Eckol isolated from Ecklonia cava attenuates oxidative stress induced cell damage in lung fibroblast cells

The Impact of Chitinase Binding Domain Truncation on the Properties of CaChi18B from Chitinilyticum aquatile CSC-1

The chitinase binding domain (ChBD) plays a crucial role in the properties of enzymes. To assess its impact, we cloned a truncated mutant of the chitinase gene CaChi18B from the novel chitinase-producing facultative anaerobic bacterium Chitinilyticum aquatile CSC-1, designated as CaChi18B_ΔChBDs. The recombinant chitinase was successfully expressed and purified, exhibiting a specific activity of 3.48 U/mg on colloidal chitin, with optimal conditions at 45 °C and pH 6.0, and retaining over 80% activity at temperatures up to 40 °C. Kinetic analysis revealed that the Km value was 1.159 mg mL-1 and the Vmax was 10.37 μM min-1 mg-1. Compared to CaChi18B_ΔChBD1, which has only the first ChBD truncated at the N-terminus, CaChi18B_ΔChBDs exhibited minor changes in the optimal temperature and pH, while the Km and Vmax values increased significantly. CaChi18B_ΔChBDs exhibited tolerance to various metal ions, with K+ and NH4+ enhancing activity, while Cu2+ significantly inhibited it. Most organic reagents had minimal impact, except for formic acid, which severely reduced activity. The primary hydrolysis product in the initial phase was GlcNAc, contrasting with (GlcNAc)2 for CaChi18B_ΔChBD1. These findings indicated that the ChBD influences the enzyme's Km, Vmax, and product distribution, enhancing our understanding of ChBD's roles and advancing chitin utilization.

Marine Polyphenols in Cardiovascular Health: Unraveling Structure-Activity Relationships, Mechanisms, and Therapeutic Implications

Cardiovascular diseases (CVDs) are responsible for significant mortality rates globally that have been raised due to the limitation of the available treatments and prevalence of CVDs. The innovative research and identification of potential preventives for CVDs are essential to alleviate global deaths and complications. The marine environment is a rich source of bioactive substances and provides a unique chemical arsenal against numerous ailments due to its unrivaled biodiversity. Marine polyphenolic compounds (MPCs) are unique because of their structural variety and biologically significant activity. Further, MPCs are well-reported for their valuable biological activities, such as anti-inflammatory, cardioprotective, and antioxidant, demonstrating encouraging results in preventing and treating CVDs. Therefore, investigation of the structure-activity relationship (SAR) between MPCs and CVDs provides insights that reveal how the structural components of these compounds affect their effectiveness. Further, comprehending this correlation is essential for advancing medications and nutraceuticals sourced from marine sources, which could transform the strategy for treating and preventing cardiovascular diseases. Therefore, this study provides a comprehensive analysis of existing research by emphasizing the role of MPCs in CVD treatments and evaluating the SAR between MPCs and CVDs with challenges and future directions.

Safety evaluation and effects of dietary phlorotannins on the growth, health, and intestinal microbiota of Litopenaeus vannamei

Phlorotannins are phenolic compounds with diverse biological activities, yet their efficacy in aquatic animals currently remains unclear. This investigation scrutinized the influence of phlorotannins on the growth, immunity, antioxidant capacity, and intestinal microbiota in Litopenaeus vannamei, concurrently evaluating the potential adverse effects of phlorotannins on L. vannamei. A base diet without phlorotannins supplementation was used as a control, and 4 groups of diets with different concentrations (0, 0.5, 1.0, 2.0 g kg-1) of phlorotannins were formulated and fed to juvenile shrimp (0.25 ± 0.01 g) for 60 days followed by a 24-h challenge with Vibrio parahaemolyticus with triplicate in each group. Compared with the control, dietary 2.0 g kg-1 phlorotannins significantly improved the growth of the shrimp. The activities of enzymes related to cellular immunity, humoral immunity, and antioxidants, along with a notable upregulation in the expression of related genes, significantly increased. After V. parahaemolyticus challenge, the cumulative survival rates of the shrimp demonstrated a positive correlation with elevated concentrations of phlorotannins. In addition, the abundance of Bacteroidetes and functional genes associated with metabolism increased in phlorotannins supplementation groups. Phlorotannins did not elicit any detrimental effects on the biological macromolecules or histological integrity of the hepatopancreas or intestines. Simultaneously, it led to a significant reduction in malondialdehyde content. All results indicated that phlorotannins at concentrations of 2.0 g kg-1 can be used as safe feed additives to promote the growth, stimulate the immune response, improve the antioxidant capacity and intestinal health of L. vannamei, and an protect shrimp from damage caused by oxidative stress.

Marine Macroalgae Polyphenols as Potential Neuroprotective Antioxidants in Neurodegenerative Diseases

Polyphenols are beneficial natural compounds with antioxidant properties that have recently gain a lot of interest for their potential therapeutic applications. Marine polyphenols derived from marine macroalgae have been discovered to possess interesting antioxidant properties; therefore, these compounds can be included in several areas of drug development. Authors have considered the use of polyphenol extracts from seaweeds as neuroprotective antioxidants in neurodegenerative diseases. Marine polyphenols may slow the progression and limit neuronal cell loss due to their antioxidant activity; therefore, the use of these natural compounds would improve the quality of life for patients affected with neurodegenerative diseases. Marine polyphenols have distinct characteristics and potential. Among seaweeds, brown algae are the main sources of polyphenols, and present the highest antioxidant activity in comparison to red algae and green algae. The present paper collects the most recent in vitro and in vivo evidence from investigations regarding polyphenols extracted from seaweeds that exhibit neuroprotective antioxidant activity. Throughout the review, oxidative stress in neurodegeneration and the mechanism of action of marine polyphenol antioxidant activity are discussed to evidence the potential of algal polyphenols for future use in drug development to delay cell loss in patients with neurodegenerative disorders.

Colloidal Nanoparticles Isolated from Duck Soup Exhibit Antioxidant Effect on Macrophages and Enterocytes

Food-derived colloidal nanoparticles (CNPs) have been found in many food cooking processes, and their specific effects on human health need to be further explored. Here, we report on the successful isolation of CNPs from duck soup. The hydrodynamic diameters of the obtained CNPs were 255.23 ± 12.77 nm, which comprised lipids (51.2%), protein (30.8%), and carbohydrates (7.9%). As indicated by the tests of free radical scavenging and ferric reducing capacities, the CNPs possessed remarkable antioxidant activity. Macrophages and enterocytes are essential for intestinal homeostasis. Therefore, RAW 264.7 and Caco-2 were applied to establish an oxidative stress model to investigate the antioxidant characteristics of the CNPs. The results showed that the CNPs from duck soup could be engulfed by these two cell lines, and could significantly alleviate 2,2'-Azobis(2-methylpropionamidine) dihydrochloride (AAPH)-induced oxidative damage. It indicates that the intake of duck soup is beneficial for intestinal health. These data contribute to revealing the underlying functional mechanism of Chinese traditional duck soup and the development of food-derived functional components.

Anti-oxidative properties of nanocrocin in Zearalenone induced toxicity on Hek293 cell; The novel formulation and cellular assessment

BACKGROUND

Zearalenone (ZEA) is a mycotoxin produced by fungi and induces cytotoxicity by the generation of reactive oxygen species. The aim of this study was to evaluate and compare the nephroprotective effects of crocin and nano-crocin against ZEA-induced toxicity in HEK293 cell line via modulation of oxidative stress and special formulation to make nano-crocin.

METHOD

Nano-crocin physicochemical properties, such as size, load, appearance, and drug release profile were determined. Also, the viability of intoxicated HEK293 cells was evaluated by MTT assay. Furthermore, lactate dehydrogenase lipid Peroxidation (LPO), and oxidative stress biomarkers were measured.

RESULT

The best nano-crocin formulation with superior entrapment effectiveness (54.66 ± 6.02), more significant drug loading (1.89 ± 0.01), better zeta potential (-23.4 ± 2.844), and smaller particle size (140.3 ± 18.0 nm) was chosen. This study showed that treatment with crocin and nano-crocin in ZEA-induced cells, significantly decreased LDH and LPO levels and increased superoxide dismutase (SOD), catalase (CAT) activities, and total antioxidant capacity (TAC) levels compared to the control group. Moreover, nano-crocin had a more curative effect against oxidative stress than crocin.

CONCLUSION

Niosomal structure of crocin, when administered with the special formulation, may be more beneficial in reducing ZEA-induced in vitro toxicity than conventional crocin.

The protective effects of thymol and carvacrol against di (2-ethylhexyl) phthalate-induced cytotoxicity in HEK-293 cells

The protective effects of thymol and carvacrol, two phenolic monoterpenes with a wide spectrum of pharmacological effects, against the oxidative stress produced by the di (2-ethylhexyl) phthalate (DEHP) in human embryonic kidney cells 293 cells (HEK-293 cells) were investigated in this study. The cytotoxicity was monitored by cell viability, while oxidative stress generation was assessed by reactive oxygen species (ROS) quantification, antioxidant enzyme activities measurement, glutathione concentration, and malondialdehyde (MDA) quantification. The genotoxicity was evaluated by the measurement of DNA fragmentation through the Comet assay. Our results demonstrated that the pretreatment of HEK-293 cells with thymol or carvacrol, 2 h before DEHP exposure, significantly increased the cell viability, decreased the ROS overproduction, modulated catalase (CAT), and superoxide dismutase (SOD) activities, restored the reduced glutathione content, and reduced the MDA level. The DNA fragmentation was also decreased by thymol and carvacrol pretreatment. These findings suggest that thymol and carvacrol could protect HEK-293 cells from DEHP-induced oxidative stress.

Molecular Targets of Brown Algae Phlorotannins for the Therapy of Inflammatory Processes of Various Origins

Inflammatory reactions are part of a complex biological response that plays a vital role in the appearance of various stimuli resulting from tissue and cell damage, the invasion of pathogenic bacteria, and the formation of the subsequent adaptive immune response. The production of many triggers and mediators of inflammation, which are inducers of pro-inflammatory factors, is controlled by numerous differentiation programs, through which inflammation is resolved and tissue homeostasis is restored. However, prolonged inflammatory responses or dysregulation of pro-inflammatory mechanisms can lead to chronic inflammation. Modern advances in biotechnology have made it possible to characterize the anti-inflammatory activity of phlorotannins, polyphenolic compounds from brown seaweed, and the mechanisms by which they modulate the inflammatory response. The purpose of this review is to analyze and summarize the results of numerous experimental in vitro and in vivo studies, illustrating the regulatory mechanisms of these compounds, which have a wide range of biological effects on the body. The results of these studies and the need for further research are discussed.

Anticancer Activities of Marine-Derived Phenolic Compounds and Their Derivatives

Since the middle of the last century, marine organisms have been identified as producers of chemically and biologically diverse secondary metabolites which have exerted various biological activities including anticancer, anti-inflammatory, antioxidant, antimicrobial, antifouling and others. This review primarily focuses on the marine phenolic compounds and their derivatives with potent anticancer activity, isolated and/or modified in the last decade. Reports on the elucidation of their structures as well as biosynthetic studies and total synthesis are also covered. Presented phenolic compounds inhibited cancer cells proliferation or migration, at sub-micromolar or nanomolar concentrations (lamellarins D (37), M (38), K (39), aspergiolide B (41), fradimycin B (62), makulavamine J (66), mayamycin (69), N-acetyl-N-demethylmayamycin (70) or norhierridin B (75)). In addition, they exhibited anticancer properties by a diverse biological mechanism including induction of apoptosis or inhibition of cell migration and invasive potential. Finally, phlorotannins 1–7 and bromophenols 12–29 represent the most researched phenolic compounds, of which the former are recognized as protective agents against UVB or gamma radiation-induced skin damages. Finally, phenolic metabolites were assorted into six main classes: phlorotannins, bromophenols, flavonoids, coumarins, terpenophenolics, quinones and hydroquinones. The derivatives that could not be attributed to any of the above-mentioned classes were grouped in a separate class named miscellaneous compounds.

A Phlorotanin, 6,6'-bieckol from Ecklonia cava, Against Photoaging by Inhibiting MMP-1, -3 and -9 Expression on UVB-induced HaCaT Keratinocytes

Skin is the outmost layer of human and sustains most of the external UVB irradiation, which possibly causes the skin photoaging. As a natural antioxidant, marine natural products have been paid more and more attention to their positive effects on photoaging. 6,6'-bieckol is a phlorotanin isolated from Ecklonia cava, while its antiphotoaging bioactivity and mechanism have not been clear yet. This study proves that 6,6'-bieckol enhances cells viability and decreases the level of ROS in UVB-induced human immortalized keratinocytes (HaCaT) cells. It also resulted in significant downregulation of matrix metalloproteinases (MMPs), p-c-Fos, phosphorylated JNK, p38, IκB and p65. In addition, molecular docking also showed that 6,6'-bieckol could bind to MMP-1, MMP-3 and MMP-9. Finally, it was proved that 6,6'-bieckol acts on MMPs through the MAPK/AP-1 and NF-κB pathways to reduce UVB-induced oxidative stress damage in HaCaT cells. Therefore, 6,6'-bieckol is a functional food and skin care ingredient with great potential in preventing photoaging.

Laxative Effects of Phlorotannins Derived from Ecklonia cava on Loperamide-Induced Constipation in SD Rats

This study investigated the laxative effects of phlorotannins (Pt) derived from Ecklonia cava (E. cave) on chronic constipation by evaluating alterations in stool parameters, gastrointestinal motility, histopathological structure, mucin secretion, gastrointestinal hormones, muscarinic cholinergic regulation, and fecal microbiota in SD rats with loperamide (Lop)-induced constipation subjected to Pt treatment. Stool-related parameters (including stool number, weight, and water contents), gastrointestinal motility, and length of intestine were significantly enhanced in the Lop+Pt-treated group as compared to the Lop+Vehicle-treated group. A similar recovery was detected in the histopathological and cytological structure of the mid-colon of Lop+Pt-treated rats, although the level of mucin secretion remained constant. Moreover, rats with Lop-induced constipation subjected to Pt treatment showed significant improvements in water channel expression, gastrointestinal hormone secretions, and expression of muscarinic acetylcholine receptors M2/M3 (mAChRs M2/M3) and their mediators of muscarinic cholinergic regulation. Furthermore, the Lop+Pt-treated group showed a significant recovery of Bifidobacteriaceae, Muribaculaceae, Clostridiaceae, and Eubacteriaceae families in fecal microbiota. Taken together, these results provide the first evidence that exposure of SD rats with Lop-induced constipation to Pt improves the constipation phenotype through the regulation of membrane water channel expression, GI hormones, the mAChR signaling pathway, and fecal microbiota.

Metabolites with Antioxidant Activity from Marine Macroalgae

Reactive oxygen species (ROS) attack biological molecules, such as lipids, proteins, enzymes, DNA, and RNA, causing cellular and tissue damage. Hence, the disturbance of cellular antioxidant homeostasis can lead to oxidative stress and the onset of a plethora of diseases. Macroalgae, growing in stressful conditions under intense exposure to UV radiation, have developed protective mechanisms and have been recognized as an important source of secondary metabolites and macromolecules with antioxidant activity. In parallel, the fact that many algae can be cultivated in coastal areas ensures the provision of sufficient quantities of fine chemicals and biopolymers for commercial utilization, rendering them a viable source of antioxidants. This review focuses on the progress made concerning the discovery of antioxidant compounds derived from marine macroalgae, covering the literature up to December 2020. The present report presents the antioxidant potential and biogenetic origin of 301 macroalgal metabolites, categorized according to their chemical classes, highlighting the mechanisms of antioxidative action when known.

The antioxidant dieckol reduces damage of oxidative stress-exposed porcine oocytes and enhances subsequent parthenotes embryo development

This study investigated the effect of the antioxidant dieckol, a component of Ecklonia cava, on maturation and developmental competence of porcine oocytes exposed to oxidative stress in vitro. Oocytes were matured in in vitro maturation (IVM) medium containing various concentrations of dieckol. The blastocyst formation rate was highest in the 0.5 μM dieckol-treated (0.5 DEK) group. The reactive oxygen species level was decreased, and the level of glutathione and expression of antioxidant genes (NFE2L, SOD1, and SOD2) at metaphase II were increased in the 0.5 DEK group. Abnormal spindle organization and chromosome misalignment were prevented in the 0.5 DEK group. Expression of maternal markers (CCNB1 and MOS) and activity of p44/42 mitogen-activated protein kinase were increased in the 0.5 DEK group. After parthenogenetic activation, the total number of cells per blastocyst was increased and the percentage of apoptotic cells was decreased in the 0.5 DEK group. Expression of development-related genes (CX45, CDX2, POU5F1, and NANOG), antiapoptotic genes (BCL2L1 and BIRC5), and a proapoptotic gene (CASP3) were altered in the 0.5 DEK group. These results indicate that the antioxidant dieckol improves IVM and subsequent development of porcine oocytes and can be used to improve the quality of oocytes under peroxidation experimental conditions.

Moringa oleifera Protects SH-SY5YCells from DEHP-Induced Endoplasmic Reticulum Stress and Apoptosis

Moringa oleifera (MO) is a medicinal plant that has been shown to possess antioxidant, anticarcinogenic and antibiotic activities. In a rat model, MO extract (MOe) has been shown to have a protective effect against brain damage and memory decline. As an extending study, here, we have examined the protective effect of MOe against oxidative stress and apoptosis caused in human neuroblastome (SH-SY5Y) cells by di-(2-ethylhexyl) phthalate (DEHP), a plasticizer known to induce neurotoxicity. Our data show that MOe prevents oxidative damage by lowering reactive oxygen species (ROS) formation, restoring mitochondrial respiratory chain complex activities, and, in addition, by modulating the expression of vitagenes, i.e., antioxidant proteins Nrf2 and HO-1. Moreover, MOe prevented neuronal damage by partly inhibiting endoplasmic reticulum (ER) stress response, as indicated by decreased expression of CCAAT-enhancer-binding protein homologous protein (CHOP) and Glucose-regulated protein 78 (GRP78) proteins. MOe also protected SH-SY5Y cells from DEHP-induced apoptosis, preserving mitochondrial membrane permeability and caspase-3 activation. Our findings provide insight into understanding of molecular mechanisms involved in neuroprotective effects by MOe against DEHP damage.

Antioxidant activity and laxative effects of tannin-enriched extract of Ecklonia cava in loperamide-induced constipation of SD rats

To investigate the role of tannin-enriched extracts of Ecklonia cava (TEE) on the regulation of oxidative balance and laxative activity in chronic constipation, we investigated alterations after exposure to TEE, on constipation phenotypes, muscarinic cholinergic regulation, and oxidative stress responses in the transverse colons of SD rats with loperamide (Lop)-induced constipation. This extract contains high levels of total condensed tannin content (326.5 mg/g), and exhibited high inhibitory activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals. TEE treatment induced significant improvements in reactive oxygen species (ROS) production, superoxide dismutase (SOD) expression and nuclear factor erythroid 2-related factor 2 (Nrf2) phosphorylation in primary smooth muscles of rat intestine cells (pRISMCs) and transverse colon of constipation model. Also, Lop+TEE treated groups showed alleviated outcomes for the following: most stool parameters, gastrointestinal transit, and intestine length were remarkably recovered; a similar recovery pattern was observed in the histopathological structure, mucin secretion, water channel expression and gastrointestinal hormones secretion in the transverse colon; expressions of muscarinic acetylcholine receptors M2/M3 (mAChR M2/M3) and their mediators on muscarinic cholinergic regulation were significantly recovered. Taken together, these results provide the first evidence that TEE stimulates oxidative stress modulation and muscarinic cholinergic regulation when exerting its laxative effects in chronic constipation models.

Neuroprotective effects of Myricetin on Epoxiconazole-induced toxicity in F98 cells

Epoxiconazole is one of the most commonly used fungicides in the world. The exposition of humans to pesticides is mainly attributed to its residue in food or occupational exposure in agricultural production. Because of its lipophilic character, Epoxiconazole can accumulate in the brain Heusinkveld et al. (2013) [1]. Consequently, it is urgent to explore efficient strategies to prevent or treat Epoxiconazole-related brain damages. The use of natural molecules commonly found in our diet represents a promising avenue. Flavonoids belong to a major sub-group compounds possessing powerful antioxidant activities based on their different structural and sterical properties [2]. We choose to evaluate Myricetin, a flavonoid with a wide spectrum of pharmacological effects, for its possible protective functions against Epoxiconazole-induced toxicities. The cytotoxicity induced by this fungicide was evaluated by the cell viability, cell cycle arrest, ROS generation, antioxidant enzyme activities, and Malondialdehyde production, as previously described in Hamdi et al., 2019 [3]. The apoptosis was assessed through the evaluation of the mitochondrial transmembrane potential (ΔΨm), caspases activation, DNA fragmentation, cytoskeleton disruption, nuclear condensation, appearance of sub-G0/G1 peak (fragmentation of the nucleus) and externalization of Phosphatidylserine. This study indicates that pre-treatment of F98 cells with Myricetin during 2 h before Epoxiconazole exposure significantly increased the survival of cells, restored DNA synthesis of the S phase, abrogated the ROS generation, regulated the activities of Catalase (CAT) and Superoxide Dismutase (SOD), and reduced the MDA level. The loss of mitochondrial membrane potential, DNA fragmentation, cytoskeleton disruption, chromatin condensation, Phosphatidylserine externalization, and Caspases activation were also reduced by Myricetin. Together, these findings indicate that Myricetin is a powerful natural product able to protect cells from Epoxiconazole-induced cytotoxicity and apoptosis.

Metabolomic Approach for Characterization of Polyphenolic Compounds in Laminaria japonica, Undaria pinnatifida, Sargassum fusiforme and Ascophyllum nodosum

Profiling of polyphenolics in four types of brown macroalgae, namely Laminaria japonica (L. japonica), Undaria pinnatifida (U. pinnatifida), Sargassum fusiforme (S. fusiforme), and Ascophyllum nodosum (A. nodosum), and their effect on oxidation resistance were investigated for the first time. Polyphenolic extracts from marine brown macroalgae were shown to effectively remove oxidants from cells and cellular systems. A. nodosum showed the highest antioxidant activity among evaluated brown macroalgae, showing a better scavenging effect on 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical and alleviating oxidative damage caused by hydrogen peroxide to human keratinocytes (HaCaT) cells. Through Q-Exactive HF-X mass spectrometry analysis, 12 polyphenolic compounds were preliminarily identified, including phlorotannins, phenolic acids, and flavonoids. Significant differences in content and variety of polyphenolics were found in evaluated brown macroalgae, which could be related to differences in antioxidant activity in vivo and in vitro. Moreover, the antioxidant activity might be related to the total phenolic content and the types of polyphenolics, especially phlorotannins. The findings presented in this study indicate that A. nodosum could be used as an important substitute for functional ingredients in foods and pharmaceutical preparations, as well as a raw material for phlorotannins research.

Comparison of the scavenging capacities of phloroglucinol and 2,4,6-trihydroxypyridine towards HO˙ radical: a computational study

In this work the scavenging capacities of biologically active phloroglucinol (1,3,5-trihydroxybenzene, THB-OH) and structurally similar 2,4,6-trihydroxypyridine (THP-OH) towards HO˙ were examined. This task was realized by means of density functional theory, through investigation of all favorable antioxidative pathways in two solvents of different polarity: benzene and water. It was found that in benzene both compounds conform to the hydrogen atom transfer (HAT) and radical adduct formation (RAF) mechanisms. In water, the mechanisms of antioxidative action of the investigated compounds are far more complex, especially those of THB-OH. This compound and HO˙ undergo all four investigated mechanisms: HAT, RAF, sequential proton loss electron transfer (SPLET), and single electron transfer-proton transfer (SET-PT). HAT, RAF and SPLET are operative mechanisms in the case of THP-OH. Independently of solvent polarity, both investigated compounds are more reactive towards HO˙ in comparison to Trolox. Our final remark is as follows: the electron-withdrawing effect of the nitrogen is stronger than the electron-donating effect of the OH groups in the molecule of THP-OH. As a consequence, THB-OH is more powerful antioxidant than THP-OH, thus implying that the presence of nitrogen decreases the scavenging capacity of the respective compound.

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.

Eckol from Ecklonia cava ameliorates TNF-α/IFN-γ-induced inflammatory responses via regulating MAPKs and NF-κB signaling pathway in HaCaT cells

We investigated the protective effect of the bioactive compound eckol on inflammatory-related skin lesions in vitro. HaCaT cells were stimulated with tumor necrosis factor-alpha (TNF-α) and interferon-gamma (IFN-γ) mixture, and treated with various concentration of eckol (25, 50, and 100 µg/ml). The expression of pro-inflammatory cytokines and chemokines were analyzed by enzyme-linked immunosorbent assay (ELISA) and reverse transcription polymerase chain reaction (RT-PCR), respectively. Mitogen-activated protein kinase (MAPKs) and nuclear factor-kappa B (NF-κB) signaling pathways regulate immune and inflammation responses. Phosphorylation of MAPKs and NF-κB, indicating activation of respective signaling pathways, was examined by western blot analysis. Treatment of TNF-α and IFN-γ promoted the mRNA expression and production of pro-inflammatory cytokines and chemokines in HaCaT cells. However, eckol significantly suppressed the these mediators. Furthermore, activation of TNF-α/IFN-γ-induced MAPKs and NF-κB signaling pathway was inhibited by eckol treatment. Eckol also hampered the TNF-α/IFN-γ-mediated nuclear translocation of NF-κB p65 in HaCaT cells. Taken together, our findings demonstrate that eckol shows effective protective activity against TNF-α/IFN-γ-induced skin inflammation.

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.

Can Plant Phenolic Compounds Protect the Skin from Airborne Particulate Matter?

The skin is directly exposed to the polluted atmospheric environment, and skin diseases, such as atopic dermatitis and acne vulgaris, can be induced or exacerbated by airborne particulate matter (PM). PM can also promote premature skin aging with its accompanying functional and morphological changes. PM-induced skin diseases and premature skin aging are largely mediated by reactive oxygen species (ROS), and the harmful effects of PM may be ameliorated by safe and effective natural antioxidants. Experimental studies have shown that the extracts and phenolic compounds derived from many plants, such as cocoa, green tea, grape, pomegranate, and some marine algae, have antioxidant and anti-inflammatory effects on PM-exposed cells. The phenolic compounds can decrease the levels of ROS in cells and/or enhance cellular antioxidant capacity and, thereby, can attenuate PM-induced oxidative damage to nucleic acids, proteins, and lipids. They also lower the levels of cytokines, chemokines, cell adhesion molecules, prostaglandins, and matrix metalloproteinases implicated in cellular inflammatory responses to PM. Although there is still much research to be done, current studies in this field suggest that plant-derived phenolic compounds may have a protective effect on skin exposed to high levels of air pollution.

Eckol inhibits Reg3A-induced proliferation of human SW1990 pancreatic cancer cells

Pancreatic cancer (PaC) is characterized by a highly inflammatory tumor microenvironment, and inflammatory mediators are implicated in the progression of this cancer. Regenerating gene protein (Reg) 3A is significantly upregulated during pancreatic inflammation, and has been demonstrated to serve an important role during PaC progression, based on its increased expression levels in PaC and potent cell proliferation-promoting activity. The aim of the present study was to investigate the effect of eckol, a phlorotannin compound with a variety of biological activities including anti-inflammatory, anti-tumor and cytoprotective effects, on Reg3A-induced proliferation of human SW1990 PaC cells. SW1990 cells were pre-treated with eckol for 48 h at concentrations of 5, 10 and 20 µg/ml. Subsequently, Reg3A protein was added to the culture media at a final concentration of 50 ng/ml in the presence or absence of eckol for 24 h. The cytotoxicity and proliferative capacity of the SW1990 cells was determined using an MTT and flow cytometry analysis. Cell colony formation was also used to determine the effect of eckol on the anchorage-independent growth and colony-forming capacity of Reg3A-treated PaC cells. The expression levels of cyclin D1, STAT3, JAK2, and NF-κB p65 were measured with reverse transcription-quantitative PCR and western blotting. Eckol reduced Reg3A-promoted cell survival, inhibited Reg3A-induced cell cycle progression and inhibited colony growth of SW1990 cells in soft agar in a concentration-dependent manner. Additionally, the Reg3A-mediated upregulation of expression of JAK2, STAT3, NF-κBp65 and cyclin D1 was reduced when treated with eckol. Reg3A is upregulated during pancreatic inflammation and exhibits a pro-growth function and may thus serve a critical role during inflammation-driven PaC malignancies. Eckol may be a potential protective agent against progression of PaC accompanied by pancreatic inflammation.

Eckol Inhibits Particulate Matter 2.5-Induced Skin Keratinocyte Damage via MAPK Signaling Pathway

Toxicity of particulate matter (PM) towards the epidermis has been well established in many epidemiological studies. It is manifested in cancer, aging, and skin damage. In this study, we aimed to show the mechanism underlying the protective effects of eckol, a phlorotannin isolated from brown seaweed, on human HaCaT keratinocytes against PM_2.5-induced cell damage. First, to elucidate the underlying mechanism of toxicity of PM_2.5, we checked the reactive oxygen species (ROS) level, which contributed significantly to cell damage. Experimental data indicate that excessive ROS caused damage to lipids, proteins, and DNA and induced mitochondrial dysfunction. Furthermore, eckol (30 μM) decreased ROS generation, ensuring the stability of molecules, and maintaining a steady mitochondrial state. The western blot analysis showed that PM_2.5 promoted apoptosis-related protein levels and activated MAPK signaling pathway, whereas eckol protected cells from apoptosis by inhibiting MAPK signaling pathway. This was further reinforced by detailed investigations using MAPK inhibitors. Thus, our results demonstrated that inhibition of PM_2.5-induced cell apoptosis by eckol was through MAPK signaling pathway. In conclusion, eckol could protect skin HaCaT cells from PM_2.5-induced apoptosis via inhibiting ROS generation.

An in vivo anti-tumor effect of eckol from marine brown algae by improving the immune response

The anti-cancer activities of brown algae and some active extracts or components from brown algae have been demonstrated. But the anti-tumor activities of eckol, a new natural phlorotannin derived from marine brown algae, are poorly understood. In order to investigate the in vivo anti-tumor effect and its potential mechanisms of eckol in a sarcoma 180 (S180) xenograft-bearing animal model, S180 xenograft-bearing mice were randomly divided into 4 groups: model control, and eckol low-dose (0.25 mg kg-1), middle-dose (0.5 mg kg-1) and high-dose (1.0 mg kg-1) groups. After eckol administration, the tumor inhibition, tumor tissue histology, thymus index and spleen index were measured. The apoptotic tumor cells were detected using the terminal deoxynucleotidyl transferase mediated dUTP nick end labelling (TUNEL) assay. The protein expression levels of cleaved Caspase-3 and Caspase-9 (two key apoptotic proteins), Bcl-2 and Bax (two key anti-apoptosis-related genes), as well as epidermal growth factor receptor (EGFR, a well-known cell proliferation-stimulating molecule in tumorigenesis) and p-EGFR in tumor tissues were determined by western blot. A carbon particle clearance test, measurement of serum cytokine levels, a splenic T lymphocyte proliferation test, and T lymphocyte subpopulation analysis were used to evaluate the effect of eckol on the immune function of tumor-bearing mice. Moreover, CD11c+-dendritic cell (DC) infiltration in tumor tissues was detected by immunohistochemistry, and the surface molecules on bone marrow-derived DCs were analyzed using flow cytometry. The pro-apoptosis and anti-proliferation activities of eckol were manifested by the increased TUNEL-positive apoptotic cells, the upregulated Caspase-3 and Caspase-9 expression, and the downregulated expression of Bcl-2, Bax, EGFR and p-EGFR in eckol-treated transplanted S180 tumors. Most importantly, eckol stimulated the mononuclear phagocytic system, recruited and activated DCs, promoted the tumor-specific Th1 responses, increased the CD4+/CD8+ T lymphocyte ratio, and enhanced cytotoxic T lymphocyte responses in the eckol-treated animals, suggesting its potent stimulatory property on innate and adaptive immune responses. This study suggested that eckol might act as a functional food constituent derived from marine brown algae with a potential in vivo anti-tumor effect achieved by improving the immune response.

Characterizing Eckol as a Therapeutic Aid: A Systematic Review

The marine biosphere is a treasure trove of natural bioactive secondary metabolites and the richest source of structurally diverse and unique compounds, such as phlorotannins and halo-compounds, with high therapeutic potential. Eckol is a precursor compound representing the dibenzo-1,4-dioxin class of phlorotannins abundant in the Ecklonia species, which are marine brown algae having a ubiquitous distribution. In search of compounds having biological activity from macro algae during the past three decades, this particular compound has attracted massive attention for its multiple therapeutic properties and health benefits. Although several varieties of marine algae, seaweed, and phlorotannins have already been well scrutinized, eckol deserves a place of its own because of the therapeutic properties it possesses. The relevant information about this particular compound has not yet been collected in one place; therefore, this review focuses on its biological applications, including its potential health benefits and possible applications to restrain diseases leading to good health. The facts compiled in this review could contribute to novel insights into the functions of eckol and potentially enable its use in different uninvestigated fields.

Therapeutic Effect of Ecklonia cava Extract in Letrozole-Induced Polycystic Ovary Syndrome Rats

Polycystic ovary syndrome (PCOS) is an endocrinal disorder that afflicts mainly women of childbearing age. The symptoms of PCOS are irregular menstrual cycles, weight gain, subfertility and infertility. However, because the etiology is unclear, management and treatment methods for PCOS are not well established. Recently, natural substances have been used for PCOS therapy. Ecklonia cava (E. cava) is a well-known natural substance that attenuates the effects of inflammation, allergies, and cancer. In this study, we investigated the effects of E. cava extract in rats with PCOS. When rats with letrozole-induced PCOS were exposed to the E. cava extract, the regular estrus cycle was restored, similar to that in placebo rats. Hormone levels, including the levels of testosterone, estrogen, luteinizing hormone (LH), follicle stimulating hormone (FSH), and anti-Müllerian hormone (AMH), were restored to their normal states. Histological analysis revealed that the polycystic ovary symptoms were significantly decreased in the E. cava-treated rats and were comparable to those of normal ovaries. At the transcriptional and translational levels, Ar, and Esr2 levels were markedly increased in the E. cava-treated rats with PCOS compared with the rats with letrozole-induced PCOS. These results suggest that the E. cava extract inhibits the symptoms of PCOS by restoring imbalanced hormonal levels and irregular ovarian cycles in letrozole-induced female rats.

Metabolites Unravel Nutraceutical Potential of Edible Seaweeds: An Emerging Source of Functional Food

Functional foods are nutritional compounds which also provide health and medicinal benefits. Daily food intake has much impact on the quality of life, and therefore inclusion of functional foods is now essential to our diet. Nutraceuticals are neither food nor drug but are added to food to provide extra nutritional and physiological properties. Though nutraceutical compounds provide minimal actions, their regular involvement in the diet can provide major and long-term health benefits. Global demand for additional and sustainable biomass for the production of important metabolites with nutraceutical potential has resulted in renewed interest in seaweeds. Seaweeds have been consumed from ancient times in Asian areas, and in recent times they have been demonstrated to possess many medicinal effects. Seaweeds are considered a rich source of various nutritional ingredients and metabolites that have pharmaceutical properties. It has been observed that total protein, from terrestrial plants such as soybean and wheat, produces an allergic response on consumption. Therefore, seaweed proteins can be considered a promising source for food industries. Overall, seaweeds are a rich source of PUFAs, metabolites, proteins, sulfated polysaccharides, vitamins, and minerals, which are all responsible for different bioactivities; they are therefore considered a promising functional food (nutraceutical). In this review we discuss the nutraceutical potential of seaweeds regarding different metabolites (primary and secondary), variation in composition, probable biological applications, limitations, research gaps, and future prospects.

Protective Effect of Eckol against Acute Hepatic Injury Induced by Carbon Tetrachloride in Mice

Several in vitro studies have shown the potential hepatoprotective properties of eckol, a natural phlorotannin derived from the brown alga. However, the in vivo hepatoprotective potential of eckol has not been determined. In this study, we performed an in vivo study to investigate the protective effect of eckol and its possible mechanisms on the carbon tetrachloride (CCl₄)-induced acute liver injury model in mice. Results revealed that eckol pre-treatment at the dose of 0.5 and 1.0 mg/kg/day for 7 days significantly suppressed the CCl₄-induced increases of alanine transaminase (ALT) and aspartate aminotransferase (AST) levels in serum and meliorated morphological liver injury. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling (TUNEL) analysis showed that the number of positive apoptotic hepatocytes in the eckol-treated group was lower than that in the CCl₄ model group. Western blotting analysis also demonstrated the enhanced expression of bcl-2 and suppressed expression of cleaved caspase-3 by eckol. The CCl₄-induced oxidative stress in liver was significantly ameliorated by eckol, which was characterized by reduced malondialdehyde (MDA) formations, and enhanced superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) activities and glutathione (GSH) content. Moreover, the CCl₄-induced elevations of pro-inflammatory cytokines tumor necrosis factor (TNF)-α, interleukin (IL)-1β and IL-6 were markedly suppressed in the eckol-treated group. However, eckol enhanced the level of IL-10, a potent anti-inflammatory cytokine, and recruited CD11c⁺ dendritic cells into the liver tissues of CCl₄-treated mice. These results indicated that eckol has the protective effect on CCl₄-induced acute liver injury via multiple mechanisms including anti-apoptosis, anti-oxidation, anti-inflammation and immune regulation.

Natural products: a hope for glioblastoma patients

Glioblastoma (GBM) is one of the most aggressive malignant tumors with an overall dismal survival averaging one year despite multimodality therapeutic interventions including surgery, radiotherapy and concomitant and adjuvant chemotherapy. Few drugs are FDA approved for GBM, and the addition of temozolomide (TMZ) to standard therapy increases the median survival by only 2.5 months. Targeted therapy appeared promising in in vitro monolayer cultures, but disappointed in preclinical and clinical trials, partly due to the poor penetration of drugs through the blood brain barrier (BBB). Cancer stem cells (CSCs) have intrinsic resistance to initial chemoradiation therapy (CRT) and acquire further resistance via deregulation of many signaling pathways. Due to the failure of classical chemotherapies and targeted drugs, research efforts focusing on the use of less toxic agents have increased. Interestingly, multiple natural compounds have shown antitumor and apoptotic effects in TMZ resistant and p53 mutant GBM cell lines and also displayed synergistic effects with TMZ. In this review, we have summarized the current literature on natural products or product analogs used to modulate the BBB permeability, induce cell death, eradicate CSCs and sensitize GBM to CRT.

Anti-obesity effects of pectinase and cellulase enzyme‑treated Ecklonia cava extract in high‑fat diet‑fed C57BL/6N mice

The present study investigated the anti‑obesity effects of enzyme‑treated Ecklonia cava extract (EEc) in C57BL/6N mice with high‑fat diet (HFD)‑induced obesity. The EEc was separated and purified with the digestive enzymes pectinase (Rapidase X‑Press L) and cellulase (Rohament CL) and its effects on the progression of HFD‑induced obesity were examined over 10 weeks. The mice were divided into 6 groups (n=10/group) as follows: Normal diet group, HFD group, mice fed a HFD with 25 mg/kg/day Garcinia cambogia extract and mice fed a HFD with 5, 25 or 150 mg/kg/day EEc (EHD groups). Changes in body weight, fat, serum lipid levels and lipogenic enzyme levels were determined. The body weight and liver weight were increased in the HFD group compared with those in the ND group, which was significantly reduced by EEc supplementation. In addition, significant reductions in epididymal, perirenal and mesenteric white adipose tissues were present in the EHD groups and all three EHD groups exhibited decreases in insulin, leptin and glutamate pyruvate transaminase levels compared with those in the HFD group. In addition, EEc treatment significantly decreased the serum and hepatic triglyceride levels compared with those in the HFD group. However, the levels of high‑density lipoprotein cholesterol/total cholesterol ration increased significantly in EHD‑25 and ‑150 groups compared with those in the HFD group. Changes in adipogenic and lipogenic protein expression in the liver was assessed by western blot analysis. The EHD‑25 and -150 groups exhibited reduced levels of CCAAT/enhancer‑binding protein α and peroxisome proliferator activated receptor γ. However, the phosphorylation ratios of AMP‑activated protein kinase and acetyl‑CoA carboxylase were significantly increased in the liver tissue obtained from the EHD (5, ‑25 and ‑150 mg/kg/day) groups compared with those in the HFD group. EEc supplementation reduced levels of sterol regulatory element‑binding protein‑1c, adipose fatty acid‑binding protein, fatty acid synthase and leptin, while it significantly increased glucose transporter type 4 and adiponectin protein levels in the liver tissues of all three EHD groups compared with those in the HFD group. Taken together, these results suggest that EEc exerts anti‑obesity effects by reducing body weight and the serum and hepatic levels of obesity‑associated factors. Thus, EEc supplementation reduces HFD‑induced obesity in C57BL/6N mice and has the potential to prevent obesity and subsequent metabolic disorders.

Efficacy of algal Ecklonia cava extract against viral hemorrhagic septicemia virus (VHSV)

The inhibition efficacy of an extract from Ecklonia cava (E. cava) was studied to determine whether the extract and compounds exhibited inhibitory activity against VHSV in the fathead minnow (FHM) cell line and following oral administration to the olive flounder. Based on its low toxicity and effective concentration, the E. cava extract (Ext) and compounds (eckol and phlorofucofuroeckol A) were selected for further analysis. In the plaque reduction assay, simultaneous co-exposure of VHSV to Ext, eckol and phlorofucofuroeckol A showed a higher level of inhibition than the pre- and post-exposure groups. The antiviral activity in the FHM cell line was time-dependent and increased with the exposure time with the virus and Ext or the compounds. In the in vivo experiments, different Ext concentrations were orally administered to the olive flounder. In trial I, the relative percent survival (RPS) following oral administration of 500 and 50 μg/g/day of Ext was 31.25% and 12.50%, respectively. In trial II, the RPS for 1000, 500 and 50 μg/g/day of Ext was 31.57%, 0% and 0%, respectively. In trial III, the RPS after 1 and 2 weeks (1000 μg/g/day) of exposure to Ext was 26.31% and 31.57%, respectively. Oral administration of Ext (1000 μg/g/day) significantly induced inflammatory cytokine responses (IL-1β, IL-6 and IFN-γ) at 1 and 2 days post-oral administration (dpa). Additionally, IFN-α/β (7-12 dpa), ISG15 (2, 7 and 10 dpa) and Mx (7-12 dpa) were significantly activated in the olive flounder. In conclusion, we demonstrated an inhibitory ability of the E. cava extract and compounds against VHSV in the FHM cell line. Moreover, oral administration of the E. cava extract to the olive flounder enhanced antiviral immune responses and the efficacy of protection against VHSV, resulting in an anti-viral status in the olive flounder.

A phlorotannin constituent of Ecklonia cava alleviates postprandial hyperglycemia in diabetic mice

CONTEXT

2,7″-Phloroglucinol-6,6'-bieckol is a type of phlorotannin isolated from brown algae, Ecklonia cava Kjellman (Phaeophyceae; Laminareaceae). 2,7″-Phloroglucinol-6,6'-bieckol mediates antioxidant activities. However, there has been no research on improving postprandial hyperglycaemia using 2,7″-phloroglucinol-6,6'-bieckol.

OBJECTIVE

This study investigated the inhibitory effects of 2,7″-phloroglucinol-6,6'-bieckol on activities of α-glucosidase and α-amylase as well as its alleviating effect on postprandial hyperglycaemia in streptozotocin-induced diabetic mice.

MATERIALS AND METHODS

α-Glucosidase and α-amylase inhibitory assays were carried out. The effect of 2,7″-phloroglucinol-6,6'-bieckol on hyperglycaemia after a meal was measured by postprandial blood glucose in streptozotocin-induced diabetic and normal mice. The mice were treated orally with soluble starch (2 g/kg BW) alone (control) or with 2,7″-phloroglucinol-6,6'-bieckol (10 mg/kg bw) or acarbose (10 mg/kg BW) dissolved in 0.2 mL water. Blood samples were taken from tail veins at 0, 30, 60, and 120 min and blood glucose was measured by a glucometer.

RESULTS

2,7″-Phloroglucinol-6,6'-bieckol showed higher inhibitory activities than acarbose, a positive control against α-glucosidase and α-amylase. The IC50 values of 2,7″-phloroglucinol-6,6'-bieckol against α-glucosidase and α-amylase were 23.35 and 6.94 μM, respectively, which was found more effective than observed with acarbose (α-glucosidase IC50 of 130.04 μM; α-amylase IC50 of 165.12 μM). In normal mice, 2,7″-phloroglucinol-6,6'-bieckol significantly suppressed the postprandial hyperglycaemia caused by starch. The 2,7″-phloroglucinol-6,6'-bieckol administration group (2349.3 mmol·min/L) had a lower area under the curve (AUC) glucose response than the control group (2690.83 mmol·min/L) in diabetic mice.

DISCUSSION AND CONCLUSION

2,7″-Phloroglucinol-6,6'-bieckol might be used as an inhibitor of α-glucosidase and α-amylase as well as to delay absorption of dietary carbohydrates.

Cardioprotective Effects of a Phlorotannin Extract Against Doxorubicin-Induced Cardiotoxicity in a Rat Model

Long-term therapy with doxorubicin (DOX) is associated with high incidence of cumulative and irreversible dilated cardiomyopathy. The goal of this study was to evaluate the cardioprotective effects and safety of a phlorotannin extract from a brown algae Ecklonia cava (Seapolynol™, SPN) against DOX-induced cardiotoxicity in a rat model. A total of 42 rats were divided into six groups: control, low-dose SPN (LDS), high-dose SPN (HDS), DOX, DOX with low-dose SPN (DOX+LDS), and DOX with high-dose SPN (DOX+HDS). Echocardiography was performed at baseline and after 6 weeks. In left ventricular (LV) ejection fraction, DOX and DOX+LDS groups showed significant decreases (P < .001), while LDS, HDS, and DOX+HDS groups showed no significant change compared with control group. In LV mass index, DOX and DOX+LDS groups showed significant increases (P < .001 and P = .013), while LDS, HDS, and DOX+HDS groups showed no significant change compared with control group. In electron microscopy of the LV wall tissue, DOX+HDS group showed markedly less impaired myofibrils and mitochondria compared with both DOX and DOX+LDS groups. On the findings in echocardiography and electron microscopy, 6-week oral administration of SPN was safe and cardioprotective in a DOX-induced rat cardiotoxicity model in a dose-dependent manner.

Antioxidant and Cytoprotective Activities of Fucus spiralis Seaweed on a Human Cell in Vitro Model

Antioxidants play an important role as Reactive Oxygen Species (ROS) chelating agents and, therefore, the screening for potent antioxidants from natural sources as potential protective agents is of great relevance. The main aim of this study was to obtain antioxidant-enriched fractions from the common seaweed Fucus spiralis and evaluate their activity and efficiency in protecting human cells (MCF-7 cells) on an oxidative stress condition induced by H₂O₂. Five fractions, F1-F5, were obtained by reversed-phase vacuum liquid chromatography. F3, F4 and F5 revealed the highest phlorotannin content, also showing the strongest antioxidant effects. The cell death induced by H₂O₂ was reduced by all fractions following the potency order F4 > F2 > F3 > F5 > F1. Only fraction F4 completely inhibited the H₂O₂ effect. To understand the possible mechanisms of action of these fractions, the cellular production of H₂O₂, the mitochondrial membrane potential and the caspase 9 activity were studied. Fractions F3 and F4 presented the highest reduction on H₂O₂ cell production. All fractions decreased both caspase-9 activity and cell membrane depolarization (except F1). Taken all together, the edible F. spiralis reveal that they provide protection against oxidative stress induced by H₂O₂ on the human MCF-7 cellular model, probably acting as upstream blockers of apoptosis.

Effect of Ecklonia Cava Polyphenol Extract in House Ear Institute-Organ of Corti 1 Cells Against Cisplatin Ototoxicity: A Preliminary Study

Objective

Cisplatin is a widely used agent for the treatment of adult and childhood malignancies. Side effects such as nephrotoxicity, neurotoxicity, and ototoxicity lead to dose limitations. Ecklonia cava polyphenol extract (ECP) is a molecule obtained from algae that live in seawater in the Far East. ECP has recently been shown to have protective effects against oxidative stress. The aim of this study was to evaluate the possible protective effects of ECP on cisplatin ototoxicity.

Methods

In this study, we investigated the protective effects of ECP against cisplatin-induced cell death in mouse-derived House Ear Institute Organ of Corti (HEI-OC1) cochlear cells. Cisplatin (100 μM) and 1, 10, and 25 μM doses of ECP were administered to the cells, and the protective effects of ECP at 24 and 72 hours were investigated. Cell viability was evaluated by the WST-1 (water soluble tetrazolium salt).

Results

Cisplatin (100 μM) reduced cell viability in both the 24^th and 72^nd hour evaluation. Although the 25 μM dose of ECP showed otoprotective effects in the 24^th hour, in the 72^nd hour this effect disappeared. Other doses of ECP showed no otoprotective effects in the 24^th and 72^nd hours.

Conclusion

Although ECP showed some protective effects in the 24^th hour against cisplatin ototoxicity, these effects disappeared by the 72^nd hour. Further studies using recurrent and higher doses of ECP are required.

Phlorofucofuroeckol Improves Glutamate-Induced Neurotoxicity through Modulation of Oxidative Stress-Mediated Mitochondrial Dysfunction in PC12 Cells

Stroke is a complex neurodegenerative disorder with a clinically high prevalence and mortality. Despite many efforts to protect against ischemic stroke, its incidence and related permanent disabilities continue to increase. In this study, we found that pretreatment with phlorofucofuroeckol (PFF), isolated from brown algae species, significantly increased cell viability in glutamate-stimulated PC12 cells. Additionally, glutamate-stimulated cells showed irregular morphology, but PFF pretreatment resulted in improved cell morphology, which resembled that in cells cultured under normal conditions. We further showed that PFF pretreatment effectively inhibited glutamate-induced apoptotic cell death in a caspase-dependent manner. Reactive oxygen species (ROS) induced by oxidative stress are closely associated with ischemia-induced neurological diseases. Exposure of PC12 cells to glutamate induced abundant production of intracellular ROS and mitochondrial dysfunction, which was attenuated by PFF in a dose-dependent manner. In vivo studies revealed that PFF-mediated prevention was achieved predominantly through inhibition of apoptosis and mitochondrial ROS generation. Taken together, these results suggest the possibility of PFF as a neuroprotective agent in ischemic stroke.

Enhancement of Human Hair Growth Using Ecklonia cava Polyphenols

BACKGROUND

Ecklonia cava is a brown alga that contains various compounds, including carotenoids, fucoidans, and phlorotannins. E. cava polyphenols (ECPs) are known to increase fibroblast survival. The human dermal papilla cell (hDPC) has the properties of mesenchymal-origin fibroblasts.

OBJECTIVE

This study aims to investigate the effect of ECPs on human hair growth promotion in vitro and ex vivo.

METHODS

MTT assays were conducted to examine the effect of ECPs on hDPC proliferation. Hair growth was measured using ex-vivo hair follicle cultures. Real-time polymerase chain reaction was performed to evaluate the mRNA expression of various growth factors in ECP-treated hDPCs.

RESULTS

Treatment with 10 µg/ml purified polyphenols from E. cava (PPE) enhanced the proliferation of hDPCs 30.3% more than in the negative control (p<0.001). Furthermore, 0.1 µg/ml PPE extended the human hair shaft 30.8% longer than the negative control over 9 days (p<0.05). Insulin-like growth factor-1 (IGF-1) mRNA expression increased 3.2-fold in hDPCs following treatment with 6 µg/ml PPE (p<0.05). Vascular endothelial growth factor (VEGF) mRNA expression was also increased 2.0-fold by 3 µg/ml PPE (p<0.05). Treatment with 10 µg/ml PPE reduced oxidative stress in hDPCs (p<0.05).

CONCLUSION

These results suggest that PPE could enhance human hair growth. This can be explained by hDPC proliferation coupled with increases in growth factors such as IGF-1 and VEGF. Reducing oxidative stress is also thought to help increase hDPCs. These favorable results suggest that PPE is a promising therapeutic candidate for hair loss.

Quercetin protects HCT116 cells from Dichlorvos-induced oxidative stress and apoptosis

The present study was designed to assess the possible protective effects of Quercetin (QUER), a flavonoid with well-known pharmacological effects, against Dichlorvos (DDVP)-induced toxicity in vitro using HCT116 cells. The cytotoxicity was monitored by cell viability, reactive oxygen species (ROS) generation, anti-oxidant enzyme activities, malondialdehyde (MDA) production, and DNA fragmentation. The apoptosis was assessed through the measurement of the mitochondrial transmembrane potential (ΔΨm) and caspase activation. The results indicated that pretreatment of HCT116 cells with QUER, 2 h prior to DDVP exposure, significantly decreased the DDVP-induced cell death, inhibited the ROS generation, modulated the activities of catalase (CAT) and superoxide dismutase (SOD), and reduced the MDA level. The reductions in mitochondrial membrane potential, DNA fragmentation, and caspase activation were also attenuated by QUER. These findings suggest that dietary QUER can protect HCT116 cells against DDVP-induced oxidative stress and apoptosis.

Protective effect of Crocin against zearalenone-induced oxidative stress in liver and kidney of Balb/c mice

Zearalenone (ZEN) is a mycotoxin from Fusarium species commonly found in many food commodities and known to cause reproductive disorders. Several studies have shown that ZEN is hematotoxic and hepatotoxic and causes several alterations of immunological parameters. In the present study, we aimed to evaluate the protective effect of Crocin (CRO), a natural carotenoid, against ZEN-induced toxicity in both renal and hepatic tissues of Balb/c mice. We demonstrated that ZEN (40 mg/kg body weight (b.w.)) induced oxidative stress in both kidney and liver as monitored by measuring the malondialdehyde (MDA) level, the protein carbonyl generation, the catalase and superoxide dismutase activity, and the expression of the heat shock proteins (Hsp70). However, combined treatment of ZEN with different doses of CRO (50, 100, and 250 mg/kg b.w.) significantly reduced ZEN-induced alterations in all tested oxidative stress markers. It could be concluded that CRO was effective in the protection against ZEN-induced toxicity in the liver and kidney of Balb/c mice.

Multifunctional activity of polyphenolic compounds associated with a potential for Alzheimer's disease therapy from Ecklonia cava

Five polyphenols were isolated and purified from a brown alga Ecklonia cava. These compounds showed diverse biological activities such as antioxidative, antiinflammatory, and enzyme inhibitory activities. This led us to investigate the potential of these compounds as Alzheimer's disease drugs. All of the compounds showed moderate acetylcholinesterase inhibitory activity in a micromolar range (IC50 from 16.0 to 96.3 μM). For butyrylcholinesterase, a new target for the treatment of Alzheimer's disease, phlorofucofuroeckol-A (PFF-A), showed a particularly potent inhibitory activity (IC50 0.95 μM), which is over 100-fold greater than for acetylcholinesterase. These compounds inhibited glycogen synthase kinase 3 beta, which is related to the formation of hyperphosphorylated tau and generation Aβ. Bieckol and PFF-A inhibited amyloid precursor protein biosynthesis. PFF-A also showed very strong β-secretase inhibitory activity with IC50 of submicromole. These results render these compounds as interesting potential drug candidates for Alzheimer's disease.