Fucoxanthin Activates Apoptosis via Inhibition of PI3K/Akt/mTOR Pathway and Suppresses Invasion and Migration by Restriction of p38-MMP-2/9 Pathway in Human Glioblastoma Cells

Marine-Derived Anticancer Agents Targeting Apoptotic Pathways: Exploring the Depths for Novel Cancer Therapies

Extensive research has been conducted on the isolation and study of bioactive compounds derived from marine sources. Several natural products have demonstrated potential as inducers of apoptosis and are currently under investigation in clinical trials. These marine-derived compounds selectively interact with extrinsic and intrinsic apoptotic pathways using a variety of molecular mechanisms, resulting in cell shrinkage, chromatin condensation, cytoplasmic blebs, apoptotic bodies, and phagocytosis by adjacent parenchymal cells, neoplastic cells, or macrophages. Numerous marine-derived compounds are currently undergoing rigorous examination for their potential application in cancer therapy. This review examines a total of 21 marine-derived compounds, along with their synthetic derivatives, sourced from marine organisms such as sponges, corals, tunicates, mollusks, ascidians, algae, cyanobacteria, fungi, and actinobacteria. These compounds are currently undergoing preclinical and clinical trials to evaluate their potential as apoptosis inducers for the treatment of different types of cancer. This review further examined the compound's properties and mode of action, preclinical investigations, clinical trial studies on single or combination therapy, and the prospective development of marine-derived anticancer therapies.

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.

Combretastatin A-4 suppresses the invasive and metastatic behavior of glioma cells and induces apoptosis in them: in-vitro study

The most common primary brain malignancy, glioblastoma multiforme, is tremendously resistant to conventional treatments due to its potency for metastasis to surrounding brain tissue. Temozolomide is a chemotherapeutic agent that currently is administrated during the treatment procedure. Studies have attempted to investigate new agents with higher effectiveness and fewer side effects. Combretastatin A-4 (CA-4), a natural compound derived from Combretum caffrum, has been recently considered for its potent antitumor activities in a wide variety of preclinical solid tumor models. Our findings have shown that CA-4 exerts potent anti-proliferative and apoptotic effects on glioma cells, and ROS generation may be involved in these cellular events. CA-4 has imposed G2 arrest in U-87 cells. We also observed that CA-4 significantly reduced the migration and invasion capability of U-87 cells. Furthermore, the gene expression and enzyme activity of MMP-2 and MMP-9 were significantly inhibited in the presence of CA-4. We also observed a considerable decrease in PI3K and Akt protein expression following treatment with CA-4. In conclusion, our findings showed significant apoptogenic and anti-metastatic effects of CA-4 on glioma cells and also suggested that the PI3K/Akt/MMP-2/-9 and also ROS pathway might play roles in these cellular events.

Fucoxanthin exert dose-dependent antifibrotic and anti-inflammatory effects on CCl4-induced liver fibrosis

The lack of an effective non-surgical liver fibrosis treatment is a major problem in hepatology. Fucoxanthin is a marine xanthophyll that exhibits anti-inflammatory, antioxidant, and hepatoprotective properties, thereby indicating its potential effectiveness in the treatment of liver fibrosis. The study aims to investigate the antifibrotic and anti-inflammatory effects of fucoxanthin and its main mechanisms on carbon tetrachloride (CCl4)-induced liver fibrosis in 50 outbred ICR/CD1 mice. 2 μl/g of CCl4 were injected intraperitoneally 2 times a week for 6 weeks. Fucoxanthin (5, 10, 30 mg/kg) was administered via gavage. Liver histopathology was evaluated by Hematoxylin-Eosin (H&E) and Sirius Red staining using the METAVIR scale. The immunohistochemical method was used to determine the number of CD45 and α-smooth muscle actin (α-SMA) positive cells, and tissue inhibitor of matrix metalloproteinases-1 (TIMP-1), matrix metalloproteinase-9 (MMP-9), and α-SMA positive areas. Using enzyme immunoassays, procollagen 1 (COL1A1), transforming growth factor-β (TGF-β), and hepatocyte growth factor (HGF) were determined in homogenate, and interleukin-1ß (IL-1ß) and tumor necrosis factor-α (TNF-α) were determined in blood serum. Serum alanine aminotransferase (ALT) and aspartate transaminase (AST) activity, albumin (ALB), and total bilirubin (Tbil) levels are determined by biochemical assays. Fucoxanthin significantly reduced the severity of liver fibrosis, profibrogenic markers, inflammatory infiltration, and pro-inflammatory cytokines. In summary, we confirmed that fucoxanthin has a dose-dependent antifibrotic effect on CCl4-induced liver fibrosis. We found that the anti-inflammatory effect of fucoxanthin is related to the inhibition of IL-1β and TNF-α synthesis, as well as the decrease in the number of leukocytes in the injured liver.

Epigenetic drugs as new emerging therapeutics: What is the scale's orientation of application and challenges?

Epigenetics is the study of heritable changes in gene expression or function without altering the DNA sequence. Important factors are part of epigenetic events, such as methylation, DNA histone rearrangements, nucleosome transposition, and non-coding RNAs. Dysregulated epigenetic mechanics are associated with various cancers' initiation, development, and metastasis. It is known that the occurrence and development of cancer can be controlled by regulating unexpected epigenetic events. Epi-drugs are used singly or in combination with chemotherapy and enhance antitumor activity, reduce drug resistance, and stimulate the host immune response. Despite these benefits, epigenetic therapy as a single therapy or in combination with other drugs leads to adverse effects. This review article introduces and compares the advantages, disadvantages, and side effects of using these drugs for the first time since their introduction. Also, this article describes the mechanism of action of various epigenetic drugs. Recommendations for future use of epigenetic drugs as cancer therapeutics are suggested as an overall conclusion.

Fucoxanthin triggers ferroptosis in glioblastoma cells by stabilizing the transferrin receptor

Glioblastoma (GBM) is the most common and lethal tumor in the world, possessing high stemness, aggressiveness and resistance. Fucoxanthin is a bio-active compound extracted from seaweeds that shows anti-tumor effects to different types of tumors. Here, we show that fucoxanthin inhibits the survival of GBM cells by triggering ferroptosis, a ferric ion and reactive oxygen species (ROS) dependent cell death and ferrostatin-1 could block it. Furthermore, we identified that fucoxanthin targets the transferrin receptor (TFRC). Fucoxanthin is able to block degradation and maintain high levels of TFRC, and similarly inhibits the growth of GBM xenografts in vivo, downregulates the expression of proliferating cell nuclear antigen (PCNA) and upregulates the levels of TFRC in tumor tissues. In conclusion, we demonstrate that fucoxanthin has a significant anti-GBM effect by triggering ferroptosis.

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.

Progress in targeting PTEN/PI3K/Akt axis in glioblastoma therapy: Revisiting molecular interactions

Glioblastoma (GBM) is one of the most malignant cancers of central nervous system and due to its sensitive location, surgical resection has high risk and therefore, chemotherapy and radiotherapy are utilized for its treatment. However, chemoresistance and radio-resistance are other problems in GBM treatment. Hence, new therapies based on genes are recommended for treatment of GBM. PTEN is a tumor-suppressor operator in cancer that inhibits PI3K/Akt/mTOR axis in diminishing growth, metastasis and drug resistance. In the current review, the function of PTEN/PI3K/Akt axis in GBM progression is evaluated. Mutation or depletion of PTEN leads to increase in GBM progression. Low expression level of PTEN mediates poor prognosis in GBM and by increasing proliferation and invasion, promotes malignancy of tumor cells. Moreover, loss of PTEN signaling can result in therapy resistance in GBM. Activation of PTEN signaling impairs GBM metabolism via glycolysis inhibition. In contrast to PTEN, PI3K/Akt signaling has oncogenic function and during tumor progression, expression level of PI3K/Akt enhances. PI3K/Akt signaling shows positive association with oncogenic pathways and its expression similar to PTEN signaling, is regulated by non-coding RNAs. PTEN upregulation and PI3K/Akt signaling inhibition by anti-cancer agents can be beneficial in interfering GBM progression. This review emphasizes on the signaling networks related to PTEN/PI3K/Akt and provides new insights for targeting this axis in effective GBM treatment.

Carotenoids in Drug Discovery and Medicine: Pathways and Molecular Targets Implicated in Human Diseases

Carotenoids are isoprenoid-derived natural products produced in plants, algae, fungi, and photosynthetic bacteria. Most animals cannot synthesize carotenoids because the biosynthetic machinery to create carotenoids de novo is absent in animals, except arthropods. Carotenoids are biosynthesized from two C20 geranylgeranyl pyrophosphate (GGPP) molecules made from isopentenyl pyrophosphate (IPP) and dimethylallyl pyrophosphate (DMAPP) via the methylerythritol 4-phosphate (MEP) route. Carotenoids can be extracted by a variety of methods, including maceration, Soxhlet extraction, supercritical fluid extraction (SFE), microwave-assisted extraction (MAE), accelerated solvent extraction (ASE), ultrasound-assisted extraction (UAE), pulsed electric field (PEF)-assisted extraction, and enzyme-assisted extraction (EAE). Carotenoids have been reported to exert various biochemical actions, including the inhibition of the Akt/mTOR, Bcl-2, SAPK/JNK, JAK/STAT, MAPK, Nrf2/Keap1, and NF-κB signaling pathways and the ability to increase cholesterol efflux to HDL. Carotenoids are absorbed in the intestine. A handful of carotenoids and carotenoid-based compounds are in clinical trials, while some are currently used as medicines. The application of metabolic engineering techniques for carotenoid production, whole-genome sequencing, and the use of plants as cell factories to produce specialty carotenoids presents a promising future for carotenoid research. In this review, we discussed the biosynthesis and extraction of carotenoids, the roles of carotenoids in human health, the metabolism of carotenoids, and carotenoids as a source of drugs and supplements.

Fucoxanthin: A Promising Phytochemical on Diverse Pharmacological Targets

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

Brown Algae as Functional Food Source of Fucoxanthin: A Review

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

PEI-PEG-Coated Mesoporous Silica Nanoparticles Enhance the Antitumor Activity of Tanshinone IIA and Serve as a Gene Transfer Vector

Tanshinone IIA (TanIIA) and gene therapy both hold promising potentials in hepatocellular carcinoma (HCC) treatment. However, low solubility and poor bioavailability of TanIIA limit its clinical application. Similarly, gene therapy with GPC3-shRNA, a type of short hairpin RNAs (shRNAs) capable of silencing the glypican-3 (GPC3) expression, is seriously limited due to its susceptibility to nuclease degradation and high off-target effects. In the present study, polyethyleneimine (PEI)-polyethylene glycol (PEG)-coated mesoporous silica nanoparticles (MSN-PEG) were used as a drug carrier. By encapsulating TanIIA into MSN-PEG, we synthesized MSN-TanIIA-PEG nanoparticles and observed the involved characteristics. This was followed by exploration of antitumor activity on the HepG2 cell lines in vitro. Meanwhile, in order to construct GPC3-shRNA plasmids, a shRNA sequence targeting GPC3 was synthesized and cloned into the pSLenti-U6 vector. Accordingly, the performance of MSN-PEG as a gene transfer carrier for GPC3-shRNA gene therapy of HCC in vitro was evaluated, including transfection efficiency and DNA binding biological characteristics. The results indicated successful encapsulation of TanIIA in MSN-PEG, which had satisfactory efficacy, favorable dispersity, suitable particle size, and sustained release effect. The in vitro anti-HCC effects of nano-TanIIA were greatly improved, which outperformed free-TanIIA in terms of proliferation and invasion inhibition, as well as apoptosis induction of HCC cells. As expected, MSN-PEG possessed excellent gene delivery capacity with good binding, release, and protection from RNase digestion. Using MSN-PEG as a gene carrier, the plasmids were successfully transfected into HepG2 cells, and both the mRNA and protein expressions of GPC3 were significantly downregulated. It was thus concluded that a sustained release TanIIA delivery system for HCC treatment was synthesized and that MSN-PEG could also serve as a gene transfer carrier for gene therapy. More interestingly, MSN-PEG may be a potential delivery platform that combines TanIIA and GPC3-shRNA together to enhance their synergistic effect.

Suppression of C-C chemokine receptor 1 is a key regulation for colon cancer chemoprevention in AOM/DSS mice by fucoxanthin

Fucoxanthin (Fx) has shown potential cancer chemopreventive functions in a carcinogenic murine azoxymethane/dextran sodium sulfate (AOM/DSS) model. However, the molecular mechanisms based on transcriptome profiles in vivo remain poorly understood. We investigated Fx-dependent alterations of the transcriptome with cancer-associated proteins in colorectal mucosal tissue obtained from AOM/DSS mice with or without Fx treatment. Fx administration (50 mg/kg body weight for 14 weeks) significantly prevented the onset of colorectal adenocarcinoma in AOM/DSS mice. A transcriptome analysis revealed that 11 signals, including adhesion, cell cycle, chemokine receptor, interleukin, MAPK, PI3K/AKT, p53, RAS, STAT, TGF-β, and Wnt were remarkably altered by Fx administration. In particular, chemokine (C-C motif) receptor 1 (Ccr1), which is contained in a gene set related to cytokine-cytokine receptor interactions, was the only significantly down-regulated gene after Fx administration for both 7 and 14 weeks. CCR1, AKT, Cyclin D1, and Smad2 were found to play central roles in the 11 signals shown above. Fx administration significantly down-regulated CCR1 (0.3- and 0.5-fold in mucosal crypts and lamina propria, respectively), pAKT(Ser⁴⁷³) (0.2-fold in mucosal crypts), Cyclin D1 (0.4-fold in mucosal crypts), and pSmad2(Ser^465/467) (0.7-fold in mucosal crypts) compared with proteins in these tissues of control mice after Fx administration for 14 weeks. Our findings suggested that Fx exerts a chemopreventive effect in AOM/DSS mice through attenuation of CCR1 expression along with 11 cancer-associated signals.

Anti-Inflammatory and Anticancer Effects of Microalgal Carotenoids

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

Bioactive Compounds with Antiglioma Activity from Marine Species

The search for new chemical compounds with antitumor pharmacological activity is a necessary process for creating more effective drugs for each specific malignancy type. This review presents the outcomes of screening studies of natural compounds with high anti-glioma activity. Despite significant advances in cancer therapy, there are still some tumors currently considered completely incurable including brain gliomas. This review covers the main problems of the glioma chemotherapy including drug resistance, side effects of common anti-glioma drugs, and genetic diversity of brain tumors. The main emphasis is made on the characterization of natural compounds isolated from marine organisms because taxonomic diversity of organisms in seawaters significantly exceeds that of terrestrial species. Thus, we should expect greater chemical diversity of marine compounds and greater likelihood of finding effective molecules with antiglioma activity. The review covers at least 15 classes of organic compounds with their chemical formulas provided as well as semi-inhibitory concentrations, mechanisms of action, and pharmacokinetic profiles. In conclusion, the analysis of the taxonomic diversity of marine species containing bioactives with antiglioma activity is performed noting cytotoxicity indicators and to the tumor cells in comparison with similar indicators of antitumor agents approved for clinical use as antiglioblastoma chemotherapeutics.

Experimental evidence and mechanism of action of some popular neuro-nutraceutical herbs

Brain and neuronal circuits constitute the most complex organ networks in human body. They not only control and coordinate functions of all other organs, but also represent one of the most-affected systems with stress, lifestyle and age. With global increase in aging populations, these neuropathologies have emerged as major concern for maintaining quality of life. Recent era has witnessed a surge in nutritional remediation of brain dysfunctions primarily by "nutraceuticals" that refer to functional foods and supplements with pharmacological potential. Specific dietary patterns with a balanced intake of carbohydrates, fatty acids, vitamins and micronutrients have also been ascertained to promote brain health. Dietary herbs and their phytochemicals with wide range of biological and pharmacological activities and minimal adverse effects have gained remarkable attention as neuro-nutraceuticals. Neuro-nutraceutical potentials of herbs are often expressed as effects on cognitive response, circadian rhythm, neuromodulatory, antioxidant and anti-inflammatory activities that are mediated by effects on gene expression, epigenetics, protein synthesis along with their turnover and metabolic pathways. Epidemiological and experimental evidence have implicated enormous applications of herbal supplementation in neurodegenerative and psychiatric disorders. The present review highlights the identification, experimental evidence and applications of some herbs including Bacopa monniera, Withania somnifera, Curcuma longa, Helicteres angustifolia, Undaria pinnatifida, Haematococcus pluvialis, and Vitis vinifera, as neuro-nutraceuticals.

The Healthy Taiwanese Eating Approach is inversely associated with all-cause and cause-specific mortality: A prospective study on the Nutrition and Health Survey in Taiwan, 1993-1996

Background

Few longitudinal studies have investigated the association between foods/dietary pattern and mortality risk in the Asian population. We investigated the prospective association between foods/dietary pattern and risk of death among ethnic Chinese adults in Taiwan.

Methods

The study population included 2475 young and middle-aged adults (aged 18–65 years at baseline) who completed the questionnaires and physical examinations in the Nutrition and Health Survey in Taiwan from 1993 to 1996. A food frequency questionnaire was administered to assess food consumption habits in a face-to-face interview. With survey data linked to the Taiwanese Death Registry, Cox proportional hazard model was used to identify the foods associated with all-cause mortality(followed until 2012), which were then tallied to calculate a dietary pattern score called Taiwanese Eating Approach(TEA) score. The TEA scores were then associated with various kinds of mortality outcomes. In addition, data from 431 elders (aged≥65 yrs) with 288 death endpoints were used to conduct a sensitivity analysis.

Results

A total of 385(15.6%) participants died (111 cardiovascular related deaths and 122 cancer related deaths) during the 17.8-year follow-up period(41274 person-years). Twelve foods (9 inverse [vegetables/fish/milk/tea](+1) and 3 positive[fatty meats/fermented vegetables/sweet drinks](-1)) were significantly associated with all-cause mortality risk. All adults were grouped by their cumulative food score into three diet groups: poor diet(29.3% of all subjects), average diet(44.0%), and healthy diet(26.70%). The better the diet, the lower the total, cardiovascular, and other cause mortality outcomes (trend-p < .001). The hazard ratio for the healthy diet was 0.64 (95% confidence interval:0.47–0.87) for total mortality, and 0.52(0.28–0.95) for cardiovascular death, compared with the poor diet in the multivariable models. This phenomenon was also seen in older adults for all-cause, cancer, and other cause mortalities.

Conclusion

Consuming a healthy Taiwanese Eating Approach (TEA) diet is negatively associated with all-cause, cardiovascular, and other-cause mortalities in Taiwan.

BIRB796, an Inhibitor of p38 Mitogen-Activated Protein Kinase, Inhibits Proliferation and Invasion in Glioblastoma Cells

Glioblastoma (GBM) is the most common malignant tumor, and it is characterized by high cellular proliferation and invasion in the central nervous system of adults. Due to its high degree of heterogeneity and mortality, there is no effective therapy for GBM. In our study, we investigated the effect of the p38-MAPK signaling pathway inhibitor BIRB796 on GBM cells. Cell Counting Kit-8 (CCK-8) assay, 5-ethynyl-2'-deoxyuridine (EDU) staining, and cell cycle distribution analysis were performed, and the results showed that BIRB796 decreased proliferation in U87 and U251 cells. Moreover, wound healing and invasion assays were performed, which showed that BIRB796 inhibited the migration and invasion of human GBM cells. We found that BIRB796 treatment significantly decreased the formation of the cytoskeleton and thus downregulated the movement ability of the cells, as shown by phalloidin staining and vimentin immunofluorescence staining. Real-time polymerase chain reaction showed that the mRNA levels of MMP-2, Vimentin, CyclinD1, and Snail-1 were downregulated. Consistently, the expressions of MMP-2, Vimentin, CyclinD1, and p-p38 were also decreased after BIRB796 treatment. Taken together, all our results demonstrated that BIRB796 could play an antitumor role by inhibiting the proliferation and invasion in GBM cells. Thus, BIRB796 may be used as an adjuvant therapy to improve the therapeutic efficacy of GBM treatment.

Effect of Fucoxanthinol on Pancreatic Ductal Adenocarcinoma Cells from an N-Nitrosobis(2-oxopropyl)amine-initiated Syrian Golden Hamster Pancreatic Carcinogenesis Model

BACKGROUND/AIM

Fucoxanthinol (FxOH) is a marine carotenoid metabolite with potent anti-cancer activity. However, little is known about the efficacy of FxOH in pancreatic cancer. In the present study, we investigated the inhibitory effect of FxOH on six types of cells cloned from N-nitrosobis(2-oxopropyl)amine (BOP)-induced hamster pancreatic cancer (HaPC) cells.

MATERIALS AND METHODS

FxOH action and its molecular mechanisms were investigated in HaPC cells using flow-cytometry, comprehensive gene array, and western blotting analyses.

RESULTS

FxOH (5.0 μM) significantly suppressed the growth of four out of six types of HaPC cells. Moreover, FxOH significantly suppressed cell cycle, chemokine, integrin, actin polymerization, microtubule organization and PI3K/AKT and TGF-β signals, and activated caspase-3 followed by apoptosis and anoikis induction in HaPC-5 cells.

CONCLUSION

FxOH may have a high potential as a cancer chemopreventive agent in a hamster pancreatic carcinogenesis model.

ARID4B Knockdown Suppresses PI3K/AKT Signaling and Induces Apoptosis in Human Glioma Cells

PURPOSE

Glioblastoma multiforme is a highly malignant primary brain cancer with a poor prognosis. We recently reported that ARID4B could potentially serve as a biomarker associated with poor survival in glioma patients. However, the function of ARID4B in human gliomas remains unclear. The aim of this study is to investigate the molecular cell biology role of ARID4B in human glioma cells.

MATERIALS AND METHODS

Gene Expression Omnibus (GEO) and Human Protein Atlas (HPA) datasets were analyzed for the expression of ARID4B in WHO pathological grading, overall survival and immunohistochemical staining. Using quantitative RT-PCR and Western blotting, those findings were confirmed in normal brain tissue and glioma cell lines. ARID4B knockdown was conducted via lentivirus-based transfection of small hairpin RNA in human glioma cells to investigate cell proliferation, cell cycle, and apoptosis.

RESULTS

In the present study, our analysis of GEO datasets showed that ARID4B mRNA expression is higher in WHO grade IV tumors (n = 81) than in non-tumor control tissue (n = 23, P <0.0001). ARID4B knockdown suppressed glioma cell proliferation and induced G1 phase arrest via the PI3K/AKT pathway. It also increased expression of HDAC1, leading to higher acetyl-p53 and acetyl-H3 levels and reduced glioma cell migration and invasion. These effects were mediated via downregulation of AKT pathway components, including p-mTOR, p-PI3K and p-AKT. ARID4B knockdown also led to downregulation of Cyclin D1, which increased apoptosis in human glioma cells.

CONCLUSION

These findings that ARID4B expression correlates positively with WHO pathologic grading in glioma. ARID4B knockdown suppresses PI3K/AKT signaling and induces apoptosis in human glioma cells. These results suggests that ARID4B acts as an oncogene in human gliomas.

A Fucoxanthinol Induces Apoptosis in a Pancreatic Intraepithelial Neoplasia Cell

BACKGROUND/AIM

Fucoxanthinol (FxOH), a predominant metabolite from fucoxanthin (Fx), can exert potential anti-cancer effects in various cancers. However, limited data are available on the effect of FxOH or Fx on pancreatic cancer. The present study investigated the effect of FxOH on a cell line derived from pancreatic cancer tissue developed in Ptf1aCre/+; LSL-k-rasG12D/+ mice.

MATERIALS AND METHODS

Using flow-cytometric, microarrays, and western blotting analyses, alterations in FxOH-induced apoptosis-related gene expression and protein levels were evaluated in a mice pancreatic cancer cell line, KMPC44.

RESULTS

FxOH significantly arrested the cells at S phase along with suppression of many gene sets, such as cytokine- cytokine receptor interaction and cell adhesion molecule CAMS. Moreover, attenuated protein levels for cytokine receptors, adhesion, phosphatidylinositol-3 kinase/protein kinase B, and mitogen-activated protein kinase were observed.

CONCLUSION

FxOH may prevent pancreatic cancer development in a murine cancer model.

A Marine Carotenoid of Fucoxanthinol Accelerates the Growth of Human Pancreatic Cancer PANC-1 Cells

Fucoxanthin and its metabolite fucoxanthinol (FxOH), highly polar xanthophylls, exert strong anticancer effects against many cancer cell types. However, the effects of Fx and FxOH on pancreatic cancer, a high mortality cancer, remain unclear. We herein investigated whether FxOH induces apoptosis in human pancreatic cancer cells. FxOH (5.0 μmol/L) significantly promoted the growth of human pancreatic cancer PANC-1 cells, but induced apoptosis in human colorectal cancer DLD-1 cells. A microarray-based gene analysis revealed that the gene sets of cell cycle, adhesion, PI3K/AKT, MAPK, NRF2, adipogenesis, TGF-β, STAT, and Wnt signals in PANC-1 cells were markedly altered by FxOH. A western blot analysis showed that FxOH up-regulated the expression of integrin β1 and PPARγ as well as the activation of pFAK(Tyr³⁹⁷), pPaxillin(Tyr³¹), and pAKT(Ser⁴⁷³) in PANC-1 cells, but exerted the opposite effects in DLD-1 cells. Moreover, the expression of FYN, a downstream target of integrin subunits, was up-regulated (7.4-fold by qPCR) in FxOH-treated PANC-1 cells. These results suggest that FxOH accelerates the growth of PANC-1 cells by up-regulating the expression of integrin β1, FAK, Paxillin, FYN, AKT, and PPARγ.

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

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

Fucoxanthin extracted from Laminaria Japonica inhibits metastasis and enhances the sensitivity of lung cancer to Gefitinib

ETHNOPHARMACOLOGICAL RELEVANCE

Laminaria japonica, a brown seaweed, has been used in Traditional Chinese Medicine (TCM) to treat a variety of diseases including lung cancer.

AIM OF THE STUDY

To demonstrate the effects of Fucoxanthin (FX), a major active component extracted from Laminaria japonica on metastasis and Gefitinib (Gef) sensitivity in human lung cancer cells both in vitro and in vivo.

MATERIALS AND METHODS

Invasion and migration of lung cancer cells were detected using the wound healing assay and transwell assay. Epithelial-to-mesenchymal transition (EMT) factors and PI3K/AKT/NF-κB pathways were analyzed by western blotting. RNA interference (RNAi) technology was used to silence TIMP-2 gene expression in A549 cells. The anti-metastatic effect of FX was evaluated in vivo in an experimental lung metastatic tumor model. On the other hand, cell counting kit-8 assay was used to study the cell viability of human lung cancer PC9 cells and Gef resistant PC9 cells (PC9/G) after Gef, FX or FX combined with Gef treatment. PC9 xenograft model was established to explore the anti-tumor effect of FX or combined with Gef. Immunohistochemistry staining assay and immunofluorescence staining assay were used to reveal the effects of FX on lung cancer cell proliferation and apoptosis.

RESULTS

FX was able to significantly inhibit lung cancer cells migration and invasion in vitro. FX suppressed the expressions of Snail, Twist, Fibronectin, N-cadherin, MMP-2, PI3K, p-AKT and NF-κB, and increased the expression of TIMP-2. Furthermore, knockdown of TIMP-2 attenuated FX-mediated invasion inhibition. Additionally, we demonstrated that FX inhibited lung cancer cells metastasis in vivo. The anti-metastatic effects of FX on lung cancer cells might be attributed to inhibition of EMT and PI3K/AKT/NF-κB pathway. We further demonstrated that the anti-tumor activity of FX was not only limited to the drug sensitive cell lines, but also prominent on lung cancer cells with Gef resistant phenotype. Furthermore, in vivo xenograft assay confirmed that FX inhibited tumor growth and enhanced the sensitivity of lung cancer cells to Gef and this effect may be due to inhibition of tumor cell proliferation and activation of apoptosis.

CONCLUSION

Collectively, our findings suggested that FX suppresses metastasis of lung cancer cells and overcomes EGFR TKIs resistance. Thus, FX is worthy of further investigation as a drug candidate for the treatment of lung cancer.

Advances in Studies on the Pharmacological Activities of Fucoxanthin

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

Carotenoids in Cancer Metastasis-Status Quo and Outlook

Metastasis represents a major obstacle in cancer treatment and the leading cause of cancer-related deaths. Therefore, the identification of compounds targeting the multi-step and complex process of metastasis could improve outcomes in the management of cancer patients. Carotenoids are naturally occurring pigments with a plethora of biological activities. Carotenoids exert a potent anti-cancer capacity in various cancer models in vitro and in vivo, mediated by the modulation of signaling pathways involved in the migration and invasion of cancer cells and metastatic progression, including key regulators of the epithelial-mesenchymal transition and regulatory molecules, such as matrix metalloproteinases (MMPs), tissue inhibitors of metalloproteinases (TIMPs), urokinase plasminogen activator (uPA) and its receptor (uPAR), hypoxia-inducible factor-1α (HIF-1α), and others. Moreover, carotenoids modulate the expression of genes associated with cancer progression and inflammatory processes as key mediators of the complex process involved in metastasis. Nevertheless, due to the predominantly preclinical nature of the known anti-tumor effects of carotenoids, and unclear results from certain carotenoids in specific cancer types and/or specific parts of the population, a precise analysis of the anti-cancer effects of carotenoids is essential. The identification of carotenoids as effective compounds targeting the complex process of cancer progression could improve the outcomes of advanced cancer patients.

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

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

Protein kinases as targets for developing anticancer agents from marine organisms

Protein kinases play a fundamental role in the intracellular transduction because of their ability to phosphorylate plethora of proteins. Over the past three decades, numerous protein kinase inhibitors have been identified and are being used clinically successfully. The biodiversity of marine organisms provides a rich source for the discovery and development of novel anticancer agents in the treatment of human malignancies and a lot of bioactive ingredients from marine organisms display anticancer effects by affecting the protein kinases-mediated pathways. In the present mini-review, anticancer compounds from marine source were reviewed and discussed in context of their targeted pathways associated with protein kinases and the progress of these compounds as anticancer agents in recent five years were emphasized. The molecular entities and their modes of actions were presented. We focused on protein kinases-mediated signaling pathways including PI3K/Akt/mTOR, p38 MAPK, and EGFR. The marine compounds targeting special pathways of protein kinases were highlighted. We have also discussed the existing challenges and prospects related to design and development of novel protein kinase inhibitors from marine sources.

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

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

Carotenoids in Cancer Apoptosis-The Road from Bench to Bedside and Back

An incidence and mortality of cancer are rapidly growing worldwide, especially due to heterogeneous character of the disease that is associated with irreversible impairment of cellular homeostasis and function. Targeting apoptosis, one of cancer hallmarks, represents a potent cancer treatment strategy. Carotenoids are phytochemicals represented by carotenes, xanthophylls, and derived compounds such as apocarotenoids that demonstrate a broad spectrum of anti-cancer effects involving pro-apoptotic signaling through extrinsic and intrinsic pathways. As demonstrated in preclinical oncology research, the apoptotic modulation is performed at post-genomic levels. Further, carotenoids demonstrate additive/synergistic action in combination with conventional oncostatic agents. In addition, a sensitization of tumor cells to anti-cancer conventional treatment can be achieved by carotenoids. The disadvantage of anti-cancer application of carotenoids is associated with their low solubility and, therefore, poor bioavailability. However, this deficiency can be improved by using nanotechnological approaches, solid dispersions, microemulsions or biofortification that significantly increase the anti-cancer and pro-apoptotic efficacy of carotenoids. Only limited number of studies dealing with apoptotic potential of carotenoids has been published in clinical sphere. Pro-apoptotic effects of carotenoids should be beneficial for individuals at high risk of cancer development. The article considers the utility of carotenoids in the framework of 3P medicine.

Health benefits of fucoxanthin in the prevention of chronic diseases

Fucoxanthin is a xanthophyll carotenoid abundant in macroalgae, such as brown seaweeds. When fucoxanthin is consumed, it can be esterified or hydrolyzed to fucoxanthinol in the gastrointestinal tract and further converted into amarouciaxanthin A in the liver. It has a unique chemical structure that confers its biological effects. Fucoxanthin has a strong antioxidant capacity by scavenging singlet molecular oxygen and free radicals. Also, it exerts an anti-inflammatory effect. Studies have demonstrated potential health benefits of fucoxanthin for the prevention of chronic diseases, such as cancer, obesity, diabetes mellitus, and liver disease. Animal studies have shown that fucoxanthin supplementation has no adverse effects. However, investigation of the safety of fucoxanthin consumption in humans is lacking. Clinical trials are required to assess the safety of fucoxanthin in conjunction with the study of mechanisms by which fucoxanthin exhibits its health benefits. This review focuses on current knowledge of metabolism and functions of fucoxanthin with its potential health benefits. This article is part of a Special Issue entitled Carotenoids recent advances in cell and molecular biology edited by Johannes von Lintig and Loredana Quadro.

Dietary Fucoxanthin Induces Anoikis in Colorectal Adenocarcinoma by Suppressing Integrin Signaling in a Murine Colorectal Cancer Model

Fucoxanthin (Fx), abundantly contained in edible brown algae, is a carotenoid with strong anti-cancer potential. Anoikis is an anchor-dependent apoptosis particularly related to integrin signaling, and a target for cancer preventive strategies. We recently demonstrated that Fx prevented colon cancer in azoxymethane-dextrane sodium sulfate (AOM/DSS) carcinogenic model mice, and that it increased anoikis-like integrin β1^low/-/cleaved caspase-3^high cells in colonic mucosal crypts. However, an induction mechanism of anoikis by Fx in adenocarcinoma tissue remains unresolved. Thus, we investigated anoikis in colonic adenocarcinoma in AOM/DSS mice. Fx administration (30 mg/kg body weight) significantly suppressed the incidence and multiplicity of colonic adenocarcinoma in AOM/DSS mice. A number of anoikis-like integrin β1^low/-/cleaved caspase-3^high cells in colonic adenocarcinoma and mucosal crypts were significantly increased, 8.3- and 3.5-fold in the Fx group compared with those of the control group, respectively. The results indicated the increase of anoikis-like cells occurred more strongly in colonic adenocarcinoma than in colonic mucosal crypts. In addition, integrin β1 expression, and pFAK (Tyr³⁹⁷) and pPaxillin (Tyr³¹) activation in mucosal tissue decreased 0.7-, 0.5- and 0.6-fold by Fx administration, respectively. The results suggest that Fx induces anoikis in colonic adenocarcinoma developed by AOM/DSS treatment through attenuation of integrin signaling.

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

BACKGROUND

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

AIM

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

METHODS

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

RESULTS AND DISCUSSION

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

CONCLUSION

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

Fucoxanthin and Rosmarinic Acid Combination Has Anti-Inflammatory Effects through Regulation of NLRP3 Inflammasome in UVB-Exposed HaCaT Keratinocytes

Excessive exposure to ultraviolet (UV) radiation is the main risk factor to develop skin pathologies or cancer because it encourages oxidative condition and skin inflammation. In this sense, strategies for its prevention are currently being evaluated. Natural products such as carotenoids or polyphenols, which are abundant in the marine environment, have been used in the prevention of oxidative stress due to their demonstrated antioxidant activities. Nevertheless, the anti-inflammatory activity and its implication in photo-prevention have not been extensively studied. Thus, we aimed to evaluate the combination of fucoxanthin (FX) and rosmarinic acid (RA) on cell viability, apoptosis induction, inflammasome regulation, and anti-oxidative response activation in UVB-irradiated HaCaT keratinocytes. We demonstrated for the first time that the combination of FX and RA (5 µM RA plus 5 μM FX, designated as M2) improved antioxidant and anti-inflammatory profiles in comparison to compounds assayed individually, by reducing UVB-induced apoptosis and the consequent ROS production. Furthermore, the M2 combination modulated the inflammatory response through down-regulation of inflammasome components such as NLRP3, ASC, and Caspase-1, and the interleukin (IL)-1β production. In addition, Nrf2 and HO-1 antioxidant genes expression increased in UVB-exposed HaCaT cells pre-treated with M2. These results suggest that this combination of natural products exerts photo-protective effects by down-regulating NRLP3-inflammasome and increasing Nrf2 signalling pathway.

Assessment of Potential Anticancer Activity of Brown Seaweed Compounds Using Zebrafish Phenotypic Assay

Despite the extensive work on anticancer drug discovery, the number of potent lead compounds that enter the preclinical and clinical trials thus far is still low due to the poor selectivity and understanding in pharmacodynamics. In view of the homology between zebrafish embryogenesis and carcinogenesis in human, zebrafish embryos can be used in the screening platform to elucidate the molecular targets of potential anticancer compounds. In the present study, the possible targets modulating the potential anticancer effects of selected brown seaweed-derived compounds (ie alginate, fucoidan, phloroglucinol, fucosterol, and fucoxanthin) were examined. Teratogenic effects induced by the compounds were observed after 72 hours post-fertilization. Fucoidan, phloroglucinol, and fucosterol were observed to significantly reduce the pigmentation of the zebrafish in a dose-dependent manner at low concentrations (fucoidan, <60 µg/mL; phloroglucinol, <10 µg/mL; fucosterol, <3 µg/mL). On the other hand, embryos treated with fucoxanthin at 200 µg/mL and 300 µg/mL exhibited either phenotypes of curved trunk or bent tail. Further validation work using dual antiplatelet therapy (DAPT) and dorsomorphin as positive controls suggest that fucoxanthin might target the Notch and bone morphogenetic protein (BMP) pathways, respectively. Findings from this exploratory study henceforth have demonstrated the utility of zebrafish embryo to accelerate the discovery of potential compounds for targeted anticancer therapy.

Rat Glioma Cell-Based Functional Characterization of Anti-Stress and Protein Deaggregation Activities in the Marine Carotenoids, Astaxanthin and Fucoxanthin

Stress, protein aggregation, and loss of functional properties of cells have been shown to contribute to several deleterious pathologies including cancer and neurodegeneration. The incidence of these pathologies has also been shown to increase with age and are often presented as evidence to the cumulative effect of stress and protein aggregation. Prevention or delay of onset of these diseases may prove to be unprecedentedly beneficial. In this study, we explored the anti-stress and differentiation-inducing potential of two marine bioactive carotenoids (astaxanthin and fucoxanthin) using rat glioma cells as a model. We found that the low (nontoxic) doses of both protected cells against UV-induced DNA damage, heavy metal, and heat-induced protein misfolding and aggregation of proteins. Their long-term treatment in glioma cells caused the induction of physiological differentiation into astrocytes. These phenotypes were supported by upregulation of proteins that regulate cell proliferation, DNA damage repair mechanism, and glial differentiation, suggesting their potential for prevention and treatment of stress, protein aggregation, and age-related pathologies.

Induction of Apoptosis in Human Glioma Cells by Fucoxanthin via Triggering of ROS-Mediated Oxidative Damage and Regulation of MAPKs and PI3K-AKT Pathways

Fucoxanthin, a natural carotenoid derived from algae, exhibits novel anticancer potential. However, fucoxanthin with high purity is hard to prepare, and the anticancer mechanism remains elusive. In the present study, fucoxanthin with high purity was prepared and purified from the marine microalgae Nitzschia sp. by silica-gel column chromatography (SGCC), and the underlying mechanism against human glioma cells was evaluated. The results showed that fucoxanthin time- and dose-dependently inhibited U251-human-glioma-cell growth by induction of apoptosis (64.4 ± 4.8, P < 0.01) accompanied by PARP cleavage and caspase activation (244 ± 14.2, P < 0.01). Mechanically, fucoxanthin time-dependently triggered reactive-oxygen-species (ROS)-mediated DNA damage (100 ± 7.38, P < 0.01), as evidenced by the phosphorylation activation of Ser1981-ATM, Ser428-ATR, Ser15-p53, and Ser139-histone. Moreover, fucoxanthin treatment also time-dependently caused dysfunction of MAPKs and PI3K-AKT pathways, as demonstrated by the phosphorylation activation of Thr183-JNK, Thr180-p38, and Thr202-ERK and the phosphorylation inactivation of Ser473-AKT. The addition of kinase inhibitors further confirmed the importance of MAPKs and PI3K-AKT pathways in fucoxanthin-induced cell-growth inhibition (32.5 ± 3.6, P < 0.01). However, ROS inhibition by the antioxidant glutathione (GSH) effectively inhibited fucoxanthin-induced DNA damage, attenuated the dysfunction of MAPKs and PI3K-AKT pathways, and eventually blocked fucoxanthin-induced cytotoxicity (54.3 ± 5.6, P < 0.05) and cell apoptosis (32.7 ± 2.5, P < 0.05), indicating that ROS production, an early apoptotic event, is involved in the fucoxanthin-mediated anticancer mechanism. Taken together, these results suggested that fucoxanthin induced U251-human-glioma-cell apoptosis by triggering ROS-mediated oxidative damage and dysfunction of MAPKs and PI3K-AKT pathways, which validated that fucoxanthin may be a candidate for potential applications in cancer chemotherapy and chemoprevention.

Brown Seaweed Egregia menziesii's Cytotoxic Activity against Brain Cancer Cell Lines

Brown seaweeds contain bioactive compounds that show anti-tumorigenic effects. These characteristics have been repeatedly observed in the Lessoniaceae family. Egregia menziesii, a member of this family, is distributed in the North Pacific and its properties have been barely studied. We evaluated herein the cytotoxic and anti-proliferative activity of extracts of this seaweed, through toxicity assay in Artemia salina and lymphocytes, and MTT proliferation assay, in Bergmann glia cells, 3T3-L1 and brain cancer cell lines. E. menziesii’s extracts inhibited the spread of all the tested cell lines. The hexane extract showed the highest cytotoxic activity, while the methanol extract was moderately cytotoxic. Interestingly, seaweed extracts displayed a selective inhibition pattern. These results suggest that E. menziesii’s extracts might be good candidates for cancer prevention and the development of novel chemotherapies due to its highest cytotoxicity in transformed cells compare to glia primary cultures.

The anticancer effects and mechanisms of fucoxanthin combined with other drugs

PURPOSE

Fucoxanthin (Fx) is a characteristic carotenoid present in brown seaweed that has been shown to have various benefits, including anticancer effects. In vitro studies demonstrated these various effects, including the suppression of cell viability, the promotion of apoptosis, and antiangiogenic, antiproliferative, and antimetastatic activity. Interestingly, combinations of Fx with other drugs have better effects than either Fx or other drugs alone. Although the antiproliferative and cancer prevention activities of the combination of Fx and other drugs are still unclear, several effects have been discovered, including the induction of apoptosis, cell cycle arrest at G1/G0, enhanced gap junctional intercellular communication, and the induction of autophagy via various mechanisms, such as decreasing P-gp, activating the CYP3A4 promoter, increasing reactive oxygen species and cellular uptake and suppressing the PI3K/Akt/NFκB pathway. In this review, we address the anticancer effects and mechanisms of the combination of Fx and other drugs in different types of cancer.

METHODS

The relevant literature from PubMed and Web of Science databases is reviewed in this article.

RESULTS

Fx combined with other drugs could enhance the effect of both Fx and the other drug or reduce the dose without reducing the effect, which may create more effective and less harmful therapeutic strategies.

CONCLUSION

Fx combined with other drugs has significant anticancer effects by various mechanisms and could be a potential therapeutic strategy for different types of cancer.

Seaweed Secondary Metabolites In Vitro and In Vivo Anticancer Activity

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

Drug resistance in glioblastoma and cytotoxicity of seaweed compounds, alone and in combination with anticancer drugs: A mini review

BACKGROUND

Glioblastomas (GBM) are one of the most aggressive tumor of the central nervous system with an average life expectancy of only 1-2 years after diagnosis, even with the use of advanced treatments with surgery, radiation, and chemotherapy. There are several anticancer drugs with alkylating properties that have been used in the therapy of malignant gliomas. Temozolomide (TMZ) is one of them, widely used even in combination with ionizing radiation. However, the main disadvantage of using these types of drugs in the treatment of GBM is the development of cancer drug resistance. Research of bioactive compounds with anticancer activity has been heavily explored.

PURPOSE

This review focuses on a carotenoid and a phlorotannin present in seaweed, namely fucoxanthin and phloroglucinol, and their anticancer activity against glioblastoma. The combination of natural compounds with conventional drugs is also discussed.

CONCLUSION

Several natural compounds existing in seaweeds, such as fucoxanthin and phoroglucinol, have shown cytotoxic activity in models in vitro and in vivo, acting through different molecular mechanisms, such as antioxidant, antiproliferative, DNA damage/DNA repair, proapoptotic, antiangiogenic and antimetastic. Within the scope of interactions with conventional drugs, there are evidences that some seaweed compounds could be used to potentiate the action of anticancer drugs. However, their effects and mechanisms of action, alone or in combination with anticancer drugs, namely TMZ, in glioblastoma cell, still few explored and require more attention due to the unquestionable high potential of these marine compounds.

Effects of fucoxanthin on autophagy and apoptosis in SGC-7901cells and the mechanism

Autophagy and apoptosis are involved in the development of a variety of cancers. Fucoxanthin is a natural compound known to have antitumor effects, so we aimed to explore its effects on autophagy and apoptosis in gastric cancer SGC7901 cells. Specifically, we performed methyl thiazolyl tetrazolium assay, transmission electron microscopy, real-time polymerase chain reaction, Western blot analysis, immunofluorescence assay, and cell apoptosis analysis to clarify the role of fucoxanthin in SGC-7901 cells. Our results indicate that fucoxanthin significantly inhibits the viability of SGC-7901 cells, effectively inducing both autophagy and apoptosis by up-regulating the expressions of beclin-1, LC3, and cleaved caspase-3 (CC3), and by down regulating Bcl-2. Fucoxanthin-induced autophagy also seems to occur before, and may promote apoptosis.

Fucoxanthin administration delays occurrence of tumors in xenograft mice by colonospheres, with an anti-tumor predictor of glycine

Fucoxanthin and its major metabolite, fucoxanthinol, have potent anti-cancer properties in carcinogenic model mice and against cancer cells. Evidence has accumulated regarding the diagnostic potential of biological metabolites as invasive and non-invasive obtainable approaches. We recently demonstrated that glycine was an effective predictor of the suppression of sphere formation and epithelial mesenchymal transition by fucoxanthinol in human colorectal cancer stem-like spheroids (colonospheres) under normoxia and hypoxia. In the present study, we investigated the suppressive effect of fucoxanthin on tumorigenesis derived from colonospheres in xenograft mice, and the alteration on the metabolite profiles of mouse tumors by fucoxanthin was evaluated. Fucoxanthin administration at 2.5 mg/kg body weight (p.o.) for 4 weeks significantly inhibited the incidence of tumors by inoculation of colonospheres suspension in BALB/c nu/nu mice compared with control mice, but not tumor sizes. In addition, fucoxanthin down-regulated tumor Cyclin D1 expression by 0.7-fold of that observed in the tumors of the control mice. Moreover, the tumor glycine level in the xenograft mice was decreased by fucoxanthin administration to 0.5-fold. These results imply the possibility of tumor metabolites as a prediction marker of tumorigenicity derived from colorectal cancer stem cells in mice.