Marine algal carotenoids inhibit angiogenesis by down-regulating FGF-2-mediated intracellular signals in vascular endothelial cells

The Ethyl Acetate Extract of Caulerpa microphysa Promotes Collagen Homeostasis and Inhibits Inflammation in the Skin

Inflammation and collagen-degrading enzymes' overexpression promote collagen decomposition, which affects the structural integrity of the extracellular matrix. The polysaccharide and peptide extracts of the green alga Caulerpa microphysa (C. microphysa) have been proven to have anti-inflammatory, wound healing, and antioxidant effects in vivo and in vitro. However, the biological properties of the non-water-soluble components of C. microphysa are still unknown. In the present study, we demonstrated the higher effective anti-inflammatory functions of C. microphysa ethyl acetate (EA) extract than water extract up to 16-30% in LPS-induced HaCaT cells, including reducing the production of interleukin (IL)-1β, IL-6, IL-8, and tumor necrosis factor-α (TNF-α). Furthermore, the excellent collagen homeostasis effects from C. microphysa were proven by suppressing the matrix metalloproteinase-1 (MMP-1) secretion, enhancing type 1 procollagen and collagen expressions dose-dependently in WS1 cells. Moreover, using UHPLC-QTOF-MS analysis, four terpenoids, siphonaxanthin, caulerpenyne, caulerpal A, and caulerpal B, were identified and may be involved in the superior collagen homeostasis and anti-inflammatory effects of the C. microphysa EA extract.

Skeletonema marinoi Extracts and Associated Carotenoid Fucoxanthin Downregulate Pro-Angiogenic Mediators on Prostate Cancer and Endothelial Cells

The exploration of natural preventive molecules for nutraceutical and pharmaceutical use has recently increased. In this scenario, marine microorganisms represent an underestimated source of bioactive products endowed with beneficial effects on health that include anti-oxidant, anti-inflammatory, differentiating, anti-tumor, and anti-angiogenic activities. Here, we tested the potential chemopreventive and anti-angiogenic activities of an extract from the marine coastal diatom Skeletonema marinoi Sarno and Zingone (Sm) on prostate cancer (PCa) and endothelial cells. We also tested one of the main carotenoids of the diatom, the xanthophyll pigment fucoxanthin (Fuco). Fuco from the literature is a potential candidate compound involved in chemopreventive activities. Sm extract and Fuco were able to inhibit PCa cell growth and hinder vascular network formation of endothelial cells. The reduced number of cells was partially due to growth inhibition and apoptosis. We studied the molecular targets by qPCR and membrane antibody arrays. Angiogenesis and inflammation molecules were modulated. In particular, Fuco downregulated the expression of Angiopoietin 2, CXCL5, TGFβ, IL6, STAT3, MMP1, TIMP1 and TIMP2 in both prostate and endothelial cells. Our study confirmed microalgae-derived drugs as potentially relevant sources of novel nutraceuticals, providing candidates for potential dietary or dietary supplement intervention in cancer prevention approaches.

Inhibition of antioxidant enzyme activities enhances carotenogenesis in microalga Dactylococcus dissociatus MT1

Microalgal biotechnology has become a promising field of research for the production of valuable, sustainable and environmentally friendly byproducts, especially for carotenoids. Bulk accumulation of secondary carotenoids in microalgae are mostly induced by oxidative stress of cells. In this research, we investigated the effects of antioxidant enzyme activity inhibition on carotenogenesis in a microalga Dactylococcus dissociatus MT1. The activities of four major antioxidant enzyme families, namely superoxide dismutase (SOD), catalases (CAT), glutathione peroxydases (GPX) and ascorbate perxodases (APX), were inhibited by relevant inhibitors during the stressed cultivation of D. dissociatus to observe the effects on carotenogensis. A 91% decrease in activity was observed for CAT, comparing with controls without any inhibitors added, followed by 65%, 61%, and 47% for the enzymes SOD, APX, and GPX, respectively. Concomitantly, it was found that this partial inhibition had substantial influences on the accumulation of carotenoids, with the highest production levels obtained in CAT inhibition conditions and an increase of 2.6 times of carotenoid concentration observed, comparing with control cultivation conditions. We conclude that the modulation of antioxidant enzyme activities could lead to the overproduction of carotenoids in this microalgal cell culture, and we expect that this novel approach of optimizing carotenogenesis processes for D. dissociatus cell cultures could be transferrable to other cell culture systems and might have an important impact on the carotenoid production industry.

Brown Algae as Functional Food Source of Fucoxanthin: A Review

Fucoxanthin is an algae-specific xanthophyll of aquatic carotenoid. It is prevalent in brown seaweed because it functions as a light-harvesting complex for algal photosynthesis and photoprotection. Its exceptional chemical structure exhibits numerous biological activities that benefit human health. Due to these valuable properties, fucoxanthin's potential as a potent source for functional food, feed, and medicine is being explored extensively today. This article has thoroughly reviewed the availability and biosynthesis of fucoxanthin in the brown seaweed, as well as the mechanism behind it. We included the literature findings concerning the beneficial bioactivities of fucoxanthin such as antioxidant, anti-inflammatory, anti-obesity, antidiabetic, anticancer, and other potential activities. Last, an additional view on its potential as a functional food ingredient has been discussed to facilitate a broader application of fucoxanthin as a promising bioactive compound.

An Overview of Potential Seaweed-Derived Bioactive Compounds for Pharmaceutical Applications

Nowadays, seaweeds are widely involved in biotechnological applications. Due to the variety of bioactive compounds in their composition, species of phylum Ochrophyta, class Phaeophyceae, phylum Rhodophyta and Chlorophyta are valuable for the food, cosmetic, pharmaceutical and nutraceutical industries. Seaweeds have been consumed as whole food since ancient times and used to treat several diseases, even though the mechanisms of action were unknown. During the last decades, research has demonstrated that those unique compounds express beneficial properties for human health. Each compound has peculiar properties (e.g., antioxidant, antimicrobial, antiviral activities, etc.) that can be exploited to enhance human health. Seaweed’s extracted polysaccharides are already involved in the pharmaceutical industry, with the aim of replacing synthetic compounds with components of natural origin. This review aims at a better understanding of the recent uses of algae in drug development, with the scope of replacing synthetic compounds and the multiple biotechnological applications that make up seaweed’s potential in industrial companies. Further research is needed to better understand the mechanisms of action of seaweed’s compounds and to embrace the use of seaweeds in pharmaceutical companies and other applications, with the final scope being to produce sustainable and healthier products.

Carotenoids from Marine Sources as a New Approach in Neuroplasticity Enhancement

An increasing number of people experience disorders related to the central nervous system (CNS). Thus, new forms of therapy, which may be helpful in repairing processes' enhancement and restoring declined brain functions, are constantly being sought. One of the most relevant physiological processes occurring in the brain for its entire life is neuroplasticity. It has tremendous significance concerning CNS disorders since neurological recovery mainly depends on restoring its structural and functional organization. The main factors contributing to nerve tissue damage are oxidative stress and inflammation. Hence, marine carotenoids, abundantly occurring in the aquatic environment, being potent antioxidant compounds, may play a pivotal role in nerve cell protection. Furthermore, recent results revealed another valuable characteristic of these compounds in CNS therapy. By inhibiting oxidative stress and neuroinflammation, carotenoids promote synaptogenesis and neurogenesis, consequently presenting neuroprotective activity. Therefore, this paper focuses on the carotenoids obtained from marine sources and their impact on neuroplasticity enhancement.

Therapeutic Potential of Seaweed-Derived Bioactive Compounds for Cardiovascular Disease Treatment

Cardiovascular diseases are closely related to hypertension, type 2 diabetes mellitus, obesity, and hyperlipidemia. Many studies have reported that an unhealthy diet and sedentary lifestyle are critical factors that enhance these diseases. Recently, many bioactive compounds isolated from marine seaweeds have been studied for their benefits in improving human health. In particular, several unique bioactive metabolites such as polyphenols, polysaccharides, peptides, carotene, and sterol are the most effective components responsible for these activities. This review summarizes the current in vitro, in vivo, and clinical studies related to the protective effects of bioactive compounds isolated from seaweeds against cardiovascular disorders, including anti-diabetic, anti-hypertensive, anti-hyperlipidemia, and anti-obesity effects. Therefore, this present review summarizes these concepts and provides a basis for further in-depth research.

Anti-Angiogenetic Agents from the Sea: A New Potential Preventive and Therapeutic Wave?

Angiogenesis, generation of novel blood vessels from pre-existing ones, is a prerequisite for the physiological expansion, reparation, and functioning of body tissues and systems. However, it is also involved in some pathological inflammatory situations, such as oncologic and chronic degenerative disorders. The correct angiogenesis and neo-vascular response also accompanies wound healing, interaction with biocompatible materials, and tissue regeneration. In this respect, natural products deriving from terrestrial and marine plants/organisms may prevent and even cure various angiogenesis-dependent disorders. Bioactive natural compounds with antioxidant and anti-inflammatory activities could concur to maintain adequate vascularization and endothelial functions and inhibit angiogenesis, thus controlling tumor development. This review aims to illustrate the role of some marine-derived compounds as anti-angiogenetic agents.

Fucoxanthin may inhibit cervical cancer cell proliferation via downregulation of HIST1H3D

Objective

To investigate the role of fucoxanthin, reported to have significant anticancer effects, and histone Cluster 1 H3 Family Member D (HIST1H3D; implicated in tumorigenesis) in cervical cancer.

Methods

The half maximal inhibitory concentration (IC50) of fucoxanthin against HeLa and SiHa cervical cancer cells was determined. Differentially expressed genes (DEGs) in SiHa cells treated with IC50 fucoxanthin were screened by high-throughput techniques and subjected to signal enrichment. Following identification of HIST1H3D as a candidate gene, HIST1H3D-knockdown models were created via transfection with a short hairpin HIST1H3D payload. Impacts on cell proliferation, cell-cycle distribution, colony formation, and apoptosis were studied.

Results

The fucoxanthin IC50 was 1 445 and 1 641 µM (Hela and SiHa cells, respectively). Chip results revealed 2 255 DEGs, including 943 upregulated and 1 312 downregulated genes, in fucoxanthin-treated versus untreated SiHa cells. Disease and function analysis indicated that these DEGs are primarily associated with cancer and organismal injuries and abnormalities, and online integrated pathway analysis showed that the DEGs were mainly enriched in p53 signalling. HIST1H3D was significantly downregulated in response to fucoxanthin. Inhibition of HIST1H3D mRNA significantly reduced cell proliferation and colony formation, significantly augmented the percentage of apoptotic HeLa and SiHa cells, and cells were arrested in G₀/G₁ cell cycle phase.

Conclusion

The results suggest that HIST1H3D may be an oncogene in cervical carcinogenesis and a potential fucoxanthin target in treating cervical cancer.

Advances in Studies on the Pharmacological Activities of Fucoxanthin

Fucoxanthin is a natural carotenoid derived mostly from many species of marine brown algae. It is characterized by small molecular weight, is chemically active, can be easily oxidized, and has diverse biological activities, thus protecting cell components from ROS. Fucoxanthin inhibits the proliferation of a variety of cancer cells, promotes weight loss, acts as an antioxidant and anti-inflammatory agent, interacts with the intestinal flora to protect intestinal health, prevents organ fibrosis, and exerts a multitude of other beneficial effects. Thus, fucoxanthin has a wide range of applications and broad prospects. This review focuses primarily on the latest progress in research on its pharmacological activity and underlying mechanisms.

Fucoxanthin, a Marine-Derived Carotenoid from Brown Seaweeds and Microalgae: A Promising Bioactive Compound for Cancer Therapy

Fucoxanthin is a well-known carotenoid of the xanthophyll family, mainly produced by marine organisms such as the macroalgae of the fucus genus or microalgae such as Phaeodactylum tricornutum. Fucoxanthin has antioxidant and anti-inflammatory properties but also several anticancer effects. Fucoxanthin induces cell growth arrest, apoptosis, and/or autophagy in several cancer cell lines as well as in animal models of cancer. Fucoxanthin treatment leads to the inhibition of metastasis-related migration, invasion, epithelial–mesenchymal transition, and angiogenesis. Fucoxanthin also affects the DNA repair pathways, which could be involved in the resistance phenotype of tumor cells. Moreover, combined treatments of fucoxanthin, or its metabolite fucoxanthinol, with usual anticancer treatments can support conventional therapeutic strategies by reducing drug resistance. This review focuses on the current knowledge of fucoxanthin with its potential anticancer properties, showing that fucoxanthin could be a promising compound for cancer therapy by acting on most of the classical hallmarks of tumor cells.

Evaluation of Intestinal Absorption of Dietary Halocynthiaxanthin, a Carotenoid from the Sea Squirt Halocynthia roretzi

Halocynthiaxanthin is an acetylenic carotenoid mainly found in Halocynthia roretzi. To date, several bioactivities of halocynthiaxanthin have been reported, but its mechanism of digestion and absorption in mammals has not been studied yet. In this study, we evaluated the intestinal absorption of halocynthiaxanthin in mice. The halocynthiaxanthin-rich fraction was prepared from the tunicate Halocynthia roretzi. Mice were orally administered the fraction at a dose of 5 mg/kg body weight. The halocynthiaxanthin levels in the plasma, liver, and small intestine, were quantified using HPLC-PDA, 1, 3, 6, and 9 h after ingestion. The halocynthiaxanthin-rich fraction mainly consisted of the all-trans form and a small amount of cis forms. These three isomers were detected in the plasma of mice 3 h after ingestion. Time-course changes after the ingestion of this fraction were found, with cis isomers being more abundant than the all-trans isomer in the mouse plasma and liver. In the small intestine, however, the all-trans isomer was primarily detected. The possibility that cis isomers might be absorbed rapidly from the small intestine cannot be denied, but our results suggest that dietary all-trans-halocynthiaxanthin might be isomerized to the cis isomer after intestinal absorption.

Fucoxanthin activities motivate its nano/micro-encapsulation for food or nutraceutical application: a review

Fucoxanthin is a xanthophyll carotenoid abundant in marine brown algae. The potential therapeutic effects of fucoxanthin on tumor intervention have been well documented, which have aroused great interests in utilizing fucoxanthin in functional foods and nutraceuticals. However, the utilization of fucoxanthin as a nutraceutical in food and nutrient supplements is currently limited due to its low water solubility, poor stability, and limited bioaccessibility. Nano/micro-encapsulation is a technology that can overcome these challenges. A systematic review on the recent progresses in nano/micro-delivery systems to encapsulate fucoxanthin in foods or nutraceuticals is warranted. This article starts with a brief introduction of fucoxanthin and the challenges of oral delivery of fucoxanthin. Nano/micro-encapsulation technology is then covered, including materials and strategies for constructing the delivery system. Finally, future prospective has been discussed on properly designed oral delivery systems of fucoxanthin for managing cancer. Natural edible materials such as whey protein, casein, zein, gelatin, and starch have been successfully utilized to fabricate lipid-based, gel-based, or emulsion-based delivery systems, molecular nanocomplexes, and biopolymer nanoparticles with the aid of advanced processing techniques, such as freeze-drying, high pressure homogenization, sonication, anti-solvent precipitation, coacervation, ion crosslinking, ionic gelation, emulsification, and enzymatic conjugation. These formulated nano/micro-capsules have proven to be effective in stabilizing and enhancing the bioaccessibility of fucoxanthin. This review will inspire a surge of multidisciplinary research in a broader community of foods and motivate material scientists and researchers to focus on nano/micro-encapsulated fucoxanthin in order to facilitate the commercialization of orally-deliverable tumor intervention products.

Marine Cyanobacteria and Microalgae Metabolites-A Rich Source of Potential Anticancer Drugs

Cancer is at present one of the utmost deadly diseases worldwide. Past efforts in cancer research have focused on natural medicinal products. Over the past decades, a great deal of initiatives was invested towards isolating and identifying new marine metabolites via pharmaceutical companies, and research institutions in general. Secondary marine metabolites are looked at as a favorable source of potentially new pharmaceutically active compounds, having a vast structural diversity and diverse biological activities; therefore, this is an astonishing source of potentially new anticancer therapy. This review contains an extensive critical discussion on the potential of marine microbial compounds and marine microalgae metabolites as anticancer drugs, highlighting their chemical structure and exploring the underlying mechanisms of action. Current limitation, challenges, and future research pathways were also presented.

Absorption and Tissue Distribution of Siphonaxanthin from Green Algae

Siphonaxanthin has been known to possess inhibitory effects against obesity, inflammation, and angiogenesis. However, little information on its in vivo bioavailability and biotransformation is available. To assess the bioavailability and metabolism of siphonaxanthin, its absorption and accumulation were evaluated using intestinal Caco-2 cells and Institute of Cancer Research (ICR) mice. Siphonaxanthin was absorbed and exhibited non-uniform accumulation and distribution patterns in tissues of ICR mice. Notably, in addition to siphonaxanthin, three main compounds were detected following dietary administration of siphonaxanthin. Because the compounds showed changes on mass spectra compared with that of siphonaxanthin, they were presumed to be metabolites of siphonaxanthin in ICR mice. Siphonaxanthin mainly accumulated in stomach and small intestine, while putative metabolites of siphonaxanthin mainly accumulated in liver and adipose tissues. Furthermore, siphonaxanthin and its putative metabolites selectively accumulated in white adipose tissue (WAT), especially mesenteric WAT. These results provide useful evidence regarding the in vivo bioactivity of siphonaxanthin. In particular, the results regarding the specific accumulation of siphonaxanthin and its metabolites in WAT have important implications for understanding their anti-obesity effects and regulatory roles in lipid metabolism.

Dietary carotenoids in cancer chemoprevention and chemotherapy: A review of emerging evidence

In recent years, natural products have reemerged as biotherapeutic options, with several dietary carotenoids, viz. astaxanthin, fucoxanthin, siphonaxanthin, β-cryptoxanthin, α-carotene, β-carotene, and lycopene, developing as potential candidates for chemoprevention and chemotherapeutics of breast, colorectal, lung, and prostate cancers. The potent cytotoxic and antiproliferative effects of carotenoids against various cancer cells are mediated by a wide range of molecular mechanisms modulating oxidative stress and redox balance, mitogen-activated protein kinases (MAPK) and other cellular signaling proteins, transcription factors, caspase cascade pathways of apoptosis, cell cycle progression and proliferation, angiogenesis, metastasis, gap junction intercellular communication (GJIC), and multidrug resistance (MDR). This review discusses recent evidence demonstrating the crucial roles of carotenoids in these cellular and molecular events of cancer cell cytotoxicity. In addition, recent case-control and cohort studies are discussed to support the potential role of carotenoids in cancer prevention and therapy.

Siphonaxanthin, a carotenoid from green algae Codium cylindricum, protects Ob/Ob mice fed on a high-fat diet against lipotoxicity by ameliorating somatic stresses and restoring anti-oxidative capacity

Oxidative stress is implicated in the pathogenesis of many diseases including obesity, non-alcoholic fatty liver disease, and diabetes mellitus. Previously, we reported that siphonaxanthin, a carotenoid from green algae, elicited a potent inhibitory effect on hepatic de novo lipogenesis, and an anti-obesity effect in both 3T3L1 cells and KKAy mice. Thus, we hypothesized that consumption of siphonaxanthin could improve metabolic disorders including hepatic steatosis and systemic adiposity, as well as ameliorate somatic stress under obese conditions. Both the hepatocyte cell line HepG2 and a mouse model of severe obesity, produced by feeding Ob/Ob mice on a high-fat diet (HFD), were used to test this hypothesis. In obese mice, siphonaxanthin intake did not improve liver steatosis or systemic adiposity. However, intake did lower plasma glucose and alanine aminotransferase (ALT) levels and diminished hepatic lipid peroxidation products and antioxidant gene expression, which increased significantly in control group obese mice. Renal protein carbonyl content decreased significantly in the siphonaxanthin group, which might also indicate an ameliorated oxidative stress. Siphonaxanthin restored gene expression related to antioxidant signaling, lipid β-oxidation, and endoplasmic-reticulum-associated protein degradation in the kidney, which decreased significantly in obese mice. Liver and kidney responded to obesity-induced somatic stress in a divergent pattern. In addition, we confirmed that siphonaxanthin potently induced Nrf2-regulated antioxidant signaling in HepG2 cells. In conclusion, our results indicated that siphonaxanthin might protect obesity-leading somatic stress through restoration of Nrf2-regulated antioxidant signaling, and might be a promising nutritional supplement.

Friend or foe, the role of EGR-1 in cancer

Early growth response-1 (EGR-1), also termed NEFI-A and Krox-24, as a multi-domain protein is implicated in several vital physiological processes, including development, metabolism, cell growth and proliferation. Previous studies have implied that EGR-1 was producing in response to the tissue injury, immune response and fibrosis. Meanwhile, emerging studies stressed the pronounced correlation of EGR-1 and human cancers. Nevertheless, the intricate mechanisms of cancer-reduce EGR-1 alteration still poorly characterized. In the review, we evaluated the effects of EGR-1 in tumor cell proliferation, apoptosis, migration, invasion and tumor microenvironment, and then, we dwell on the intricate signaling pathways that EGR-1 involved in. The aberrantly expressed of EGR-1 in cancers are expected to provide a new cancer therapy strategy or a new marker for assessing treatment efficacy.

Targeting hallmarks of cancer with a food-system-based approach

Although extensive resources are dedicated to the development and study of cancer drugs, the cancer burden is expected to rise by about 70% over the next 2 decade. This highlights a critical need to develop effective, evidence-based strategies for countering the global rise in cancer incidence. Except in high-risk populations, cancer drugs are not generally suitable for use in cancer prevention owing to potential side effects and substantial monetary costs (Sporn, 2011). There is overwhelming epidemiological and experimental evidence that the dietary bioactive compounds found in whole plant-based foods have significant anticancer and chemopreventative properties. These bioactive compounds often exert pleiotropic effects and act synergistically to simultaneously target multiple pathways of cancer. Common bioactive compounds in fruits and vegetables include carotenoids, glucosinolates, and polyphenols. These compounds have been shown to target multiple hallmarks of cancer in vitro and in vivo and potentially to address the diversity and heterogeneity of certain cancers. Although many studies have been conducted over the past 30 y, the scientific community has still not reached a consensus on exactly how the benefit of bioactive compounds in fruits and vegetables can be best harnessed to help reduce the risk for cancer. Different stages of the food processing system, from "farm-to-fork," can affect the retention of bioactive compounds and thus the chemopreventative properties of whole foods, and there are opportunities to improve handling of foods throughout the stages in order to best retain their chemopreventative properties. Potential target stages include, but are not limited to, pre- and postharvest management, storage, processing, and consumer practices. Therefore, there is a need for a comprehensive food-system-based approach that not only taking into account the effects of the food system on anticancer activity of whole foods, but also exploring solutions for consumers, policymakers, processors, and producers. Improved knowledge about this area of the food system can help us adjust farm-to-fork operations in order to consistently and predictably deliver desired bioactive compounds, thus better utilizing them as invaluable chemopreventative tools in the fight to reduce the growing burden of cancer worldwide.

Pivotal micro factors associated with endothelial cells

Objective:

Recent studies have shown the important influence of various micro factors on the general biological activity and function of endothelial cells (ECs). Vascular endothelial growth factor (VEGF) and angiogenin (ANG) are classic micro factors that promote proliferation, differentiation, and migration of ECs. The underlying pathophysiological mechanisms and related pathways of these micro factors remain the focus of current research.

Data sources:

An extensive search was undertaken in the PubMed database by using keywords including “micro factors” and “endothelial cell.” This search covered relevant research articles published between January 1, 2007 and December 31, 2018.

Study selection:

Original articles, reviews, and other articles were searched and reviewed for content on micro factors of ECs.

Results:

VEGF and ANG have critical functions in the occurrence, development, and status of the physiological pathology of ECs. Other EC-associated micro factors include interleukin 10, tumor protein P53, nuclear factor kappa B subunit, interleukin 6, and tumor necrosis factor. The results of Gene Ontology analysis revealed that variations were mainly enriched in positive regulation of transcription by the RNA polymerase II promoter, cellular response to lipopolysaccharides, negative regulation of apoptotic processes, external side of the plasma membrane, cytoplasm, extracellular regions, cytokine activity, growth factor activity, and identical protein binding. The results of the Kyoto Encyclopedia of Genes and Genomes analysis revealed that micro factors were predominantly enriched in inflammatory diseases.

Conclusions:

In summary, the main mediators, factors, or genes associated with ECs include VEGF and ANG. The effect of micro factors on ECs is complex and multifaceted. This review summarizes the correlation between ECs and several micro factors.

Fucoxanthin-An Antibacterial Carotenoid

Fucoxanthin is a carotenoid produced by brown algae and diatoms. This compound has several biological properties such as antioxidant, anti-obesity, anti-diabetic, anticancer, and antimicrobial activities. Unfortunately, until now the latter effect has been poorly confirmed. The aim of this study was an evaluation of fucoxanthin activity against 20 bacterial species. Antimicrobial effect of fucoxanthin was determined by using the agar disc-diffusion and micro-dilution methods. The studied carotenoid acted against 13 bacteria growing in aerobic conditions. It was observed to have a significantly stronger impact on Gram-positive than Gram-negative bacteria. Mean zones of growth inhibition (ZOIs) for Gram-positive bacteria ranged between 9.0 and 12.2 mm, while for Gram-negative were from 7.2 to 10.2 mm. According to the agar disc-diffusion method, the highest activity of fucoxanthin was exhibited against Streptococcus agalactiae (mean ZOI 12.2 mm), Staphylococcus epidermidis (mean ZOI 11.2 mm), and Staphylococcus aureus (mean ZOI 11.0 mm), and in the microdilution test towards Streptococcus agalactiae with the minimal inhibitory concentration (MIC) of 62.5 µg/mL. On the other hand, fucoxanthin was not active against strict anaerobic bacteria.

Marine Carotenoid Fucoxanthin Possesses Anti-Metastasis Activity: Molecular Evidence

Fucoxanthin is commonly found in marine organisms; however, to date, it has been one of the scarcely explored natural compounds. We investigated its activities in human cancer cell culture-based viability, migration, and molecular assays, and found that it possesses strong anticancer and anti-metastatic activities that work irrespective of the p53 status of cancer cells. In our experiments, fucoxanthin caused the transcriptional suppression of mortalin. Cell phenotype-driven molecular analyses on control and treated cells demonstrated that fucoxanthin caused a decrease in hallmark proteins associated with cell proliferation, survival, and the metastatic spread of cancer cells at doses that were relatively safe to the normal cells. The data suggested that the cancer therapy regimen may benefit from the recruitment of fucoxanthin; hence, it warrants further attention for basic mechanistic studies as well as drug development.

A critical review on anti-angiogenic property of phytochemicals

Angiogenesis, a process involved in neovascularization, has been found to be associated with several metabolic diseases like cancer, retinopathy etc. Thus, currently, the focus on anti-angiogenic therapy for treatment and prevention of diseases has gained significant attention. Currently available Food and Drug Administration (FDA) approved drugs are targeting either vascular endothelial growth factor or it's receptor, but in the long term, these approaches were shown to cause several side effects and the chances of developing resistance to these drugs is also high. Therefore, identification of safe and cost-effective anti-angiogenic molecules is highly imperative. Over the past decades, dietary based natural compounds have been studied for their anti-angiogenic potential which provided avenues in improving the angiogenesis based therapy. In this review, major emphasis is given to the molecular mechanism behind anti-angiogenic effect of natural compounds from dietary sources.

Fucoxanthin Protects against oxLDL-Induced Endothelial Damage via Activating the AMPK-Akt-CREB-PGC1α Pathway

SCOPE

Atherosclerotic cardiovascular disease is the most prevalent cause of mortality and morbidity. Fucoxanthin (FX) possesses anti-hypertensive and anti-obesity properties. However, the molecular mechanisms underlying the inhibitory effects of FX on oxidized low-density lipoprotein (oxLDL)-induced oxidative injuries in human endothelial cells are still largely unknown. This study aims to test the hypothesis that FX protects against oxLDL-induced oxidative stress by upregulating AMP-activated protein kinase (AMPK) and to explore the roles of cAMP response element binding protein (CREB) and peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α).

METHODS AND RESULTS

Human umbilical vein endothelial cells are treated with oxLDL in the presence or absence of FX. FX significantly increases AMPK phosphorylation. In addition, FX diminishes oxLDL-mediated nicotinamide adenine dinucleotide phosphate oxidase activation by inhibiting protein kinase C and subsequently inducing reactive oxygen species generation and impairing the activity of the endogenous antioxidant enzyme superoxidase dismutase. Furthermore, FX restores oxLDL-mediated dephosphorylation of phosphoinositide-3-kinase/Akt and decreases CREB and PGC-1α expression to nearly normal levels. Moreover, FX ameliorates the oxLDL-mediated suppression of mitochondrial function and apoptosis.

CONCLUSION

These findings provide new insights into the possible molecular mechanisms by which FX mitigates oxLDL-induced endothelial oxidative stress and mitochondrial dysfunction.

Fucoxanthin inhibits tumour-related lymphangiogenesis and growth of breast cancer

Tumour lymphangiogenesis plays an important role in promoting the growth and lymphatic metastasis of tumours. The process is associated with cell proliferation, migration and tube-like structure formation in lymphatic endothelial cells (LEC), but no antilymphangiogenic agent is currently used in clinical practice. Fucoxanthin is a material found in brown algae that holds promise in the context of drug development. Fucoxanthin is a carotenoid with variety of pharmacological functions, including antitumour and anti-inflammatory effects. The ability of fucoxanthin to inhibit lymphangiogenesis remains unclear. The results of experiments performed as part of this study show that fucoxanthin, extracted from Undaria pinnatifida (Wakame), inhibits proliferation, migration and formation of tube-like structures in human LEC (HLEC). In this study, fucoxanthin also suppressed the malignant phenotype in human breast cancer MDA-MB-231 cells and decreased tumour-induced lymphangiogenesis when used in combination with a conditional medium culture system. Fucoxanthin significantly decreased levels of vascular endothelial growth factor (VEGF)-C, VEGF receptor-3, nuclear factor kappa B, phospho-Akt and phospho-PI3K in HLEC. Fucoxanthin also decreased micro-lymphatic vascular density (micro-LVD) in a MDA-MB-231 nude mouse model of breast cancer. These findings suggest that fucoxanthin inhibits tumour-induced lymphangiogenesis in vitro and in vivo, highlighting its potential use as an antilymphangiogenic agent for antitumour metastatic comprehensive therapy in patients with breast cancer.

Extracellular signal-regulated kinase-1 phosphorylates early growth response-1 at serine 26

Egr-1, an immediate-early gene product and master regulator was originally described as a phosphoprotein following its discovery in the 1980s. However specific residue(s) phosphorylated in Egr-1 remain elusive. Here we phosphorylated recombinant Egr-1 in vitro with ERK1 prior to mass spectrometry, which identified phosphorylation of Ser¹² and Ser²⁶ with the latter ∼12 times more abundant than Ser¹². Phosphorylation of wild-type recombinant Egr-1 (as compared with Ser²⁶>Ala²⁶ mutant Egr-1) revealed that Ser²⁶ accounts for the majority of phosphorylation of Egr-1 by ERK1. N-FGSFPH(pS)PTMDNYC-C was used as an antigen to generate mouse monoclonal antibodies (pS26 MAb). pS26 MAb recognised ERK1-phosphorylated Egr-1 but not Egr-1 bearing a point mutation at Ser²⁶. pS26 MAb recognised inducible ∼75 kDa and 100 kDa species in nuclear extracts of cells exposed to FGF-2. Peptide blocking revealed both inducible species were phosphosite-specific. Immunoprecipitation of nuclear extracts of cells exposed to FGF-2 with pS26 MAb followed by SDS-PAGE and mass spectrometry identified Egr-1 sequences corresponding to the ∼75 kDa species but not ∼100 kDa species. This study identifies a specific amino acid phosphorylated in endogenous Egr-1.

Seaweed Secondary Metabolites In Vitro and In Vivo Anticancer Activity

Isolation, finding or discovery of novel anticancer agents is very important for cancer treatment, and seaweeds are one of the largest producers of chemically active metabolites with valuable cytotoxic properties, and therefore can be used as new chemotherapeutic agents or source of inspiration to develop new ones. Identification of the more potent and selective anticancer components isolated from brown, green and red seaweeds, as well as studies of their mode of action is very attractive and constitute a small but relevant progress for pharmacological applications. Several researchers have carried out in vitro and in vivo studies in various cell lines and have disclosed the active metabolites among the terpenoids, including carotenoids, polyphenols and alkaloids that can be found in seaweeds. In this review the type of metabolites and their cytotoxic or antiproliferative effects will be discussed additionally their mode of action, structure-activity relationship and selectivity will also be revealed. The diterpene dictyolactone, the sterol cholest-5-en-3β,7α-diol and the halogenated monoterpene halomon are among the reported compounds, the ones that present sub-micromolar cytotoxicity. Additionally, one dimeric sesquiterpene of the cyclolaurane-type, three bromophenols and one halogenated monoterpene should be emphasized because they exhibit half maximal inhibitory concentration (IC₅₀) values between 1–5 µM against several cell lines.

Selected Methods of Extracting Carotenoids, Characterization, and Health Concerns: A Review

Carotenoids are the most powerful nutrients (medicine) on earth due to their potent antioxidant properties. The ability of these tetraterpenoids in obviating human chronic ailments like cancer, cardiovascular disease, osteoporosis, and diabetes has drawn public attention toward these novel compounds. Conventionally, carotenoids have been extracted from plant materials and agro-industrial byproduct using different solvents, but these procedures result in contaminating the target compound (carotenoids) with extraction solvents. Furthermore, some utilized solvents are not safe and hence are harmful to the environment. This has attracted criticism from consumers, ecologists, environmentalists, and public health workers. However, there is clear consumer preference for carotenoids from natural origin without traces of extracting solvent. Therefore, this review seeks to discuss methods for higher recovery of pure carotenoids without contamination from a solvent. Methods such as enzyme-based extraction, supercritical fluid extraction, microwave-assisted extraction, Soxhlet extraction, ultrasonic extraction, and postextraction treatment (saponification) are discussed. Merits and demerits of these methods along with health concerns during intake of carotenoids were also considered.

A Review of the Biological Activities of Microalgal Carotenoids and Their Potential Use in Healthcare and Cosmetic Industries

Carotenoids are natural pigments that play pivotal roles in many physiological functions. The characteristics of carotenoids, their effects on health, and the cosmetic benefits of their usage have been under investigation for a long time; however, most reviews on this subject focus on carotenoids obtained from several microalgae, vegetables, fruits, and higher plants. Recently, microalgae have received much attention due to their abilities in producing novel bioactive metabolites, including a wide range of different carotenoids that can provide for health and cosmetic benefits. The main objectives of this review are to provide an updated view of recent work on the health and cosmetic benefits associated with carotenoid use, as well as to provide a list of microalgae that produce different types of carotenoids. This review could provide new insights to researchers on the potential role of carotenoids in improving human health.

β-Cryptoxanthin Inhibits Angiogenesis in Human Umbilical Vein Endothelial Cells Through Retinoic Acid Receptor

SCOPE

β-Cryptoxanthin is an abundant carotenoid in fruits and vegetables that can be quantified in human blood serum. Yet, contrary to other carotenoids, its effects on endothelial cells and angiogenesis remain unknown.

METHODS AND RESULTS

Human umbilical vein endothelial cells (HUVEC) are treated with 0.01, 0.1, or 1 μm of β-cryptoxanthin. Antioxidant activity is determined by its free radical scavenging and oxygen-radical absorbance capacity. The effect on migration and formation of tubular structures is studied. Additionally, effect on angiogenesis is also analyzed using an in vivo model. β-Cryptoxanthin exhibits scavenging ability, having an antioxidant effect on HUVEC. Interestingly, β-cryptoxanthin reduces their migration and angiogenesis, even in the presence of vascular endothelial growth factor (VEGF). Additionally, such carotenoid inhibits in vivo angiogenesis induced by VEGF. In addition, treatment of HUVEC with LE540 (retinoic acid receptor [RAR] panantagonist) inhibits β-cryptoxanthin antiangiogenic effect on HUVEC.

CONCLUSION

β-Cryptoxanthin inhibits angiogenesis through RAR. Thus, this carotenoid and food containing it may be useful for the prevention and treatment of angiogenic pathologies. That includes tumoral growth and wet macular degeneration associated with aging. To the best of our knowledge, this is the first report of the antioxidant effect and antiangiogenic activity of this carotenoid on HUVEC, both in vitro and in vivo.

Angiomodulators in cancer therapy: New perspectives

The formation of new blood vessels plays a crucial for the development and progression of pathophysiological changes associated with a variety of disorders, including carcinogenesis. Angiogenesis inhibitors (anti-angiogenics) are an important part of treatment for some types of cancer. Some natural products isolated from marine invertebrates have revealed antiangiogenic activities, which are diverse in structure and mechanisms of action. Many preclinical studies have generated new models for further modification and optimization of anti-angiogenic substances, and new information for mechanistic studies and new anti-cancer drug candidates for clinical practice. Moreover, in the last decade it has become apparent that galectins are important regulators of tumor angiogenesis, as well as microRNA. MicroRNAs have been validated to modulate endothelial cell migration or endothelial tube organization. In the present review we summarize the current knowledge regarding the role of marine-derived natural products, galectins and microRNAs in tumor angiogenesis.

Marine Carotenoids against Oxidative Stress: Effects on Human Health

Carotenoids are lipid-soluble pigments that are produced in some plants, algae, fungi, and bacterial species, which accounts for their orange and yellow hues. Carotenoids are powerful antioxidants thanks to their ability to quench singlet oxygen, to be oxidized, to be isomerized, and to scavenge free radicals, which plays a crucial role in the etiology of several diseases. Unusual marine environments are associated with a great chemical diversity, resulting in novel bioactive molecules. Thus, marine organisms may represent an important source of novel biologically active substances for the development of therapeutics. In this respect, various novel marine carotenoids have recently been isolated from marine organisms and displayed several utilizations as nutraceuticals and pharmaceuticals. Marine carotenoids (astaxanthin, fucoxanthin, β-carotene, lutein but also the rare siphonaxanthin, sioxanthin, and myxol) have recently shown antioxidant properties in reducing oxidative stress markers. This review aims to describe the role of marine carotenoids against oxidative stress and their potential applications in preventing and treating inflammatory diseases.

Fucoxanthin and Its Metabolite Fucoxanthinol in Cancer Prevention and Treatment

Fucoxanthin is a carotenoid present in the chloroplasts of brown seaweeds. When ingested, it is metabolized mainly to fucoxanthinol by digestive enzymes of the gastrointestinal tract. These compounds have been shown to have many beneficial health effects, including anti-mutagenic, anti-diabetic, anti-obesity, anti-inflammatory and anti-neoplastic actions. In every cancer tested, modulatory actions of fucoxanthinol on viability, cell-cycle arrest, apoptosis and members of the NF-κB pathway were more pronounced than that of fucoxanthin. Anti-proliferative and cancer preventing influences of fucoxanthin and fucoxanthinol are mediated through different signalling pathways, including the caspases, Bcl-2 proteins, MAPK, PI3K/Akt, JAK/STAT, AP-1, GADD45, and several other molecules that are involved in cell cycle arrest, apoptosis, anti-angiogenesis or inhibition of metastasis. In this review, we address the mechanisms of action of fucoxanthin and fucoxanthinol according to different types of cancers. Current findings suggest that these compounds could be effective for treatment and/or prevention of cancer development and aggressiveness.

The green algal carotenoid siphonaxanthin inhibits adipogenesis in 3T3-L1 preadipocytes and the accumulation of lipids in white adipose tissue of KK-Ay mice

BACKGROUND

Siphonaxanthin, a xanthophyll present in green algae, has been shown to possess antiangiogenic and apoptosis-inducing activities.

OBJECTIVE

We evaluated the antiobesity effects of siphonaxanthin by using a 3T3-L1 cell culture system and in diabetic KK-Ay mice.

METHODS

3T3-L1 cells were differentiated with or without 5 μmol/L siphonaxanthin, and lipid accumulation and critical gene expressions for adipogenesis were examined. In vivo, 4-wk-old male KK-Ay mice were administered daily oral treatment of 1.3 mg siphonaxanthin for 6 wk and body weight, visceral fat weight, serum variables, and gene expressions involved in lipid metabolism were evaluated.

RESULTS

Compared with the other carotenoids evaluated, siphonaxanthin potently inhibited adipocyte differentiation. Siphonaxanthin significantly suppressed lipid accumulation at noncytotoxic concentrations of 2.5 and 5 μmol/L by 29% and 43%, respectively. The effects of siphonaxanthin were largely limited to the early stages of adipogenesis. Siphonaxanthin significantly inhibited protein kinase B phosphorylation by 48% and 72% at 90 and 120 min, respectively. The expressions of key adipogenesis genes, including CCAAT/enhancer binding protein α (Cebpa), peroxisome proliferator activated receptor γ (Pparg), fatty acid binding protein 4 (Fabp4), and stearoyl coenzyme A desaturase 1 (Scd1), were elevated by 1.6- to 166-fold during adipogenesis. After 8 d of adipocyte differentiation, siphonaxanthin significantly lowered gene expression of Cebpa, Pparg, Fabp4, and Scd1 by 94%, 83%, 95%, and 90%, respectively. Moreover, oral administration of siphonaxanthin to KK-Ay mice significantly reduced the total weight of white adipose tissue (WAT) by 13%, especially the mesenteric WAT by 28%. Furthermore, siphonaxanthin administration reduced lipogenesis and enhanced fatty acid oxidation in adipose tissue. Siphonaxanthin was observed to highly accumulate in mesenteric WAT, and the accumulation in the mesenteric WAT was almost 2- and 3-fold that in epididymal (P = 0.14) and perirenal (P < 0.05) WAT, respectively.

CONCLUSION

These results provide evidence that siphonaxanthin may effectively regulate adipogenesis in 3T3-L1 cells and diabetic KK-Ay mice.

Siphonaxanthin, a green algal carotenoid, as a novel functional compound

Siphonaxanthin is a specific keto-carotenoid in green algae whose bio-functional properties are yet to be identified. This review focuses on siphonaxanthin as a bioactive compound and outlines the evidence associated with functionality. Siphonaxanthin has been reported to potently inhibit the viability of human leukemia HL-60 cells via induction of apoptosis. In comparison with fucoxanthin, siphonaxanthin markedly reduced cell viability as early as 6 h after treatment. The cellular uptake of siphonaxanthin was 2-fold higher than fucoxanthin. It has been proposed that siphonaxanthin possesses significant anti-angiogenic activity in studies using human umbilical vein endothelial cells and rat aortic ring. The results of these studies suggested that the anti-angiogenic effect of siphonaxanthin is due to the down-regulation of signal transduction by fibroblast growth factor receptor-1 in vascular endothelial cells. Siphonaxanthin also exhibited inhibitory effects on antigen-induced degranulation of mast cells. These findings open up new avenues for future research on siphonaxanthin as a bioactive compound, and additional investigation, especially in vivo studies, are required to validate these findings. In addition, further studies are needed to determine its bioavailability and metabolic fate.

Cancer preventive efficacy of marine carotenoid fucoxanthin: cell cycle arrest and apoptosis

Epidemiological investigations have shown that overcoming the risk of cancer is related to the consumption of green vegetables and fruits. Many compounds from different origins, such as terrestrial plants and marine and microbial sources, have been reported to have therapeutic effects of which marine sources are the most important because the diversity of marine life is more varied than other sources. Fucoxanthin is one important compound with a marine origin and belongs to the group of carotenoids; it can be found in marine brown seaweeds, macroalgae, and diatoms, all of which have remarkable biological properties. Numerous studies have shown that fucoxanthin has considerable medicinal potential and promising applications in human health. In this review, we summarize the anticancer effects of fucoxanthin through several different mechanisms including anti-proliferation, induction of apoptosis, cell cycle arrest and anti-angiogenesis, and its possible role in the treatment of cancer.