Yangerduo" is a widely recognized traditional herbal medicine in China, Korea, and Vietnam. For thousands of years, it has been used to treat dry eye disease, conjunctivitis, keratitis, eye ulcers, eye pain, cough, asthma, hemoptysis, and other medical conditions.

AIM OF THE REVIEW

This review article aims to provide a concise summary of the botany, ethnopharmacology, phytochemistry, pharmacology, medicinal potential, and application of B. officinalis in treating ophthalmic diseases and critically evaluates the existing literature to establish a scientific basis for its reasonable utilization and further investigation.

MATERIALS AND METHODS

The information reviewed in this study was collected from various electronic resources, including the Web of Science, PubMed, and Google Scholar.

RESULTS

To date, 80 structurally diverse compounds have been isolated and characterized from B. officinalis, primarily flavonoids, phenylethanoids, triterpenoids, and monoterpenes. Extracts and compounds derived from B. officinalis have been reported to possess broad pharmacological effects including anti-dry eye disease, anti-inflammation, anti-oxidation, anti-diabetes, anti-obesity, improving osteoporosis and treatment of skin diseases. This review provides a reference for the future studies on of B. officinalis.

CONCLUSIONS

As a natural medicinal plant, B. officinalis is worthy of further development in botany, ethnopharmacology, phytochemistry, pharmacology, and therapeutic potential for ophthalmic diseases. Although some components have demonstrated multiple pharmacological activities, their mechanisms of action remain unclear. Further studies on the underlying molecular basis and mechanism of action are warranted.

Anti-Obesity Effects of Marine Macroalgae Extract Caulerpa lentillifera in a Caenorhabditis elegans Model

Obesity is a multifactorial disease characterized by an excessive accumulation of fat, which in turn poses a significant risk to health. Bioactive compounds obtained from macroalgae have demonstrated their efficacy in combating obesity in various animal models. The green macroalgae Caulerpa lentillifera (CL) contains numerous active constituents. Hence, in the present study, we aimed to elucidate the beneficial anti-obesity effects of extracts derived from C. lentillifera using a Caenorhabditis elegans obesity model. The ethanol (CLET) and ethyl acetate (CLEA) extracts caused a significant decrease in fat consumption, reaching up to approximately 50-60%. Triglyceride levels in 50 mM glucose-fed worms were significantly reduced by approximately 200%. The GFP-labeled dhs-3, a marker for lipid droplets, exhibited a significant reduction in its level to approximately 30%. Furthermore, the level of intracellular ROS displayed a significant decrease of 18.26 to 23.91% in high-glucose-fed worms treated with CL extracts, while their lifespan remained unchanged. Additionally, the mRNA expression of genes associated with lipogenesis, such as sbp-1, showed a significant down-regulation following treatment with CL extracts. This finding was supported by a significant decrease (at 16.22-18.29%) in GFP-labeled sbp-1 gene expression. These results suggest that C. lentillifera extracts may facilitate a reduction in total fat accumulation induced by glucose through sbp-1 pathways. In summary, this study highlights the anti-obesity potential of compounds derived from C. lentillifera extracts in a C. elegans model of obesity, mediated by the suppression of lipogenesis pathways.

Immunostimulatory effects of marine algae extracts on in vitro antigen-presenting cell activation and in vivo immune cell recruitment

Marine algae are photosynthetic eukaryotic organisms that are widely used as sources of food, cosmetics, and drugs. However, their biological and immunological effects on immune cells have not been fully elucidated. To unravel their immunological activity and broaden their application, we generated antigen-presenting cells (APCs), including dendritic cells (DCs) and macrophages, from mouse bone marrow cells and treated them with six different marine algae extracts (MAEs). We evaluated cell viability, activation marker expression, and pro-inflammatory cytokine production by APCs after 2 days of MAE treatment. All six MAEs significantly induced cytokine production of APCs, among which Pyropia yezoensis (PY), Peyssonnelia caulifera (PC), and Meristotheca papulosa (MP) extracts exhibited the strongest effect. Cladophora wrightiana var. minor (CW) extract moderately upregulated cytokine levels but increased the expression of activation markers on DCs. Moreover, PY, PC, MP, Sargassum pectinifera (SP), and Caulerpa okamurae (CO) pre-treated APCs effectively stimulated T-cell proliferation and cytokine production. Furthermore, the mice injected with MAEs exhibited higher cytokine (TNF-α, IL-6, and IL-1β) production as well as enhanced innate immune cell recruitment capacities (DCs, monocytes, neutrophils, and natural killer cells) in the peritoneal cavity of the mice compared to those of the non-treated mice. Therefore, all MAEs exhibited immunostimulatory potential, with PY, PC, CW, and MP extracts being the most effective in stimulating immune responses and cell activation. To the best of our knowledge, this is the first study to determine the immunomodulatory activities of six MAEs both in vitro and in vivo.

Subcritical water extraction of Gracilaria chorda abbreviates lipid accumulation and obesity-induced inflammation

Obesity-induced inflammation is crucial in the pathogenesis of insulin resistance and type 2 diabetes. In this study, we investigated the effects of the Gracilaria chorda (GC) on lipid accumulation and obesity-induced inflammatory changes or glucose homeostasis in cell models (3T3-L1 adipocytes and RAW 264.7 macrophages). Samples of GC were extracted using solvents (water, methanol, and ethanol) and subcritical water (SW) at different temperatures (90, 150, and 210°C). The total phenolic content of GCSW extract at 210°C (GCSW210) showed the highest content compared to others, and GCSW210 highly inhibited lipid accumulation and significantly reduced gene expressions of peroxisome proliferatoractivated receptor-γ, CCAAT/enhancer-binding protein-α, sterol regulatory element-binding protein-1c, and fatty acid synthase in 3T3-L1 adipocytes. In addition, GCSW210 effectively downregulated the pro-inflammatory cytokine regulator pathways in RAW 264.7 macrophages, including mitogen-activated protein kinase, signal transducers and activators of transcription and nuclear factor-κB. In co-culture of 3T3-L1 adipocytes and RAW 264.7 macrophages, GCSW210 significantly reduced nitric oxide production and interleukin-6 levels, and improved glucose uptake with dose-dependent manner. These findings suggest that GCSW210 improves glucose metabolism by attenuating obesity-induced inflammation in adipocytes, which may be used as a possible treatment option for managing obesity and associated metabolic disorders.

Garcinia Cambogia Improves High-Fat Diet-Induced Glucose Imbalance by Enhancing Calcium/CaMKII/AMPK/GLUT4-Mediated Glucose Uptake in Skeletal Muscle

SCOPE

Garcinia cambogia (G. cambogia) is known to have antiobesity effects. In this study, the therapeutic effects of G. cambogia on glucose homeostasis in obesity-induced diabetes are explored and the underlying mechanisms are investigated.

METHODS AND RESULTS

C2C12 myotubes are treated with G. cambogia; glucose uptake, intracellular Ca²⁺ levels, and related alterations in signaling pathways are examined. High-fat diet (HFD)-fed mice are administered G. cambogia for 8 weeks; oral glucose tolerance is evaluated, and the regulation of identified targets of signaling pathways in quadriceps skeletal muscle are examined in vivo. G. cambogia increases glucose uptake in C2C12 myotubes and induces the upregulation of AMPK, ACC, and p38 MAPK phosphorylation. Notably, G. cambogia markedly elevates both intracellular Ca²⁺ levels, activating CaMKII, a Ca²⁺ -sensing protein, and TBC1D4-mediated GLUT4 translocation, to facilitate glucose uptake. Furthermore, high-glucose-induced inhibition of glucose uptake and signal transduction is reverted by G. cambogia. In an HFD-induced diabetes mouse model, G. cambogia administration results in significant blood glucose-lowering effects, which are attributed to the regulation of targets that have been identified in vitro, in quadricep skeletal muscle.

CONCLUSION

These findings provide new insights into the mechanism by which G. cambogia regulates glucose homeostasis in obesity-induced diabetes.

Influence of the ecological environment on the structural characteristics and bioactivities of polysaccharides from alfalfa (Medicago sativa L.)

Polysaccharides from alfalfa (Medicago sativa L.) (APS) exhibit a variety of bioactivities; however, little information is available on the effects of the ecological environment on the structural characteristics and bioactivities of APS.

Garcinia cambogia Ameliorates Non-Alcoholic Fatty Liver Disease by Inhibiting Oxidative Stress-Mediated Steatosis and Apoptosis through NRF2-ARE Activation

Excessive free fatty acids (FFAs) causes reactive oxygen species (ROS) generation and non-alcoholic fatty liver disease (NAFLD) development. Garcinia cambogia (G. cambogia) is used as an anti-obesity supplement, and its protective potential against NAFLD has been investigated. This study aims to present the therapeutic effects of G. cambogia on NAFLD and reveal underlying mechanisms. High-fat diet (HFD)-fed mice were administered G. cambogia for eight weeks, and steatosis, apoptosis, and biochemical parameters were examined in vivo. FFA-induced HepG2 cells were treated with G. cambogia, and lipid accumulation, apoptosis, ROS level, and signal alterations were examined. The results showed that G. cambogia inhibited HFD-induced steatosis and apoptosis and abrogated abnormalities in serum chemistry. G. cambogia increased in NRF2 nuclear expression and activated antioxidant responsive element (ARE), causing induction of antioxidant gene expression. NRF2 activation inhibited FFA-induced ROS production, which suppressed lipogenic transcription factors, C/EBPα and PPARγ. Moreover, the ability of G. cambogia to inhibit ROS production suppressed apoptosis by normalizing the Bcl-2/BAX ratio and PARP cleavage. Lastly, these therapeutic effects of G. cambogia were due to hydroxycitric acid (HCA). These findings provide new insight into the mechanism by which G. cambogia regulates NAFLD progression.

Effect of Microalgae and Macroalgae Extracts on Non-Alcoholic Fatty Liver Disease

The present review aims to gather scientific evidence regarding the beneficial effects of microalgae and macroalgae extracts on non-alcoholic fatty liver disease (NAFLD). The described data show that both microalgae and macroalgae improved this alteration. The majority of the reported studies analysed the preventive effects because algae were administered to animals concurrent with the diet that induced NAFLD. The positive effects were demonstrated using a wide range of doses, from 7.5 to 300 mg/kg body weight/day or from 1 to 10% in the diet, and experimental periods ranged from 3 to 16 weeks. Two important limitations on the scientific knowledge available to date are that very few studies have researched the mechanisms of action underlying the preventive effects of microalgae on NAFLD and that, for the majority of the algae studied, a single paper has been reported. For these reasons, it is not possible to establish the best conditions in order to know the beneficial effects that these algae could bring. In this scenario, further studies are needed. Moreover, the beneficial effects of algae observed in rodent need to be confirmed in humans before we can start considering these products as new tools in the fight against fatty liver disease.

Medium-, long- and medium-chain-type structured lipids ameliorate high-fat diet-induced atherosclerosis by regulating inflammation, adipogenesis, and gut microbiota in ApoE-/- mice

Accumulating evidence has suggested that medium-, long-, and medium-chain (MLM) structured lipids have anti-obesity effects, but whether they can alleviate the development of atherosclerosis (AS) and affect the composition of the gut microbiota in high-fat diet-fed ApoE-/- mice has not been elucidated. The present study found that MLM structured lipid supplementation could significantly decrease obesity-related parameters compared with high-fat diet alone in ApoE-/- mice. Additionally, MLM structured lipids could significantly decrease the blood glucose and increase the serum total antioxidant capacity (T-AOC) and superoxide dismutase (SOD) levels. Additionally, high-dose MLM structured lipids supplementation could reduce the area of atherosclerotic lesions and decrease the expression of VCAM-1, MCP-1 and CD68, which are related to inflammation in aortic tissue. Further analysis showed that MLM structured lipids could significantly reduce lipid accumulation in the adipose tissue of high-fat diet-fed ApoE-/- mice. The relative protein expression of SREBP-1, ACC, FAS, C/EBPα and PPARγ was decreased and the ratio of p-AMPK/AMPK was increased in epididymis white adipose tissue (eWAT) after MLM structured lipids treatment. Additionally, MLM structured lipids supplementation regulated the bacterial composition, including reducing the Firmicutes/Bacteroidetes ratio, increasing the relative abundance of short-chain fatty acid-producing bacteria (Blautia and Anaerotruncus), decreasing the relative abundance of [Ruminococcus] torques group, Ruminiclostridium 9, Catenibacterium and [Eubacterium] fissicatena group. Spearman's correlation analysis revealed significant correlations between changes in the gut microbiota and atherosclerosis-related indices. The results demonstrated that the alleviating effects of MLM structured lipids supplementation on AS in high-fat diet-fed ApoE-/- mice were closely related to reshaping the composition of the gut microbiota.

Investigation of Obesity-Alleviation Effect of Eurycoma longifolia on Mice Fed with a High-Fat Diet through Metabolomics Revealed Enhanced Decomposition and Inhibition of Accumulation of Lipids

The metabolic and bioactivity effects of Eurycoma longifolia (Eucalyptus longifolia) in obesity treatment were studied in mice fed with a high-fat diet using a metabolomics approach. Aqueous extracts of E. longifolia were obtained via grinding, dissolving, and freeze-drying. The hepatic steatosis effect of E. longifolia was characterized by hematoxylin and eosin histological staining. External performance of the obesity-alleviation effect was monitored by measuring body and food weight. In addition, the metabolomics analysis of the E. longifolia-mice interaction system was performed using the established platform combining liquid chromatography-tandem mass spectrometry with statistical analysis. The presence and spatial distribution patterns of differential molecules were further evaluated through desorption electrospray ionization-mass spectrometry imaging. The results showed that E. longifolia played a vital role in downregulating lipid accumulation (especially triacylglycerols) and fatty acids biosynthesis together with enhanced lipid decomposition and healing in Bagg albino mice. During such a process, E. longifolia mainly induced metabolomic alterations of amino acids, organic acids, phospholipids, and glycerolipids. Moreover, under the experimental concentrations, E. longifolia induced more fluctuations of aqueous-soluble metabolites in the plasma and lipids in the liver than in the kidneys. This study provides an advanced alternative to traditional E. longifolia-based studies for evaluating the metabolic effects and bioactivity of E. longifolia through metabolomics technology, revealing potential technological improvement and clinical application.

Lutein attenuates excessive lipid accumulation in differentiated 3T3-L1 cells and abdominal adipose tissue of rats by the SIRT1-mediated pathway

OBJECTIVE

Obesity is now a worldwide disease and is mainly attributable to increased body fat deposition. In a growing number of epidemiological studies, lutein has been revealed to have different degrees of anti-obesity properties, but the potential underlying mechanisms that have been reported are limited. Therefore, we aimed to clarify the protective effects of lutein against excessive lipid accumulation, and we explored the role of SIRT1 and SIRT1-mediated pathways both in abdominal adipose tissue and mature 3T3-L1 cells during lutein administration.

METHODS

In our design, male Sprague-Dawley rats were fed either control or high-fat diets with or without 25 mg/kg·bw/day lutein for 5 weeks. Additionally, differentiated 3T3-L1 cells were incubated with 40 μM lutein or 10 μM Ex527 for 24 h.

RESULTS

Lutein supplementation decreased the body weight, abdominal fat index ratio, frequency and mean area of larger adipocytes in HE staining induced by the high-fat diet and then activated the expression of SIRT1 and thus upregulated FoxO1, ATGL, and HSL expression and downregulated SREBP-1, FAS, and ACC expression both in abdominal adipose tissue and differentiated 3T3-L1 cells. However, coincubation with Ex527 and lutein suppressed the activation of SIRT1 and reversed the expression of FoxO1, ATGL, HSL, SREBP-1, FAS, and ACC in comparison to those in the Lut group.

CONCLUSIONS

Overall, we suggest that the effects of lutein on attenuating excessive lipid accumulation are dependent on the SIRT1-mediated pathway in vivo and in vitro, which indicates that lutein administration may be a potential strategy for preventing excessive lipid accumulation and obesity.

Anti-obesity effects of red seaweed, Plocamium telfairiae, in C57BL/6 mice fed a high-fat diet

This study aimed to demonstrate the anti-obesity effect of Plocamium telfairiae (PT), a red seaweed. Different percentages of ethanol (0%, 20%, 40%, 60%, 80%, and 100%) were used for the preparation of PT extract. Furthermore, 3T3-L1 cells were used to determine the percentage of ethanol for optimal anti-adipogenesis of PT, and the anti-obesity properties of the optimized extract of PT (PTE) (40%) was assessed in obese mice. The results indicate that 40% ethanol extract (40 PTE) significantly decreased fat accumulation and suppressed the expression of major adipogenesis factors such as peroxisome proliferator-activated receptor-γ (PPAR-γ), sterol regulatory element-binding protein 1 (SREBP-1), CCAAT/enhancer-binding protein (C/EBP)-α, and phosphorylated ACC (pACC) in 3T3-L1 cells. Furthermore, in the high-fat diet-induced obese mice, 40 PTE significantly reduced the weights of white adipose tissue, as well as the levels of triglyceride, total cholesterol, adiponectin, and insulin in the serum. Liver histopathology showed that steatosis decreased in all the PTE treatment groups. The adipogenesis-related proteins, PPAR-γ and SREBP-1, were also significantly decreased in PTE treatment groups. Additionally, 40 PTE increased mRNA expression of mitochondrial uncoupling proteins (UCP)-1 and UCP-3 in brown adipose tissue. These findings provide evidence that 40 PTE can alleviate lipid droplet accumulation in 3T3-L1 adipocytes and obese C57BL/6 mice, indicating that PTE has strong anti-obesity effects and could be used as a therapeutic agent or a component of pharmaceutical drugs and functional foods.

Anti-obesity effects of Grifola frondosa through the modulation of lipid metabolism via ceramide in mice fed a high-fat diet

Obesity is characterized by massive fat deposition and is related to a series of metabolic complications, such as insulin resistance (IR) and steatohepatitis. Grifola frondosa (GF) is a basidiomycete fungus and a source of various nutritional ingredients related to human health. In this study, after a systematic analysis of its nutritional ingredients, GF was administered to mice fed a high-fat diet (HFD) to investigate its effects on lipid metabolism. In HFD-fed mice, GF significantly controlled the body weight, blood glucose and related organ indices, and effectively counteracted hyperlipidemia and IR triggered by the HFD. GF administration efficiently alleviated hepatic steatosis and adipocyte hypertrophy, and regulated alanine aminotransferase and aspartate aminotransferase in the liver. An analysis of the intestinal microflora showed that GF reversed obesity-induced dysbiosis by affecting the relative abundance of certain bacteria, reducing lipopolysaccharide production and regulating the superpathway of heme biosynthesis associated with inflammation. According to the results of lipidomics, ceramide, a metabolite related to inflammation and IR, was found to be dysregulated in HFD-fed mice. However, GF regulated the ceramide levels and restored lipid metabolism via the suppression of Toll-like receptor 4/nuclear factor kappa-B signaling, which is involved in inflammation and IR. This study provides the experimental basis for the application of GF as an agent for obesity.

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.

A Candidate Drug for Nonalcoholic Fatty Liver Disease: A Review of Pharmacological Activities of Polygoni Multiflori Radix

Nonalcoholic fatty liver disease, a type of metabolic syndrome, continues to rise globally. Currently, there is no approved drug for its treatment. Improving lifestyle and exercise can alleviate symptoms, but patients' compliance is poor. More and more studies have shown the potential of Polygoni Multiflori Radix (PMR) in the treatment of NAFLD and metabolic syndrome. Therefore, this paper reviews the pharmacological effects of PMR and its main chemical components (tetrahydroxystilbene glucoside, emodin, and resveratrol) on NAFLD. PMR can inhibit the production of fatty acids and promote the decomposition of triglycerides, reduce inflammation, and inhibit the occurrence of liver fibrosis. At the same time, it maintains an oxidation equilibrium status in the body, to achieve the therapeutic purpose of NAFLD and metabolic syndrome. Although more standardized studies and clinical trials are needed to confirm its efficacy, PMR may be a potential drug for the treatment of NAFLD and its complications. However, the occurrence of adverse reactions of PMR has affected its extensive clinical application. Therefore, it is necessary to further study its toxicity mechanism, enhance efficacy and control toxicity, and even reduce toxicity, which will contribute to the safe clinical use of PMR.

Caulerpa okamurae extract attenuates inflammatory interaction, regulates glucose metabolism and increases insulin sensitivity in 3T3-L1 adipocytes and RAW 264.7 macrophages

OBJECTIVE

To examine whether Caulerpa okamurae ethanolic extract (COE) could inhibit obesity-mediated inflammation, improve glucose metabolism and increase insulin sensitivity, using in vitro cell models of RAW 264.7 macrophages and 3T3-L1 adipocytes.

METHODS

We cocultured 3T3-L1 adipocytes in direct contact with lipopolysaccharide-stimulated RAW 264.7 macrophages and induced insulin resistance in 3T3-L1 adipocytes with tumor necrosis factor-α (TNF-α) in the presence or absence of 250 µg/mL of COE. We investigated various markers of inflammation, glucose regulation and insulin sensitivity in these models using Griess reagent to measure nitric oxide (NO) production, 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl) amino]-2-deoxyglucose to measure glucose uptake, Western blot analysis to quantify protein expression and reverse transcriptase-polymerase chain reaction to evaluate mRNA expression.

RESULTS

We found that COE (250 µg/mL) significantly inhibited the lipopolysaccharide-induced inflammatory response in RAW 264.7 macrophages by downregulating NO production, nitric oxide synthase 2 expression and nuclear translocation of nuclear factor-κB. COE also showed similar anti-inflammatory activity in coculture, along with decreased TNF-α, interleukin-6 and monocyte chemoattractant protein mRNA expression. In addition, COE also improved glucose uptake in coculture by upregulating glucose transporter-4 (GLUT-4) and adiponectin and reducing serine phosphorylation of insulin receptor substrate-1 (IRS1). In the TNF-α-induced insulin resistance model of 3T3-L1 adipocytes, COE significantly improved both basal and insulin-stimulated glucose uptake, accompanied by phosphorylation of IRS1 at tyrosine 632, phospho-5' adenosine monophosphate-activated protein kinase α and glycogen synthase kinase-3β (Ser9) as well as upregulation of GLUT-4.

CONCLUSION

Together, these findings suggest that COE has potential to treat or prevent obesity-induced metabolic disorders.

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.

Seaweeds-derived compounds modulating effects on signal transduction pathways: A systematic review

BACKGROUND

Recently, the study of marine natural products has gained interest due to their relevant biological activities. Specially, seaweeds produce bioactive compounds that could act as modulators of cell signaling pathways involved in a plethora of diseases. Thereby, the description of the molecular mechanisms by which seaweeds elicit its biological functions will certainly pave the way to the pharmacological development of drugs.

AIM

This review describes the molecular mechanisms by which seaweeds act and its possible utilization in the design of new drugs.

METHODS

This review was conducted according to the PRISMA-P guidelines for systematic reviews. Two independent authors searched into four different databases using combinations of keywords. Two more authors selected the articles following the eligibility criteria. Information extraction was conducted by two separated authors and entered into spreadsheets. Methodological quality and risk of bias were determined applying a 12-question Risk of Bias criteria tool.

RESULTS AND DISCUSSION

We found 2360 articles (SCOPUS: 998; PubMed: 678; Wiley: 645 and EBSCO: 39) using the established keywords, of which 113 articles fit the inclusion criteria and were included in the review. This work comprises studies in cell lines, and animal models, any clinical trial was excluded. The articles were published from 2005 up to March 31st 2018. The biggest amount of articles was published in 2017. Furthermore, the seaweeds tested in the studies were collected in 15 countries, mainly in Eastern countries. We found that the main modulated signaling pathways by seaweeds-derivate extracts and compounds were: L-Arginine/NO, TNF-α, MAPKs, PI3K/AKT/GSK, mTOR, NF-κB, extrinsic and intrinsic apoptosis, cell cycle, MMPs and Nrf2. Finally, the articles we analyzed showed moderate risk of bias in almost all the parameters evaluated. However, the studies fail to describe the place and characteristics of sample collection, the sample size, and the blindness of the experimental design.

CONCLUSION

In this review we identified and summarized relevant information related to seaweed-isolated compounds and extracts having biological activity; their role in different signal pathways to better understand their potential to further development of cures for cancer, diabetes, and inflammation-related diseases.

Modelos experimentais de obesidade: análise crítica do perfil metabólico e da aplicabilidade

Introdução: a prevalência da obesidade e de outras doenças relacionadas está aumentando em todo o mundo de forma preocupante. Caracterizada pelo aumento do peso corporal ou do acúmulo excessivo de gordura corporal, a obesidade tem sido associada ao aumento da mortalidade decorrente de maior incidência de hipertensão, diabetes e vários tipos de câncer. Os modelos animais fornecem dados fundamentais para a compreensão dos parâmetros básicos que regulam os componentes do nosso balanço energético. Objetivo: esta revisão selecionou artigos que utilizaram modelos animais (ratos e camundongos) de obesidade focando nas principais alterações metabólicas causadas pela obesidade com o objetivo de apresentar os principais modelos utilizados nos últimos 5 anos. Material e Métodos: Foram realizadas duas buscas na base de dados PubMed utilizando as expressões: “obesity” AND “metabolism” AND “animal model” AND “mice” e “obesity” AND “metabolism” AND “animal model” AND “rat”, sendo selecionados os estudos considerados mais relevantes a partir dos critérios: descrição detalhada do modelo experimental e análise dos parâmetros metabólicos de interesse: peso, perfil lipídico e perfil glicêmico. Outras referências foram utilizadas para elucidar melhor os modelos encontrados e também aqueles que não foram citados, mas, que possuem importância no entendimento da evolução dos modelos animais de obesidade. Resultados: A espécie mais utilizada foi o camundongo, o sexo predominante foi o masculino, a faixa etária dos roedores variou de neonatos até 44 semanas e o período de acompanhamento chegou até 53 semanas. A obesidade foi confirmada pelo aumento significativo do peso e na maioria dos estudos foram encontradas alterações no metabolismo lipídico e glicêmico. Encontramos cinco grupos de mecanismos de indução da obesidade porém a maioria dos estudos utilizou dietas hiperlipídicas, modelo que mais se assemelha às alterações metabólicas encontradas em humanos. Conclusão: Investigar as causas e efeitos da obesidade induzida em modelos experimentais pode fornecer uma melhor compreensão da fisiopatologia da obesidade, e proporcionar novas opções de prevenção e tratamento.

Heshouwu (Polygonum multiflorum Thunb.) ethanol extract suppresses pre-adipocytes differentiation in 3T3-L1 cells and adiposity in obese mice

This study investigated whether Heshouwu (Polygonum multiflorum Thunb.) root ethanol extract (PME) has anti-obesity activity using 3T3-L1 cells and high-fat diet (HFD)-induced obese mice. Treatment with PME (5 and 10 μg/mL) dose-dependently suppressed 3T3-L1 pre-adipocyte differentiation to adipocytes and cellular triglyceride contents. In addition, PME inhibited mRNA and protein expression of adipogenic transcription factors such as CCAAT/enhancer-binding protein α (C/EBPα) and peroxisome proliferator-activated receptor γ (PPARγ), which led to down-regulation of fatty acid synthase gene expression. After feeding mice PME (0.05%) with HFD for 12 weeks, their visceral fat mass, size and body weight were significantly reduced compared with the HFD group. Furthermore, PME supplementation significantly up-regulated the PPARα, CPT1, CPT2, UCP1 and HSL mRNA levels compared with the HFD group, whereas it down-regulated expression of the PPARγ and DGAT2 genes. Finally, HFD increased serum leptin, insulin, glucose and insulin and glucose levels; however, PME reversed these changes. These results demonstrated that PME might relieve obesity that occurs via inhibition of adipogenesis and lipogenesis as well as through lipolysis and fatty acid oxidation in 3T3-L1 cells and HFD-induced obese mice.