Anti-inflammatory effects of apo-9'-fucoxanthinone from the brown alga, Sargassum muticum

Annotation of GC-MS Data of Antimicrobial Constituents in the Antarctic Seaweed Phaeurus antarcticus by Molecular Networking

Phaeurus antarcticus is a member of the Desmarestiaceae family endemic to the Antarctic Peninsula. Reports addressing its chemical composition and biological activities are scarce. Herein, bioactive non-polar compounds of P. antarcticus against pathogenic bacteria, Leishmania amazonensis and Neospora caninum parasites were targeted through GC-MS Molecular Networking and multivariate analysis (OPLS-DA). The effects on horseradish peroxidase (HRP) were also evaluated. P. antarcticus exhibited selective bacteriostatic and bactericidal activities against Staphylococcus aureus with MIC and MBC values from 6.25-100 μg mL-1 . Fractions HX-FC and HX-FD were the most active against L. amazonensis with EC50 ranging from 18.5-62.3 μg mL-1 . Additionally, fractions HX-FC and HX-FD showed potent inhibition of N. caninum at EC50 values of 2.8 and 6.3 μg mL-1 , respectively. All fractions inhibited HRP activity, indicating possible interactions with Heme proteins. It was possible to annotate compounds from tree mains clusters, containing terpenoids, steroids, fatty acids, and alcohols by correlating the spectral data of the GC-MS analysis with Molecular Networking and the OPLS-DA results.

Properties and anti-inflammatory effects of Sargassum muticum enzymatic extracts decomposed using crude enzyme from Shewanella oneidensis PKA1008

This study was conducted to investigate the general properties of an enzymatic extract of Sargassum muticum (SM) produced using a crude enzyme from Shewanella oneidensis PKA 1008 and their anti-inflammatory activities. The SM was mixed with crude enzymes from S. oneidensis PKA 1008 (1:1 (v/v)) and incubated at 30 °C for 0, 3, 6, 12, 24, 48, and 60 h. S. oneidensis PKA 1008 crude enzyme showed the highest SM enzymatic extracts degradation ability when reacted with SM for 48 h. These evaluations demonstrated a 134.25% increase in reducing sugar content and a 14.90% reduction in viscosity at 48 h. The pH, lightness (L*) and yellowness (b*) of the SM enzymatic extracts decreased significantly with increasing reaction time. Moreover, the SM enzymatic extracts demonstrated significant anti-inflammatory activity. These results indicate that the crude enzyme from S. oneidensis PKA 1008 can be used to enhance the polysaccharide degradation of SM, and the resultant oligosaccharides may have an anti-inflammatory effect.

The genus Turbinaria: chemical and pharmacological diversity

The Genus Turbinaria is still chemically and pharmacologically underexplored. These brown algae belong to the family Sargassaceae. Therapeutic potentials of pure compounds isolated from the Genus Turbinaria are extraordinarily promising as antiproliferative, antipyretic, anti-inflammatory immunostimulatory, anti-diabetic, anti-obesity, antiviral, antimicrobial, cardioprotective, hepatoprotective and hypolipidemic. Those activities are represented by diverse classes of compounds including sterols, amino acids, fatty acids, alcohols, halocarbons, hydrocarbons, carbohydrates, esters and cyclic tetrapyrrole compounds. This review focuses on the Genus Turbinaria during the period 1972 to 2019.

Seasonal Changes in the Nutritional Composition of Agarophyton vermiculophyllum (Rhodophyta, Gracilariales) from the Center of Portugal

Seaweeds exhibit high nutritional value due to a balanced concentration of proteins, vitamins and minerals, a high concentration of low digestibility polysaccharides, and reduced levels of lipids, many of which are n-3 and n-6 fatty acids. The species Agarophyton vermiculophyllum is no exception and, as such, a comprehensive study of the chemical and nutritional profile of this red seaweed was carried out for 1 year. Seasonal variations in moisture, ash, protein and amino acids content, crude fibers, ascorbic acid, agar, lipids, and the corresponding fatty acid profile, were analyzed. We found low levels of fatty acids and a high protein content, but also noticed interesting seasonal change patterns in these compounds. The present study gives insights on the environmental conditions that can lead to changes in the nutritional composition of this species, aiming, therefore, to bring new conclusions about the manipulation of environmental conditions that allow for maximizing the nutritional value of this seaweed.

Invasive Seaweeds in the Iberian Peninsula: A Contribution for Food Supply

The introduction of exotic organisms in marine ecosystems can lead to economic and ecological losses. Globally, seaweeds represent a significant part of these non-indigenous species (NIS), with 407 introduced algal species. Furthermore, the presence of NIS seaweeds has been reported as a major concern worldwide since the patterns of their potential invasion mechanisms and vectors are not yet fully understood. Currently, in the Iberian Peninsula, around 50 NIS seaweeds have been recorded. Some of these are also considered invasive due to their overgrowth characteristic and competition with other species. However, invasive seaweeds are suitable for industrial applications due to their high feedstock. Hence, seaweeds' historical use in daily food diet, allied to research findings, showed that macroalgae are a source of nutrients and bioactive compounds with nutraceutical properties. The main goal of this review is to evaluate the records of NIS seaweeds in the Iberian Peninsula and critically analyze the potential of invasive seaweeds application in the food industry.

Dietary supplementation of Sargassum latifolium modulates thermo-respiratory response, inflammation, and oxidative stress in bacterial endotoxin-challenged male Barki sheep

Endotoxemia is mainly caused by translocation of bacterial lipopolysaccharides (LPS) into the bloodstream. This in turn enhances systemic inflammation and inappropriate production of reactive oxygen species, leading to oxidative injury of vital internal organs and other dangerous effects that can be life-threatening. Here, we evaluated/compared the modulatory effects of consuming two different doses (2% and 4% of the diet) of brown seaweeds (Sargassum latifolium) for 40 consecutive days on thermo-respiratory response, inflammation, and oxidative stress in Barki male sheep (Ovis aries) challenged twice with bacterial LPS (1.25 μg/kg body weight, injected intravenously on days 28 and 35 of the experimental period). The results showed that the diet containing Sargassum latifolium (especially at 4%) modulated significantly (P < 0.05-0.001) the increase in the thermo-respiratory response (skin and rectal temperatures, and respiration rate) and the obtained systemic inflammation (blood leukocytosis, the elevation in the erythrocyte sedimentation rate, and the increase in serum proinflammatory cytokines and heat shock protein-70 concentrations) in the LPS-challenged sheep. In addition, it improved significantly (P < 0.001, especially at 4%) the total antioxidant capacity of the blood of LPS-challenged sheep by increasing the catalase and superoxide dismutase activities. Moreover, it decreased the blood markers of tissue damage (malondialdehyde concentration and the activities of alanine aminotransferase and lactate dehydrogenase) in the LPS-challenged sheep. In conclusion, the diet containing 4% Sargassum latifolium may have potential impact in protecting the ruminant livestock from the serious effects of endotoxemia through improving the animals' antioxidant defense system and regulating their inflammatory and thermo-respiratory responses.

Sargassum Seaweed as a Source of Anti-Inflammatory Substances and the Potential Insight of the Tropical Species: A Review

Sargassum is recognized both empirically and scientifically as a potential anti-inflammatory agent. Inflammation is an important response in the body that helps to overcome various challenges to body homeostasis such as microbial infections, tissue stress, and certain injuries. Excessive and uncontrolled inflammatory conditions can affect the pathogenesis of various diseases. This review aims to explore the potential of Sargassum's anti-inflammatory activity, not only in crude extracts but also in sulfated polysaccharides and purified compounds. The tropical region has a promising availability of Sargassum biomass because its climate allows for the optimal growth of seaweed throughout the year. This is important for its commercial utilization as functional ingredients for both food and non-food applications. To the best of our knowledge, studies related to Sargassum's anti-inflammatory activity are still dominated by subtropical species. Studies on tropical Sargassum are mainly focused on the polysaccharides group, though there are some other potentially bioactive compounds such as polyphenols, terpenoids, fucoxanthin, fatty acids and their derivatives, typical polar lipids, and other groups. Information on the modulation mechanism of Sargassum's bioactive compounds on the inflammatory response is also discussed here, but specific mechanisms related to the interaction between bioactive compounds and targets in cells still need to be further studied.

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.

Degradation of Fucoxanthin to Elucidate the Relationship between the Fucoxanthin Molecular Structure and Its Antiproliferative Effect on Caco-2 Cells

Fucoxanthin has an antiproliferative effect on cancer cells, but its detailed structure⁻activity correlation has not yet been elucidated. To elucidate this correlation, fucoxanthin was degraded by ozonolysis. The degraded compounds of fucoxanthin obtained by ozonolysis were purified by HPLC and analyzed by NMR. The polyene chain of fucoxanthin was cleaved by ozonolysis, and the fucoxanthin was divided into two types of cyclohexyl derivatives, one with a β,γ-epoxy ketone group and the other with an allenic bond. In order to elucidate the structure⁻activity correlation, Caco-2 cells (human colorectal carcinoma) were treated with fucoxanthin degradation compounds. It was found that the entire structure of fucoxanthin is not essential for its antiproliferative effect and that even a partial structure exerts this effect.

Anti-inflammatory effect of Apo-9'-fucoxanthinone via inhibition of MAPKs and NF-kB signaling pathway in LPS-stimulated RAW 264.7 macrophages and zebrafish model

In this study, we confirmed the anti-inflammatory effect of Apo-9-fucoxanthinone (AF) in in vitro RAW 264.7 cells and in vivo zebrafish model. In lipopolysaccharide (LPS)-stimulated zebrafish, AF significantly decreased the production of reactive oxygen species (ROS), nitric oxide (NO) and cell death. In addition, the mRNA expression of inducible nitric oxide synthase (iNOS), suppressed cyclooxygenase-2 (COX-2) and an inflammatory cytokines; IL-1β, TNF-α were shown reduction. And AF significantly inhibited NO production and expression of iNOS in LPS-stimulated RAW 264.7 cells. Further, AF suppressed COX-2, prostaglandin E2 (PGE₂), and pro-inflammatory cytokines such as interleukin-6 (IL-6), IL-1β, and tumor necrosis factor-α (TNF-α) at 25, 50 and 100 μg/mL, respectively. Further mechanistic studies showed that AF suppressed the nuclear factor-kB (NF-kB) pathway and phosphorylation of mitogen-activated protein kinase (MAPK) pathway molecules such as extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK). According to the results, AF can be used and applied as a useful anti-inflammatory agent of nutraceutical or pharmaceutical.

APO-9'-Fucoxanthinone Extracted from Undariopsis peteseniana Protects Oxidative Stress-Mediated Apoptosis in Cigarette Smoke-Exposed Human Airway Epithelial Cells

Long-term cigarette smoking increases the risk for chronic obstructive pulmonary disease (COPD), characterized by irreversible expiratory airflow limitation. The pathogenesis of COPD involves oxidative stress and chronic inflammation. Various natural marine compounds possess both anti-oxidant and anti-inflammatory properties, but few have been tested for their efficacy in COPD models. In this study, we conducted an in vitro screening test to identify natural compounds isolated from various brown algae species that might provide protection against cigarette smoke extract (CSE)-induced cytotoxicity. Among nine selected natural compounds, apo-9'-fucoxanthinone (Apo9F) exhibited the highest protection against CSE-induced cytotoxicity in immortalized human bronchial epithelial cells (HBEC2). Furthermore, the protective effects of Apo9F were observed to be associated with a significant reduction in apoptotic cell death, DNA damage, and the levels of mitochondrial reactive oxygen species (ROS) released from CSE-exposed HBEC2 cells. These results suggest that Apo9F protects against CSE-induced DNA damage and apoptosis by regulating mitochondrial ROS production.

External Application of Apo-9'-fucoxanthinone, Isolated from Sargassum muticum, Suppresses Inflammatory Responses in a Mouse Model of Atopic Dermatitis

Allergic skin inflammation such as atopic dermatitis is characterized by skin barrier dysfunction, edema, and infiltration with various inflammatory cells. The anti-inflammatory effects of Apo-9′-fucoxanthinone, isolated from Sargassum muticum, have been described in many diseases, but the mechanism by which it modulates the immune system is poorly understood. In this study, the ability of Apo-9′-fucoxanthinone to suppress allergic reactions was investigated using a mouse model of atopic dermatitis. The Apo-9′-fucoxanthinone-treated group showed significantly decreased immunoglobulin E in serum. Also, Apo-9′-fucoxanthinone treatment resulted in a smaller lymph node size with reduced the thickness and length compared to the induction group. In addition, Apo-9′-fucoxanthinone inhibited the expression of interleukin-4, interferon-gamma and tumor necrosis factor-alpha by phorbol 12-myristate 13-acetate and ionomycin-stimulated lymphocytes. These results suggest that Apo-9′-fucoxanthinone may be a useful therapeutic strategy for treating chronic inflammatory diseases.

Promotion Effect of Apo-9'-fucoxanthinone from Sargassum muticum on Hair Growth via the Activation of Wnt/β-Catenin and VEGF-R2

This study was conducted to evaluate the effects of Sargassum muticum extract and apo-9'-fucoxanthinone, a principal component of S. muticum, on hair growth. When rat vibrissa follicles were treated with S. muticum extract for 21 d, the hair-fiber lengths for the vibrissa follicles increased significantly. Treatment with the S. muticum extract and the EtOAc fraction of the S. muticum extract markedly increased the proliferation of dermal papilla cells (DPCs) and decreased the 5α-reductase activity. In addition, the EtOAc fraction of the S. muticum extract significantly promoted anagen initiation in C57BL/6 mice. Especially, apo-9'-fucoxanthinone, an active constituent from the S. muticum extract, caused an increase in DPC proliferation and a decrease in 5α-reductase activity. To elucidate the molecular mechanisms of apo-9'-fucoxanthinone on the proliferation of DPCs, we examined the level of various signaling proteins. Apo-9'-fucoxanthinone increased the level of vascular endothelial growth factor receptor-2 (VEGF-R2), Wnt/β-catenin signaling proteins such as phospho(ser9)-glycogen synthase kinase-3β (GSK-3β) and phospho(ser552)-β-catenin, whereas apo-9'-fucoxanthinone did not affect the transforming growth factor-β (TGF-β) signaling proteins such as Smad2/3. These results suggest that apo-9'-fucoxanthinone from S. muticum could have the potential for hair growth with DPC proliferation via the activation of Wnt/β-catenin signaling and the VEGF-R2 pathway.

Anti-inflammatory effects of isoketocharbroic acid from brown alga, Sargassum micracanthum

During our on-going screening program designed to isolate natural compounds from marine environments, we isolated isoketochabrolic acid (IKCA) from Sargassum micracanthum, an important brown algae distributed in Jeju Island, Korea. Furthermore, we evaluated the inhibitory effects of IKCA on nitric oxide (NO) production in lipopolysaccharide (LPS)-triggered macrophages. IKCA strongly inhibited NO production, with an IC₅₀ value of 58.31 μM. Subsequent studies demonstrated that IKCA potently and concentration-dependently reduced prostaglandin E₂ (PGE₂), tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1β, and IL-6 cytokine production. In conclusion, to the best of our knowledge, this is the first study to show that IKCA isolated from S. micracanthum has a potent anti-inflammatory activity. Therefore, IKCA might be useful as an anti-inflammatory health supplement or functional cosmetics.

Jeju seaweeds suppress lipopolysaccharide-stimulated proinflammatory response in RAW 264.7 murine macrophages

OBJECTIVE

To investigate the anti-inflammatory effects of Jeju seaweeds on macrophage RAW 264.7 cells under lipopolysaccharide (LPS) stimulation.

METHODS

Ethyl acetate fractions were prepared from five different types of Jeju seaweeds, Dictyopteris divaricata (D. divaricata), Dictyopteris prolifera (D. prolifera), Prionitis cornea (P. cornea), Grateloupia lanceolata (G. lanceolata), and Grateloupia filicina (G. filicina). They were screened for inhibitory effects on proinflammatory mediators and cytokines such as nitric oxide (NO), prostaglandin E2, tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6).

RESULTS

Our results revealed that D. divaricata, D. prolifera, P. cornea, G. lanceolata, and G. filicina potently inhibited LPS-stimulated NO production (IC50 values were 18.0, 38.36, 38.43, 32.81 and 37.14 µg/mL, respectively). Consistent with these findings, D. divaricata, D. prolifera, P. cornea, and G. filicina also reduced the LPS-induced and prostaglandin E2 production in a concentration-dependent manner. Expectedly, they suppressed the expression of inducible NO synthase and cyclooxygenase-2 at the protein level in a dose-dependent manner in the RAW 264.7 cells, as determined by western blotting. In addition, the levels of TNF-α and IL-6, released into the medium, were also reduced by D. divaricata, D. prolifera, P. cornea, G. lanceolata, and G. filicina in a dose-dependent manner (IC50 values for TNF-α were 16.11, 28.21, 84.27, 45.52 and 74.75 µg/mL, respectively; IC50 values for IL-6 were 37.35, 80.08, 103.28, 62.53 and 84.28 µg/mL, respectively). The total phlorotannin content was measured by the Folin-Ciocalteu method and expressed as phloroglucinol equivalents. The content was 92.0 µg/mg for D. divaricata, 151.8 µg/mg for D. prolifera, 57.2 µg/mg for P. cornea, 53.0 µg/mg for G. lanceolata, and 40.2 µg/mg for G. filicina.

CONCLUSIONS

Thus, these findings suggest that Jeju seaweed extracts have potential therapeutic applications for inflammatory responses.

The ethyl acetate fraction of Sargassum muticum attenuates ultraviolet B radiation-induced apoptotic cell death via regulation of MAPK- and caspase-dependent signaling pathways in human HaCaT keratinocytes

CONTEXT

Our previous work demonstrated that an ethyl acetate extract derived from Sargassum muticum (Yendo) Fenshol (SME) protected human HaCaT keratinocytes against ultraviolet B (UVB)-induced oxidative stress by increasing antioxidant activity in the cells, thereby inhibiting apoptosis.

OBJECTIVE

The aim of the current study was to further elucidate the anti-apoptotic mechanism of SME against UVB-induced cell damage.

MATERIALS AND METHODS

The expression levels of several apoptotic-associated and mitogen-activated kinase (MAPK) signaling proteins were determined by western blot analysis of UVB-irradiated HaCaT cells with or without prior SME treatment. In addition, the loss of mitochondrial membrane potential (Δψm) was detected using flow cytometry or confocal microscopy and the mitochondria membrane-permeate dye, JC-1. Apoptosis was assessed by quantifying DNA fragmentation and apoptotic body formation. Furthermore, cell viability was evaluated using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay.

RESULTS

SME absorbed electromagnetic radiation in the UVB range (280-320 nm) of the UV/visible light spectrum. SME also increased Bcl-2 and Mcl-1 expression in UVB-irradiated cells and decreased the Bax expression. Moreover, SME inhibited the UVB-induced disruption of mitochondrial membrane potential and prevented UVB-mediated increases in activated caspase-9 and caspase-3 (an apoptotic initiator and executor, respectively) levels. Notably, treatment with a pan-caspase inhibitor enhanced the anti-apoptotic effects of SME in UVB-irradiated cells. Finally, SME reduced the UVB-mediated phosphorylation of p38 MAPK and JNK, and prevented the UVB-mediated dephosphorylation of Erk1/2 and Akt.

DISCUSSION AND CONCLUSION

The present results indicate that SME safeguards HaCaT keratinocytes from UVB-mediated apoptosis by inhibiting a caspase-dependent signaling pathway.

Chemical Composition and Anti-inflammation Activity of Essential Oils from Citrus unshiu Flower

Though many essential oils from citrus peels are claimed to have several medicinal functions, the chemical composition and biological activities of the essential oils of Citrus flowers have not been well described. Therefore, this study intended to investigate the chemical composition and anti-inflammatory potential of essential oils from C. unshiu flower (CEO) to support its purported beneficial health effects. The chemical constituents of the CEO, analyzed by gas chromatography-mass spectrometry (GC-MS), included γ-terpinene (24.7%), 2-β-pinene (16.6%), 1-methyl-2-isopropylbenzene (11.5%), L-limonene (5.7%), β-ocimene (5.6%), and α-pinene (4.7%). The effects of the CEO on nitric oxide (NO) and prostaglandin E2 (PGE2) production in lipopolysaccharide (LPS)-activated RAW 264.7 macrophages were also examined. The results indicate that the CEO is an effective inhibitor of LPS-induced NO and PGE2 production in RAW 264.7 cells. Additionally, CEO was shown to suppress the production of inflammatory cytokines including interleukin (IL)-1β, tumor necrosis factor (TNF)-α, and IL-6. Based on these results, CEO may be considered a potential anti-inflammatory candidate with human health benefits.

Hypochoeris radicata attenuates LPS-induced inflammation by suppressing p38, ERK, and JNK phosphorylation in RAW 264.7 macrophages

Hypochoeris radicata, an invasive plant species, is a large and growing threat to ecosystem integrity on Jeju Island, a UNESCO World Heritage site. Therefore, research into the utilization of H. radicata is important and urgently required in order to solve this invasive plant problem in Jeju Island. The broader aim of our research is to elucidate the biological activities of H. radicata, which would facilitate the conversion of this invasive species into high value-added products. The present study was undertaken to identify the pharmacological effects of H. radicata flower on the production of inflammatory mediators in macrophages. The results indicate that the ethyl acetate fraction of H. radicata extract (HRF-EA) inhibited the production of pro-inflammatory molecules such as NO, iNOS, PGE2, and COX-2, and cytokines such as TNF-α, IL-1ß, and IL-6 in LPS-stimulated RAW 264.7 cells. Furthermore, the phosphorylation of MAPKs such as p38, ERK, and JNK was suppressed by HRF-EA in a concentration-dependent manner. In addition, through HPLC and UPLC fingerprinting, luteolins were also identified and quantified as extract constituents. On the basis of these results, we suggest that H. radicata may be considered possible anti-inflammatory candidates for pharmaceutical and/or cosmetic applications.