Isolation of fucoidan from Sargassum polycystum brown algae: Structural characterization, in vitro antioxidant and anticancer activity

Anticandidal potentiality of biosynthesized and decorated nanometals with fucoidan

Candidagenus includes many hazardous and risky species that can develop resistance toward various antifungal types. Metals nanoparticles (NPs) possess powerful antimicrobial actions, but their potential human toxicity could limit their practices. The algal polysaccharide fucoidan (Fu) was extracted from the macro-brown algae,Cystoseira barbata, analyzed, and used for biosynthesizing nanoparticles of silver (Ag-NPs) and selenium (Se-NPs). The extracted Fu had elevated fucose levels (58.73% of total monosaccharides) and exhibited the main biochemical characteristic of customary Fu. The Fu biosynthesis of Ag-NPs and Se-NPs was achieved via facile direct protocol; Fu-synthesized NPs had 12.86 and 16.18 nm average diameters, respectively. The ultrastructure of Fu-synthesized NPs emphasized well-distributed and spherical particles that were embedded/capped in Fu as combined clusters. The Fu/Ag-NPs and Fu/Se-NPs anticandidal assessments, againstCandida albicans,Candida glabrata, andCandida parapsilosis, revealed that both NPs had powerful fungicidal actions against the examined pathogens. The ultrastructure imaging of subjectedC. albicansandC. parapsilosisto NPs revealed that Fu/Ag-NPs and Fu/Se-NPs triggered remarkable distortions, pore formation, and destructive lysis in cell surfaces within 10 h of exposure. The innovative usage ofC. barbataFu for Ag-NP and Se-NP synthesis and the application of their composites as powerful anticandidal agents, with minimized human toxicity, are concluded.

Microbial Biosurfactant: A New Frontier for Sustainable Agriculture and Pharmaceutical Industries

In the current scenario of changing climatic conditions and the rising global population, there is an urgent need to explore novel, efficient, and economical natural products for the benefit of humankind. Biosurfactants are one of the latest explored microbial synthesized biomolecules that have been used in numerous fields, including agriculture, pharmaceuticals, cosmetics, food processing, and environment-cleaning industries, as a source of raw materials, for the lubrication, wetting, foaming, emulsions formulations, and as stabilizing dispersions. The amphiphilic nature of biosurfactants have shown to be a great advantage, distributing themselves into two immiscible surfaces by reducing the interfacial surface tension and increasing the solubility of hydrophobic compounds. Furthermore, their eco-friendly nature, low or even no toxic nature, durability at higher temperatures, and ability to withstand a wide range of pH fluctuations make microbial surfactants preferable compared to their chemical counterparts. Additionally, biosurfactants can obviate the oxidation flow by eliciting antioxidant properties, antimicrobial and anticancer activities, and drug delivery systems, further broadening their applicability in the food and pharmaceutical industries. Nowadays, biosurfactants have been broadly utilized to improve the soil quality by improving the concentration of trace elements and have either been mixed with pesticides or applied singly on the plant surfaces for plant disease management. In the present review, we summarize the latest research on microbial synthesized biosurfactant compounds, the limiting factors of biosurfactant production, their application in improving soil quality and plant disease management, and their use as antioxidant or antimicrobial compounds in the pharmaceutical industries.

Extraction, Structural Characterisation, and Immunomodulatory Properties of Edible Amanitahemibapha subspecies javanica (Corner and Bas) Mucilage Polysaccharide as a Potential of Functional Food

This research aimed to extract mucilage polysaccharides (MP) from Amanita hemibapha subspecies javanica (Corner and Bas), and further fractionate them using anion-exchange chromatography, yielding two fractions (MPF1 and MPF2). The crude extract, and fractions mainly consisted of carbohydrates (83.5-93.2%) with minor amounts of proteins (5.40-7.20%), and sulphates (1.40-9.30%). Determination of the monosaccharide composition revealed that glucose was the major unit, followed by galactose, mannose, rhamnose, and arabinose. The average molecular weight (MW) of the crude extract and fractions was in the range 104.0-479.4 × 103 g/mol. Interestingly, the crude extract, and fractions did not cause any toxic effect in RAW264.7 cells. However, they stimulated the RAW264.7 cells to release nitric oxide and cytokines through the activation of nuclear factor-kappa B (NF-κB), and mitogen-activated protein kinase (MAPK) pathways via cell surface TLR4. Structural analysis of the most immunestimulating extract fraction, MPF2, revealed that the main backbone consisted of α-D-(1→6)-glucopyranoside. These results suggest that the MPs derived from A. hemibapha subspecies javanica (Corner and Bas) are potent in enhancing immunity; hence, they can be used as a functional ingredient in food products.

Fucoidans and Bowel Health

Fucoidans are cell wall polysaccharides found in various species of brown seaweeds. They are fucose-containing sulfated polysaccharides (FCSPs) and comprise 5-20% of the algal dry weight. Fucoidans possess multiple bioactivities, including antioxidant, anticoagulant, antithrombotic, anti-inflammatory, antiviral, anti-lipidemic, anti-metastatic, anti-diabetic and anti-cancer effects. Dietary fucoidans provide small but constant amounts of FCSPs to the intestinal tract, which can reorganize the composition of commensal microbiota altered by FCSPs, and consequently control inflammation symptoms in the intestine. Although the bioactivities of fucoidans have been well described, there is limited evidence to implicate their effect on gut microbiota and bowel health. In this review, we summarize the recent studies that introduce the fundamental characteristics of various kinds of fucoidans and discuss their potential in altering commensal microorganisms and influencing intestinal diseases.

Low-Molecular-Weight Fucoidan as Complementary Therapy of Fluoropyrimidine-Based Chemotherapy in Colorectal Cancer

This study investigated the roles of low-molecular-weight fucoidan (LMWF) in enhancing the anti-cancer effects of fluoropyrimidine-based chemotherapy. HCT116 and Caco-2 cells were treated with LMWF and 5-FU. Cell viability, cell cycle, apoptosis, and migration were analyzed in both cell types. Potential mechanisms underlying how LMWF enhances the anti-cancer effects of fluoropyrimidine-based chemotherapy were also explored. The cell viability of HCT116 and Caco-2 cells was significantly reduced after treatment with a LMWF-–5FU combination. In HCT116 cells, LMWF enhanced the suppressive effects of 5-FU on cell viability through the (1) induction of cell cycle arrest in the S phase and (2) late apoptosis mediated by the Jun-N-terminal kinase (JNK) signaling pathway. In Caco-2 cells, LMWF enhanced the suppressive effects of 5-FU on cell viability through both the c-mesenchymal–epithelial transition (MET)/Kirsten rat sarcoma virus (KRAS)/extracellular signal-regulated kinase (ERK) and the c-MET/phosphatidyl-inositol 3-kinases (PI3K)/protein kinase B (AKT) signaling pathways. Moreover, LMWF enhanced the suppressive effects of 5-FU on tumor cell migration through the c-MET/matrix metalloproteinase (MMP)-2 signaling pathway in both HCT116 and Caco-2 cells. Our results demonstrated that LMWF is a potential complementary therapy for enhancing the efficacies of fluoropyrimidine-based chemotherapy in colorectal cancers (CRCs) with the wild-type or mutated KRAS gene through different mechanisms. However, in vivo studies and in clinical trials are required in order to validate the results of the present study.

Bioactive Compounds of Nutraceutical Value from Fishery and Aquaculture Discards

Seafood by-products, produced by a range of different organisms, such as fishes, shellfishes, squids, and bivalves, are usually discarded as wastes, despite their possible use for innovative formulations of functional foods. Considering that “wastes” of industrial processing represent up to 75% of the whole organisms, the loss of profit may be coupled with the loss of ecological sustainability, due to the scarce recycling of natural resources. Fish head, viscera, skin, bones, scales, as well as exoskeletons, pens, ink, and clam shells can be considered as useful wastes, in various weight percentages, according to the considered species and taxa. Besides several protein sources, still underexploited, the most interesting applications of fisheries and aquaculture by-products are foreseen in the biotechnological field. In fact, by-products obtained from marine sources may supply bioactive molecules, such as collagen, peptides, polyunsaturated fatty acids, antioxidant compounds, and chitin, as well as catalysts in biodiesel synthesis. In addition, those sources can be processed via chemical procedures, enzymatic and fermentation technologies, and chemical modifications, to obtain compounds with antioxidant, anti-microbial, anti-cancer, anti-hypertensive, anti-diabetic, and anti-coagulant effects. Here, we review the main discards from fishery and aquaculture practices and analyse several bioactive compounds isolated from seafood by-products. In particular, we focus on the possible valorisation of seafood and their by-products, which represent a source of biomolecules, useful for the sustainable production of high-value nutraceutical compounds in our circular economy era.

Comparative Study of Sargassum fusiforme Polysaccharides in Regulating Cecal and Fecal Microbiota of High-Fat Diet-Fed Mice

Seaweed polysaccharides represent a kind of novel gut microbiota regulator. The advantages and disadvantages of using cecal and fecal microbiota to represent gut microbiota have been discussed, but the regulatory effects of seaweed polysaccharides on cecal and fecal microbiota, which would benefit the study of seaweed polysaccharide-based gut microbiota regulator, have not been compared. Here, the effects of two Sargassum fusiforme polysaccharides prepared by water extraction (SfW) and acid extraction (SfA) on the cecal and fecal microbiota of high-fat diet (HFD) fed mice were investigated by 16S rRNA gene sequencing. The results indicated that 16 weeks of HFD dramatically impaired the homeostasis of both the cecal and fecal microbiota, including the dominant phyla Bacteroidetes and Actinobacteria, and genera Coriobacteriaceae, S24-7, and Ruminococcus, but did not affect the relative abundance of Firmicutes, Clostridiales, Oscillospira, and Ruminococcaceae in cecal microbiota and the Simpson's index of fecal microbiota. Co-treatments with SfW and SfA exacerbated body weight gain and partially reversed HFD-induced alterations of Clostridiales and Ruminococcaceae. Moreover, the administration of SfW and SfA also altered the abundance of genes encoding monosaccharide-transporting ATPase, α-galactosidase, β-fructofuranosidase, and β-glucosidase with the latter showing more significant potency. Our findings revealed the difference of cecal and fecal microbiota in HFD-fed mice and demonstrated that SfW and SfA could more significantly regulate the cecal microbiota and lay important foundations for the study of seaweed polysaccharide-based gut microbiota regulators.

Anti-glycation effect of Ecklonia cava polysaccharides extracted by combined ultrasound and enzyme-assisted extraction

The anti-glycation effects of polysaccharides from Ecklonia cava were examined according to extraction method-hot buffer (HP), ultrasound (UP), enzyme (EP), or a combination of ultrasound and enzyme (UEP). The physicochemical properties, monosaccharide compositions, and structural characteristics of the polysaccharides were determined. UP, EP, and UEP had higher fucose and galactose compositions than HP. The FT-IR spectra of samples showed the presence of sulfate esters and 4-sulfate galactose. 1H NMR indicated that alginate was removed by purification. UP, EP, and UEP possessed higher sulfate contents than HP. UEP presented with the highest extraction yield and lowest protein and uronic acid contents. The levels of AGE formation, as well as fructosamine, α-dicarbonyl, and protein carbonyl contents were determined during a 3-week incubation in a BSA/fructose system. UEP and UP effectively inhibited AGE, although the inhibition effect was lower than that of aminoguanidine. However, UP and UEP showed higher inhibition of fructosamine, α-dicarbonyl, and protein carbonyl than aminoguanidine. AGE formation was negatively correlated with sulfate content and some monosaccharide compositions (fucose, galactose, and glucose), but positively correlated with molecular weight. Overall, the present study suggests that UEP is a suitable extraction method for obtaining anti-glycation agents from E. cava.

Fucoidan Extracted From Sporophyll of Undaria pinnatifida Grown in Weihai, China - Chemical Composition and Comparison of Antioxidant Activity of Different Molecular Weight Fractions

Fucoidan is a multifunctional marine carbohydrate polymer that differs in its chemical composition and bioactivity both between seaweed species and within species from different locations across the globe. In this study, fucoidan was extracted from the sporophyll of Undaria pinnatifida grown in Weihai, Shandong Province, China. Fucoidan fractions with molecular weight cutoffs (MWCO) of >300 kDa and <10 kDa were obtained via dialysis. The fucoidan standard from Sigma (Fstd, ≥95, CAS: 9072-19-9), fucoidan crude extract (WH), >300 kDa fraction (300k) and <10 kDa fraction (10k) were compared in terms of chemical composition and antioxidant capacity. Based on Fourier transform infrared spectroscopy (FT-IR) analysis, Fstd, WH, and 300k all showed strong bands around 830 cm⁻¹, corresponding to the sulfate substituent in the molecule. The results showed that compared with WH and 300 k, the degree of sulfation at 10k was the lowest. From Nuclear magnetic resonance spectroscopy (NMR) result, the four fucoidan samples all contain α-_L-fucose. The primary antioxidant ability of the 10k is significantly higher than that of the 300k, WH, and Fstd, but the secondary antioxidant capabilities of the 10k and 300k were similar, and both were higher than that of the butylated hydroxyanisole (BHA). The ferric reducing antioxidant ability was higher in the 300k and WH fractions. This demonstrates that fucoidan extracted from U. pinnatifida grown in Weihai, China should be a useful nutraceutical resource.

Effect of Oversulfation on the Composition, Structure, and In Vitro Anti-Lung Cancer Activity of Fucoidans Extracted from Sargassum aquifolium

Intensive efforts have been undertaken in the fields of prevention, diagnosis, and therapy of lung cancer. Fucoidans exhibit a wide range of biological activities, which are dependent on the degree of sulfation, sulfation pattern, glycosidic branches, and molecular weight of fucoidan. The determination of oversulfation of fucoidan and its effect on anti-lung cancer activity and related signaling cascades is challenging. In this investigation, we used a previously developed fucoidan (SCA), which served as a native fucoidan, to generate two oversulfated fucoidan derivatives (SCA-S1 and SCA-S2). SCA, SCA-S1, and SCA-S2 showed differences in compositions and had the characteristic structural features of fucoidan by Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) analyses. The anticancer properties of SCA, SCA-S1, and SCA-S2 against human lung carcinoma A-549 cells were analyzed in terms of cytotoxicity, cell cycle, Bcl-2 expression, mitochondrial membrane potential (MMP), expression of caspase-3, cytochrome c release, Annexin V/propidium iodide (PI) staining, DNA fragmentation, and the underlying signaling cascades. Our findings indicate that the oversulfation of fucoidan promotes apoptosis of lung cancer cells and the mechanism may involve the Akt/mTOR/S6 pathway. Further in vivo research is needed to establish the precise mechanism whereby oversulfated fucoidan mitigates the progression of lung cancer.

Valorization of pelagic sargassum biomass into sustainable applications: Current trends and challenges

Since long ago, pelagic Sargassum mats have been known to be abundant in the Sargasso Sea, where they provide habitat to diverse organisms. However, over the last few years, massive amounts of pelagic Sargassum have reached the coast of several countries in the Caribbean and West Africa, causing economic and environmental problems. Aiming for lessening the impacts of the blooms, governments and private companies remove the seaweeds from the shore, but this process results expensive. The valorization of this abundant biomass can render Sargassum tides into an economic opportunity and concurrently solve their associated environmental problems. Despite the diverse fields where algae have found applications and the relevance of this recurrent situation, Sargassum biomass remains without large scale applications. Therefore, this review aims to present the potential uses of these algae, identifying the limitations that must be assessed to effectively valorize this bioresource. Due to the constraints identified for each of the presented applications, it is concluded that a biorefinery approach should be developed to effectively valorize this abundant biomass. However, there is an urgent need for investigations focusing on holopelagic Sargassum to be able to truly valorize this seaweed.

Characterization and hypoglycemic effects of sulfated polysaccharides derived from brown seaweed Undaria pinnatifida

The brown seaweed Undaria pinnatifida polysaccharides show various biological activities, but their hypoglycemic activity and the underlying mechanism remain unclear. Here, three fractions of sulfated polysaccharides Up-3, Up-4, and Up-5 were prepared by microwave-assisted extraction from U. pinnatifida. In vitro assays demonstrated that Up-3 and Up-4 had strong α-glucosidase inhibitory activity, and Up-3, Up-4, and Up-5 could improve the glucose uptake in insulin-resistant HepG2 cells without affecting their viability. In vivo studies indicated Up-3 and Up-4 markedly reduced postprandial blood glucose levels. Up-U (a mixture of Up-3, Up-4, and Up-5), reduced fasting blood glucose levels, increased glucose tolerance and alleviated insulin resistance in HFD/STZ-induced hyperglycemic mice. Histopathological observation and hepatic glycogen measurement showed that Up-U alleviated the damage of the pancreas islet cell, reduced hepatic steatosis, and promoted hepatic glycogen synthesis. These findings suggest that Up-U could alleviate postprandial and HFD/STZ-induced hyperglycemia and was a potential agent for diabetes treatment.

The development of analytical methods for the purity determination of fucoidan extracted from brown seaweed species

To determine the purity of extracted fucoidan from brown seaweeds, analytical methods were developed, including spectroscopy (i.e., Attenuate total reflectance (ATR) - Fourier-transform infrared (FT-IR) and Raman) combined with chemometrics; and the results were compared with those of high performance liquid chromatography (HPLC) and other two chemistry methods (i.e., fucoidan estimation based on fucose content and a cationic dye method based on sulphated polysaccharide estimation). Quantitative models (i.e., partial least squares regression (PLSR)) were developed and cross-validated using FT-IR spectroscopic methods (R2CV ~ 0.998, RMSECV ~1.7%). The models were also validated using other four commercial fucoidan products. On the other hand, the same commercial samples were used to validate the two chemistry methods and the HPLC method. Estimation results of these analytical methods were discussed based on the potential of these analytical methods for fucoidan purity determination. The results demonstrated FT-IR spectroscopy with chemometrics potentially could be used for non-destructive and real time determination.

Brown seaweed Cystoseira schiffneri as a promising source of sulfated fucans: Seasonal variability of structural, chemical, and antioxidant properties

A fucoidan, sulfated polysaccharide, was extracted from the brown seaweed Cystoseira schiffneri during 4 harvest periods (December, April, July, and September) and studied for its structural and chemical properties. The Cystoseira schiffneri fucoidan (CSF) showed important variation in sulfate content ranging from 7.8% in December to 34.8% in July. This was confirmed by Fourier transform infrared and nuclear magnetic resonance spectroscopies showing characteristic signals of sulfated polysaccharides. Molecular mass of the CSF varied as a function of season from 3,745 in December to 26,390 Da in July. Gas chromatography-mass spectroscopy showed that CSF fractions were "mannogalactofucans" composed mainly of mannose, fucose, and galactose with low levels of other monosaccharides. Moreover, interesting in vitro antioxidant activities that depend on the harvest season were noted for CSF. Thus, the present work might contribute to establish criteria for extracting bioactive fucoidans from an endemic Tunisian seaweed C. schiffneri.

Toxicity Profiling of Biosurfactants Produced by Novel Marine Bacterial Strains

Surface active agents (SAAs), currently used in modern industry, are synthetic chemicals produced from non-renewable sources, with potential toxic impacts on humans and the environment. Thus, there is an increased interest for the identification and utilization of natural derived SAAs. As such, the marine environment is considered a promising source of biosurfactants with low toxicity, environmental compatibility, and biodegradation compared to their synthetic counterparts. MARISURF is a Horizon 2020 EU-funded project aiming to identify and functionally characterize SAAs, derived from a unique marine bacterial collection, towards commercial exploitation. Specifically, rhamnolipids produced by Marinobacter MCTG107b and Pseudomonas MCTG214(3b1) strains were previously identified and characterized while currently their toxicity profile was assessed by utilizing well-established methodologies. Our results showed a lack of cytotoxicity in in vitro models of human skin and liver as indicated by alamar blue and propidium iodide assays. Additionally, the use of the single gel electrophoresis assay, under oxidative stress conditions, revealed absence of any significant mutagenic/anti-mutagenic potential. Finally, both 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonicacid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) cell-free assays, revealed no significant anti-oxidant capacity for neither of the tested compounds. Consequently, the absence of significant cytotoxicity and/or mutagenicity justifies their commercial exploitation and potential development into industrial end-user applications as natural and environmentally friendly biosurfactants.

Fucoidan Fractionated from Sargassum coreanum via Step-Gradient Ethanol Precipitation Indicate Promising UVB-Protective Effects in Human Keratinocytes

Fucoidans exhibit a wide range of bioactivities and receive significant attention in functional food and cosmetic research. Industrial applications of fucoidan are limited partially due to high extraction and purification costs. The present study implements an enzyme-assisted extraction and step-gradient ethanol precipitation for fractionating fucoidan from Sargassum coreanum based on its charge and molecular weight and evaluation of ultraviolet B (UVB) protective effects in human keratinocytes (HaCaT). The fucoidan fraction SCOC4 indicated higher fucose and sulfate contents with Fourier-transform infrared and ¹H NMR spectral patterns resembling fucoidans. SCOC4 dose-dependently abated UVB-induced keratinocyte damage via suppressing intracellular reactive oxygen species, apoptotic body formation, DNA damage via suppressing mitochondria-mediated apoptosis. UVB-protective effects of SCOC4 were further attributable to the augmentation of nuclear factor erythroid 2-related factor 2 mediated cellular antioxidant defense enzymes. Step-gradient ethanol precipitation was a convenient approach of fractionating fucoidans based on molecular weight and charge (depend on the degree of sulfation). Further evaluation of seasonal variations, biocompatibility parameters, efficacy, and shelf life may widen the use of S. coreanum fucoidans in developing UVB-protective cosmetics and functional foods.

Low molecular weight fucoidan fraction ameliorates inflammation and deterioration of skin barrier in fine-dust stimulated keratinocytes

Recently evidence linking the effects of fine-dust (FD) on skin inflammation is exaggerating. Fucoidan derived from brown algae has great potential for ameliorating oxidative stress and inflammation. Herein, a fucoidan fraction (SHC4-6) was purified from an enzymatic (Celluclast) extract of an invasive seaweed, Sargassum horneri following gradient ethanol precipitation and anion exchange chromatography. Effectiveness of SHC4-6 in ameliorating FD (from Beijing, China)-induced inflammatory responses in HaCaT keratinocytes and recovery of skin barrier dysfunction was evaluated. SHC4-6 was comprising of sulfated mannofucans with their molecular weights distributed around 45 kDa. SHC4-6 dose-dependently lowered ROS levels in FD-induced HaCaT keratinocytes, ameliorating viability at 50 μg mL-1. SHC4-6 downregulated inflammatory cytokines, tumor necrosis factor-α, interleukin (IL)-1β, -5, -6, -8, -13, interferon-γ, and chemokines, macrophage-derived chemokine, eotaxin, and thymus and activation regulated chemokine by inhibiting mitogen-activated protein kinase and nuclear factor-κB pathways. SHC4-6 treatment ameliorated key tight junction proteins and skin hydration factors, depicting the effects of fucoidan in reducing FD-induced inflammation and skin barrier deterioration. With further studies in place, SHC4-6 could be used as an ingredient for developing cosmetics to relieve FD-induced skin inflammation.

Functional polysaccharides of fucoidan, laminaran and alginate from Malaysian brown seaweeds (Sargassum polycystum, Turbinaria ornata and Padina boryana)

Brown seaweeds are rich source of functional polysaccharides that exhibit various bioactivities. However, Malaysian seaweeds are under-utilised, leading to low revenue throughout the supply chain of the seaweed industry. The aims of this study were to extract the functional polysaccharides, namely fucoidan (F), laminaran (L) and alginate (A) from Malaysian brown seaweeds (Sargassum polycystum, Turbinaria ornata and Padina boryana) and subsequently evaluate the properties of the extracted polysaccharides. P. boryana recorded the significantly (p ≤ 0.05) highest carbohydrate content (74.78 ± 1.63%) with highest fucoidan yield (Fpad = 1.59 ± 0.16%) while T. ornata contained significantly (p ≤ 0.05) highest alginate yield (Atur = 105.19 ± 3.45%). Water activities of these extracted polysaccharides varied from 0.63-0.71 with average score of browning indexes (~40). Fourier transform infrared (FTIR) spectroscopy analysis demonstrated that the extracted polysaccharides exhibited similar spectral pattern of spectra with the respective standards. Meanwhile, laminaran extracts showed the significantly highest (p ≤ 0.05) total phenolic contents (Lsar = 43.29 ± 0.43 mgGAE/g) and superoxide anion scavenging activity (Lsig = 21.7 ± 3.6%). On the other hand, the significantly highest (p ≤ 0.05) DPPH scavenging activity was recorded in alginate with Asar at 85.3 ± 0.8%. These findings reported the properties and bioactivities of natural polysaccharides from Malaysian brown seaweeds that revealed the potential to develop high-value functional ingredients from Malaysian brown seaweeds.

Sulfated polysaccharides from Undaria pinnatifida improved high fat diet-induced metabolic syndrome, gut microbiota dysbiosis and inflammation in BALB/c mice

Undaria pinnatifida was shown to reduce serum lipids and fat accumulation and produce beneficial effect on type 2 diabetes, but its effect on intestinal micro-ecology remains unclear. This study showed that sulfated polysaccharides from U. pinnatifida (UPSP) reduced weight gain, fat accumulation and metabolic disorders in mice fed with high fat diet (HFD). UPSP not only alleviated HFD-induced microbiota dysbiosis indicated as increased abundances of some Bacteroidales members that had positive correlations with the improvement of physiological indexes, but also maintained gut barrier integrity and reduced metabolic endotoxemia. A dose-effect relationship was observed between the dose of UPSP and its effect on some physiological indexes, gut microbiota community and nutrient utilization. The in vitro result showed that the use of Bacteroides species within Bacteroidales on UPSP was species-dependent, and the dose of UPSP affected the growth properties of some Bacteroides species. It implied that UPSP can be considered as prebiotic agent to prevent gut dysbiosis and obesity-related diseases in obese individuals.

Structure and Biological Activity Analysis of Fucoidan Isolated from Sargassum siliquosum

Fucoidans are heterologous polysaccharides commonly seen in brown macroalgae and are known for their biological activity including anticancer, antiangiogenic, immunomodulation, and antiviral properties. The brown macroalga Sargassum siliquosum was used for the extraction and analysis of fucoidan in this study. The S. siliquosum fucoidan was indicated as a galactofucoidan composed of sugars, uronate, and sulfate at a ratio of 12:1:4 and its purity was 85% based on the abovementioned three major components. Structural analysis by electrospray ionization collision-induced dissociation tandem mass spectroscopy revealed that the purified fucoidan consisted of a carbohydrate chain composed of (1→3)-linked or (1→4)-linked l-fucose residues, with sulfate groups at C-2 and C-4 positions. Galactose residues with (1→4)-linkages function as the branch points and they are located at the C-3 or C-4 position of fucose residues. Galactose residues are sulfated mainly at C-4 and C-6, while some sulfation can also be seen at C-2. The fucoidan purified from S. siliquosum demonstrated antioxidant, anti-inflammatory, and antilipogenic activities.

Fucoidan refined by Sargassum confusum indicate protective effects suppressing photo-oxidative stress and skin barrier perturbation in UVB-induced human keratinocytes

Damage from ultraviolet (UV)B exposure is cumulative and proceeds via augmenting cellular oxidative stress. The present study investigates UVB-protective effects of Sargassum confusum derived fucoidans in human keratinocytes. Algae was extracted using Celluclast, and fucoidan fractions were recovered by step gradient ethanol precipitation. Refined fucoidan fractions were treated to human HaCaT keratinocytes and exposed to UVB (50 mJ cm-2). Among fucoidan fractions, SCFC4, the lowest molecular weight (MW) fraction indicated better UVB-protective effects with dose-dependent reduction of intracellular ROS levels, while recovering the cell viability. SCFC4 suppressed UVB-induced apoptotic body formation, sub-G1 cell content, and DNA damage by hindering the mitochondria-mediated apoptotic pathway. Also, SCFC4 repressed upstream mediators of UVB-induced inflammatory responses, which would impair stratum corneum hydration. The above therapeutic effects of SCFC4 could be attributed to suppression of nuclear factor (NF)-κB and mitogen-activated protein kinase (MAPK) pathways while activating nuclear factor erythroid 2-related factor 2 (Nrf2) mediated production of antioxidant enzymes. SCFC4 was identified as a fucoidan (MW ≈ 20 kDa) with a 64.64% fucose and 23.62% sulfate contents. Further analysis of shelf life, safety, and efficacy could promote SCFC4's use as a cosmetic ingredient.

Anti-Inflammatory Effects of Sulfated Polysaccharide from Sargassum Swartzii in Macrophages via Blocking TLR/NF-Κb Signal Transduction

This study involves enzymatic extraction of fucoidan from Sargassum swartzii and further purification via ion-exchange chromatography. The chemical and molecular characteristics of isolated fucoidan is evaluated concerning its anti-inflammatory potential in RAW 264.7 macrophages under LPS induced conditions. Structural properties of fucoidan were assessed via FTIR and NMR spectroscopy. NO production stimulated by LPS was significantly declined by fucoidan. This was witnessed to be achieved via fucoidan acting on mediators such as iNOS and COX-2 including pro-inflammatory cytokines (TNF-α, IL-6, and IL-1β), with dose dependent down-regulation. Further, the effect is exhibited by the suppression of TLR mediated MyD88, IKK complex, ultimately hindering NF-κB and MAPK activation, proposing its therapeutic applications in inflammation related disorders. The research findings provide an insight in relation to the sustainable utilization of fucoidan from marine brown algae S. swartzii as a potent anti-inflammatory agent in the nutritional, pharmaceutical, and cosmeceutical sectors.

Fucoidan Characterization: Determination of Purity and Physicochemical and Chemical Properties

Fucoidans are marine sulfated biopolysaccharides that have heterogenous and complicated chemical structures. Various sugar monomers, glycosidic linkages, molecular masses, branching sites, and sulfate ester pattern and content are involved within their backbones. Additionally, sources, downstream processes, and geographical and seasonal factors show potential effects on fucoidan structural characteristics. These characteristics are documented to be highly related to fucoidan potential activities. Therefore, numerous chemical qualitative and quantitative determinations and structural elucidation methods are conducted to characterize fucoidans regarding their physicochemical and chemical features. Characterization of fucoidan polymers is considered a bottleneck for further biological and industrial applications. Consequently, the obtained results may be related to different activities, which could be improved afterward by further functional modifications. The current article highlights the different spectrometric and nonspectrometric methods applied for the characterization of native fucoidans, including degree of purity, sugar monomeric composition, sulfation pattern and content, molecular mass, and glycosidic linkages.

Step gradient alcohol precipitation for the purification of low molecular weight fucoidan from Sargassum siliquastrum and its UVB protective effects

Ultraviolet B (UVB) can induce oxidative damage to outermost layers of skin causing suntans, sunburns, and, in severe cases, blisters leading to photoaging. Low molecular weight (MW) fucoidan is renowned for possessing enhanced antioxidant activities. The present study discloses the use of step gradient ethanol precipitation in refining fucoidan fractions (SSQC1-SSQC4) from Sargassum siliquastrum and evaluation of their UVB-protective effects in human HaCaT keratinocytes. Among the fractions, SSQC4 indicated the best bioactive effects. 1H NMR, FTIR, monosaccharide composition by HPAEC-PAD analysis, MW estimation by agarose gel electrophoresis were used to characterize the fractions. SSQC4 was comprising of fucoidan, with an estimated MW distribution of 8-25 kDa. Exposure of UVB increased intracellular ROS, DNA damage, loss of mitochondrial membrane potential, apoptotic body formation causing cell death through the mitochondria-mediated apoptosis pathway. SSQC4 treatment could dose-dependently attenuate the ROS levels and suppress mitochondria-mediated apoptosis in UVB exposed keratinocytes. SSQC4 treatment enhanced cellular antioxidant defense by increasing Nrf2 mediated HO-1 generation, which was identified as the cause of observed bioactivities. The safety and stability of SSQC4 could be further evaluated to promote its use as a bioactive natural ingredient in UV-protective cosmetics.

Macroalgae-A Sustainable Source of Chemical Compounds with Biological Activities

Nowadays, one of the most important research directions that concerns the scientific world is to exploit the earth's resources in a sustainable way. Considering the increasing interest in finding new sources of bioactive molecules and functional products, many research studies focused their interest on demonstrating the sustainability of exploiting marine macroalgal biomass as feedstock for wastewater treatment and natural fertilizer, conversion into green biofuels, active ingredients in pharmaceutical and nutraceutical products, or even for the production of functional ingredients and integration in the human food chain. The objective of the present paper was to provide an overview on the recent progress in the exploitation of different macroalgae species as a source of bioactive compounds, mainly emphasizing the latter published data regarding their potential bioactivities, health benefits, and industrial applications.

Studies on isolation, characterization of fucoidan from brown algae Turbinaria decurrens and evaluation of it's in vivo and in vitro anti-inflammatory activities

In the present study, the anti-nociception and anti-inflammatory activity of fucoidan isolated from T. decurrens on formalin induced paw-edema in mice model were investigated. The extracted fucoidan contain 54.86% of total sugar, 23.51% of sulfate and 3.4% of protein. The monosaccharide composition analysis revealed that fucoidan encompassed of fucose (59.3%), galactose (12.6%), mannose (9.6%), rhamnose (6.4%) and xylose (11.4%). Further, the structural characterization was done by UV-visible spectroscopy, X-ray diffraction, FT-IR and 1HNMR analysis. The fucoidan reduced the licking time thereby suggesting anti-nociceptive effect and decreased the size of paw swelling in the formalin induced inflammatory edema condition. The isolated fucoidan could significantly decreased the MDA and also increase the SOD, CAT, GPx, GST and GSH activity in paw edema tissue of formalin injected mice. Furthermore, fucoidan administration retained p65/NF-κB transcription factor in the cytosol thereby showing down regulation of the gene expression of pro-inflammatory mediators such as IL-1β, COX-2 and MMP-9 in fucoidan treated mice. The anti-inflammatory effect of fucoidan was attributed to its capacity on modulating the levels of enzymatic antioxidants, master regulator NF-κB and pro-inflammatory cytokines. The fucoidan has reduced LPS induced cytotoxicity in IC-21 macrophage at a dose depended on manner.

Fucoidan from acid-processed Hizikia fusiforme attenuates oxidative damage and regulate apoptosis

We had observed in our previous study that the active fucoidan (JHCF4), isolated from the crude fucoidan in acid-processed Hizikia fusiforme, possessed an anticancer effect. In this study, the antioxidant effect of JHCF4 was evaluated. Among the fractions, JHCF4 showed the highest scavenging activity against 2, 2-diphenyl-1-picrylhydrazyl (DPPH), alkyl, and hydroxyl radicals, as well as protective effect against reactive oxygen species (ROS) in 2, 2'-azobis (2-amidinopropane) dihydrochloride (AAPH)-treated Vero cells. Furthermore, JHCF4 showed a protective activity against AAPH-induced apoptosis, as observed by nuclear staining with Hoechst 33342. Our results showed that JHCF4 can up-regulate Bcl-xL, down-regulate Bax and cleave caspase-3 with increased concentrations in AAPH-induced Vero cells. JHCF4 induced anti-apoptosis via a mitochondria-mediated pathway. Additionally, JHCF4 was selected for further in vivo screening in a zebrafish model, which markedly decreased ROS generation and lipid peroxidation. Thus, JHCF4 showed a potential protective activity against AAPH-induced ROS both in vitro and in the zebrafish model.

Bioactive Polysaccharides from Seaweeds

Bioactive compounds with diverse chemical structures play a significant role in disease prevention and maintenance of physiological functions. Due to the increase in industrial demand for new biosourced molecules, several types of biomasses are being exploited for the identification of bioactive metabolites and techno-functional biomolecules that are suitable for the subsequent uses in cosmetic, food and pharmaceutical fields. Among the various biomasses available, macroalgae are gaining popularity because of their potential nutraceutical and health benefits. Such health effects are delivered by specific diterpenes, pigments (fucoxanthin, phycocyanin, and carotenoids), bioactive peptides and polysaccharides. Abundant and recent studies have identified valuable biological activities of native algae polysaccharides, but also of their derivatives, including oligosaccharides and (bio)chemically modified polysaccharides. However, only a few of them can be industrially developed and open up new markets of active molecules, extracts or ingredients. In this respect, the health and nutraceutical claims associated with marine algal bioactive polysaccharides are summarized and comprehensively discussed in this review.

Degradation of Sargassum crassifolium Fucoidan by Ascorbic Acid and Hydrogen Peroxide, and Compositional, Structural, and In Vitro Anti-Lung Cancer Analyses of the Degradation Products

Fucoidans possess multiple biological functions including anti-cancer activity. Moreover, low-molecular-weight fucoidans are reported to possess more bioactivities than native fucoidans. In the present study, a native fucoidan (SC) was extracted from Sargassum crassifolium pretreated by single-screw extrusion, and three degraded fucoidans, namely, SCA (degradation of SC by ascorbic acid), SCH (degradation of SC by hydrogen peroxide), and SCAH (degradation of SC by ascorbic acid + hydrogen peroxide), were produced. The extrusion pretreatment can increase the extraction yield of fucoidan by approximately 4.2-fold as compared to the non-extruded sample. Among SC, SCA, SCH, and SCAH, the chemical compositions varied but structural features were similar. SC, SCA, SCH, and SCAH showed apoptotic effects on human lung carcinoma A-549 cells, as illustrated by loss of mitochondrial membrane potential (MMP), decreased B-cell leukemia-2 (Bcl-2) expression, increased cytochrome c release, increased active caspase-9 and -3, and increased late apoptosis of A-549 cells. In general, SCA was found to exhibit high cytotoxicity to A-549 cells and a strong ability to suppress Bcl-2 expression. SCA also showed high efficacy to induce cytochrome c release, activate caspase-9 and -3, and promote late apoptosis of A-549 cells. Therefore, our data suggest that SCA could have an adjuvant therapeutic potential in the treatment of lung cancer. Additionally, we explored that the Akt/mammalian target of rapamycin (mTOR) signaling pathway is involved in SC-, SCA-, SCH-, and SCAH-induced apoptosis of A-549 cells.

Bioactive and thermostable sulphated polysaccharide from Sargassum swartzii with drug delivery applications

Sulphated Polysaccharides (SP) were extracted from a brown seaweed Sargassum swartzii by two extraction methods using hydrochloric acid and hot water. The sulphated polysaccharide yield using the hot water extraction method was found to be higher and hence used for further study. The extracted polysaccharide was characterized using UV, FT-IR, biochemical and thin layer chromatography analyses. Further, the purity of the extracted polysaccharide was ascertained by HPLC analysis. The sugars present in the sulphated polysaccharide were revealed by acid hydrolysis. The structure of the extracted SP was revealed as fucoidan using the NMR spectrum. Thermal stability of the sulphated polysaccharide was assessed using Thermogravimetric analysis and polymer was found to be stable up to 700 °C. Anti-oxidant and anti-inflammatory activities were evaluated using phosphomolybdenum and BSA assay, respectively. Cell proliferation analysis using MTT assay against normal cell lines revealed that the polysaccharide is biocompatible while with cancer cell lines, the compound exhibited potential anti-proliferative activity. Application of this sulphated polysaccharide as a carrier for drug delivery with rutin as a model drug was explored. The drug release kinetics was modeled and the stability of the rutin encapsulated SP nano formulation was studied.

Marine-Derived Surface Active Agents: Health-Promoting Properties and Blue Biotechnology-Based Applications

Surface active agents are characterized for their capacity to adsorb to fluid and solid-water interfaces. They can be classified as surfactants and emulsifiers based on their molecular weight (MW) and properties. Over the years, the chemical surfactant industry has been rapidly increasing to meet consumer demands. Consequently, such a boost has led to the search for more sustainable and biodegradable alternatives, as chemical surfactants are non-biodegradable, thus causing an adverse effect on the environment. To these ends, many microbial and/or marine-derived molecules have been shown to possess various biological properties that could allow manufacturers to make additional health-promoting claims for their products. Our aim, in this review article, is to provide up to date information of critical health-promoting properties of these molecules and their use in blue-based biotechnology (i.e., biotechnology using aquatic organisms) with a focus on food, cosmetic and pharmaceutical/biomedical applications.

Sulfated galactan from Halymenia dilatata enhance the antioxidant properties and prevents Aeromonas hydrophila infection in tilapia fish: In vitro and in vivo study

The structural characterization and pharmaceutical perspective of sulfated galactan from Halymenia dilatata (Hd-SG) were reported in this study. The Hd-SG consists of carbohydrate (58.5 ± 0.9%), sulfate (28.7 ± 0.9%) and protein (2.7 ± 0.2%). The existence of carbon (28.14%), hydrogen (5.50%), nitrogen (0.51%) and sulfur (8.26%) was confirmed in CHNS analysis. The Hd-SG was mainly comprising of galactose and mannose connected by (1 → 4)-glycosidic linkages, and it shows the molecular weight of 900.9 × 103 g/mol in high-performance size exclusion chromatography (HPSEC). The Hd-SG exhibited the dose depended on antioxidant activities. The in vitro and in vivo studies proved the antibacterial efficacy of Hd-SG against Aeromonas hydrophila. The pre-treated Oreochromis fish with Hd-SG (2.0 g/0.1 kg of feed) showed the highest survival, antioxidant, and improved histological changes than the fish infected with A. hydrophila alone. These results concluded that the isolated Hd-SG has extensive therapeutic properties, and it can be used as preventive medicine.

Human Keratinocyte UVB-Protective Effects of a Low Molecular Weight Fucoidan from Sargassum horneri Purified by Step Gradient Ethanol Precipitation

Ultraviolet B (UVB) radiation-induced oxidative skin cell damage is a major cause of photoaging. In the present study, a low molecular weight fucoidan fraction (SHC4) was obtained from Sargassum horneri by Celluclast-assisted extraction, followed by step gradient ethanol precipitation. The protective effect of SHC4 was investigated in human keratinocytes against UVB-induced oxidative stress. The purified fucoidan was characterized by Fourier-transform infrared spectroscopy (FTIR), ¹H nuclear magnetic resonance (NMR), agarose gel-based molecular weight analysis and monosaccharide composition analysis. SHC4 had a mean molecular weight of 60 kDa, with 37.43% fucose and 28.01 ± 0.50% sulfate content. The structure was mainly composed of α-L-Fucp-(1→4) linked fucose units. SHC4 treatment dose-dependently reduced intracellular reactive oxygen species (ROS) levels and increased the cell viability of UVB exposed HaCaT keratinocytes. Moreover, SHC4 dose-dependently inhibited UVB-induced apoptotic body formation, sub-G₁ accumulation of cells and DNA damage. Inhibition of apoptosis was mediated via the mitochondria-mediated pathway, re-establishing the loss of mitochondrial membrane potential. The UVB protective effect of SHC4 was facilitated by enhancing intracellular antioxidant defense via nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling. Further studies may promote the use of SHC4 as an active ingredient in cosmetics and nutricosmetics.

Fucoidan from Laminaria japonica exerts antitumor effects on angiogenesis and micrometastasis in triple-negative breast cancer cells

Fucoidan is a fucose-rich polysaccharide that has gained attention for its various anticancer properties. However, the effect and underlying mechanism of fucoidan on triple-negative breast cancer (TNBC) are still unknown. Herein, we investigated the anticancer potential of fucoidan from Laminaria japonica. We found that fucoidan showed modest antiproliferative activity against TNBC cells, while it effectively reduced migratory and invasive capacities. Mechanistically, fucoidan suppressed activation of MAPK and PI3K followed by inhibition of AP-1 and NF-κB signaling in TNBC. Additionally, fucoidan downregulated expressions of proangiogenic factors in TNBC cells, and fucoidan blocked tumor-elicited tube formation by human umbilical vascular endothelial cells (HUVECs). We also observed that fucoidan blocked tumor adhesion and invasion towards HUVECs. Surprisingly, fucoidan robustly suppressed tube formation on HUVECs. Moreover, fucoidan inhibited in vivo angiogenesis and micrometastasis in a transgenic zebrafish model. Together, L. japonica fucoidan exhibits potent antitumor effects by its attenuation of invasiveness and proangiogenesis in TNBC.

Gastric protective activities of fucoidan from brown alga Kjellmaniella crassifolia through the NF-κB signaling pathway

Fucoidan has been reported to have abundant biological activities. The objective of the present study was to detect the protective effects of fucoidan from Kjellmaniella crassifolia (KF) newly cultured in Dalian, North of China on aspirin-induced gastric ulcers of the Wistar rat model. The present study showed that inflammatory cytokines tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6 and IL-10 were effectively regulated in rats pretreated with KF. Superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities increased significantly in the KF pretreated groups, while the levels of maleic dialdehyde (MDA) decreased. The findings obtained by RT-PCR and western blotting indicated that KF could suppress aspirin-induced NF-κB activation via stabilization of IκB-α and thereby induced the downregulation of COX-2 and iNOS. It was demonstrated that KF exerted positive gastric protective effects via suppression of the inflammatory response and oxidative stress, and the mechanism of KF appeared to mediate the NF-κB signaling pathway.

Fucoidan Purified from Sargassum polycystum Induces Apoptosis through Mitochondria-Mediated Pathway in HL-60 and MCF-7 Cells

Fucoidans are biocompatible, heterogeneous, and fucose rich sulfated polysaccharides biosynthesized in brown algae, which are renowned for their broad-spectrum biofunctional properties. As a continuation of our preliminary screening studies, the present work was undertaken to extract polysaccharides from the edible brown algae Sargassum polycystum by a modified enzyme assisted extraction process using Celluclast, a food-grade cellulase, and to purify fucoidan by DEAE-cellulose anion exchange chromatography. The apoptotic and antiproliferative properties of the purified fucoidan (F5) were evaluated on HL-60 and MCF-7 cells. Structural features were characterized by FTIR and NMR analysis. F5 indicated profound antiproliferative effects on HL-60 leukemia and MCF-7 breast cancer cells with IC50 values of 84.63 ± 0.08 µg mL-1 and 93.62 ± 3.53 µg mL-1 respectively. Further, F5 treatment increased the apoptotic body formation, DNA damage, and accumulation of HL-60 and MCF-7 cells in the Sub-G1 phase of the cell cycle. The effects were found to proceed via the mitochondria-mediated apoptosis pathway. The Celluclast assisted extraction is a cost-efficient method of yielding fucoidan. With further studies in place, purified fucoidan of S. polycystum could be applied as functional ingredients in food and pharmaceuticals.

Enzymatic-assisted polymerization of the lignin obtained from a macroalgae consortium, using an extracellular laccase-like enzyme (Tg-laccase) from Tetraselmis gracilis

In the past decade, Mexican coasts have received an enormous influx of macroalgae species, producing serious environmental and public health concerns. Here, we developed a green methodology to generate a new polymer from the lignin contained in the macroalgae. The methodology consists in lignin extraction-by-boiling and its subsequent polymerization with a laccase-like enzyme from the green algae Tetraselmis gracilis (Tg-laccase). Mass spectrometry revealed the presence of guaiacyl (G), p-hydroxyphenyl (H), and sinapyl alcohol as the main monolignols in the lignin from Sargassum sp. On the other hand, MALDI-TOF spectra shows an increase in the size of the lignin chain after enzymatic polymerization process with Tg-laccase. Besides, the characterization of the novel polymer -using ¹H NMR, FTIR, SEC-FPLC, and UV/Vis- allowed establishing that during the polymerization process there is a decrease in the number of phenolic groups as well as loss of aromatic protons, which allowed proposing a polimerizacion mechanism. This methodology could be promising in the development of a new lignin-based polymer and would open a new direction for the environmental management of the macroalgae on the Mexican beaches.

Hepatoprotective effect of a fucoidan extract from Sargassum fluitans Borgesen against CCl4-induced toxicity in rats

The in vivo antifibrotic effect of a fucoidan extract (FE) from Sargassum fluitans Borgesen was evaluated in a carbon tetrachloride-induced liver damage model in rats over twelve weeks. Chemical analysis showed the FE to contain carbohydrates, sulfates, uronic acids, protein, phenols, and to have a molecular weight of ~60 kDa. Physiological, biochemical, histological and genetic assays were done. Daily oral administration of FE (50 mg/kg) reduced liver enzymatic activity, liver infiltration of inflammatory cells, collagen fiber deposition and gene expression cytokines such as interleukin beta 1 (IL-β1), tumor necrosis factor alpha (TNF-α), transforming growth factor beta 1 (TGF-β1), Smad-3, Smad-2, collagen 1 alpha 1 (col1α1) and tissue inhibitor of metalloproteinase 1 (TIMP-1). It also increased RNA expression of Smad-7 and metalloproteinase 2 and 9 (MMP2 and MMP9). The fucoidan extract exhibited an antifibrotic effect mediated by the inhibiting TGF-β1/Smad pathway, as well as anti-inflammatory effects.

Fucoidan Inhibition of Osteosarcoma Cells Is Species and Molecular Weight Dependent

Fucoidan is a brown algae-derived polysaccharide having several biomedical applications. This study simultaneously compares the anti-cancer activities of crude fucoidans from Fucus vesiculosus and Sargassum filipendula, and effects of low (LMW, 10-50 kDa), medium (MMW, 50-100 kDa) and high (HMW, >100 kDa) molecular weight fractions of S. filipendula fucoidan against osteosarcoma cells. Glucose, fucose and acid levels were lower and sulphation was higher in F. vesiculosus crude fucoidan compared to S. filipendula crude fucoidan. MMW had the highest levels of sugars, acids and sulphation among molecular weight fractions. There was a dose-dependent drop in focal adhesion formation and proliferation of cells for all fucoidan-types, but F. vesiculosus fucoidan and HMW had the strongest effects. G1-phase arrest was induced by F. vesiculosus fucoidan, MMW and HMW, however F. vesiculosus fucoidan treatment also caused accumulation in the sub-G1-phase. Mitochondrial damage occurred for all fucoidan-types, however F. vesiculosus fucoidan led to mitochondrial fragmentation. Annexin V/PI, TUNEL and cytochrome c staining confirmed stress-induced apoptosis-like cell death for F. vesiculosus fucoidan and features of stress-induced necrosis-like cell death for S. filipendula fucoidans. There was also variation in penetrability of different fucoidans inside the cell. These differences in anti-cancer activity of fucoidans are applicable for osteosarcoma treatment.

Pharmacological and natural products diversity of the brown algae genus Sargassum

Sargassum (F. Sargassaceae) is an important seaweed excessively distributed in tropical and subtropical regions.