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.

Fucoidan isolated from Padina commersonii inhibit LPS-induced inflammation in macrophages blocking TLR/NF-κB signal pathway

Brown seaweeds are well-known source of bioactive compounds, which are producing a variety of secondary metabolites with promising bioactive properties. Traditionally, seaweeds used as ingredients in medicine for many centuries in Asian countries. However, the protective mechanisms of many metabolites found in seaweeds are remains to be determined. Thus, applications of seaweeds are limited because of poor understanding of their structural features and mechanisms responsible for their bioactive properties. In the present study, anti-inflammatory properties of fucoidan isolated from the brown seaweed Padina commersonii (PCF) was evaluated against LPS-activated RAW 264.7 macrophages. PCF was characterized using NMR, FT-IR, and HPAE-PAD spectrum (for mono sugar composition). It was observed that PCF is rich in fucose and sulfate as well as a similar structure to the commercial fucoidan. Western blots and RT-qPCR analysis were used to determine the protective effects of PCF after LPS challenge using RAW 264.7 macrophages. According to the results, PCF significantly down-regulated LPS-activated mRNA and protein expression levels of TLR2, TLR4, and MyD88 which are known inducers/activators of NF-κB transcriptional factors. The results, obtained from this study demonstrated PCF has a potential to inhibit LPS-induced inflammatory responses via blocking TLR/MyD88/ NF-κB signal transduction.

Isolation and purification of fucoidan fraction in Turbinaria ornata from the Maldives; Inflammation inhibitory potential under LPS stimulated conditions in in-vitro and in-vivo models

Fucoidan, referred to as fucose containing sulfated polysaccharides (FCSP), is a polymer from brown algae cell wall that is reported to exhibit potential anti-inflammatory activity. In the present study, the fucoidans are extracted from Turbinaria ornata (TO) from the Maldives. The method involves enzyme assisted extraction and is modified in order to improve the effectiveness and purity of final product. Purified fucoidan fraction was identified as F10, and its chemical properties were verified via FTIR, 1H NMR and monosaccharide analysis. Selected inflammatory mediators were studied to evaluate the anti-inflammatory potential using RAW 264.7 macrophages. F10 successfully inhibited NO production (IC50 = 30.83 ± 1.02 μg mL-1). F10 dose-dependently down-regulated iNOS, COX-2, and pro-inflammatory cytokines including PGE2 levels. The in vivo experiments were assisted by zebrafish embryo model. This exhibited reduction in ROS, NO expression levels. To our knowledge, this is the first report to illustrate potential anti-inflammatory activity of FCSPs' extracted from the brown algae T. ornata. Concisely, the results suggest that fucoidan purified from T. ornata increases the macrophage cellular and zebrafish embryo resistance against LPS-induced inflammation. Based on the observations, the fucoidans are promising candidates to be used in the pharmaceutical and cosmeceutical sectors.

Beijing urban particulate matter-induced injury and inflammation in human lung epithelial cells and the protective effects of fucosterol from Sargassum binderi (Sonder ex J. Agardh)

Particulate matter (PM) air pollution has gradually become a widespread problem in East Asia. PM may cause unfamiliar inflammatory responses, oxidative stress, and pulmonary tissue damage, and a comprehensive understanding of the underlying mechanisms is required in order to develop effective anti-inflammatory agents. In this study, fine dust collected from Beijing, China (CPM) (size < PM13 with majority < PM2.5) was evaluated for its oxidative stress- and inflammation-inducing effects, which cause cell damage, in A459 human lung epithelial cells. Oxidative stress was marked by an increase in intracellular ROS levels and the production of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), and heme oxygenase-1 (HO-1). Upon induction of oxidative stress, a marked increase was observed in the expression of key inflammatory mediators such as COX-2 and PGE2 and the pro-inflammatory cytokines TNF-α and IL-6 via NF-kB and MAPK pathways. Cellular damage was marked by a reduction in viability, increased lactate dehydrogenase (LDH) release, formation of apoptotic and necrotic bodies, accumulation of sub-G1 phase cells, and DNA damage. Apoptosis was found to be mediated via the activation of caspases through the mitochondria-mediated pathway. Fucosterol, purified from the brown alga Sargassum binderi (Sonder ex J. Agardh) by bio-assay-guided fractionation and purification, exhibited potential therapeutic effects against CPM-induced detrimental effects. Further studies could focus on developing fucosterol, in forms such as steroidal inhalers, against PM-induced pulmonary tissue inflammation.

Free radical scavenging activity of the peptide from the Alcalase hydrolysate of the edible aquacultural seahorse (Hippocampus abdominalis)

Seahorses, Hippocampus abdominalis, have a long history in traditional Chinese medicine as an important healthy ingredient in foods. This study evaluated the antioxidant activity of an enzymatic hydrolysate prepared from a seahorse bred in Jeju, South Korea. Experiments were performed in vitro using electron spin resonance spectrometry (ESR) to determine the free radical scavenging activity and in vivo using a zebrafish model to determine the protective effects against 2,2-azobis hydrochloride (AAPH)-induced oxidative damage. H. abdominalis protein hydrolysate (HPH) exhibited peroxyl radical scavenging activity (IC₅₀  = 0.58 mg/ml) generated by the water-soluble AAPH (azo initiator of peroxyl radicals). HPH reduced dose-dependently both intracellular reactive oxygen species (ROS) levels in AAPH-induced cells and cell death in AAPH-induced zebrafish embryos. The antioxidant peptide purified from HPH was identified as a tripeptide (alanine-glycine-aspartic acid) using Q-TOF ESI mass spectroscopy. Thus, this study demonstrated that HPH contains antioxidant peptides that exhibit a strong antioxidant activity. PRACTICAL APPLICATIONS: Hippocampus abdominalis is one of the largest seahorse species and cultivated in many countries. Because of its large body size compared to other seahorse species, H. abdominalis has acquired considerable consumer attraction in the global market. Owing to its biologically useful properties, it recently gained attention as the natural products obtained from H. abdominalis have varied applications in the field of medicine, health care products, and functional foods. Thus, commercial products of this particular seahorse species are popular among customers, especially in China. The purpose of this study was to evaluate the antioxidant property of H. abdominalism, cultured in a commercial seahorse farm in Jeju Island. Owing to its prominent antioxidant activity, it could be used as an ingredient in medicinal preparations, nutraceuticals, and functional foods.

Anti-inflammatory potential of alginic acid from Sargassum horneri against urban aerosol-induced inflammatory responses in keratinocytes and macrophages

The airborne particulate pollutants originating in the deserts of Mongolia and China which becomes contaminated with industrial effluents and traffic emissions while moving with the wind currents towards East Asia has recently become a serious environmental and health issue in the region. They cause asthma, collateral lung tissue damage, oxidative stress, allergic reactions, and inflammation. The current study was undertaken to evaluate the protective effects of alginate extracted from the invasive alga Sargassum horneri (SHA) against fine dust collected from Beijing, China (Chinese fine dust; CFD). It was found that CFD induces inflammation in HaCaT keratinocytes and inhibits macrophage activation. All of the particulate matter (PM) comprising CFD was < PM13 majority being < PM2.5 which is defined for mineral elements and polycyclic aromatic hydrocarbons. SHA attenuated PGE2 levels in CFD-induced HaCaT keratinocytes. The IC50 for SHA was 36.63 ± 4.11 µg mL-l. SHA also reduced the levels of COX-2, IL-6, and TNF-α, and inhibited certain key molecular mediators of the NF-κB and MAPK pathways in keratinocytes. SHA substantially reduced the levels of CFD-derived metal ions like Pb2+ and Ca2+ in keratinocytes attributable to its metal ion chelating properties. CFD-induced HaCaT keratinocyte culture media increased inflammatory responses in RAW 264.7 macrophages. These cells presented with increased levels of NO, iNOS, COX-2, PGE2, and pro-inflammatory cytokines. It was found that the aforementioned effects could be reversed in RAW 264.7 macrophages when keratinocytes were treated with SHA. Therefore, SHA could be used against fine dust-induced inflammation in keratinocytes.

Sargassum horneri (Turner) C. Agardh ethanol extract inhibits the fine dust inflammation response via activating Nrf2/HO-1 signaling in RAW 264.7 cells

BACKGROUND

Among the different kinds of pollution, air pollution continues to increase globally. East Asia is considered to be significantly affected. As a result, the populations in these regions face serious health issues including respiratory disorders. This study investigated the impact of fine dust (FD) particles (CRM No. 28) on macrophage cells as a model for alveolar lung cells.

METHODS

The research focused on inflammation and oxidative stress induced by FD and Sargassum horneri (Turner) C. Agardh ethanol extract (SHE) as a potential treatment. S. horneri is a type of brown algae that has demonstrated anti-inflammatory effects against RAW 264.7 macrophages in previous studies. MTT, Griess, ELISA, western blotting, and mRNA expression analyses using PCR techniques were used in this study.

RESULTS

The optimum FD concentration was determined to be 125 μg mL- 1. FD particles stimulated inflammatory mediators production (iNOS, COX-2, and PGE2) and pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α), leading to NO production. These mediators were dose-dependently downregulated by treatment with SHE. IL-6 and TNF-α were identified as biomarkers for FD. SHE treatment induced HO-1 and Nrf2 activity in a dose-dependent manner under FD stimulation. This confirmed the cytoprotective effect against oxidative stress induced via FD. Furthermore, treatment of the cells with a p38 MAPK inhibitor (SB202190) induced FD-stimulated NO production.

CONCLUSIONS

The results suggest that SHE increases macrophage cellular resistance to FD-induced inflammation and oxidative stress, probably via the p38 MAPK pathway and Nrf2/HO-1 expression.

Apoptotic and antiproliferative effects of Stigmast-5-en-3-ol from Dendronephthya gigantea on human leukemia HL-60 and human breast cancer MCF-7 cells

The genus Dendronephthya encompasses marine soft corals that produce a wide spectrum of biofunctional terpenoids. Anticancer properties of these metabolites are widely exploited as potential chemotherapeutic agents. The present study reports the purification and isolation of a potential antiproliferative constituent, stigmast-5-en-3-ol from the 70% ethanol extract of the soft coral Dendronephthya gigantea. Among several other 3β-hydroxy-Δ5-steroidal congeners, stigmast-5-en-3-ol indicated prominent antiproliferative effects on HL-60 (leukemia) and MCF-7 (breast cancer) cell lines with IC₅₀ values of 37.82 and 45.17 μg/ml respectively. Stigmast-5-en-3-ol increased apoptotic body formation, accumulation of sub G1 apoptotic cells, and DNA damage in HL-60 and MCF-7 cells. It increased the expression of Bax, caspases, and PARP cleavage while decreasing Bcl-xL levels in both cancer cell lines indicating that the effects are arbitrated via the mitochondria-mediated apoptotic pathway. Steroidal derivatives were identified by GC MS/MS and the identity of stigmast-5-en-3-ol was confirmed by NMR spectra. The present study suggests that stigmast-5-en-3-ol could be a promising candidate for anticancer drug research.

Antioxidant and anti-inflammatory functionality of ten Sri Lankan seaweed extracts obtained by carbohydrase assisted extraction

Enzyme-assisted extraction is a cost-effective, safe, and efficient method to obtain bioactives from plant materials. During this study, 10 different marine algae from Sri Lanka were individually extracted by using five commercial food-grade carbohydrases. The enzymatic and water extracts of the seaweeds were analyzed for their antioxidant and anti-inflammatory activities. The highest DPPH, hydrogen peroxide (H₂O₂) and intracellular H₂O₂ scavenging abilities were observed from the Celluclast extract of Sargassum polycystum (CSp). CSp exerted protective effects against oxidative stress-induced cell death in hydrogen peroxide-induced Chang cells and in model zebrafish. The Celluclast extract of Chnoospora minima (CCm) showed the strongest anti-inflammatory activity against lipopolysaccharide (LPS)-induced NO production in RAW 264.7 macrophages (IC₅₀ = 44.47 µg/mL) and in model zebrafish. CCm inhibited the levels of iNOS, COX-2, PGE₂, and TNF-α in LPS stimulated RAW 264.7 macrophages. Hence, CSp and CCm could be utilized in developing functional ingredients for foods, and cosmeceuticals.

3-Chloro-4,5-dihydroxybenzaldehyde inhibits adipogenesis in 3T3-L1 adipocytes by regulating expression of adipogenic transcription factors and AMPK activation

Obesity is a serious health issue in many industrialized countries. It is a medical condition with excessive levels of fat accumulated in adipocytes. The objective of the present study was to determine the inhibitory effect of 3-chloro-4,5-dihydroxybenzaldehyde (CDB) on adipogenesis in 3T3-L1 adipocyte cells. CDB suppressed the differentiation and decreased lipid accumulation and triglycerides contents in 3T3-L1 adipocytes. Its suppression effect on fat accumulation was mediated via expression of adipogenesis factors (C/EBPα, SREBP-1c, PPARγ, and adiponectin) during adipocyte differentiation in white adipocyte cells. CDB's ability to suppress fat accumulation was increased in a concentration-dependent manner. It inhibited fatty acid synthesis related proteins including FAS, FABP4, leptin, and perilipin. It also increased expression of phosphorylated AMPK in adipocytes cells. These observations suggest that CDB has potential anti-obesity effect with ability to improve metabolic diseases.

In vitro and in vivo anti-inflammatory activities of high molecular weight sulfated polysaccharide; containing fucose separated from Sargassum horneri: Short communication

Recent studies on crude and pure compounds from Sargassum horneri have shown promising bioactive properties. However, anti-inflammatory potentials of fucose-rich sulfated polysaccharides from S. horneri have not yet been discovered. In the present study, we evaluated the in vitro and in vivo anti-inflammatory activities of four polysaccharide fractions separated from membrane filters according to their molecular weights (<5kDa (f1), 5-10kDa (f2), 10-30kDa (f3), and >30kDa (f4)). According to the results, F4 fraction inhibited the lipopolysaccharides (LPS)-induced nitric oxide (NO) (IC50=87.12μg/mL) and prostaglandin E2 production as well as pro-inflammatory cytokine production in RAW 264.7 cells through down-regulating nuclear factor-κB signaling cascade. According to the results, f4 has a potential to down-regulate LPS-induced toxicity, cell death and NO production levels in LPS-induced in vivo zebrafish embryo model. These results suggest that f4 fraction has the potential to develop functional materials or drugs to treat inflammatory diseases.

3β-Hydroxy-Δ5-steroidal congeners from a column fraction of Dendronephthya puetteri attenuate LPS-induced inflammatory responses in RAW 264.7 macrophages and zebrafish embryo model

Bioactive compounds from marine organisms and their action mechanisms have provided new insights into medicinal and natural product research. Here, we report the identification of 3β-hydroxy-Δ5-steroidal congeners from a purified column fraction (DPCMH24) of the soft coral Dendronephthya puetteri harvested from Jeju, South Korea. DPCMH24 exerted strong anti-inflammatory effects through a dose-dependent decrease in the levels of nitric oxide (NO) in LPS-induced RAW 264.7 macrophages (IC₅₀ value = 6.54 ± 0.38 μg mL⁻¹). Further, DPCMH24 attenuated the levels of PGE₂ and the pro-inflammatory cytokines, TNF-α, IL-1β, and IL-6. The above effects were mediated via the inhibition of nuclear factor κB activation and mitogen-activated protein kinase pathways. In vivo evaluation indicated that DPCMH24 reduced NO, iNOS, COX-2, ROS production and cell death in LPS-induced zebrafish embryos, confirming its anti-inflammatory potential. The constituent compounds were identified by GC-MS/MS analysis. These findings suggest that the steroidal congeners from D. puetteri may offer ample therapeutic potential against LPS-induced inflammation.

Bioactive compounds from marine organisms and their action mechanisms have provided new insights into medicinal and natural product research.

Reduction of heavy metal (Pb2+) biosorption in zebrafish model using alginic acid purified from Ecklonia cava and two of its synthetic derivatives

Heavy metal contamination has become a major problem that causes severe environmental and health issues due to their biosorption, bioaccumulation, and toxicity. This study was designed to evaluate heavy metal chelating abilities of alginic acid (AA) extracted from the brown seaweed Ecklonia cava and two of its derivatives prepared by the partial oxidation of the 2° OH groups (OAA) and partial carboxylation of the monomeric units (CAA) upon reducing the heavy metal biosorption in zebrafish (Danio rerio) modal. Metal ions were quantified using ICP-OES and biopolymers were characterized by FTIR and XRD analysis. All investigated biopolymers indicated potential ability for chelating Pb2+, Cu2+, Cd2+, As3+, and Ag+. The sorption capacities were in the order of CAA>OAA>AA. All biopolymers indicated a comparatively higher chelation towards Pb2+. AA, OAA, and CAA could effectively reduce Pb2+ induced toxicity and Pb2+ stress-induced ROS production in zebrafish embryos. Besides, they could reduce the biosorption of Pb2+ in adult zebrafish which could lead to bioaccumulation. Since alginic acid purified from E. cava and its derivatives could be utilized as seaweed derived biopolymers to purify heavy metals contaminated water and as a dietary supplement to reduce heavy metal biosorption in organisms.

A fucoidan fraction purified from Chnoospora minima; a potential inhibitor of LPS-induced inflammatory responses

Fucoidans are an interesting group of bioactive sulfated polysaccharides abundant in brown seaweeds. The current study highlights the enrichment and extraction of fucoidan from Chnoospora minima by means of enzyme-assistant extraction using Celluclast and evaluation of its anti-inflammatory potential through in vitro and in vivo studies. The purified C. minima fucoidan (F2,4) inhibited the nitrous oxide (NO) production (IC50=27.82±0.88μg/ml) and expression of PGE2 through the subsequent downregulation of iNOS and COX-2 expression in lipopolysaccharide (LPS) stimulated RAW 264.7 macrophages. F2,4 downregulated TNF-α, IL1-β, and IL-6 in RAW 264.7 macrophages in a dose-dependent manner and suppressed NO and ROS production in LPS stimulated zebrafish embryos while exerting a protective effect against the cell damage caused by LPS. Polysaccharide structural characterization was performed using FTIR, HPAE-PAD analysis of the monosaccharide content and NMR spectroscopy. Current findings confirm the potential anti-inflammatory activity of fucoidan purified from C. minima and elaborate its potential application as a functional ingredient in consumer products.

Identification of sterols from the soft coral Dendronephthya gigantea and their anti-inflammatory potential

Exploration of anti-inflammatory phytochemicals has received tremendous attention worldwide owing to the rapid increase in inflammatory diseases. Current study reveals the identification of eight 3β-hydroxy-Δ⁵-steroidal congeners from a nonpolar column fraction of the ethanol solubles from the soft coral Dendronephthya gigantea collected from Jeju Island South Korea, using GC-MS/MS analysis. The sterol-rich fraction (DGEH21) showed a significant anti-inflammatory activity as exhibited by the inhibition of NO production (IC₅₀ 4.33±0.50μg/mL) and PGE₂ production in LPS-stimulated RAW 264.7 macrophages. It also suppressed the expression levels of proinflammatory cytokines, TNF-α, IL-1β, and IL-6 in a dose-dependent manner. Furthermore, DGEH21 effectively downregulated the expression levels of iNOS, and COX-2 and reduced NO and ROS production as well as cell death in LPS-stimulated in-vivo zebrafish embryo model. However, DGEH21 at relatively high concentrations indicated cytotoxicity in both RAW cells and zebrafish embryos with RAW cell viability being nearly 80% after treatment with 25μg/mL DGEH21. This study highlights the synergistic anti-inflammatory activity of several steroids found in D. gigantea. Their actions may be useful in the development of anti-inflammatory cosmeceuticals, pharmaceutical agents, and other consumer products.

Potential anti-inflammatory natural products from marine algae

Inflammatory diseases have become one of the leading causes of health issue throughout the world, having a considerable influence on healthcare costs. With the emerging developments in natural product, synthetic and combinatorial chemistry, a notable success has been achieved in discovering natural products and their synthetic structural analogs with anti-inflammatory activity. However, many of these therapeutics have indicated detrimental side effects upon prolonged usage. Marine algae have been identified as an underexplored reservoir of unique anti-inflammatory compounds. These include polyphenols, sulfated polysaccharides, terpenes, fatty acids, proteins and several other bioactives. Consumption of these marine algae could provide defense against the pathophysiology of many chronic inflammatory diseases. With further investigation, algal anti-inflammatory phytochemicals have the potential to be used as therapeutics or in the synthesis of structural analogs with profound anti-inflammatory activity with reduced side effects. The current review summarizes the latest knowledge about the potential anti-inflammatory compounds discovered from marine algae.

Anti-inflammatory effect of supercritical extract and its constituents from Ishige okamurae

The anti-inflammatory properties of the supercritical fluid extract of Ishige okamurae (SFEIO) on lipopolysaccharide (LPS)-stimulated murine RAW 264.7 macrophages. The lipid profile of the SFEIO, reviled the presence of palmitic acid (220.2 mg/g), linoleic acid (168.0 mg/g), and oleic acid (123.0 mg/g). SFEIO was found to exert it's anti-inflammatory effects through inhibiting nitric oxide (NO), prostaglandin E₂ (PGE₂), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 production in LPS-stimulated RAW 264.7 cells, without inducing cytotoxicity. SFEIO did not effect on the LPS-induced p38 kinase phosphorylation, whereas it attenuated the extracellular-related signaling kinase (ERK) and c-Jun N-terminal kinase (JNK) phosphorylation. Furthermore, SFEIO inhibited the LPS-induced IκB-α degradation and p50 NF-κB activation. These results suggest that SFEIO exerts its anti-inflammatory effects in LPS-activated RAW 264.7 cells by down-regulating the activation of ERK, JNK, and NF-κB.

Separation of glycine-rich proteins from sea hare eggs and their anti-cancer activity against U937 leukemia cell line

The present study was designed to investigate the anti-cancer effects of Sea hare eggs (SE) in U937 cells and its major active components. The aqueous extract of SE (ASE), which contained the highest protein content, dose-dependently inhibited the cancer cell's growth (IC₅₀ value, 10.42 ± 0.5 µg/mL). Additionally, ASE markedly caused DNA damage by inducing apoptotic body formation, DNA fragmentation, and accumulation of sub-G₁ DNA contents. ASE induced apoptosis by activating caspase-3 and 9 and poly (ADP-ribose) polymerase (PARP) by regulating the expression of Bcl-2/Bax. Moreover, among its molecular weight fractions, the > 30 kDa fraction showed the highest cell-growth-inhibitory effects, which was inhibited by heat treatment. Furthermore, the > 30 kDa fraction had markedly higher glycine content than the ASE. The presence of two protein bands at around 16 and 32 kDa was identified. In addition, two fractions, F1 and F2, were obtained using anion-exchange chromatography, with the F1 having an improved cell-growth-inhibitory effect than the > 30 kDa fraction. Taken together, these results suggest that the ASE contains glycine-rich proteins, including the active 16 and 32 kDa proteins, which account for its anti-cancer effects by inducing apoptosis via regulation of the mitochondrial pathway.