Anticancer effects of marine carotenoids, fucoxanthin and its deacetylated product, fucoxanthinol, on osteosarcoma

The Antitumour Mechanisms of Carotenoids: A Comprehensive Review

Carotenoids, known for their antioxidant properties, have garnered significant attention for their potential antitumour activities. This comprehensive review aims to elucidate the diverse mechanisms by which carotenoids exert antitumour effects, focusing on both well-established and novel findings. We explore their role in inducing apoptosis, inhibiting cell cycle progression and preventing metastasis by affecting oncogenic and tumour suppressor proteins. The review also explores the pro-oxidant function of carotenoids within cancer cells. In fact, although their overall contribution to cellular antioxidant defences is well known and significant, some carotenoids can exhibit pro-oxidant effects under certain conditions and are able to elevate reactive oxygen species (ROS) levels in tumoural cells, triggering mitochondrial pathways that would lead to cell death. The final balance between their antioxidant and pro-oxidant activities depends on several factors, including the specific carotenoid, its concentration and the redox environment of the cell. Clinical trials are discussed, highlighting the conflicting results of carotenoids in cancer treatment and the importance of personalized approaches. Emerging research on rare carotenoids like bacterioruberin showcases their superior antioxidant capacity and selective cytotoxicity against aggressive cancer subtypes, such as triple-negative breast cancer. Future directions include innovative delivery systems, novel combinations and personalized treatments, aiming to enhance the therapeutic potential of carotenoids. This review highlights the promising yet complex landscape of carotenoid-based cancer therapies, calling for continued research and clinical exploration.

Fucoxanthin, a Functional Food Ingredient: Challenges in Bioavailability

PURPOSE OF REVIEW

Fucoxanthin is an orange-red xanthophyll carotenoid found in brown seaweeds and known for its many bioactive properties. In recent years, the bioactive properties of fucoxanthin have been widely explored, making it a compound of immense interest for various health applications like anti-cancer, anti-tumour, anti-diabetic and anti-obesity properties. However, the poor bioavailability and instability of fucoxanthin in the gastrointestinal tract have major limitations. Encapsulation is a promising approach to overcome these challenges by enclosing fucoxanthin in a protective layer, such as liposomes or nano-particles. Encapsulation can improve the stability of fucoxanthin by protecting it from exposure to heat, pH, illumination, gastric acids and enzymes that can accelerate its degradation.

RECENT FINDINGS

Studies have shown that lipid-based encapsulation systems such as liposomes or nano-structured lipid carriers may solubilise fucoxanthin and enhance its bioavailability (from 25 to 61.2%). In addition, encapsulation can also improve the solubility of hydrophobic fucoxanthin, which is important for its absorption and bioavailability. This review highlights the challenges involved in the absorption of fucoxanthin in the living system, role of micro- and nano-encapsulation of fucoxanthin and their potential to enhance intestinal absorption.

Overexpression of plastid lipid-associated protein in marine diatom enhances the xanthophyll synthesis and storage

Plastoglobules, which are lipoprotein structures surrounded by a single hydrophobic phospholipid membrane, are subcellular organelles in plant chromoplasts and chloroplasts. They contain neutral lipids, tocopherols, quinones, chlorophyll metabolites, carotenoids and their derivatives. Proteomic studies indicated that plastoglobules are involved in carotenoid metabolism and storage. In this study, one of the plastid lipid-associated proteins (PAP), the major protein in plastoglobules, was selected and overexpressed in Phaeodactylum tricornutum. The diameter of the plastoglobules in mutants was decreased by a mean of 19.2% versus the wild-type, while the fucoxanthin level was increased by a mean of 51.2%. All mutants exhibited morphological differences from the wild-type, including a prominent increase in the transverse diameter. Moreover, the unsaturated fatty acid levels were increased in different mutants, including an 18.9-59.3% increase in eicosapentaenoic acid content. Transcriptomic analysis revealed that PAP expression and the morphological changes altered xanthophyll synthesis and storage, which affected the assembly of the fucoxanthin chlorophyll a/c-binding protein and expression of antenna proteins as well as reduced the non-photochemical quenching activity of diatom cells. Therefore, metabolic regulation at the suborganelle level can be achieved by modulating PAP expression. These findings provide a subcellular structural site and target for synthetic biology to modify pigment and lipid metabolism in microalgae chassis cells.

Anticancer Effects of Fucoxanthin through Cell Cycle Arrest, Apoptosis Induction, Angiogenesis Inhibition, and Autophagy Modulation

Cancer accounts for one in seven deaths worldwide and is the second leading cause of death in the United States, after heart disease. One of the standard cancer treatments is chemotherapy which sometimes can lead to chemoresistance and treatment failure. Therefore, there is a great need for novel therapeutic approaches to treat these patients. Novel natural products have exhibited anticancer effects that may be beneficial in treating many kinds of cancer, having fewer side effects, low toxicity, and affordability. Numerous marine natural compounds have been found to inhibit molecular events and signaling pathways associated with various stages of cancer development. Fucoxanthin is a well-known marine carotenoid of the xanthophyll family with bioactive compounds. It is profusely found in brown seaweeds, providing more than 10% of the total creation of natural carotenoids. Fucoxanthin is found in edible brown seaweed macroalgae such as Undaria pinnatifida, Laminaria japonica, and Eisenia bicyclis. Many of fucoxanthin's pharmacological properties include antioxidant, anti-tumor, anti-inflammatory, antiobesity, anticancer, and antihypertensive effects. Fucoxanthin inhibits many cancer cell lines' proliferation, angiogenesis, migration, invasion, and metastasis. In addition, it modulates miRNA and induces cell cycle growth arrest, apoptosis, and autophagy. Moreover, the literature shows fucoxanthin's ability to inhibit cytokines and growth factors such as TNF-α and VEGF, which stimulates the activation of downstream signaling pathways such as PI3K/Akt autophagy, and pathways of apoptosis. This review highlights the different critical mechanisms by which fucoxanthin inhibits diverse cancer types, such as breast, prostate, gastric, lung, and bladder development and progression. Moreover, this article reviews the existing literature and provides critical supportive evidence for fucoxanthin's possible therapeutic use in cancer.

Bioactive Compounds from Marine Sponges and Algae: Effects on Cancer Cell Metabolome and Chemical Structures

Metabolomics represent the set of small organic molecules generally called metabolites, which are located within cells, tissues or organisms. This new “omic” technology, together with other similar technologies (genomics, transcriptomics and proteomics) is becoming a widely used tool in cancer research, aiming at the understanding of global biology systems in their physiologic or altered conditions. Cancer is among the most alarming human diseases and it causes a considerable number of deaths each year. Cancer research is one of the most important fields in life sciences. In fact, several scientific advances have been made in recent years, aiming to illuminate the metabolism of cancer cells, which is different from that of healthy cells, as suggested by Otto Warburg in the 1950s. Studies on sponges and algae revealed that these organisms are the main sources of the marine bioactive compounds involved in drug discovery for cancer treatment and prevention. In this review, we analyzed these two promising groups of marine organisms to focus on new metabolomics approaches for the study of metabolic changes in cancer cell lines treated with chemical extracts from sponges and algae, and for the classification of the chemical structures of bioactive compounds that may potentially prove useful for specific biotechnological applications.

Fucoxanthin: A Promising Phytochemical on Diverse Pharmacological Targets

Fucoxanthin (FX) is a special carotenoid having an allenic bond in its structure. FX is extracted from a variety of algae and edible seaweeds. It has been proved to contain numerous health benefits and preventive effects against diseases like diabetes, obesity, liver cirrhosis, malignant cancer, etc. Thus, FX can be used as a potent source of both pharmacological and nutritional ingredient to prevent infectious diseases. In this review, we gathered the information regarding the current findings on antimicrobial, antioxidant, anti-inflammatory, skin protective, anti-obesity, antidiabetic, hepatoprotective, and other properties of FX including its bioavailability and stability characteristics. This review aims to assist further biochemical studies in order to develop further pharmaceutical assets and nutritional products in combination with FX and its various metabolites.

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.

Phytochemicals, Nutrition, Metabolism, Bioavailability, and Health Benefits in Lettuce-A Comprehensive Review

Lettuce is one of the most famous leafy vegetables worldwide with lots of applications from food to other specific uses. There are different types in the lettuce group for consumers to choose from. Additionally, lettuce is an excellent source of bioactive compounds such as polyphenols, carotenoids, and chlorophyll with related health benefits. At the same time, nutrient composition and antioxidant compounds are different between lettuce varieties, especially for green and red lettuce types. The benefit of lettuce consumption depends on its composition, particularly antioxidants, which can function as nutrients. The health benefits rely on their biochemical effect when reaching the bloodstream. Some components can be released from the food matrix and altered in the digestive system. Indeed, the bioaccessibility of lettuce is measuring the quantity of these compounds released from the food matrix during digestion, which is important for health-promoting features. Extraction of bioactive compounds is one of the new trends observed in lettuce and is necessarily used for several application fields. Therefore, this review aims to demonstrate the nutritional value of lettuce and its pharmacological properties. Due to their bioaccessibility and bioavailability, the consumer will be able to comprehensively understand choosing a healthier lettuce diet. The common utilization pattern of lettuce extracted nutrients will also be summarized for further direction.

Phytochemical and Potential Properties of Seaweeds and Their Recent Applications: A Review

Since ancient times, seaweeds have been employed as source of highly bioactive secondary metabolites that could act as key medicinal components. Furthermore, research into the biological activity of certain seaweed compounds has progressed significantly, with an emphasis on their composition and application for human and animal nutrition. Seaweeds have many uses: they are consumed as fodder, and have been used in medicines, cosmetics, energy, fertilizers, and industrial agar and alginate biosynthesis. The beneficial effects of seaweed are mostly due to the presence of minerals, vitamins, phenols, polysaccharides, and sterols, as well as several other bioactive compounds. These compounds seem to have antioxidant, anti-inflammatory, anti-cancer, antimicrobial, and anti-diabetic activities. Recent advances and limitations for seaweed bioactive as a nutraceutical in terms of bioavailability are explored in order to better comprehend their therapeutic development. To further understand the mechanism of action of seaweed chemicals, more research is needed as is an investigation into their potential usage in pharmaceutical companies and other applications, with the ultimate objective of developing sustainable and healthier products. The objective of this review is to collect information about the role of seaweeds on nutritional, pharmacological, industrial, and biochemical applications, as well as their impact on human health.

Synthetic and Naturally Occurring Heterocyclic Anticancer Compounds with Multiple Biological Targets

Cancer is a complex group of diseases initiated by abnormal cell division with the potential of spreading to other parts of the body. The advancement in the discoveries of omics and bio- and cheminformatics has led to the identification of drugs inhibiting putative targets including vascular endothelial growth factor (VEGF) family receptors, fibroblast growth factors (FGF), platelet derived growth factors (PDGF), epidermal growth factor (EGF), thymidine phosphorylase (TP), and neuropeptide Y4 (NY4), amongst others. Drug resistance, systemic toxicity, and drug ineffectiveness for various cancer chemo-treatments are widespread. Due to this, efficient therapeutic agents targeting two or more of the putative targets in different cancer cells are proposed as cutting edge treatments. Heterocyclic compounds, both synthetic and natural products, have, however, contributed immensely to chemotherapeutics for treatments of various diseases, but little is known about such compounds and their multimodal anticancer properties. A compendium of heterocyclic synthetic and natural product multitarget anticancer compounds, their IC50, and biological targets of inhibition are therefore presented in this review.

Anti-Inflammatory and Anticancer Effects of Microalgal Carotenoids

Acute inflammation is a key component of the immune system's response to pathogens, toxic agents, or tissue injury, involving the stimulation of defense mechanisms aimed to removing pathogenic factors and restoring tissue homeostasis. However, uncontrolled acute inflammatory response may lead to chronic inflammation, which is involved in the development of many diseases, including cancer. Nowadays, the need to find new potential therapeutic compounds has raised the worldwide scientific interest to study the marine environment. Specifically, microalgae are considered rich sources of bioactive molecules, such as carotenoids, which are natural isoprenoid pigments with important beneficial effects for health due to their biological activities. Carotenoids are essential nutrients for mammals, but they are unable to synthesize them; instead, a dietary intake of these compounds is required. Carotenoids are classified as carotenes (hydrocarbon carotenoids), such as α- and β-carotene, and xanthophylls (oxygenate derivatives) including zeaxanthin, astaxanthin, fucoxanthin, lutein, α- and β-cryptoxanthin, and canthaxanthin. This review summarizes the present up-to-date knowledge of the anti-inflammatory and anticancer activities of microalgal carotenoids both in vitro and in vivo, as well as the latest status of human studies for their potential use in prevention and treatment of inflammatory diseases and cancer.

Natural medicine delivery from biomedical devices to treat bone disorders: A review

With an increasing life expectancy and aging population, orthopedic defects and bone graft surgeries are increasing in global prevalence. Research to date has advanced the understanding of bone biology and defect repair mechanism, leading to a marked success in the development of synthetic bone substitutes. Yet, the quest for functionalized bone grafts prompted the researchers to find a viable alternative that regulates cellular activity and supports bone regeneration and healing process without causing serious side-effects. Recently, researchers have introduced natural medicinal compounds (NMCs) in bone scaffold that enables them to release at a desirable rate, maintains a sustained release allowing sufficient time for tissue in-growth, and guides bone regeneration process with minimized risk of tissue toxicity. According to World Health Organization (WHO), NMCs are gaining popularity in western countries for the last two decades and are being used by 80% of the population worldwide. Compared to synthetic drugs, NMCs have a broader range of safety window and thus suitable for prolonged localized delivery for bone regeneration. There is limited literature focusing on the integration of bone grafts and natural medicines that provides detailed scientific evidences on NMCs, their toxic limits and particular application in bone tissue engineering, which could guide the researchers to develop functionalized implants for various bone disorders. This review will discuss the emerging trend of NMC delivery from bone grafts, including 3D-printed structures and surface-modified implants, highlighting the significance and potential of NMCs for bone health, guiding future paths toward the development of an ideal bone tissue engineering scaffold. STATEMENT OF SIGNIFICANCE: To date, additive manufacturing technology provids us with many advanced patient specific or defect specific bone constructs exhibiting three-dimensional, well-defined microstructure with interconnected porous networks for defect-repair applications. However, an ideal scaffold should also be able to supply biological signals that actively guide tissue regeneration while simultaneously preventing post-implantation complications. Natural biomolecules are gaining popularity in tissue engineering since they possess a safer, effective approach compared to synthetic drugs. The integration of bone scaffolds and natural biomolecules exploits the advantages of customized, multi-functional bone implants to provide localized delivery of biochemical signals in a controlled manner. This review presents an overview of bone scaffolds as delivery systems for natural biomolecules, which may provide prominent advancement in bone development and improve defect-healing caused by various musculoskeletal disorders.

Antitumor Effects of a Sesquiterpene Derivative from Marine Sponge in Human Breast Cancer Cells

In this study, the anti-proliferative effect of ilimaquinone, a sesquiterpene derivative from the marine sponge, in breast cancer cells was investigated. Ilimaquinone inhibited the proliferation of MCF-7 and MDA-MB-231 breast cancer cells with IC₅₀ values of 10.6 μM and 13.5 μM, respectively. Non-tumorigenic human breast epithelial cells were less sensitive to ilimaquinone than breast cancer cells. Flow cytometric and Western blot analysis showed that ilimaquinone induced S-phase arrest by modulating the expression of p-CDC-2 and p21. Ilimaquinone induces apoptosis, which is accompanied by multiple biological biomarkers, including the downregulation of Akt, ERK, and Bax, upregulation of p38, loss of mitochondrial membrane potential, increased reactive oxygen species generation, and induced autophagy. Collectively, these findings suggest that ilimaquinone causes cell cycle arrest as well as induces apoptosis and autophagy in breast cancer cells.

Carotenoids and Some Other Pigments from Fungi and Yeasts

Carotenoids are an essential group of compounds that may be obtained by microbiological synthesis. They are instrumental in various areas of industry, medicine, agriculture, and ecology. The increase of carotenoids' demand at the global market is now essential. At the moment, the production of natural carotenoids is more expensive than obtaining their synthetic forms, but several new approaches/directions on how to decrease this difference were developed during the last decades. This review briefly describes the information accumulated until now about the beneficial effects of carotenoids on human health protection, their possible application in the treatments of various diseases, and their use in the food and feed industry. This review also describes some issues that are linked with biotechnological production of fungal and yeasts carotenoids, as well as new approaches/directions to make their biotechnological production more efficient.

Fucoxanthin induced apoptotic cell death in oral squamous carcinoma (KB) cells

Fucoxanthin (Fx) is an active compound commonly found in the many types of seaweed with numerous biological activities. The main goal of this investigation is to explore the effect of Fx against the cell proliferation, apoptotic induction and oxidative stress in the oral squamous (KB) cell line. Cytotoxicity of Fx was determined by MTT assay. The intracellular ROS production, mitochondrial membrane potential (MMP) and apoptosis induction in KB cells were examined through DCFH-DA, Rhodamine-123 and DAPI, and dual staining techniques. Effect of Fx on the antioxidant enzymes and lipid peroxidation in the KB cells was studied through the standard procedures. Fx treated KB cells showed morphological changes and reduced cell survival, which is exhibited by the cytotoxic activity of 50 µM/ml (IC50) Fx against the KB cells. The Fx treatment considerably induced the apoptotosis cells (EB/AO) and decreased the MMP (Rh-123) in KB cells. Further, it was pointed out that there was an increased lipid peroxidation (LPO) with decreased antioxidants (CAT, SOD and GSH). These results concluded that Fx has the cytotoxic effect against KB cells and has the potential to induce the apoptosis via increased oxidative stress. Hence, the Fx can be a promising agent for the treatment of oral cancer and it may lead to the development of cancer therapeutics.

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.

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.

Carotenoid isolates of Spondias mombin demonstrate anticancer effects in DMBA-induced breast cancer in Wistar rats through X-linked inhibitor of apoptosis protein (XIAP) antagonism and anti-inflammation

Breast cancer is the most prevalent cancer in women. X-linked inhibitor of apoptosis protein (XIAP) that is constantly overexpressed in cancer is a promising therapeutic target in cancer treatments. The mechanisms of the anticancer effects of carotenoid isolates of Spondias mombim in DMBA-induced breast cancer in Wistar rats through XIAP antagonism were investigated in the present study. Carotenoids isolated from the leaves of Spondias mombim were subjected to Liquid Chromatography/Mass Spectrometry (LC/MS) and Electrospray Ionization (ESI) for characterization. The characterized carotenoid isolates were docked against XIAP BIR2 domain and XIAP BIR3 domain. The anticancer effects of the carotenoid isolates of Spondias mombim in DMBA-induced breast cancer in Wistar rats were also investigated through the expression of XIAP, COX-2, TNF, BCl-2 mRNAs by qRT-PCR and biochemical parameters of catalase, lipid peroxidation, LDH, ALP, and ALT. These show the carotenoid isolates demonstrate anticancer effects by antagonism of XIAP, proapoptotic, and anti-inflammatory properties. PRACTICAL APPLICATIONS: The present study showed that carotenoids (astaxanthin, β-carotene-15,15'-epoxide, and 7,7',8,8'-tetrahydro-β, β-carotene) isolated from the leaves of Spondias mombim are proapoptotic, it further gives credence to the chemopreventive abilities of carotenoids. This study validated XIAP as a druggable target in cancer treatment and hence more phytochemicals should be screened against it, for possible lead compounds of plant origin. Cancer cells often explore XIAP for antiapoptotic and resistance tendencies, hence, β-carotene-15,15'-epoxide and 7,7',8,8'-tetrahydro-β, β-carotene (XIAP antagonists) are promising drug candidates that can withstand resistant and prone cancer cells to apoptotic cell death. There is a need to synthesize β-carotene-15,15'-epoxide and 7,7',8,8'-tetrahydro-β for further investigation in clinical studies.

Transcriptomics predicts compound synergy in drug and natural product treated glioblastoma cells

Pathway analysis is an informative method for comparing and contrasting drug-induced gene expression in cellular systems. Here, we define the effects of the marine natural product fucoxanthin, separately and in combination with the prototypic phosphatidylinositol 3-kinase (PI3K) inhibitor LY-294002, on gene expression in a well-established human glioblastoma cell system, U87MG. Under conditions which inhibit cell proliferation, LY-294002 and fucoxanthin modulate many pathways in common, including the retinoblastoma, DNA damage, DNA replication and cell cycle pathways. In sharp contrast, we see profound differences in the expression of genes characteristic of pathways such as apoptosis and lipid metabolism, contributing to the development of a differentiated and distinctive drug-induced gene expression signature for each compound. Furthermore, in combination, fucoxanthin synergizes with LY-294002 in inhibiting the growth of U87MG cells, suggesting complementarity in their molecular modes of action and pointing to further treatment combinations. The synergy we observe between the dietary nutraceutical fucoxanthin and the synthetic chemical LY-294002 in producing growth arrest in glioblastoma, illustrates the potential of nutri-pharmaceutical combinations in targeting this challenging disease.

Anti-Inflammatory Effects of Fucoxanthinol in LPS-Induced RAW264.7 Cells through the NAAA-PEA Pathway

Palmitoylethanolamide (PEA) is an endogenous lipid mediator with powerful anti-inflammatory and analgesic functions. PEA can be hydrolyzed by a lysosomal enzyme N-acylethanolamine acid amidase (NAAA), which is highly expressed in macrophages and other immune cells. The pharmacological inhibition of NAAA activity is a potential therapeutic strategy for inflammation-related diseases. Fucoxanthinol (FXOH) is a marine carotenoid from brown seaweeds with various beneficial effects. However, the anti-inflammatory effects and mechanism of action of FXOH in lipopolysaccharide (LPS)-stimulated macrophages remain unclear. This study aimed to explore the role of FXOH in the NAAA–PEA pathway and the anti-inflammatory effects based on this mechanism. In vitro results showed that FXOH can directly bind to the active site of NAAA protein and specifically inhibit the activity of NAAA enzyme. In an LPS-induced inflammatory model in macrophages, FXOH pretreatment significantly reversed the LPS-induced downregulation of PEA levels. FXOH also substantially attenuated the mRNA expression of inflammatory factors, including inducible nitric oxide synthase (iNOS), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α), and markedly reduced the production of TNF-α, IL-6, IL-1β, and nitric oxide (NO). Moreover, the inhibitory effect of FXOH on NO induction was significantly abolished by the peroxisome proliferator-activated receptor α (PPAR-α) inhibitor GW6471. All these findings demonstrated that FXOH can prevent LPS-induced inflammation in macrophages, and its mechanisms may be associated with the regulation of the NAAA-PEA-PPAR-α pathway.

A Microbiological, Toxicological, and Biochemical Study of the Effects of Fucoxanthin, a Marine Carotenoid, on Mycobacterium tuberculosis and the Enzymes Implicated in Its Cell Wall: A Link Between Mycobacterial Infection and Autoimmune Diseases

This study explored the antitubercular properties of fucoxanthin, a marine carotenoid, against clinical isolates of Mycobacterium tuberculosis (Mtb). Two vital enzymes involved in Mtb cell wall biosynthesis, UDP-galactopyranose mutase (UGM) and arylamine-N-acetyltransferase (TBNAT), were selected as drug targets to reveal the mechanism underlying the antitubercular effect of fucoxanthin. The obtained results showed that fucoxanthin showed a clear bacteriostatic action against the all Mtb strains tested, with minimum inhibitory concentrations (MIC) ranging from 2.8 to 4.1 µM, along with a good degree of selectivity index (ranging from 6.1 to 8.9) based on cellular toxicity evaluation compared with standard drug isoniazid (INH). The potent inhibitory actions of fucoxanthin and standard uridine-5’-diphosphate against UGM were recorded to be 98.2% and 99.2%, respectively. TBNAT was potently inactivated by fucoxanthin (half maximal inhibitory concentration (IC₅₀) = 4.8 µM; 99.1% inhibition) as compared to INH (IC₅₀ = 5.9 µM; 97.4% inhibition). Further, molecular docking approaches were achieved to endorse and rationalize the biological findings along with envisaging structure-activity relationships. Since the clinical evidence of the last decade has confirmed the correlation between bacterial infections and autoimmune diseases, in this study we have discussed the linkage between infection with Mtb and autoimmune diseases based on previous clinical observations and animal studies. In conclusion, we propose that fucoxanthin could demonstrate great therapeutic value for the treatment of tuberculosis by acting on multiple targets through a bacteriostatic effect as well as by inhibiting UGM and TBNAT. Such outcomes may lead to avoiding or decreasing the susceptibility to autoimmune diseases associated with Mtb infection in a genetically susceptible host.

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.

From Marine Origin to Therapeutics: The Antitumor Potential of Marine Algae-Derived Compounds

Marine environment has demonstrated to be an interesting source of compounds with uncommon and unique chemical features on which the molecular modeling and chemical synthesis of new drugs can be based with greater efficacy and specificity for the therapeutics. Cancer is a growing public health threat, and despite the advances in biomedical research and technology, there is an urgent need for the development of new anticancer drugs. In this field, it is estimated that more than 60% of commercially available anticancer drugs are natural biomimetic inspired. Among the marine organisms, algae have revealed to be one of the major sources of new compounds of marine origin, including those exhibiting antitumor and cytotoxic potential. These compounds demonstrated ability to mediate specific inhibitory activities on a number of key cellular processes, including apoptosis pathways, angiogenesis, migration and invasion, in both in vitro and in vivo models, revealing their potential to be used as anticancer drugs. This review will focus on the bioactive molecules from algae with antitumor potential, from their origin to their potential uses, with special emphasis to the alga Sphaerococcus coronopifolius as a producer of cytotoxic compounds.

Industrial potential of carotenoid pigments from microalgae: Current trends and future prospects

Microalgae are rich source of various bioactive molecules such as carotenoids, lipids, fatty acids, hydrocarbons, proteins, carbohydrates, amino acids, etc. and in recent Years carotenoids from algae gained commercial recognition in the global market for food and cosmeceutical applications. However, the production of carotenoids from algae is not yet fully cost effective to compete with synthetic ones. In this context the present review examines the technologies/methods in relation to mass production of algae, cell harvesting for extraction of carotenoids, optimizing extraction methods etc. Research studies from different microalgal species such as Spirulina platensis, Haematococcus pluvialis, Dunaliella salina, Chlorella sps., Nannochloropsis sps., Scenedesmus sps., Chlorococcum sps., Botryococcus braunii and Diatoms in relation to carotenoid content, chemical structure, extraction and processing of carotenoids are discussed. Further these carotenoid pigments, are useful in various health applications and their use in food, feed, nutraceutical, pharmaceutical and cosmeceutical industries was briefly touched upon. The commercial value of algal carotenoids has also been discussed in this review. Possible recommendations for future research studies are proposed.

Cytotoxic activity of carotenoid rich fractions from Haematococcus pluvialis and Dunaliella salina microalgae and the identification of the phytoconstituents using LC-DAD/ESI-MS

Microalgae represent a rich source that satisfies the growing need for novel ingredients of nutriceuticals, pharmaceuticals, and food supplements. Haematococcus pluvialis and Dunaliella salina microalgae are isolated from the Egyptian hydro-flora and are reported for their potent antioxidant activities. The cytotoxic activity of different fractions of both microalgae was investigated on 4 cell lines HePG2, MCF7, HCT116, and A549. The carotenoid rich fraction of H. pluvialis showed potent cytotoxic activity against colon cancer cell line and moderate activity against both liver and breast cancer cell lines. On the other hand, the carotenoid rich fraction of D. salina showed mild cytotoxic activity on breast and liver cancer cell lines. The carotenoid rich fraction of H. pluvialis was analysed using LC-DAD/ESI-MS and the major carotenoids were identified either free as well as bounded to fatty acids.

Carotenoids from Marine Organisms: Biological Functions and Industrial Applications

As is the case for terrestrial organisms, carotenoids represent the most common group of pigments in marine environments. They are generally biosynthesized by all autotrophic marine organisms, such as bacteria and archaea, algae and fungi. Some heterotrophic organisms also contain carotenoids probably accumulated from food or partly modified through metabolic reactions. These natural pigments are divided into two chemical classes: carotenes (such as lycopene and α- and β-carotene) that are composed of hydrogen and carbon; xanthophylls (such as astaxanthin, fucoxanthin and lutein), which are constituted by hydrogen, carbon and oxygen. Carotenoids, as antioxidant compounds, assume a key role in the protection of cells. In fact, quenching of singlet oxygen, light capture and photosynthesis protection are the most relevant biological functions of carotenoids. The present review aims at describing (i) the biological functions of carotenoids and their benefits for human health, (ii) the most common carotenoids from marine organisms and (iii) carotenoids having large success in pharmaceutical, nutraceutical and cosmeceutical industries, highlighting the scientific progress in marine species cultivation for natural pigments production.

Screening of Diatom Strains and Characterization of Cyclotella cryptica as A Potential Fucoxanthin Producer

Fucoxanthin has been receiving ever-increasing interest due to its broad health beneficial effects. Currently, seaweeds are the predominant source of natural fucoxanthin. However, the disappointingly low fucoxanthin content has impeded their use, driving the exploration of alternative fucoxanthin producers. In the present study, thirteen diatom strains were evaluated with respect to growth and fucoxanthin production potential. Cyclotella cryptica (CCMP 333), which grew well for fucoxanthin production under both photoautotrophic and heterotrophic growth conditions, was selected for further investigation. The supply of nitrate and light individually or in combination were all found to promote growth and fucoxanthin accumulation. When transferring heterotrophic cultures to light, fucoxanthin responded differentially to light intensities and was impaired by higher light intensity with a concomitant increase in diadinoxanthin and diatoxanthin, indicative of the modulation of Diadinoxanthin Cycle to cope with the light stress. Taken together, we, for the first time, performed the screening of diatom strains for fucoxanthin production potential and investigated in detail the effect of nutritional and environmental factors on C. cryptica growth and fucoxanthin accumulation. These results provide valuable implications into future engineering of C. cryptica culture parameters for improved fucoxanthin production and C. cryptica may emerge as a promising microalgal source of fucoxanthin.

Absorption of Carotenoids and Mechanisms Involved in Their Health-Related Properties

Carotenoids participate in the normal metabolism and function of the human body. They are involved in the prevention of several diseases, especially those related to the inflammation syndrome. Their main mechanisms of action are associated to their potent antioxidant activity and capacity to regulate the expression of specific genes and proteins. Recent findings suggest that carotenoid metabolites may explain several processes where the participation of their parent carotenoids was unclear. The health benefits of carotenoids strongly depend on their absorption and transformation during gastrointestinal digestion. The estimation of the 'bioaccessibility' of carotenoids through in vitro models have made possible the evaluation of the effect of a large number of factors on key stages of carotenoid digestion and intestinal absorption. The bioaccessibility of these compounds allows us to have a clear idea of their potential bioavailability, a term that implicitly involves the biological activity of these compounds.

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.

PI3K/Akt signaling in osteosarcoma

Osteosarcoma (OS) is the most common nonhematologic bone malignancy in children and adolescents. Despite the advances of adjuvant chemotherapy and significant improvement of survival, the prognosis remains generally poor. As such, the search for more effective anti-OS agents is urgent. The phosphatidylinositol 3-kinase (PI3K)/Akt pathway is thought to be one of the most important oncogenic pathways in human cancer. An increasing body of evidence has shown that this pathway is frequently hyperactivated in OS and contributes to disease initiation and development, including tumorigenesis, proliferation, invasion, cell cycle progression, inhibition of apoptosis, angiogenesis, metastasis and chemoresistance. Inhibition of this pathway through small molecule compounds represents an attractive potential therapeutic approach for OS. The aim of this review is to summarize the roles of the PI3K/Akt pathway in the development and progression of OS, and to highlight the therapeutic potential of targeting this signaling pathway. Knowledge obtained from the application of these compounds will help in further understanding the pathogenesis of OS and designing subsequent treatment strategies.

Advances in algal drug research with emphasis on enzyme inhibitors

Enzyme inhibitors are now included in all kinds of drugs essential to treat most of the human diseases including communicable, metabolic, cardiovascular, neurological diseases and cancer. Numerous marine algae have been reported to be a potential source of novel enzyme inhibitors with various pharmaceutical values. Thus, the purpose of this review is to brief the enzyme inhibitors from marine algae of therapeutic potential to treat common diseases. As per our knowledge this is the first review for the potential enzyme inhibitors from marine origin. This review contains 86 algal enzyme inhibitors reported during 1989-2013 and commercial enzyme inhibitors available in the market. Compounds in the review are grouped according to the disease conditions in which they are involved; diabetes, obesity, dementia, inflammation, melanogenesis, AIDS, hypertension and other viral diseases. The structure-activity relationship of most of the compounds are also discussed. In addition, the drug likeness properties of algal inhibitors were evaluated using Lipinski's 'Rule of Five'.

Caspase-dependent signaling underlies glioblastoma cell death in response to the fungal metabolite, fusarochromanone

Fungal metabolites continue to show promise as a viable class of anticancer agents. In the present study, we investigated the efficacy of the fungal metabolite, fusarochromanone (FC101), for its antitumor activities in glioblastomas, which have a median survival of less than two years and a poor clinical response to surgical resection, radiation therapy and chemotherapy. Using clinically applicable doses, we demonstrated that FC101 induced glioblastoma apoptotic cell death via caspase dependent signaling, as indicated by the cleavage of poly(ADP-ribose) polymerase, glioblastoma (PARP). FC101 also induced differential reactive oxygen species (ROS) levels in glioblastoma cells, contrasting a defined role of oxidative stress in apoptotic cell death observed with other fungal metabolites. Furthermore, the antitumorigenic effects of FC101 on tumor cell migration were assessed. Cell migration assays revealed that FC101 significantly reduced the migratory capacity of glioblastomas, which are incredibly invasive tumors. Taken together, the present study establishes FC101 as a candidate anticancer agent for the cooperative treatment of glioblastomas.