Fucoxanthin has potential for therapeutic efficacy in neurodegenerative disorders by acting on multiple targets

Fucoxanthin alleviates secondary brain injury in mice following intracerebral hemorrhage via PI3K-mediated inhibition of NF-κB signaling pathway

BACKGROUND

ICH is an acute clinical cerebrovascular disease without effective treatments. This study was designed to investigate the therapeutic value of fucoxanthin in ICH treatment.

METHODS

Animal ICH models were established by collagenase IV injection. ICH mice were given intraperitoneal injection of fucoxanthin (100 mg/kg). Neurological deficits, brain edema, blood-brain barrier (BBB) integrity, and histological impairment were assessed. Nissl staining and TUNEL staining were performed to detect neuronal cell loss and apoptosis. The levels of tight junction proteins, apoptosis-related proteins, Iba-1, and pathway-related proteins were measured by immunofluorescence staining, western blotting, and ELISA.

RESULTS

Fucoxanthin administration attenuated neurological deficits and brain injuries following ICH. Additionally, fucoxanthin alleviated neuronal apoptosis caused by ICH. Moreover, fucoxanthin inhibited microglia-mediated inflammation and M1 polarization in ICH models. Mechanistically, fucoxanthin inactivated the NF-κB pathway and triggered the activation of PI3K/Akt signaling after ICH, and LY294002 (a PI3K inhibitor) compromised the protective effect of fucoxanthin.

CONCLUSION

Fucoxanthin alleviates ICH-induced neurological deficits and brain injuries by suppressing the PI3K/Akt-mediated NF-κB pathway to inhibit M1 polarization and attenuate neuroinflammation, neuronal apoptosis, BBB dysfunction, and brain edema.

Neuroprotective Potential of Tetraselmis chuii Compounds: Insights into Blood-Brain Barrier Permeability and Intestinal Transport

Background/Objectives: Alzheimer's disease (AD) is the most common type of dementia, characterized by complex processes such as neuro-inflammation, oxidative damage, synaptic loss, and neuronal death. Carotenoids are among the potential therapeutic molecules that have attracted attention due to their neuroprotective properties, but their efficacy is limited mainly by their capacity to cross the blood-brain barrier (BBB). Results: The results showed that T. chuii extracts could protect neuronal cells from neurotoxic damage, especially against L-glutamate and H2O2. Moreover, the BBB permeability and the intestinal transport analyses revealed that fucoxanthinol, crocoxanthin, diatoxanthin, neoxanthin, violaxanthin, and prasinoxanthin have diverse permeabilities depending on the incubation time and the cell model used. Fucoxanthinol was the carotenoid with the highest and similar permeability in HBMEC cells (4.41%, 5.13%, and 18.94% at 2, 4, and 24 h, respectively) and Caco-2 cells (7.01%, 8.63%, and 18.36% at the same times), while crocoxanthin, diatoxanthin, and neoxanthin showed different kinetics. Methods: The neuroprotective potential of two extracts obtained from Tetraselmis chuii microalga were evaluated against Aβ1-42-, L-glutamate-, and H2O2-induced toxicities in SH-SY5Y cells. In addition, the BBB permeability and the intestinal transepithelial transport of the main carotenoids present in the extracts were evaluated and compared using two cell culture models, HBMEC and Caco-2 cells. For that aim, the transport of the bioactive molecules across the barriers was evaluated using UHPLC-q-TOF-MS after 2, 4, and 24 h of incubation. Conclusions: These findings indicate that T. chuii is a promising natural source of bioactive compounds to develop functional foods against neurodegenerative diseases.

Plant-Based Inhibitors of Protein Aggregation

The assembly of amyloidogenic proteins and peptides into toxic oligomeric and fibrillar aggregates is closely connected to the onset and progression of more than 50 protein diseases, such as Alzheimer's disease, Parkinson's disease, prion disease, and type 2 diabetes, to name only a few. Considerable research efforts at identifying the therapeutic strategies against these maladies are currently focused on preventing and inhibiting pathogenic protein aggregation by various agents. Plant-based extracts and compounds have emerged as promising sources of potential inhibitors due to their dual role as nutraceuticals as part of healthy diets and as specific pharmaceuticals when administered at higher concentrations. In recent decades, several plant extracts and plant-extracted compounds have shown potential to modulate protein aggregation. An ever-growing body of research on plant-based amyloid inhibitors requires a detail analysis of existing data to identify potential knowledge gaps. This review summarizes the recent progress in amyloid inhibition using 17 flavonoids, 11 polyphenolic non-flavonoid compounds, 23 non-phenolic inhibitors, and 59 plant extracts, with the main emphasis on directly modulating the fibrillation of four amyloid proteins, namely amyloid-β peptide, microtubule-associated protein tau, α-synuclein, and human islet amyloid polypeptide.

Carotenoids for Antiaging: Nutraceutical, Pharmaceutical, and Cosmeceutical Applications

Background: Carotenoids are bioactive tetraterpenoid C40 pigments that are actively synthesized by plants, bacteria, and fungi. Compounds such as α-carotene, β-carotene, lycopene, lutein, astaxanthin, β-cryptoxanthin, fucoxanthin, and zeaxanthin have attracted increasing attention for their antiaging properties. They exhibit antioxidant, neuroprotective, and anti-inflammatory properties, contributing to the prevention and treatment of age-related diseases. Objectives: The aim of this study was to comprehensively analyze the pharmacological potential and biological mechanisms of carotenoids associated with age-related disorders and to evaluate their application in nutraceuticals, pharmaceuticals, and cosmeceuticals. Methods: A systematic review of studies published over the past two decades was conducted using the databases PubMed, Scopus, and Web of Science. The selection criteria included clinical, in silico, in vivo, and in vitro studies investigating the pharmacological and therapeutic effects of carotenoids. Results: Carotenoids demonstrate a variety of health benefits, including the prevention of age-related macular degeneration, cancer, cognitive decline, metabolic disorders, and skin aging. Their role in nutraceuticals is well supported by their ability to modulate oxidative stress and inflammatory pathways. In pharmaceuticals, carotenoids show promising results in formulations targeting neurodegenerative diseases and metabolic disorders. In cosmeceuticals, they improve skin health by protecting it against UV radiation and oxidative damage. However, bioavailability, optimal dosages, toxicity, and interactions with other bioactive compounds remain critical factors to maximize therapeutic efficacy and still require careful evaluation by scientists. Conclusions: Carotenoids are promising bioactive compounds for antiaging interventions with potential applications in a variety of fields. Further research is needed to optimize their formulas, improve bioavailability, and confirm their long-term safety and effectiveness, especially in the aging population.

Fucoxanthin Inhibits the NMDA and AMPA Receptors Through Regulating the Calcium Response on Substantia Gelatinosa Neurons of the Trigeminal Subnucleus Caudalis in Juvenile Mice

Glutamate excitotoxicity is considered as the etiology of stroke and neurodegenerative diseases, namely, Parkinson's disease (PD), Alzheimer's disease (AD), and others. Meanwhile, substantia gelatinosa (SG) neurons of the trigeminal subnucleus caudalis (Vc), a pivotal site in regulating orofacial nociceptive transmission via Aδ and C primary afferent fibers, majorly utilize glutamate as the principal excitatory neurotransmitter. Fucoxanthin (FCX), a carotenoid pigment extracted from brown seaweed, possesses various pharmaceutical properties including neuroprotective effect in multiple neuronal populations. To date, the direct activity of FCX on the SG of the Vc has not been extensively clarified. Consequently, we investigated the effect of FCX on excitatory signaling mediated by ionotropic glutamate receptors (iGluRs), using the patch-clamp technique recorded from SG neurons of the Vc. Here, FCX directly acted on glutamate receptors independent of voltage-gated sodium channel and γ-aminobutyric acid (GABA)A/glycine receptors in the voltage-clamp mode. Specifically, the N-methyl-D-aspartic acid (NMDA)- and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-induced responses but not the kainic acid receptor (KAR)-mediated response were suppressed by FCX in standard extracellular solution. Additionally, the inhibitory effect of FCX on NMDA currents was repeatable and concentration-dependent. The FCX blockade of NMDA-mediated excitotoxicity was associated with the modulation of Ca2+ response without affecting Na+ ions. The Ca2+-dependent fluorescence intensity of brain slice was reduced in the presence of FCX. Notably, FCX significantly attenuated the spontaneous firing activity of SG neurons. Altogether, these results reveal that FCX may protect SG neurons against glutamate excitotoxicity via primarily regulating Ca2+ response, thereby inhibiting the excitatory signaling induced by NMDA and AMPA receptors (AMPARs).

Marine natural products: potential agents for depression treatment

Depression is a common psychiatric disorder. Due to the disadvantages of current clinical drugs, including poor efficacy and unnecessary side effects, research has shifted to novel natural products with minimal or no adverse effects as therapeutic alternatives. The ocean is a vast ecological home, with a wide variety of organisms that can produce a large number of natural products with unique structures, some of which have neuroprotective effects and are a valuable source for the development of new drugs for depression. In this review, we analyzed preclinical and clinical studies of natural products derived from marine organisms with antidepressant potential, including the effects on the pathophysiology of depression, and the underlying mechanisms of these effects. It is expected to provide a reference for the development of new antidepressant drugs.

Marine-Derived Components: Can They Be a Potential Therapeutic Approach to Parkinson's Disease?

The increase in the life expectancy average has led to a growing elderly population, thus leading to a prevalence of neurodegenerative disorders, such as Parkinson's disease (PD). PD is the second most common neurodegenerative disorder and is characterized by a progressive degeneration of the dopaminergic neurons in the substantia nigra pars compacta (SNpc). The marine environment has proven to be a source of unique and diverse chemical structures with great therapeutic potential to be used in the treatment of several pathologies, including neurodegenerative impairments. This review is focused on compounds isolated from marine organisms with neuroprotective activities on in vitro and in vivo models based on their chemical structures, taxonomy, neuroprotective effects, and their possible mechanism of action in PD. About 60 compounds isolated from marine bacteria, fungi, mollusk, sea cucumber, seaweed, soft coral, sponge, and starfish with neuroprotective potential on PD therapy are reported. Peptides, alkaloids, quinones, terpenes, polysaccharides, polyphenols, lipids, pigments, and mycotoxins were isolated from those marine organisms. They can act in several PD hallmarks, reducing oxidative stress, preventing mitochondrial dysfunction, α-synuclein aggregation, and blocking inflammatory pathways through the inhibition translocation of NF-kB factor, reduction of human tumor necrosis factor α (TNF-α), and interleukin-6 (IL-6). This review gathers the marine natural products that have shown pharmacological activities acting on targets belonging to different intracellular signaling pathways related to PD development, which should be considered for future pre-clinical studies.

Immunopotentiating Activity of Fucoidans and Relevance to Cancer Immunotherapy

Fucoidans, discovered in 1913, are fucose-rich sulfated polysaccharides extracted mainly from brown seaweed. These versatile and nontoxic marine-origin heteropolysaccharides have a wide range of favorable biological activities, including antitumor, immunomodulatory, antiviral, antithrombotic, anticoagulant, antithrombotic, antioxidant, and lipid-lowering activities. In the early 1980s, fucoidans were first recognized for their role in supporting the immune response and later, in the 1990s, their effects on immune potentiation began to emerge. In recent years, the understanding of the immunomodulatory effects of fucoidan has expanded significantly. The ability of fucoidan(s) to activate CTL-mediated cytotoxicity against cancer cells, strong antitumor property, and robust safety profile make fucoidans desirable for effective cancer immunotherapy. This review focusses on current progress and understanding of the immunopotentiation activity of various fucoidans, emphasizing their relevance to cancer immunotherapy. Here, we will discuss the action of fucoidans in different immune cells and review how fucoidans can be used as adjuvants in conjunction with immunotherapeutic products to improve cancer treatment and clinical outcome. Some key rationales for the possible combination of fucoidans with immunotherapy will be discussed. An update is provided on human clinical studies and available registered cancer clinical trials using fucoidans while highlighting future prospects and challenges.

Natural Carotenoids as Neuroprotective Agents for Alzheimer's Disease: An Evidence-Based Comprehensive Review

Alzheimer's disease (AD) is a neurodegenerative disorder of an ever-increasing aging population with various pathological features such as β-amyloid (Aβ) aggregation, oxidative stress, an impaired cholinergic system, and neuroinflammation. Several therapeutic drugs have been introduced to slow the progression of AD by targeting the above-mentioned pathways. In addition, emerging evidence suggests that naturally occurring compounds have the potential to serve as adjuvant therapies to alleviate AD symptoms. Carotenoids, a group of natural pigments with antioxidative and anti-inflammatory properties, are proposed to be implicated in neuroprotection. To obtain a comprehensive picture of the effect of carotenoids on AD prevention and development, we critically reviewed and discussed recent evidence from in silico, in vitro, in vivo, and human studies in databases including PubMed, Web of Science, Google Scholar, and Cochrane (CENTRAL). After analyzing the existing evidence, we found that high-quality randomized controlled trials (RCTs) are lacking to explore the neuroprotective role of carotenoids in AD pathogenesis and symptoms, especially carotenoids with solid preclinical evidence such as astaxanthin, fucoxanthin, macular carotenoids, and crocin, in order to develop effective preventive dietary supplements for AD patients to ameliorate the symptoms. This review points out directions for future studies to advance the knowledge in this field.

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.

Fucoxanthin from Algae to Human, an Extraordinary Bioresource: Insights and Advances in up and Downstream Processes

Fucoxanthin is a brown-colored pigment from algae, with great potential as a bioactive molecule due to its numerous properties. This review aims to present current knowledge on this high added-value pigment. An accurate analysis of the biological function of fucoxanthin explains its wide photon absorption capacities in golden-brown algae. The specific chemical structure of this pigment also leads to many functional activities in human health. They are outlined in this work and are supported by the latest studies in the literature. The scientific and industrial interest in fucoxanthin is correlated with great improvements in the development of algae cultures and downstream processes. The best fucoxanthin producing algae and their associated culture parameters are described. The light intensity is a major influencing factor, as it has to enable both a high biomass growth and a high fucoxanthin content. This review also insists on the most eco-friendly and innovative extraction methods and their perspective within the next years. The use of bio-based solvents, aqueous two-phase systems and the centrifugal partition chromatography are the most promising processes. The analysis of the global market and multiple applications of fucoxanthin revealed that Asian companies are major actors in the market with macroalgae. In addition, fucoxanthin from microalgae are currently produced in Israel and France, and are mostly authorized in the USA.

Saccharina japonica Ethanol Extract Ameliorates Depression/Anxiety-Like Behavior by Inhibiting Inflammation, Oxidative Stress, and Apoptosis in Dextran Sodium Sulfate Induced Ulcerative Colitis Mice

Saccharina japonica is a common marine vegetable in East Asian markets and has a variety of health benefits. This study was focused on the anti-depressant/anxiety effects of Saccharina japonica ethanol extract (SJE) on dextran sodium sulfate (DSS)-induced mice and its potential mechanism in their brain. Male C57BL/6 mice were treated with mesalazine and various doses of SJE (1, 2, and 4 g/kg body weight) for 2 weeks, followed by DSS treatment at the second week. The DSS-induced mice showed depression/anxiety-like behavior, which included shorter path length in the open field test and longer immobility time in the tail suspension test. L-SJE alleviated the depression-like behaviors. In the DSS-induced mice, reduced synaptic plasticity activated microglia, increased proinflammatory cytokines, decreased anti-inflammatory cytokine, and increased expression levels of Toll-like receptors-4, nuclear factor kappa-B, NOD-like receptors 3, apoptosis-associated speck-like protein, and Caspase-1 were observed, most of which were alleviated by SJE treatment. Furthermore, all the SJE groups could significantly enhance superoxide dismutase activity, while the L-SJE treatment decreased the contents of malondialdehyde, and the H-SJE treatment inhibited apoptosis. All these results showed that the SJE might serve as a nutritional agent for protecting the brain in ulcerative colitis mice.