Effects of Supplementation with Microalgae Extract from Phaeodactylum tricornutum (Mi136) to Support Benefits from a Weight Management Intervention in Overweight Women

BACKGROUND

Microalgae like Phaeodactylum tricornutum (PT) contain the carotenoid, fucoxanthin, which has been purported to promote fat loss, lower blood lipids, and improve glucose management. This study examined whether dietary supplementation with microalgae extracts from PT containing 4.4 mg/d of fucoxanthin affects changes in body composition or health markers in overweight women during an exercise and diet intervention.

MATERIALS AND METHODS

A total of 37 females (28.6 ± 7.9 years, 80.2 ± 14.9 kg, 29.6 ± 3.8 kg/m², 41.4 ± 4.2% fat) fasted for 12 h, donated a fasting blood sample, completed health and mood state inventories, and undertook body composition, health, and exercise assessments. In a counterbalanced, randomized, and double-blind manner, participants ingested a placebo (PL), or microalgae extract of Phaeodactylum tricornutum standardized to 4.4 mg of fucoxanthin (FX) for 12 weeks while participating in a supervised exercise program that included resistance-training and walking (3 days/week) with encouragement to accumulate 10,000 steps/day on remaining days of the week. The diet intervention involved reducing energy intake by about -300 kcal/d (i.e., ≈1400-1600 kcals/d, 55% carbohydrate, 30% fat, 15% protein) to promote a -500 kcal/d energy deficit with exercise. Follow-up testing was performed at 6 and 12 weeks. A general linear model (GLM) with repeated measures statistical analysis was used to analyze group responses and changes from baseline with 95% confidence intervals.

RESULTS

Dietary supplementation with microalgae extract from PT containing fucoxanthin for 12 weeks did not promote additional weight loss or fat loss in overweight but otherwise healthy females initiating an exercise and diet intervention designed to promote modest weight loss. However, fucoxanthin supplementation preserved bone mass, increased bone density, and saw greater improvements in walking steps/day, resting heart rate, aerobic capacity, blood lipid profiles, adherence to diet goals, functional activity tolerance, and measures of quality of life. Consequently, there appears to be some benefit to supplementing microalgae extract from PT containing fucoxanthin during a diet and exercise program. Registered clinical trial #NCT04761406.

Fucoxanthin induces human melanoma cytotoxicity by thwarting the JAK2/STAT3/BCL-xL signaling axis

Melanoma is the most lethal skin malignancy. Fucoxanthin is a marine carotenoid with significant anticancer activities. Intriguingly, Fucoxanthin's impact on human melanoma remains elusive. Signal Transducer and Activator of Transcription 3 (STAT3) represents a promising target in cancer therapy due to its persistent activation in various cancers, including melanoma. Herein, we revealed that Fucoxanthin is cytotoxic to human melanoma cell lines A2758 and A375 while showing limited cytotoxicity to normal human melanocytes. Apoptosis is a primary reason for Fucoxanthin's melanoma cytotoxicity, as the pan-caspase inhibitor z-VAD-fmk drastically abrogated Fucoxanthin-elicited clonogenicity blockage. Besides, Fucoxanthin downregulated tyrosine 705-phosphorylated STAT3 (p-STAT3 (Y705)), either inherently present in melanoma cells or inducible by interleukin 6 (IL-6) stimulation. Notably, ectopic expression of STAT3-C, a dominant-active STAT3 mutant, abolished Fucoxanthin-elicited melanoma cell apoptosis and clonogenicity inhibition, supporting the pivotal role of STAT3 blockage in Fucoxanthin's melanoma cytotoxicity. Moreover, Fucoxanthin lowered BCL-xL levels by blocking STAT3 activation, while ectopic BCL-xL expression rescued melanoma cells from Fucoxanthin-induced killing. Lastly, Fucoxanthin was found to diminish the levels of JAK2 with dual phosphorylation at tyrosine residues 1007 and 1008 in melanoma cells, suggesting that Fucoxanthin impairs STAT3 signaling by blocking JAK2 activation. Collectively, we present the first evidence that Fucoxanthin is cytotoxic selectively against human melanoma cells while sparing normal melanocytes. Mechanistically, Fucoxanthin targets the JAK2/STAT3/BCL-xL antiapoptotic axis to provoke melanoma cell death. This discovery implicates the potential application of Fucoxanthin as a chemopreventive or therapeutic strategy for melanoma management.

Orally Deliverable Sequence-Targeted Fucoxanthin-Loaded Biomimetic Extracellular Vesicles for Alleviation of Nonalcoholic Fatty Liver Disease

Extracellular vesicles (EVs) possess favorable biocompatibility and immunological characteristics, making them optimal carriers for bioactive substances. In this study, an innovative hepatic-targeted vesicle system encapsulating with fucoxanthin (GA-LpEVs-FX) was successfully designed and used to alleviate nonalcoholic fatty liver disease. The formulation entails the self-assembly of EVs derived from Lactobacillus paracasei (LpEVs), modification with glycyrrhetinic acid (GA) via amide reaction offering the system liver-targeting capacity and loading fucoxanthin (FX) through sonication treatment. In vitro experiments demonstrated that GA-LpEVs-FX effectively mitigated hepatic lipid accumulation and attenuated reactive oxygen species-induced damage resulting lipid accumulation (p < 0.05). In vivo, GA-LpEVs-FX exhibited significant downregulation of lipogenesis-related proteins, namely, fatty acid synthase (FAS), acetyl-CoA carboxylase (ACC1), and sterol regulatory element binding protein 1 (SREBP-1), subsequently ameliorating lipid metabolism disorders (p < 0.05), and the stability of GA-LpEVs-FX significantly improved compared to free FX. These findings establish a novel formulation for utilizing foodborne components for nonalcoholic fatty liver disease alleviation.

Fucoxanthin Alleviates Dextran Sulfate Sodium-Induced Colitis and Gut Microbiota Dysbiosis in Mice

The purpose of this study was to evaluate the preventive role and underlying mechanisms of fucoxanthin (Fx) on dextran sulfate sodium (DSS)-induced colitis in mice. The present data demonstrated that oral administration of Fx (50 and 200 mg/kg body weight/day) for 36 days significantly alleviated the severity of colitis in DSS-treated mice, as evidenced by attenuating body weight loss, bloody stool, diarrhea, shortened colon length, colonic epithelium distortion, a thin mucus layer, goblet cell depletion, damaged crypts, and extensive infiltration of inflammatory cells in the colonic mucosa. Additionally, Fx notably relieved DSS-induced intestinal epithelial barrier dysfunction via maintaining the tight junction function and preventing excessive apoptosis of colonic epithelial cells. Moreover, Fx effectively diminished colonic inflammation and oxidative stress in DSS-treated mice, and its mechanisms might be due to blunting the activation of NF-κB and NLRP3 inflammasome signaling pathways. Furthermore, Fx also modulates DSS-induced gut microbiota dysbiosis via recovering the richness and diversity of gut microbiota and reshaping the structure of gut microbiota, such as increasing the Firmicutes and Bacteroidota (F/B) ratio and elevating the relative abundance of some potential beneficial bacteria, including Lactobacillaceae and Lachnospiraceae. Overall, Fx might be developed as a promising functional ingredient to prevent colitis and maintain intestinal homeostasis.

Understanding the Impact of Nitrogen Availability: A Limiting Factor for Enhancing Fucoxanthin Productivity in Microalgae Cultivation

This study aimed to investigate the regulation of fucoxanthin (FX) biosynthesis under various nitrogen conditions to optimize FX productivity in Phaeodactylum tricornutum. Apart from light, nitrogen availability significantly affects the FX production of microalgae; however, the underlying mechanism remains unclear. In batch culture, P. tricornutum was cultivated with normal (NN, 0.882 mM sodium nitrate), limited (LN, 0.22 mM), and high (HN, 8.82 mM) initial nitrogen concentrations in f/2 medium. Microalgal growth and photosynthetic pigment production were examined, and day 5 samples were subjected to fucoxanthin-chlorophyll a/c-binding protein (FCP) proteomic and transcriptomic analyses. The result demonstrated that HN promoted FX productivity by extending the exponential growth phase for higher biomass and FX accumulation stage (P1), showing a continuous increase in FX accumulation on day 6. Augmented FX biosynthesis via the upregulation of carotenogenesis could be primarily attributed to enhanced FCP formation in the thylakoid membrane. Key proteins, such as LHC3/4, LHCF8, LHCF5, and LHCF10, and key genes, such as PtPSY, PtPDS, and PtVDE, were upregulated under nitrogen repletion. Finally, the combination of low light and HN prolonged the P1 stage to day 10, resulting in maximal FX productivity to 9.82 ± 0.56 mg/L/day, demonstrating an effective strategy for enhancing FX production in microalgae cultivation.

Fucus vesiculosus-Rich Extracts as Potential Functional Food Ingredients: A Holistic Extraction Approach

Brown macroalgae are rich sources of nutrients and health-promoting compounds. Nevertheless, their consumption is still limited by their strong organoleptic characteristics, thus requiring the development of extraction strategies to profit from their nutritional value. To fulfil this, two sequential extraction approaches were developed, differing in the solvent used in the first extraction step, water in approach 1 or food-grade ethanol in approach 2, to obtain economic and affordable extracts rich in specific compounds from Fucus vesiculosus. The use of water in the first step of extraction allowed us to recover water-soluble phlorotannins, laminarans and mannuronic-rich alginates, making the subsequent 70% ethanol extract richest in fucoxanthin (0.07% algae DW), and the hot water fractions purest in fucoidans and alginates with a lower mannuronic-to-guluronic (M/G) ratio (2.91). Conversely, when beginning extraction procedures with 96% ethanol, the recovered yields of phlorotannins increased (0.43 g PGE/100 g algae DW), but there was a concomitant seven-fold decrease in the recovery of fucoxanthin in the subsequent 70% ethanol extract. This approach also led to less pure hot water fractions containing fucoidans, laminarans and alginates with a higher M/G ratio (5.50). Overall, this work unveiled the potential of the first extraction steps in sustainable and holistic cascade strategies to modulate the composition of food-grade extracts, creating prospects of their application as tailored functional ingredients in food products.

Overexpression of PtVDL1 in Phaeodactylum tricornutum Increases Fucoxanthin Content under Red Light

Phaeodactylum tricornutum is a model diatom with significant biotechnological applications, including enhancing biomass, biofuel, and carotenoid production. Specifically, owing to the capacity of this organism to serve as a valuable source of essential raw materials for pharmaceuticals and nutraceuticals, ongoing research is actively focused on enhancing its productivity. One of the genes involved in various stages of fucoxanthin (Fx) biosynthesis, violaxanthin de-epoxidase like 1 (VDL1), has recently been identified. To validate the intracellular function of this gene and boost Fx production through overexpression, we established and examined three transgenic P. tricornutum lines characterized by elevated P. tricortunum VDL1 ( PtVDL1) expression and evaluate their cell growth and Fx productivity. These transgenic lines exhibited substantially increased PtVDL1 mRNA and protein levels compared to the wild type (WT). Notably, the enzyme substrate violaxanthin was entirely depleted and could not be detected in the transformants, whereas it remained at constant levels in the WT. Interestingly, under standard white light conditions, Fx productivity in the transformants remained unchanged; however, but after 48 h of exposure to red light, it increased by up to 15%. These results indicate that PtVDL1-overexpressing P. tricornutum has industrial potential, particularly for enhancing Fx production under red light conditions.

Fucoxanthin Enhances the Antifibrotic Potential of Placenta-derived Mesenchymal Stem Cells in a CCl4-induced Mouse Model of Liver Fibrosis

BACKGROUND

The effectiveness of fucoxanthin (Fx) in liver diseases has been reported due to its anti-inflammatory and antifibrotic effects. Mesenchymal stem cells (MSCs)-based therapy has also been proposed as a promising strategy for liver fibrosis treatment. Recent studies have shown that the co-administration of MSCs and drugs demonstrates a pronounced effect on liver fibrosis.

AIM

This study aimed to determine the therapeutic potential of placenta-derived MSCs (PD-MSCs) in combination with Fx to treat liver fibrosis and evaluate their impact on the main links of liver fibrosis pathogenesis.

METHODS

After PD-MSCs isolation and identification, outbred ICR/CD1 mice were divided into five groups: Control group, CCl4 group (CCl4), Fx group (CCl4+Fx), PD-MSCs group (CCl4+MSCs) and cotreatment group (CCl4+MSCs+Fx). Biochemical histopathological investigations were performed. Semiquantitative analysis of the alpha-smooth muscle actin (α-SMA+), matrix metalloproteinases (MMP-9+, MMP-13+), tissue inhibitor of matrix metalloproteinases-1 (TIMP-1+) areas, and the number of positive cells in them were studied by immunohistochemical staining. Transforming growth factor-beta (TGF-β), hepatic growth factor (HGF), procollagen-1 (COL1α1) in liver homogenate and proinflammatory cytokines in blood serum were determined using an enzyme immunoassay.

RESULTS

Compared to the single treatment with PD-MSCs or Fx, their combined administration significantly reduced liver enzyme activity, the severity of liver fibrosis, the proinflammatory cytokine levels, TGF-β level, α-SMA+, TIMP-1+ areas and the number of positive cells in them, and increased HGF level, MMP-13+, and MMP-9+ areas.

CONCLUSION

Fx enhanced the therapeutic potential of PD-MSCs in CCl4-induced liver fibrosis, but more investigations are necessary to understand the mutual impact of PD-MSCs and Fx.

The Anticancer Effects of Marine Carotenoid Fucoxanthin through Phosphatidylinositol 3-Kinase (PI3K)-AKT Signaling on Triple-Negative Breast Cancer Cells

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer that lacks specific targets such as estrogen, progesterone, and HER2 receptors. TNBC affects one in eight women in the United States, making up 15-20% of breast cancer cases. Patients with TNBC can develop resistance to chemotherapy over time, leading to treatment failure. Therefore, finding other options like natural products is necessary for treatment. The advantages of using natural products sourced from plants as anticancer agents are that they are less toxic, more affordable, and have fewer side effects. These products can modulate several cellular processes of the tumor microenvironment, such as proliferation, migration, angiogenesis, cell cycle arrest, and apoptosis. The phosphatidyl inositol 3-kinase (PI3K)-AKT signaling pathway is an important pathway that contributes to the survival and growth of the tumor microenvironment and is associated with these cellular processes. This current study examined the anticancer effects of fucoxanthin, a marine carotenoid isolated from brown seaweed, in the MDA-MB-231 and MDA-MB-468 TNBC cell lines. The methods used in this study include a cytotoxic assay, PI3K-AKT signaling pathway PCR arrays, and Wes analysis. Fucoxanthin (6.25 µM) + TNF-α (50 ng/mL) and TNF-α (50 ng/mL) showed no significant effect on cell viability compared to the control in both MDA-MB-231 and MDA-MB-468 cells after a 24 h treatment period. PI3K-AKT signaling pathway PCR array studies showed that in TNF-α-stimulated (50 ng/mL) MDA-MB-231 and MDA-MB-468 cells, fucoxanthin (6.25 µM) modulated the mRNA expression of 12 genes, including FOXO1, RASA1, HRAS, MAPK3, PDK2, IRS1, EIF4EBP1, EIF4B, PTK2, TIRAP, RHOA, and ELK1. Additionally, fucoxanthin significantly downregulated the protein expression of IRS1, EIF4B, and ELK1 in MDA-MB-231 cells, and no change in the protein expression of EIF4B and ELK1 was shown in MDA-MB-468 cells. Fucoxanthin upregulated the protein expression of RHOA in both cell lines. The modulation of the expression of genes and proteins of the PI3K-AKT signaling pathway may elucidate fucoxanthin's effects in cell cycle progression, apoptotic processes, migration, and proliferation, which shows that PI3K-AKT may be the possible molecular mechanism for fucoxanthin's effects. In conclusion, the results obtained in this study elucidate fucoxanthin's molecular mechanisms and indicate that fucoxanthin may be considered a promising candidate for breast cancer-targeted therapy.

Identification of Potential Factors for the Promotion of Fucoxanthin Synthesis by Methyl Jasmonic Acid Treatment of Phaeodactylum tricornutum

Fucoxanthin, a vital secondary metabolite produced by marine diatoms, has great economic value and research potential. However, its popularization and application have been greatly restricted due to its low content, difficult extraction, and high production cost. Methyl jasmonic acid (MeJA) exerts similar inductive hormones in the growth and development as well as metabolic processes of plants. In Phaeodactylum tricornutum (P. tricornutum), MeJA treatment can increase fucoxanthin content. In this study, the effects of different concentrations of MeJA on the cell growth and the fucoxanthin content of P. tricornutum were explored. Meanwhile, this study used high-throughput sequencing technology for transcriptome sequencing of P. tricornutum and subsequently performed differential gene expression analysis, gene ontology (GO) enrichment analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis, and weighted gene co-expression network analysis (WGCNA) for screening the hub genes for the promotion of fucoxanthin synthesis with MeJA-treated P. tricornutum. On this basis, the functions of the hub genes for the promotion of fucoxanthin synthesis with MeJA-treated P. tricornutum were further analyzed. The results revealed that the carotenoid synthesis-related genes PHATRDRAFT_54800 and PHATRDRAFT_20677 were the hub genes for the promotion of fucoxanthin synthesis with MeJA-treated P. tricornutum. PHATRDRAFT_54800 may be a carotenoid isomerase, while PHATRDRAFT_20677 may be involved in the MeJA-stimulated synthesis of fucoxanthin by exerting the role of SDR family NAD(P)-dependent oxidoreductases.

Fucoxanthin Abrogates Ionizing Radiation-Induced Inflammatory Responses by Modulating Sirtuin 1 in Macrophages

Ionizing radiation (IR) triggers an overproduction of reactive oxygen species (ROS), disrupting the normal function of both immune and metabolic systems, leading to inflammation and metabolic disturbances. To address the pressing requirement for protection against IR, fucoxanthin (FX), a naturally occurring compound extracted from algae, was utilized as an efficient radioprotective agent in macrophages. In this study, we cultured murine RAW 264.7 macrophages and treated them with FX, along with agents influencing the activity of sirtuin 1 (SIRT1) and estrogen receptor α (ERα), to investigate their impact on IR-induced cellular responses. FX significantly attenuated IR-induced upregulation of pro-inflammatory genes (Il1b, Tnf, and Ccl2) and inhibited macrophage polarization toward the pro-inflammatory M1 phenotype. Additionally, FX regulated IR-induced metabolic genes mediating glycolysis and mitochondrial biogenesis. The ability of FX to mitigate IR-induced inflammation and glycolysis was ascribed to the expression and activity of SIRT1 and ERα in macrophages. This study not only uncovers the underlying mechanisms of FX's radioprotective properties but also highlights its potential as a protective agent against the detrimental effects of IR, thus offering new opportunities for enhancing radiation protection in the future.

Sodium alginate and chitosan co-modified fucoxanthin liposomes: preparation, bioaccessibility and antioxidant activity

To improve the stability of fucoxanthin, fucoxanthin liposomes (L) were prepared by the thin-film ultrasound method, and fucoxanthin liposomes were modified with sodium alginate and chitosan by an electrostatic deposition method. The release characteristics of fucoxanthin in different types of liposomes with in vitro gastrointestinal simulation were studied. Under the optimum conditions, the results showed that the encapsulation efficiency of prepared liposomes could reach 88.56 ± 1.40% (m/m), with an average particle size of 295.27 ± 7.28 nm, a Zeta potential of -21.53 ± 2.00 mV, a polydispersity index (PDI) of 0.323 ± 0.007 and a loading capacity of 33.3 ± 0.03% (m/m). Compared with L and chitosan modified fucoxanthin liposomes (CH), sodium alginate and chitosan modified fucoxanthin liposomes (SA-CH) exhibited higher storage stability, in vitro bioaccessibility and antioxidant activity after gastrointestinal digestion. Sodium alginate and chitosan co-modified liposomes can be developed as formulations for encapsulation and delivery of functional ingredients, providing a theoretical basis for developing new fucoxanthin series products.

Fucoxanthin Inhibits Development of Sigmoid Colorectal Cancer in a PDX Model With Alterations of Growth, Adhesion, and Cell Cycle Signals

BACKGROUND/AIM

Fucoxanthin (Fx), a dietary marine xanthophyll, exerts potent anticancer effects in various colorectal cancer (CRC) animal models. However, therapeutic effects of Fx in human cancer tissues remain unclear. A patient-derived xenograft (PDX) mouse model transplanted with cancer tissues from patients is widely accepted as the best preclinical model for evaluating the anticancer potential of drug candidates.

MATERIALS AND METHODS

Herein, we investigated the anticancer effects of Fx in PDX mice transplanted with cancer tissues derived from a patient with CRC (CRC-PDX) using LC-MS/MS- and western blot-based proteome analysis.

RESULTS

The tumor in the patient with CRC was a primary adenocarcinoma (T3N0M0, stage II) showing mutations of certain genes that were tumor protein p53 (TP53), AT-rich interaction domain 1A (ARID1A), neuroblastoma RAS viral oncogene homolog (NRAS), and PMS1 homolog 2 (PMS2). Administration of Fx significantly suppressed the tumor growth (0.6-fold) and tended to induce differentiation in CRC-PDX mice. Fx up-regulated glycanated-decorin (Gc-DCN) expression, and down-regulated Kinetochore-associated protein DSN1 homolog (DSN1), phospho(p) focal adhesion kinase (pFAK)(Tyr397), pPaxillin(Tyr31), and c-MYC involved in growth, adhesion, and/or cell cycle, in the tumors of CRC-PDX mice than in control mice. Alterations in the five proteins were consistent with those in human CRC HT-29 and HCT116 cells treated with fucoxanthinol (FxOH, a major metabolite of Fx).

CONCLUSION

Fx suppresses development of human-like CRC tissues, especially through growth, adhesion, and cell cycle signals.

Improving Determination of Pigment Contents in Microalgae Suspension with Absorption Spectroscopy: Light Scattering Effect and Bouguer-Lambert-Beer Law

The Bouguer-Lambert-Beer (BLB) law serves as the fundamental basis for the spectrophotometric determination of pigment content in microalgae. Although it has been observed that the applicability of the BLB law is compromised by the light scattering effect in microalgae suspensions, in-depth research concerning the relationship between the light scattering effect and the accuracy of spectrophotometric pigment determination remains scarce. We hypothesized that (1) the precision of spectrophotometric pigment content determination using the BLB law would diminish with increasing nonlinearity of absorbance, and (2) employing the modified version of the BLB (mBLB) law would yield superior performance. To assess our hypotheses, we cultivated Phaeodactylum tricornutum under varying illumination conditions and nitrogen supplies in controlled indoor experiments, resulting in suspensions with diverse pigment contents. Subsequently, P. tricornutum samples were diluted into subsamples, and spectral measurements were conducted using different combinations of biomass concentrations and path lengths. This was carried out to assess the applicability of the BLB law and the nonlinearity of absorbance. The chlorophyll a and fucoxanthin contents in the samples were analyzed via high-performance liquid chromatography (HPLC) and subsequently used in our modeling. Our findings confirm our hypotheses, showing that the modified BLB law outperforms the original BLB law in terms of the normalized root mean square error (NRMSE): 6.3% for chlorophyll a and 5.8% for fucoxanthin, compared to 8.5% and 7.9%, respectively.

[Promoting fucoxanthin accumulation in Phaeodactylum tricornutum by multiple nitrogen supplementation and blue light enhancement]

The aim of this study was to promote fucoxanthin accumulation in Phaeodactylum tricornutum by photo-fermentation through optimizing the mode of multiple nitrogen supplementation and blue light enhancement. The results showed that the mixed nitrogen source (tryptone: urea=1:1, N mol/N mol; total nitrogen concentration at 0.02 mol/L) added to the culture system by six times was the best mode in shake flasks. Two-phase culture with light adjustment was then carried out in 5 L photo-fermenter with an enhanced blue light (R: G: B=67.1:16.7:16.3) in the second phase, leading to improved cell density (1.12×108 cells/mL), biomass productivity (330 mg/(d·L)), fucoxanthin content (19.62 mg/g), titer (69.71 mg/L) and productivity (6.97 mg/(d·L)). Compared with one-phase culture under red/blue (R: G: B=70.9:18.3:10.9) light and six-times nitrogen supplementation, the fucoxanthin content was significantly increased by 7.68% (P < 0.05) but the productivity did not change significantly (P > 0.05). Compared with one-phase culture under red/blue (R: G: B=70.9:18.3:10.9) light and one-time nitrogen supplementation, the content and productivity of fucoxanthin were significantly increased by 45.98% and 48.30% (P < 0.05), respectively. This study developed a two-phase culture mode with multiple nitrogen supplementation and blue light enhancement, which effectively promoted the accumulation of fucoxanthin and improved the efficiency of nitrogen source utilization, thus providing a new approach for fucoxanthin accumulation in P. tricornutum by photo-fermentation.

Antioxidative and Anti-Inflammatory Protective Effects of Fucoxanthin against Paracetamol-Induced Hepatotoxicity in Rats

Paracetamol or acetaminophen (PAC) is a commonly used analgesic and antipyretic drug. It has been shown that overdoses beyond the therapeutic range can cause hepatotoxicity and acute liver injury. The most common cause of drug-induced liver injury (DILI) in Saudi Arabia and worldwide is paracetamol overdose. Fucoxanthin (FUC) is an allenic carotenoid that is found in edible brown seaweeds, and it has antioxidant and anti-inflammatory effects. Several studies have shown the potential therapeutic effects of FUC in diabetes, cancers, and inflammatory disorders. This study aims to investigate the protective effect of FUC against PAC-induced acute liver injury in rats. FUC was administered (100, 200, and 500 mg/kg, p.o.) for 7 days, and then the liver injury was induced by the administration of PAC (2000 mg/kg, oral). Blood and liver tissue samples were collected from PAC-positive untreated, treated, and negative control rats. Biochemical and inflammatory parameters in the blood were measured. In addition, RT-PCR, Western blotting, and immunohistochemistry were performed for liver tissue. The serum levels of liver biomarkers (ALT, AST, and ALP) increased after PAC-induced liver toxicity; FUC-treated rats showed lower levels compared to the positive control. There was an increase in the expression of TNF-α, IL-1, IL-6, NF-kB, INF-γ, and iNOS and a decrease in IL-10, IL-22, and IL-10R expression after the FUC treatment of injured liver rats. For the hepatic inflammation and PAC-toxicity-induced oxidative stress genes and proteins, FUC-treated rats (100, 200, and 500 mg/kg) showed a reduction in the expression of oxidative stress genes. These results showed that FUC protected the liver against PAC-induced injury through antioxidant and anti-inflammatory actions. However, further clinical studies are required to confirm the findings.

Fucoxanthin ameliorates endoplasmic reticulum stress and inhibits apoptosis and alleviates intervertebral disc degeneration in rats by upregulating Sirt1

Endoplasmic reticulum stress (ERS) and apoptosis of nucleus pulposus (NP) cells are considered to be the main pathological factors of intervertebral disc degeneration (IDD). Fucoxanthin (FX), a marine carotenoid extracted from microalgae, has antioxidant, anti-inflammatory, and anticancer properties. The aim of this study was to investigate the effect of FX on NP cells induced by oxidative stress and its molecular mechanism. Primary NP cells of the lumbar vertebrae of rats were extracted and tested in vitro. qRT-PCR, western blot, immunofluorescence, and TUNEL staining were used to detect apoptosis, ERS, extracellular matrix (ECM), and Sirt1-related pathways. In vivo experiments, the recovery of IDD rats was determined by X-ray, hematoxylin and eosin, Safranin-O/Fast Green, Alcian staining, and immunohistochemistry. Our study showed that oxidative stress induced ERS, apoptosis, and ECM degradation in NP cells. After the use of FX, the expression of Sirt1 was up-regulated, the activation of PERK-eIF2α-ATF4-CHOP was decreased, and apoptosis and ECM degradation were decreased. At the same time, FX improved the degree of disc degeneration in rats in vivo. Our study demonstrates the effect of FX on improving IDD in vivo and in vitro, suggesting that FX may be a potential drug for the treatment of IDD.

Effects of Temperature, Light and Salt on the Production of Fucoxanthin from Conticribra weissflogii

Fucoxanthin is a natural active substance derived from diatoms that is beneficial to the growth and immunity of humans and aquatic animals. Temperature, light and salinity are important environmental factors affecting the accumulation of diatom actives; however, their effects on the production of fucoxanthin in C. weissflogii are unclear. In this study, single-factor experiments are designed and followed by an orthogonal experiment to determine the optimal combination of fucoxanthin production conditions in C. weissflogii. The results showed that the optimum conditions for fucoxanthin production were a temperature of 30 °C, a light intensity of 30 umol m-2 s-1 and a salinity of 25. Under these conditions, the cell density, biomass, carotenoid content and fucoxanthin content of C. weissflogii reached 1.97 × 106 cell mL-1, 0.76 g L-1, 2.209 mg L-1 and 1.372 mg g-1, respectively, which were increased to 1.53, 1.71, 2.50 and 1.48 times higher than their initial content. The work sought to give useful information that will lead to an improved understanding of the effective method of cultivation of C. weissflogii for natural fucoxanthin production.

Anticancer Effects of Fucoxanthin through Cell Cycle Arrest, Apoptosis Induction, and Angiogenesis Inhibition in Triple-Negative Breast Cancer Cells

The absence of progesterone receptors, estrogen receptors, and human epidermal growth factor receptor-2 restricts the therapy choices for treating triple-negative breast cancer (TNBC). Moreover, conventional medication is not highly effective in treating TNBC, and developing effective therapeutic agents from natural bioactive compounds is a viable option. In this study, the anticancer effects of the natural compound fucoxanthin were investigated in two genetically different models of TNBC cells: MDA-MB-231 and MDA-MB-468 cells. Fucoxanthin had a significant anticancer effect in both cell lines at a concentration range of 1.56-300 µM. The compound decreased cell viability in both cell lines with higher potency in MDA-MB-468 cells. Meanwhile, proliferation assays showed similar antiproliferative effects in both cell lines after 48 h and 72 h treatment periods. Flow cytometry and Annexin V-FITC apoptosis assay revealed the ability of fucoxanthin to induce apoptosis in MDA-MB-231 only. Cell cycle arrest analysis showed that the compound also induced cell cycle arrest at the G1 phase in both cell lines, accompanied by more cell cycle arrest in MDA-MB-231 cells at S-phase and a higher cell cycle arrest in the MDA-MB-468 cells at G2-phase. Wound healing and migration assay showed that in both cell lines, fucoxanthin prevented migration, but was more effective in MDA-MB-231 cells in a shorter time. In both angiogenic cytokine array and RT-PCR studies, fucoxanthin (6.25 µM) downregulated VEGF-A and -C expression in TNF-α-stimulated (50 ng/mL) MDA-MB-231, but not in MDA-MB-468 cells on the transcription and protein levels. In conclusion, this study shows that fucoxanthin was more effective in MDA-MB-231 TNBC cells, where it can target VEGF-A and VEGF-C, inhibit cell proliferation and cell migration, and induce cell cycle arrest and apoptosis-the most crucial cellular processes involved in breast cancer development and progression.

Fucoxanthin Attenuates Inflammation via Interferon Regulatory Factor 3 (IRF3) to Improve Sepsis

Suppression of excessive inflammatory responses improves the survival of patients with sepsis. We previously illustrated the anti-inflammatory effects of fucoxanthin (FX), a natural carotenoid isolated from brown algae; nevertheless, the underlying mechanism remains unknown. In this study, we examine the mechanism of the action of FX by targeting interferon regulatory factor 3 (IRF3) to inhibit inflammatory response. We observed that FX regulated innate immunity by inhibiting IRF3 phosphorylation in vitro. The in silico approach demonstrated a good binding mode between FX and IRF3. To examine the in vivo effects of FX, a mouse model of sepsis induced by cecal ligation and puncture (CLP) was created using both wild-type (WT) and Irf3-/- mice. FX significantly reduced pro-inflammatory cytokine levels and reactive oxygen species production, changed the circulating immune cell composition, and increased the survival rate of the CLP-induced sepsis model. Overall, FX ameliorated sepsis by targeting IRF3 activation, providing novel insights into the therapeutic potential and molecular mechanism of action of FX in the treatment of sepsis and suggesting that it may be used clinically to improve the survival rate in mice undergoing sepsis.

Isolation of Fucoxanthin from Sargassum oligocystum Montagne, 1845 Seaweed in Vietnam and Its Neuroprotective Activity

Fucoxanthin extracted and purified from Vietnamese Sargassum oligocystum Montagne, 1845 exhibits various biological activities. In this study, the ability of fucoxanthin to inhibit acetylcholinesterase (AChE), the antioxidant activities, and the expression of antioxidant enzymes were investigated. Fucoxanthin isolated from Vietnamese S. oligocystum showed no cytotoxic effects; moreover, it exhibited AChE inhibitory activity (with an IC50 value of 130.12 ± 6.65 μg mL-1) and antioxidant activity (with an IC50 value of 3.42 ± 0.15 mg mL-1). At concentrations of 50 and 100 µg mL-1, fucoxanthin provided protection against amyloid β-protein fragment 25-35-induced neurotoxicity in a C6 neuronal cell line, and the survival of C6 cells was higher than 81.01% and 80.98%, respectively, compared to the control group (59%). Moreover, antioxidant enzyme activity and quantitative PCR analysis suggested that the neuroprotective effect of fucoxanthin resulted from regulation of the gene expression of antioxidant enzymes (CAT and GPx) and ER pathways (caspase-3 and Bax), as well as the promotion of expression of genes involved in PI3K/Akt signaling (GSK-3β), autophagy (p62 and ATG5), and the biosynthesis of ACh (VAChT and ChAT). Therefore, fucoxanthin extracted from the seaweed S. oligocystum in Vietnam is a potential feedstock source for the production of health foods that exert neuroprotective effects.

Kinetic Extraction of Fucoxanthin from Undaria pinnatifida Using Ethanol as a Solvent

Fucoxanthin (Fx) has been proven to exert numerous biological properties, which makes it an interesting molecule with diverse industrial applications. In this study, the kinetic behavior of Fx was studied to optimize three variables: time (t-3 min to 7 days), temperature (T-5 to 85 °C), and concentration of ethanol in water (S-50 to 100%, v/v), in order to obtain the best Fx yield from Undaria pinnatifida using conventional heat extraction. The Fx content (Y1) was found through HPLC-DAD and expressed in µg Fx/g of algae sample dry weight (AS dw). Furthermore, extraction yield (Y2) was also found through dry weight analysis and was expressed in mg extract (E)/g AS dw. The purity of the extracts (Y3) was found and expressed in mg Fx/g E dw. The optimal conditions selected for Y1 were T = 45 °C, S = 70%, and t = 66 min, obtaining ~5.24 mg Fx/g AS; for Y2 were T = 65 °C, S = 60%, and t = ~10 min, obtaining ~450 mg E/g AS; and for Y3 were T = 45 °C, S = 70%, and t = 45 min, obtaining ~12.3 mg Fx/g E. In addition, for the selected optimums, a full screening of pigments was performed by HPLC-DAD, while phenolics and flavonoids were quantified by spectrophotometric techniques and several biological properties were evaluated (namely, antioxidant, antimicrobial, and cholinesterase inhibitory activity). These results could be of interest for future applications in the food, cosmetic, or pharmaceutical industries, as they show the Fx kinetic behavior and could help reduce costs associated with energy and solvent consumption while maximizing the extraction yields.

Effect of Fucoxanthin on Metabolic Syndrome, Insulin Sensitivity, and Insulin Secretion

The aim of this study was to evaluate the effect of fucoxanthin on metabolic syndrome (MetS), insulin sensitivity, and insulin secretion. A randomized, double-blind, placebo-controlled clinical trial was conducted in 28 patients diagnosed with MetS. Patients were randomly assigned to receive 12 mg of fucoxanthin or placebo once a day for 12 weeks. Before and after the intervention, the components of MetS, insulin sensitivity (Matsuda index), first phase of insulin secretion (Stumvoll index), and total insulin secretion were evaluated during a 2-h oral glucose tolerance test. After fucoxanthin administration, significant differences were observed in body weight (BW) (80.6 ± 11.2 vs. 79.16 ± 12.3 kg, P < .01), body mass index (BMI) (31.1 ± 3.6 vs. 30.3 ± 3.7 kg/m², P < .01), waist circumference (WC) (101.2 ± 9.1 vs. 98.9 ± 9.3 cm, P < .01), systolic blood pressure (SBP) (126.1 ± 10.3 vs. 120.8 ± 9.7 mmHg, P < .01), diastolic blood pressure (DBP) (81.5 ± 6.5 vs. 78.6 ± 6.3 mmHg, P < .01), triglycerides (TG) (2.2 ± 0.7 vs. 2.1 ± 0.7 mmol/L, P < .01), Stumvoll index (2403 ± 621 vs. 2907 ± 732, P < .05), and total insulin secretion (0.84 ± 0.31 vs. 1.02 ± 0.32, P < .05). In conclusion, fucoxanthin administration leads to a decrease in BW, BMI, WC, SBP, DBP, TG, as well as increase in the first phase of insulin secretion and total insulin secretion in patients with MetS. Clinical Trial Registration number: NCT03613740.

Protective Effect of Fucoxanthin on Zearalenone-Induced Hepatic Damage through Nrf2 Mediated by PI3K/AKT Signaling

Hepatotoxic contaminants such as zearalenone (ZEA) are widely present in foods. Marine algae have a wide range of potential applications in pharmaceuticals, cosmetics, and food products. Research is ongoing to develop treatments and products based on the compounds found in algae. Fucoxanthin (FXN) is a brown-algae-derived dietary compound that is reported to prevent hepatotoxicity caused by ZEA. This compound has multiple biological functions, including anti-diabetic, anti-obesity, anti-microbial, and anti-cancer properties. Furthermore, FXN is a powerful antioxidant. In this study, we examined the effects of FXN on ZEA-induced stress and inflammation in HepG2 cells. MTT assays, ROS generation assays, Western blots, and apoptosis analysis were used to evaluate the effects of FXN on ZEA-induced HepG2 cell inflammation. Pre-incubation with FXN reduced the cytotoxicity of ZEA toward HepG2 cells. FXN inhibited the ZEA-induced production of pro-inflammatory cytokines, including IL-1 β, IL-6, and TNF-α. Moreover, FXN increased HO-1 expression in HepG2 by activating the PI3K/AKT/NRF2 signaling pathway. In conclusion, FXN inhibits ZEA-induced inflammation and oxidative stress in hepatocytes by targeting Nrf2 via activating PI3K/AKT signaling.

Safety of an ethanolic extract of the dried biomass of the microalga Phaeodactylum tricornutum as a novel food pursuant to Regulation (EU) 2015/2283

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on an ethanolic extract of the dried biomass of the microalga Phaeodactylum tricornutum as a novel food (NF) pursuant to Regulation (EU) 2015/2283. The NF is an ethanolic extract of the dried biomass of the microalga P. tricornutum diluted in a medium-chain triglyceride oil carrier, with standardised fucoxanthin and tocopherol content. The main component of the NF is fat (78% on average), followed by crude protein (10% on average). The Panel is of the view that a consistent and safe production process has not been demonstrated. Additionally, the Panel considers that the information provided on the composition of the NF is not complete and may raise safety concerns. The applicant proposed to use the NF as a food supplement at the use level of 437 mg/day, with the target population being adults, excluding pregnant and breastfeeding women. There is no history of use of the NF or of its source, i.e. P. tricornutum. The Panel notes that the source of the NF, P. tricornutum, was not granted the qualified presumption of safety (QPS) status by the EFSA Panel on Biological Hazards (BIOHAZ), due to the lack of a safe history of use in the food chain and on its potential for production of bioactive compounds with toxic effects. There were no concerns regarding genotoxicity of the NF. In the 90-day study provided, a number of adverse effects were observed, some of them seen already at the lowest dose tested (750 mg/kg body weight (bw) day), which was identified by the Panel as the lowest-observed-adverse-effect-level (LOAEL). The potential phototoxicity of pheophorbide A and pyropheophorbide A in the NF was not addressed in this study. Although noting the uncertainties identified by the Panel regarding the analytical determination of these substances in the NF and the limitations in the publicly available toxicity data, a low margin of exposure (MoE) was calculated for these substances at the proposed use levels. The Panel concludes that the safety of the NF under the proposed uses and use levels has not been established.

Gemcitabine‑fucoxanthin combination in human pancreatic cancer cells

Gemcitabine is a chemotherapeutic agent for pancreatic cancer treatment. It has also been demonstrated to inhibit human pancreatic cancer cell lines, MIA PaCa-2 and PANC-1. The aim of the present study was to investigate the suppressive effect of fucoxanthin, a marine carotenoid, in combination with gemcitabine on pancreatic cancer cells. MTT assays and cell cycle analysis using flow cytometry were performed to study the mechanism of action. The results revealed that combining a low dose of fucoxanthin with gemcitabine enhanced the cell viability of human embryonic kidney cells, 293, while a high dose of fucoxanthin enhanced the inhibitory effect of gemcitabine on the cell viability of this cell line. In addition, the enhanced effect of fucoxanthin on the inhibitory effect of gemcitabine on PANC-1 cells was significant (P<0.01). Fucoxanthin combined with gemcitabine also exerted significant enhancement of the anti-proliferation effect in MIA PaCa-2 cells in a concentration dependent manner (P<0.05), compared with gemcitabine treatment alone. In conclusion, fucoxanthin improved the cytotoxicity of gemcitabine on human pancreatic cancer cells at concentrations that were not cytotoxic to non-cancer cells. Thus, fucoxanthin has the potential to be used as an adjunct in pancreatic cancer treatment.

Toxicology of pharmaceutical and nutritional longevity compounds

Aging is the most prominent risk factor for many diseases, which is considered to be a complicated biological process. The rate of aging depends on the effectiveness of important mechanisms such as the protection of DNA from free radicals, which protects the structural and functional integrity of cells and tissues. In any organism, not all organs may age at the same rate. Slowing down primary aging and reaching maximum lifespan is the most basic necessity. In this process, it may be possible to slow down or stabilise some diseases by using the compounds for both dietary and pharmacological purposes. Natural compounds with antioxidant and anti-inflammatory effects, mostly plant-based nutraceuticals, are preferred in the treatment of age-related chronic diseases and can also be used for other diseases. An increasing number of long-term studies on synthetic and natural compounds aim to elucidate preclinically and clinically the mechanisms underlying being healthy and prolongation of life. To delay age-related diseases and prolong the lifespan, it is necessary to take these compounds with diet or pharmaceuticals, along with detailed toxicological results. In this review, the most promising and utilised compounds will be highlighted and it will be discussed whether they have toxic effects in short/long-term use, although they are thought to be used safely.

Miyeokgui (Undaria pinnatifida Sporophyll) Characteristic under Different Relative Humidity: Microbial Safety, Antioxidant Activity, Ascorbic Acid, Fucoxanthin, α-/β-/γ-Tocopherol Contents

This study aimed to investigate the effects of different relative humidities (%) on the microbial safety, antioxidant activity, ascorbic acid, fucoxanthin, and tocopherol contents of Undaria pinnatifida sporophyll powder (UPSP) stored for 4 weeks. The caking phenomenon did not occur in the 11-53% relative humidity conditions, but it did in the 69%, 81%, and 93% relative humidity conditions with caking index values of 88.30%, 99.75%, and 99.98%, respectively. The aerobic bacterial contents increased drastically in samples stored at 69-93% relative humidity. Ascorbic acid was unstable at high relative humidity, but fucoxanthin and tocopherol were more unstable at low relative humidity. Therefore, it was most stable at intermediate relative humidity. The 69% relative humidity sample had higher DPPH (12.57 g BHAE/kg), ABTS (4.87 g AAE/kg), and FRAP (4.60 g Fe (II)/kg) than the other samples. This study could be helpful for the storage and transport of UPSP under optimum relative humidity conditions, which can significantly prevent quality losses.

Fucoxanthin levels in maternal serum at birth and eczema risk in offspring in early childhood: A birth cohort study

BACKGROUND

Fucoxanthin, a marine xanthophyll carotenoid, has been shown to exert beneficial health effects. Cell-based and animal-based experimental studies have shown that fucoxanthin has the potential to mitigate eczema symptoms. Hence, we sought to assess whether fucoxanthinol 3-arachidate, a fucoxanthin metabolite, measured in maternal serum at birth is associated with eczema development during early childhood.

METHODS

Data from the 1989/1990 Isle of Wight birth cohort were analyzed. We focused on data obtained from the 1, 2, and 4 years follow-ups. Fucoxanthinol 3-arachidate was measured in maternal serum at the child's birth as abundance relative to the reference lipids. Eczema was ascertained according to parent-reported clinical history and characteristic morphology and distribution. Log-binomial regression models were used to estimate adjusted risk ratios (aRR) and their 95% confidence intervals (CI).

RESULTS

A total of 592 subjects (49.2% males and 50.8% females) were included in the current analysis. Associations between fucoxanthinol 3-arachidate levels and eczema risk during the first 4 years of life (longitudinal analysis) were evaluated using four modeling approaches, which showed higher fucoxanthinol 3-arachidate levels were associated with reduced eczema risk: (i) aRR_{per 10 unit increase}  = 0.88, 95% CI: 0.76-1.03; (ii) aRR_{>0 vs. =0}  = 0.67, 0.45-0.99; (iii) aRR_{≥2.3 vs. <2.3}  = 0.66, 0.44-0.98; and (iv) aRR_{tertile 3 vs. tertile 1}  = 0.65, 0.42-0.99.

CONCLUSION

Our findings suggest that increased fucoxanthinol 3-arachidate levels measured in maternal serum at the child's birth is associated with reduced eczema risk during the first 4 years of the offspring life.

Advanced methods of algal pigments extraction: A review

Algae are exclusively aquatic photosynthetic organisms that are microscopic or macroscopic, unicellular or multicellular and distributed across the globe. They are a potential source of food, feed, medicine and natural pigments. A variety of natural pigments are available from algae including chlorophyll a, b, c d, phycobiliproteins, carotenes and xanthophylls. The xanthophylls include acyloxyfucoxanthin, alloxanthin, astaxanthin, crocoxanthin, diadinoxanthin, diatoxanthin, fucoxanthin, loroxanthin, monadoxanthin, neoxanthin, nostoxanthin, perdinin, Prasinoxanthin, siphonaxanthin, vaucheriaxanthin, violaxanthin, lutein, zeaxanthin, β-cryptoxanthin, while carotenes include echinenone, α-carotene, β-carotene, γ-carotene, lycopene, phytoene, phytofluene. These pigments have applications as pharmaceuticals and nutraceuticals and in the food industry for beverages and animal feed production. The conventional methods for the extraction of pigments are solid-liquid extraction, liquid-liquid extraction and soxhlet extraction. All these methods are less efficient, time-consuming and have higher solvent consumption. For a standardized extraction of natural pigments from algal biomass advanced procedures are in practice which includes Supercritical fluid extraction, Pressurized liquid extraction, Microwave-assisted extraction, Pulsed electric field, Moderate electric field, Ultrahigh pressure extraction, Ultrasound-assisted extraction, Subcritical dimethyl ether extraction, Enzyme assisted extraction and Natural deep eutectic solvents. In the present review, these methods for pigment extraction from algae are discussed in detail.

Bioactives Overproduction through Operational Strategies in the Ichthyotoxic Microalga Heterosigma akashiwo Culture

The red tide-forming microalga Heterosigma akashiwo has been associated with massive events of fish deaths, both wild and cultured. Culture conditions are responsible for the synthesis or accumulation of some metabolites with different interesting bioactivities. H. akashiwo LC269919 strain was grown in a 10 L bubble column photobioreactor artificially illuminated with multi-coloured LED lights. Growth and production of exopolysaccharides, polyunsaturated fatty acids (PUFAs), and carotenoids were evaluated under different culture modes (batch, fed-batch, semicontinuous, and continuous) at two irradiance levels (300 and 700 µE·s^-1·m^-2). Continuous mode at the dilution rate of 0.2·day^-1 and 700 µE·s^-1·m^-2 provided the highest production of biomass, PUFAs (132.6 and 2.3 mg·L^-1·day^-1), and maximum fucoxanthin productivity (0.16 mg·L^-1·day^-1). The fed-batch mode accumulated exopolysaccharides in a concentration (1.02 g·L^-1) 10-fold over the batch mode. An extraction process based on a sequential gradient partition with water and four water-immiscible organic solvents allowed the isolation of bioactive fucoxanthin from methanolic extracts of H. akashiwo. Metabolites present in H. akashiwo, fucoxanthin and polar lipids (i.e., eicosapentaenoic acid (EPA)), or probably such as phytosterol (β-Sitosterol) from other microalgae, were responsible for the antitumor activity obtained.

Xanthophyll-Rich Extract of Phaeodactylum tricornutum Bohlin as New Photoprotective Cosmeceutical Agent: Safety and Efficacy Assessment on In Vitro Reconstructed Human Epidermis Model

The nutritional and health properties of algae make them perfect functional ingredients for nutraceutical and cosmeceutical applications. In this study, the Phaeodactylum tricornutum Bohlin (Phaeodactylaceae), a pleiomorphic diatom commonly found in marine ecosystems, was investigated. The in vitro culture conditions used favoured the fusiform morphotype, characterized by a high accumulation of neutral lipids, as detected by fluorescence microscopy after BODIPY staining. These data were confirmed by HPLC-DAD-APCI-MS/MS analyses carried out on the ethanolic extract (PTE), which showed a high content of xanthophylls (98.99%), and in particular of fucoxanthin (Fx, 6.67 g/100 g PTE). The antioxidant activity (ORAC, FRAP, TEAC and β-carotene bleaching) and photostability of PTE and Fx against UVA and UVB rays were firstly evaluated by in vitro cell-free assays. After this, phototoxicity and photoprotective studies were carried out on in vitro reconstructed human epidermidis models. Results demonstrated that PTE (0.1% Fx) and 0.1% Fx, both photostable, significantly (p < 0.05) reduce oxidative and inflammatory stress markers (ROS, NO and IL-1α), as well as cytotoxicity and sunburn cells induced by UVA and UVB doses simulating the solar radiation, with an excellent safety profile. However, PTE proved to be more effective than Fx, suggesting its effective and safe use in broad-spectrum sunscreens.

The Role of Fucoxanthin in Non-Alcoholic Fatty Liver Disease

Chronic liver disease (CLD) has emerged as a leading cause of human deaths. It caused 1.32 million deaths in 2017, which affected men more than women by a two-to-one ratio. There are various causes of CLD, including obesity, excessive alcohol consumption, and viral infection. Among them, non-alcoholic fatty liver disease (NAFLD), one of obesity-induced liver diseases, is the major cause, representing the cause of more than 50% of cases. Fucoxanthin, a carotenoid mainly found in brown seaweed, exhibits various biological activities against NAFLD. Its role in NAFLD appears in several mechanisms, such as inducing thermogenesis in mitochondrial homeostasis, altering lipid metabolism, and promoting anti-inflammatory and anti-oxidant activities. The corresponding altered signaling pathways are the β3-adorenarine receptor (β3Ad), proliferator-activated receptor gamma coactivator (PGC-1), adenosine monophosphate-activated protein kinase (AMPK), peroxisome proliferator-activated receptor (PPAR), sterol regulatory element binding protein (SREBP), nuclear factor kappa B (NF-κB), mitogen-activated protein kinase (MAPK), protein kinase B (AKT), SMAD2/3, and P13K/Akt pathways. Fucoxanthin also exhibits anti-fibrogenic activity that prevents non-alcoholic steatohepatitis (NASH) development.

Fucoxanthin protects retinal ganglion cells and promotes parkin-mediated mitophagy against glutamate excitotoxicity

OBJECTIVE

To clarify whether fucoxanthin plays a protective role and regulates parkin-mediated mitophagy on retinal ganglion cells (RGCs) against glutamate excitotoxicity.

METHODS

The excitotoxicity model of primary RGCs was carried out with glutamate. Mitochondrial membrane potential was measured by JC-1 kit (Abcam, USA). The apoptotic rate and cytotoxicity were detected by Hoechst staining and lactate dehydrogenase (LDH) kit (Takara, Japan). Mitochondria was assessed by MitoTracker staining and confocal microscopy. The mRNA levels and protein expression levels of Bax, Bcl-2, parkin, optineurin, LC3, and LAMP1 in RGCs were analyzed by quantitative PCR and immunoblotting. Finally, the mitochondrial health score and mitophagy were assessed by transmission electron microscopy.

RESULTS

Fucoxanthin increased the mitochondrial membrane potential of RGCs, reduced cytotoxicity, and decreased apoptosis in RGCs under glutamate excitotoxicity. It also enhanced expression levels of parkin, optineurin, and LAMP1, and upgraded the ratio of LC3-II to LC3-I. Meanwhile, fucoxanthin increased LC3 and MitoTracker co-localization staining. In addition, up-regulated mitochondrial health score, and the number of autophagosomes and mitophagosomes were observed in fucoxanthin-treated RGCs under glutamate excitotoxicity.

CONCLUSION

Fucoxanthin may exert its neuroprotective effect on RGCs via promoting parkin-mediated mitophagy under glutamate excitotoxicity. The neuroprotective effect of fucoxanthin in glaucomatous neurodegeneration and ocular diseases characterized by impaired mitophagy warrants further investigation.

Ultrasound Assisted Extractions

Macroalgae are an extensive resource for the obtention of bioactive compounds, mainly phenolic compounds, phlorotannins, and pigments. Fucoxanthin (Fx) is the most abundant pigment present in brown algae and has shown several useful bioactivities that can be used to fortify products in the food and cosmetic industries. Nevertheless, to date, there is still insufficient literature reporting on the extraction yield of Fx from U. pinnatifida species from green technologies. In this regard, the present study aims to optimize the extraction conditions to obtain the highest Fx yield from U. pinnatifida through emerging techniques, namely microwave-assisted extraction (MAE) and ultrasound-assisted extraction (UAE). These methods will be compared with the conventional methodologies of heat-assisted extraction (HAE) and Soxhlet-assisted extraction (SAE). According to our results, even though the extraction yield could be slightly higher when using MAE than UAE, the Fx concentration obtained from the alga was double when using UAE. Thus, the Fx ratio in the final extract reached values of 124.39 mg Fx/g E. However, the optimal conditions should also be considered since UAE needed 30 min to perform the extraction, whereas MAE was able to obtain 58.83 mg Fx/g E in only 3 min and 2 bar, meaning less energy expenditure and minimum cost function. To our knowledge, this study obtains the highest concentrations of Fx ever reported (58.83 mg Fx/g E for MAE and 124.39 mg Fx/g E for UAE), with low energy consumption and short times (3.00 min for MAE and 35.16 min for UAE). Any of these results could be selected for further experiments and proposed for industrial scaling-up.

A Review of the Effects of Fucoxanthin on NAFLD

Non-alcoholic fatty liver disease (NAFLD) is the most prevalent form of chronic liver disease. Fucoxanthin, a red-orange marine carotenoid, is found in natural marine seaweeds with high antioxidant activity and several other remarkable biological features. The aim of this review is to gather evidence of the positive benefits of fucoxanthin on NAFLD. Fucoxanthin provides an extensive list of physiological and biological properties, such as hepatoprotective, anti-obesity, anti-tumor, and anti-diabetes properties, in addition to antioxidant and anti-inflammatory properties. This review focuses on published research on the preventative effects of fucoxanthin on NAFLD from the perspective of human clinical trials, animal experiments in vivo, and in vitro cell investigations. Using a variety of experimental designs, including treatment dosage, experiment model, and experimental periods, the positive effects of fucoxanthin were demonstrated. Fucoxanthin's biological activities were outlined, with an emphasis on its therapeutic efficacy in NAFLD. Fucoxanthin showed beneficial effects in modulating lipid metabolism, lipogenesis, fatty acid oxidation, adipogenesis, and oxidative stress on NAFLD. A deeper comprehension of NAFLD pathogenesis is essential for the development of novel and effective therapeutic strategies.

Fucoxanthin Alleviates Lipopolysaccharide-Induced Inflammation and Immunosuppression in RAW264.7 Macrophages

Fucoxanthin (FX) has been reported to reduce mortality in mouse models of sepsis, but its exact cause remains to be determined. In the present study, we evaluated the immunomodulatory properties of FX in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. Our results showed that FX could not only suppress the immune activation responses caused by LPS primary stimulation, but also antagonize LPS restimulation-induced immunosuppression in macrophages. The immunomodulatory capabilities of FX was mainly demonstrated by regulating the production of the inflammatory mediator under different LPS stimuli. Furthermore, we found that adenosine monophosphate-activated protein kinase (AMPK) activation was required for FX's anti-inflammatory and anti-immunosuppressive activities. Our results complement existing data supporting the clinical potential for FX in treating sepsis.

[Enhancing fucoxanthin production in Phaeodactylum tricornutum by photo-fermentation]

The aim of this study was to develop a technical system for high-efficient production of fucoxanthin by photo-fermentation of Phaeodactylum tricornutum. In a 5 L photo-fermentation tank, the effects of initial light intensity, nitrogen source and concentration as well as light quality on biomass concentration and fucoxanthin accumulation in P. tricornutum were investigated systematically under mixotrophic condition. The results showed that the biomass concentration, fucoxanthin content and productivity reached the highest level of 3.80 g/L, 13.44 mg/g and 4.70 mg/(L·d) under the optimal conditions of initial light intensity of 100 μmol/(m²·s), 0.02 mol TN/L of tryptone: urea (1:1, N mol/N mol) as mixed nitrogen source, and a mixed red/blue (R: B=6:1) light, 1.41, 1.33 and 2.05-fold higher than that before optimization, respectively. This study developed a key technology for enhancing the production of fucoxanthin by photo-fermentation of P. tricornutum, facilitating the development of marine natural products.

Exploring the key genes of fucoxanthin biosynthesis in Phaeodactylum tricornutum under phosphorus deficiency, red light and yellow light using WGCNA

Weighted gene co-expression network analysis (WGCNA) is a method for analysing gene expression patterns across multiple samples, clustering genes with similar expression patterns and identifying key genes associated with specific traits or phenotypes. In this study, we investigated the effects of fucoxanthin accumulation in Phaeodactylum tricornutum in response to abiotic stresses of phosphorus deficiency, red light, and yellow light using transcriptome sequencing and weighted gene co-expression network analysis. The results showed that compared to the control, the fucoxanthin content of P. tricornutum was significantly increased after phosphorus deficiency and red light treatment (P<0.05), but significantly decreased after yellow light treatment (P<0.05). A weighted gene co-expression network was constructed using 10,392 genes obtained from transcriptome sequencing, and β=18 (R²>0.8) was chosen as a soft threshold in order to ensure a scale-free network. A total of 10 co-expression modules were identified by correlation analysis of fucoxanthin content, with the purple module positively correlated with fucoxanthin content (r=0.9, P=1E-200), and 9 key genes were identified, including five genes in the fucoxanthin biosynthesis pathway (DXR, PSY, PDS1, ZEP2, VDL2) and 4 transcription factors (bHLH5, HOX2, CCHH13, HSF1b). Further qRT-PCR confirmed that key genes were more highly expressed in the phosphorus deficiency treatment and linear regression analysis showed that the relative gene expressions were all highly correlated with the transcriptome data. The results of this study provide a basis for further investigation of the complex regulatory mechanisms of fucoxanthin in P. tricornutum.

Photosynthetic Pigment and Carbohydrate Profiling of Fucus vesiculosus from an Iberian Coastal Lagoon

Fucus vesiculosus is a brown seaweed with applications in the food, pharmaceutic, and cosmetic industries. Among its most valuable bioactive compounds are the pigment fucoxanthin and polysaccharides (e.g., fucoidans). In this study, we profiled the photosynthetic pigments and carbohydrates of F. vesiculosus from six locations along the Ílhavo Channel in the Iberian coastal lagoon of Ria de Aveiro, Portugal. Photosynthetic performance (Fv/Fm), pigment, and carbohydrate concentrations were similar between locations, despite differences in environmental factors, such as salinity and periods of exposure to desiccation. Concentration of total carbohydrates (neutral sugars + uronic acids) averaged 418 mg g^-1 dw. Fucose was the second most abundant neutral sugar, with an average concentration of 60.7 mg g^-1 dw, indicating a high content of fucoidans. Photosynthetic pigments included chlorophylls a and c, β,β-carotene, and the xanthophylls fucoxanthin, violaxanthin, antheraxanthin, and zeaxanthin. Concentrations of fucoxanthin were higher than those reported for most brown macroalgae, averaging 0.58 mg g^-1 dw (65% of total carotenoids). This study indicates that F. vesiculosus from Ria de Aveiro is a valuable macroalgal resource for aquaculture companies operating in the region, with considerable potential to yield high-value bioactive compounds.

Characterization and Antioxidant Evaluation of Four Kinds of Marine Oils in vitro

The objective of this study was to characterize the lipid class and fatty acid composition of four kinds of marine oils including Phaeodactylum tricornutum oil (PO), Laminaria japonica oil (LO), krill oil (KO) and fish oil (FO), and evaluate their antioxidant capacities in vitro. The results indicated that compared to other three oils, PO showed the highest contents of total lipids and fucoxanthin (194.70 and 7.48 mg/g dry weight, respectively), the relatively higher content of long-chain polyunsaturated fatty acids including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) (30.94 % in total fatty acids), and total phenolic content (675.88 mg gallic acid equivalent /100 g lipids), thereby contribute to great advantages in scavenging free radicals such as 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2-azino-bis (3-ethylbenzthiazoline)-6-sulfonic acid (ABTS), peroxyl radical, as well as reducing FRAP value. In conclusion, PO should be considered as a potential ingredient for dietary supplement with antioxidant capacity.

Tisochrysis lutea as a Substrate for Lactic Acid Fermentation: Biochemical Composition, Digestibility, and Functional Properties

Microalgae, because of their high nutritional value and bioactive molecule content, are interesting candidates for functional foods, including fermented foods, in which the beneficial effects of probiotic bacteria combine with those of biomolecules lying in microalgal biomass. The aim of this work was to evaluate the potential of Tisochrysis lutea F&M-M36 as a substrate for Lactiplantibacillus plantarum ATCC 8014 and to verify fermentation effects on functionality. Bacterium selection among three lactobacilli was based on growth and resistance to in vitro digestion. Microalgal raw biomass and its digested residue were fermented in two matrixes, water and diluted organic medium, and analysed for biochemical composition and antioxidant activity along with their unfermented counterparts. Bacterial survivability to digestion and raw biomass digestibility after fermentation were also evaluated. Fucoxanthin was strongly reduced (>90%) in post-digestion residue, suggesting high bioavailability. Raw biomass in diluted organic medium gave the highest bacterial growth (8.5 logCFU mL^-1) and organic acid production (5 mg L^-1), while bacterial survivability to digestion (<3%) did not improve. After fermentation, the antioxidant activity of lipophilic extracts increased (>90%). Fermentation appears an interesting process to obtain T. lutea-based functional foods, although further investigations are needed to optimize bacterial growth and fully evaluate its effects on functionality and organoleptic features.

Free radical scavenging synergism of fucoxanthin with lipophilic plant products

Fucoxanthin demonstrates potential bioactivity, gaining greater interest with many prospective applications. The fundamental activity of fucoxanthin is antioxidant. However, some findings also report the pro-oxidant potential of carotenoids in particular concentrations and environments. In many applications, fucoxanthin requires additional materials to improve bioavailability and stability, such as lipophilic plant products (LPP). Despite much-growing evidence, little is known how fucoxanthin interacts with LPP, which is susceptible to an oxidative reaction. We hypothesised that lower concentration of fucoxanthin exerts a synergistic effect in combination with LPP. The low molecular weight of LPP may exhibit greater activity than long-chain LPP, and so it does with the concentration of unsaturated moieties. We performed free radical-scavenging assay of fucoxanthin combined with some essential oils and edible oils. Chou-Talalay theorem was employed to depict the combination effect. The current study demonstrates a staple finding and constitutes theoretical viewpoints before further fucoxanthin's utilization with LPP.

Dietary Protective Potential of Fucoxanthin as an Active Food Component on Neurological Disorders

The prevalence of neurodegenerative, cerebrovascular, and psychiatric diseases and other neurological disorders has increased dramatically worldwide. Fucoxanthin is an algal pigment with many biological functions, and there is rising evidence that fucoxanthin plays a preventive and therapeutic role in neurological disorders. This review focuses on the metabolism, bioavailability, and blood-brain barrier penetration of fucoxanthin. Furthermore, the neuroprotective potential of fucoxanthin in neurodegenerative diseases, cerebrovascular diseases, and psychiatric diseases as well as other neurological disorders such as epilepsy, neuropathic pain, and brain tumors by acting on multiple targets will be summarized. The multiple targets include regulating apoptosis, reducing oxidative stress, activating the autophagy pathway, inhibiting Aβ aggregation, improving dopamine secretion, reducing α-synuclein aggregation, attenuating neuroinflammation, modulating gut microbiota, and activating brain-derived neurotrophic factor, etc. Additionally, we look forward to brain-targeted oral transport systems due to the low bioavailability and blood-brain barrier permeability of fucoxanthin. We also propose exploring the systemic mechanisms of fucoxanthin metabolism and transport through the gut-brain process and envision new therapeutic targets for fucoxanthin to act on the central nervous system. Finally, we propose dietary fucoxanthin delivery interventions to achieve preventive effects on neurological disorders. This review provides a reference for the application of fucoxanthin in the neural field.

Manipulation in Culture Conditions of Nanofrustulum shiloi for Enhanced Fucoxanthin Production and Isolation by Preparative Chromatography

Microalgae produce a variety of high-value chemicals including carotenoids. Fucoxanthin is also a carotenoid that has many physiological functions and biological properties. For this reason, the cost-effective production of fucoxanthin at an industrial scale has gained significant attention. In the proposed study, fucoxanthin production was aimed to be increased by altering the culture conditions of N. shiloi. The effect of light intensity aeration rate, different nitrogen sources, and oxidative stress on the biomass and fucoxanthin productivity have been discussed. Based on these results, the fucoxanthin increased to 97.45 ± 2.64 mg/g by adjusting the light intensity to 50 µmol/m²s, and aeration rate at 5 L/min using oxidative stress through the addition of 0.1 mM H₂O₂ and 0.1 mM NaOCl to the culture medium. Fucoxanthin was then purified with preparative HPLC using C₃₀ carotenoid column (10 mm × 250 mm, 5 μm). After the purification procedure, Liquid chromatography tandem mass spectrometry (LC-MS/MS) and UV-vis spectroscopy were employed for the confirmation of fucoxanthin. This study presented a protocol for obtaining and purifying considerable amounts of biomass and fucoxanthin from diatom by manipulating culture conditions. With the developed methodology, N. shiloi could be evaluated as a promising source of fucoxanthin at the industrial scale for food, feed, cosmetic, and pharmaceutical industries.

Combined analysis of chromatin accessibility and gene expression profiles provide insight into Fucoxanthin biosynthesis in Isochrysis galbana under green light

Isochrysis galbana, as a potential accumulator of fucoxanthin, has become a valuable material to develop functional foods for humans. Our previous research revealed that green light effectively promotes the accumulation of fucoxanthin in I. galbana, but there is little research on chromatin accessibility in the process of transcriptional regulation. This study was conducted to reveal the mechanism of fucoxanthin biosynthesis in I. galbana under green light by analyzing promoter accessibility and gene expression profiles. Differentially accessible chromatin regions (DARs)-associated genes were enriched in carotenoid biosynthesis and photosynthesis-antenna protein formation, including IgLHCA1, IgLHCA4, IgPDS, IgZ-ISO, IglcyB, IgZEP, and IgVDE. The motifs for the MYB family were also identified as candidates controlling metabolic regulation responses to green light culture of I. galbana, including IgMYB1, IgMYB2, IgMYB33, IgMYB42, IgMYB98, IgMYB118, and IgMYB119. The results of differential expression analysis and WGCNA showed that several genes or transcription factors (TFs) related to carotenoid metabolism and photosynthesis exhibited a higher expression level and were significantly upregulated in A-G5d compared with A-0d and A-W5d, including IgMYB98, IgLHCA1, IgLHCX2, IgLHCB4, and IgLHCB5. This suggests that upregulation of these genes by green light may be the key factor leading to fucoxanthin accumulation by regulating the photosynthesis-antenna protein pathway. An integrated analysis of ATAC-seq and RNA-seq showed that 3 (IgphoA, IgPKN1, IgOTC) of 34 DARs-associated genes displayed obvious changes in their chromatin regions in ATAC-seq data, suggesting that these genes specific for green light may play a key role in fucoxanthin biosynthesis in I. galbana through a complex regulatory network of multiple metabolic pathways interacting with each other. These findings will facilitate in-depth understanding the molecular regulation mechanisms of fucoxanthin in I. galbana and its role in response to green light regulation, providing technical support for the construction of high fucoxanthin content strains.

Effects of Different Nitrogen Concentrations on Co-Production of Fucoxanthin and Fatty Acids in Conticribra weissflogii

Fucoxanthin and fatty acids are active substances that are beneficial to the growth and immunity of humans and aquatic animals. However, relatively few species have been exploited for fucoxanthin and fatty acids in the industry. At the same time, due to its low extract content, poor stability, high production cost, and serious seasonal and regional limitations, the industry cannot normally meet the greater demand of the international market. Therefore, this experiment seeks to improve the fucoxanthin and fatty acid content of C. weissflogii by adjusting the nitrogen concentration in the culture medium. It was found that when the nitrogen concentration was 150 mg L^-1, the cell number was 1.5 × 10⁶ cell mL^-1, and the average biomass was 0.75 g L^-1. The mean value of carotenoid concentration was 2.179 mg L^-1. The average concentration of fucoxanthin was 1.547 mg g^-1. When the nitrogen concentration was 75 mg L^-1, the fatty acid content reached its highest. By adjusting the concentration of nitrogen, the contents of fucoxanthin and fatty acids were increased. The results provided a theoretical basis for commercial extraction of fucoxanthin and fatty acids and further promoted the industrialization of fucoxanthin and fatty acids.

Bioactive Compounds from Brown Algae Alleviate Nonalcoholic Fatty Liver Disease: An Extensive Review

Nonalcoholic fatty liver disease (NAFLD) is one of the most prevalent chronic liver diseases. The increasing NAFLD incidences are associated with unhealthy lifestyles. Currently, there are no effective therapeutic options for NAFLD. Thus, there is a need to develop safe, efficient, and economic treatment options for NAFLD. Brown algae, which are edible, contain abundant bioactive compounds, including polysaccharides and phlorotannins. They have been shown to ameliorate insulin resistance, as well as hepatic steatosis, and all of these biological functions can potentially alleviate NAFLD. Accumulating reports have shown that increasing dietary consumption of brown algae reduces the risk for NAFLD development. In this review, we summarized the animal experiments and clinical proof of brown algae and their bioactive compounds for NAFLD treatment within the past decade. Our findings show possible avenues for further research into the pathophysiology of NAFLD and brown algae therapy.

Real time monitoring and evaluation of the inhibition effect of fucoxanthin against α-amylase activity by using QCM-A

The main symptoms of diabetes are hyperglycemia and insulin resistance. The inhibition of the starch digestion enzymes could effectively regulate starch digestion and glucose absorption, thereby slowing or treating the symptoms of postprandial hyperglycemia. Herein, we used fucoxanthin isolated from Undaria pinnatifida stems, as α-amylase inhibitor, and monitored the interactions of both biomolecules by using quartz crystal microbalance-admittance (QCM-A) instrument. All the processes of α-amylase hydrolysis of starch were also dynamically tracked by using amylose-immobilized QCM technology. In our work, we found that the kinetic parameter (k _off, k _on, and k _cat) values obtained by the QCM-A analysis were relatively consistent compared to the kinetic parameter values obtained by the conventional Michaelis-Menten analysis. For the inhibitory reactions, the results showed that fucoxanthin significantly reduced the activity of α-amylase in a dose-dependent manner. The QCM-A technology shown to be an excellent approach in obtaining comprehensive and accurate kinetic parameters, thereby providing real and accurate data for kinetic studies. It is helpful to clarify the mechanism of action of fucoxanthin on α-amylase, which further proved the potential of fucoxanthin to improve and treat postprandial hyperglycemia.

Bixin and Fuxoxanthin Alone and in Combination with Cisplatin Regulate ABCC1 and ABCC2 Transcription in A549 Lung Cancer Cells

Background

The ATP-Binding Cassette (ABC) transporter has long been studied to confer drug resistance in human tumors and play important role in metabolic processes and cellular signaling. The overexpression of ABCB1, ABCC1, ABCC2, ABCC3, and ABCG2 leads to decreased sensitivity of lung cancer to cisplatin. At the transcription level, the expression of ABC transporters is highly regulated and requires the complex interplay of factors involved in differentiation and development, cell survival and apoptosis upon intrinsic and environmental stress. The p53 regulation of drug-resistance genes is also complex yet not well understood. Previously, we demonstrated the synergistic interaction between bixin or fucoxanthin with cisplatin in A549 lung cancer cells.

Objectives

Current study aims to identify whether carotenoids enhancing therapeutic effect of Cisplatin due to the ability to reverse drug resistance associated proteins, such as ABC transporter and regulating the tumor suppressor corresponding gene, p53.

Methods

Real-Time Quantitative-Polymerase Chain Reaction (RT-qPCR) was performed to estimate the expression level of ABCC1 and ABCC2, and p53 of A549 cell lines in response to carotenoids alone and in combination with cisplatin.

Results and Conclusion

The administration of bixin or fucoxanthin decreases the expression of ABCC1 and ABCC2. Both carotenoids, either alone or in combination with cisplatin, upregulated p53 gene expression indicating the mechanism of proliferation inhibition and apoptosis occurs via the p53 caspase-independent pathway.