Fucoidan Isolated from Sargassum confusum Suppresses Inflammatory Responses and Oxidative Stress in TNF-α/IFN-γ- Stimulated HaCaT Keratinocytes by Activating Nrf2/HO-1 Signaling Pathway

Fucoidan refined from Saccharina japonica ameliorates ambient particulate matter-induced inflammation in keratinocytes, underlying fibroblasts, and 12-O-tetradecanoylphorbol 13-acetate-induced ear edema in mice

Fucoidan from Saccharina japonica (SJF) was isolated and characterized, and its anti-inflammatory effects on fine dust/ambient particulate matter (PM)-stimulated HaCaT keratinocytes were investigated. SJF increased cell viability by reducing intracellular ROS production in PM-stimulated HaCaT keratinocytes. Moreover, SJF downregulated the expression/production of inflammatory cytokines (IL-6, IL-8, IL-13, IL-25, IL-33, TNF-α, IFN-γ, and TSLP) and chemokines (MDC and TARC) through modulating NF-κB/MAPK signaling in PM-stimulated HaCaT keratinocytes. Extended studies investigated the impact of SJF-treated HaCaT keratinocyte culture media on HDFs. Interestingly, media from SJF-treated HaCaT keratinocytes on HDFs demonstrated a notable downregulation of the production of inflammatory mediators such as TSLP, IL-6, IL-8, IL-13, and TNF-α, as well as TARC and MDC. Furthermore, the study examined the impact of SJF on 12-O-tetradecanoylphorbol 13-acetate (TPA) induced ear edema in BALB/c mice and results indicated the reduced ear thickness and decreased iNOS and COX-2 expression. Our study confirmed the effectiveness of SJF in ameliorating PM-induced skin inflammation in in vitro experiments, along with the TPA-induced in vivo inflammatory model.

A review: Structure, bioactivity and potential application of algal polysaccharides in skin aging care and therapy

Skin is the first barrier of body which stands guard for defending aggressive pathogens and environmental pressures all the time. Cutaneous metabolism changes in harmful exposure, following with skin dysfunctions and diseases. Lots of researches have reported that polysaccharides extracted from seaweeds exhibited multidimensional bioactivities in dealing with skin disorder. However, few literature systematically reviews them. The aim of the present paper is to summarize structure, bioactivities and structure-function relationship of algal polysaccharides acting on skin. Algal polysaccharides show antioxidant, immunomodulating, hydration regulating, anti-melanogenesis and extracellular matrix (ECM) regulating abilities via multipath ways in skin. These bioactivities are determined by various parameters, including seaweed species, molecular weight, monosaccharides composition and substitute groups. In addition, potential usages of algae-derived polysaccharides in skin care and therapy are also elaborated. Algal polysaccharides are potential ingredients in formulation that providing anti-aging efficacy for skin.

The Ocean's Pharmacy: Health Discoveries in Marine Algae

Non-communicable diseases (NCDs) represent a global health challenge, constituting a major cause of mortality and disease burden in the 21st century. Addressing the prevention and management of NCDs is crucial for improving global public health, emphasizing the need for comprehensive strategies, early interventions, and innovative therapeutic approaches to mitigate their far-reaching consequences. Marine organisms, mainly algae, produce diverse marine natural products with significant therapeutic potential. Harnessing the largely untapped potential of algae could revolutionize drug development and contribute to combating NCDs, marking a crucial step toward natural and targeted therapeutic approaches. This review examines bioactive extracts, compounds, and commercial products derived from macro- and microalgae, exploring their protective properties against oxidative stress, inflammation, cardiovascular, gastrointestinal, metabolic diseases, and cancer across in vitro, cell-based, in vivo, and clinical studies. Most research focuses on macroalgae, demonstrating antioxidant, anti-inflammatory, cardioprotective, gut health modulation, metabolic health promotion, and anti-cancer effects. Microalgae products also exhibit anti-inflammatory, cardioprotective, and anti-cancer properties. Although studies mainly investigated extracts and fractions, isolated compounds from algae have also been explored. Notably, polysaccharides, phlorotannins, carotenoids, and terpenes emerge as prominent compounds, collectively representing 42.4% of the investigated compounds.

Fucosterol isolated from Sargassum horneri attenuates allergic responses in immunoglobulin E/bovine serum albumin-stimulated mast cells and passive cutaneous anaphylaxis in mice

Allergic diseases have become a serious problem worldwide and occur when the immune system overreacts to stimuli. Sargassum horneri is an edible marine brown alga with pharmacological relevance in treating various allergy-related conditions. Therefore, this study aimed to investigate the effect of fucosterol (FST) isolated from S. horneri on immunoglobulin E(IgE)/bovine serum albumin (BSA)-stimulated allergic reactions in mouse bone marrow-derived cultured mast cells (BMCMCs) and passive cutaneous anaphylaxis (PCA) in BALB/c mice. The in silico analysis results revealed the binding site modulatory potential of FST on the IgE and IgE-FcεRI complex. The findings of the study revealed that FST significantly suppressed the degranulation of IgE/BSA-stimulated BMCMCs by inhibiting the release of β-hexosaminidase and histamine in a dose-dependent manner. In addition, FST effectively decreased the expression of FcεRI on the surface of BMCMCs and its IgE binding. FST dose-dependently downregulated the expression of allergy-related cytokines (interleukin (IL)-4, -5, -6, -13, tumor necrosis factor (TNF)-α, and a chemokine (thymus and activation-regulated chemokine (TARC)) by suppressing the activation of nuclear factor-κB (NF-κB) and Syk-LAT-ERK-Gab2 signaling in IgE/BSA-stimulated BMCMCs. As per the histological analysis results of the in vivo studies with IgE-mediated PCA in BALB/c mice, FST treatment effectively attenuated the PCA reactions. These findings suggest that FST has an immunopharmacological potential as a naturally available bioactive compound for treating allergic reactions.

Antioxidative Sirt1 and the Keap1-Nrf2 Signaling Pathway Impair Inflammation and Positively Regulate Autophagy in Murine Mammary Epithelial Cells or Mammary Glands Infected with Streptococcus uberis

Streptococcus uberis mastitis in cattle infects mammary epithelial cells. Although oxidative responses often remove intracellular microbes, S. uberis survives, but the mechanisms are not well understood. Herein, we aimed to elucidate antioxidative mechanisms during pathogenesis of S. uberis after isolation from clinical bovine mastitis milk samples. S. uberis's in vitro pathomorphology, oxidative stress biological activities, transcription of antioxidative factors, inflammatory response cytokines, autophagosome and autophagy functions were evaluated, and in vivo S. uberis was injected into the fourth mammary gland nipple of each mouse to assess the infectiousness of S. uberis potential molecular mechanisms. The results showed that infection with S. uberis induced early oxidative stress and increased reactive oxygen species (ROS). However, over time, ROS concentrations decreased due to increased antioxidative activity, including total superoxide dismutase (T-SOD) and malondialdehyde (MDA) enzymes, plus transcription of antioxidative factors (Sirt1, Keap1, Nrf2, HO-1). Treatment with a ROS scavenger (N-acetyl cysteine, NAC) before infection with S. uberis reduced antioxidative responses and the inflammatory response, including the cytokines IL-6 and TNF-α, and the formation of the Atg5-LC3II/LC3I autophagosome. Synthesis of antioxidants determined autophagy functions, with Sirt1/Nrf2 activating autophagy in the presence of S. uberis. This study demonstrated the evasive mechanisms of S. uberis in mastitis, including suppressing inflammatory and ROS defenses by stimulating antioxidative pathways.

Antioxidant and Antimelanogenic Activities of Lactobacillus kunkeei NCHBL-003 Isolated from Honeybees

Excessive reactive oxygen species production can detrimentally impact skin cell physiology, resulting in cell growth arrest, melanogenesis, and aging. Recent clinical studies have found that lactic acid bacteria have a special effect directly or indirectly on skin organs, but the exact mechanism has not been elucidated. In this study, we investigated the mechanisms underlying the antioxidant protective effect and the inhibitory effect on melanin synthesis of Lactobacillus kunkeei culture supernatant (CSK), isolated from Apis mellifera Linnaeus (the Western honeybee). CSK exhibited notable efficacy in promoting cell migration and wound healing under oxidative stress, surpassing the performance of other strains. CSK pretreatment significantly upregulated the expression of Nrf2/HO-1 (nuclear factor erythroid 2-related factor 2/heme oxygenase-1), a key player in cellular defenses against oxidative stress, relative to the control H2O2-treated cells. The DCF-DA (dichloro-dihydro-fluorescein diacetate) assay results confirmed that CSK's ability to enhance Nrf2 and HO-1 expression aligns with its robust ability to remove H2O2-induced reactive oxygen species. Furthermore, CSK upregulated MAPK (mitogen-activated protein kinase) phosphorylation, an upstream signal for HO-1 expression, and MAPK inhibitors compromised the wound-healing effect of CSK. Additionally, CSK exhibited inhibitory effects on melanin synthesis, downregulating melanogenesis-related genes in B16F10 cells. Thus, the present study demonstrated that CSK exhibited antioxidant effects by activating the Nrf2/HO-1 pathway through MAPK phosphorylation, thereby restoring cell migration and demonstrating inhibitory effects on melanin production. These findings emphasize the antioxidant and antimelanogenic potential of CSK, suggesting its potential use as a therapeutic agent, promoting wound healing, and as an active ingredient in skin-lightening cosmetics.

Integrative single-cell transcriptomic investigation unveils long non-coding RNAs associated with localized cellular inflammation in psoriasis

Psoriasis is a complex, chronic autoimmune disorder predominantly affecting the skin. Accumulating evidence underscores the critical role of localized cellular inflammation in the development and persistence of psoriatic skin lesions, involving cell types such as keratinocytes, mesenchymal cells, and Schwann cells. However, the underlying mechanisms remain largely unexplored. Long non-coding RNAs (lncRNAs), known to regulate gene expression across various cellular processes, have been particularly implicated in immune regulation. We utilized our neural-network learning pipeline to integrate 106,675 cells from healthy human skin and 79,887 cells from psoriatic human skin. This formed the most extensive cell transcriptomic atlas of human psoriatic skin to date. The robustness of our reclassified cell-types, representing full-layer zonation in human skin, was affirmed through neural-network learning-based cross-validation. We then developed a publicly available website to present this integrated dataset. We carried out analysis for differentially expressed lncRNAs, co-regulated gene patterns, and GO-bioprocess enrichment, enabling us to pinpoint lncRNAs that modulate localized cellular inflammation in psoriasis at the single-cell level. Subsequent experimental validation with skin cell lines and primary cells from psoriatic skin confirmed these lncRNAs' functional role in localized cellular inflammation. Our study provides a comprehensive cell transcriptomic atlas of full-layer human skin in both healthy and psoriatic conditions, unveiling a new regulatory mechanism that governs localized cellular inflammation in psoriasis and highlights the therapeutic potential of lncRNAs in this disease's management.

The Anti-Inflammatory Effect of Low Molecular Weight Fucoidan from Sargassum siliquastrum in Lipopolysaccharide-Stimulated RAW 264.7 Macrophages via Inhibiting NF-κB/MAPK Signaling Pathways

Brown seaweed is a rich source of fucoidan, which exhibits a variety of biological activities. The present study discloses the protective effect of low molecular weight fucoidan (FSSQ) isolated from an edible brown alga, Sargassum siliquastrum, on lipopolysaccharide (LPS)-stimulated inflammatory responses in RAW 264.7 macrophages. The findings of the study revealed that FSSQ increases cell viability while decreasing intracellular reactive oxygen species production in LPS-stimulated RAW 264.7 macrophages dose-dependently. FSSQ reduced the iNOS and COX-2 expression, inhibiting the NO and prostaglandin E2 production. Furthermore, mRNA expression of IL-1β, IL-6, and TNF-α was downregulated by FSSQ via modulating MAPK and NF-κB signaling. The NLRP3 inflammasome protein complex, including NLRP3, ASC, and caspase-1, as well as the subsequent release of pro-inflammatory cytokines, such as IL-1β and IL-18, release in LPS-stimulated RAW 264.7 macrophages was inhibited by FSSQ. The cytoprotective effect of FSSQ is indicated via Nrf2/HO-1 signaling activation, which is considerably reduced upon suppression of HO-1 activity by ZnPP. Collectively, the study revealed the therapeutic potential of FSSQ against inflammatory responses in LPS-stimulated RAW 264.7 macrophages. Moreover, the study suggests further investigations on commercially viable methods for fucoidan isolation.

Unsaturated oxidated fatty acid 12(S)-HETE attenuates TNF-α expression in TNF-α/IFN-γ-stimulated human keratinocytes

Chronic skin inflammatory diseases are associated with abnormal immune responses characterized by skin barrier dysfunction. Keratinocytes participate in immune homeostasis regulated by immune cells. Immune homeostasis dysfunction contributes to the pathogenesis of skin diseases mediated by pro-inflammatory cytokines and chemokines, such as tumor necrosis factor (TNF)-α, which are produced by activated keratinocytes. 12(S)-Hydroxy eicosatetraenoic acid [12(S)-HETE], an arachidonic acid metabolite, has anti-inflammatory properties. However, the role of 12(S)-HETE in chronic skin inflammatory diseases has not been elucidated yet. In this study, we investigated the effect of 12(S)-HETE on TNF-α/interferon (IFN)-γ-induced pro-inflammatory cytokine and chemokine expression. Our data showed that 12(S)-HETE modulates TNF-α mRNA and protein expression in TNF-α-/IFN-γ-treated human keratinocytes. Molecular docking analyses demonstrated that 12(S)-HETE bound to extracellular signal-regulated kinase (ERK)1/2, thus preventing ERK activation and downregulating phosphorylated ERK expression. We also demonstrated that 12(S)-HETE treatment inhibited IκB and ERK phosphorylation and nuclear factor (NF)-κB, p65/p50, and CCAAT/enhancerbindingproteinβ (C/EBPβ) translocation. Overall, our results showed that 12(S)-HETE attenuated TNF-α expression and secretion by inhibiting the mitogen-activated protein kinase ERK/NF-κB and C/EBPβ signaling pathways. Overall, these results suggest that 12(S)-HETE effectively resolved TNF-α-induced inflammation.

Sulfated polygalactofucan from triangular sea bell Turbinaria decurrens attenuates inflammatory cytokines on THP-1 human monocytic macrophages

Inflammation is one of the most significant causes of several chronic diseases, which includes the expression of cytokines activating immune cells to up-regulate the inflammatory cascade. Polysaccharides from marine macroalgae are promising anti-inflammatory agents because of their potential to attenuate inflammatory cytokines. The triangular sea bell Turbinaria decurrens (Sargassaceae) among marine macroalgae is ubiquitous in oceanic waters, and a sulfated polygalactofucan SPTd-2 [→3-(α-L-fucp-(2-OSO₃^-)-(1 → 4)-α-L-fucp-(3-OAc)-(1 → 4)-β-D-galp-(1→] was purified from the species. The studied polygalactofucan SPTd-2 exhibited anti-inflammatory activities against cyclooxygenase-2 (IC₅₀ 10.56 μM) and 5-lipoxygenase (IC₅₀ 3.36 μM) with a greater selectivity index (2.35) than ibuprofen (0.44), besides attenuating pro-inflammatory cytokine production, including tumor necrosis factor-α, transforming growth factor-β, interleukin-2, 1β, and interferon-γ. Quantitative real-time polymerase chain reaction displayed that SPTd-2 blocked the mRNA of interferon-γ and interleukin-2, in the human monocytic cell line THP-1. The results showed the potential of SPTd-2 to attenuate inflammation-associated disorders.

Relevance of the Extraction Stage on the Anti-Inflammatory Action of Fucoidans

The anti-inflammatory action of fucoidans is well known, based on both in vitro and some in vivo studies. The other biological properties of these compounds, their lack of toxicity, and the possibility of obtaining them from a widely distributed and renewable source, makes them attractive novel bioactives. However, fucoidans’ heterogeneity and variability in composition, structure, and properties depending on seaweed species, biotic and abiotic factors and processing conditions, especially during extraction and purification stages, make it difficult for standardization. A review of the available technologies, including those based on intensification strategies, and their influence on fucoidan composition, structure, and anti-inflammatory potential of crude extracts and fractions is presented.

Fine-Dust-Induced Skin Inflammation: Low-Molecular-Weight Fucoidan Protects Keratinocytes and Underlying Fibroblasts in an Integrated Culture Model

Prolonged exposure to fine dust (FD) increases the risk of skin inflammation. Stimulated epidermal cells release growth factors into their extracellular environment, which can induce inflammation in dermal cells. Algae are considered rich sources of bioactive materials. The present study emphasized the effect of low-molecular-weight fucoidan isolated from Sargassum confusum (LMF) against FD-induced inflammation in HaCaT keratinocytes and underneath fibroblasts (HDFs) in an integrated culture model. HDFs were treated with media from FD-stimulated HaCaT with LMF treatments (preconditioned media). The results suggested that FD increased the oxidative stress in HaCaT, thereby increasing the sub-G₁ phase of the cell cycle up to 587%, as revealed via flow cytometric analysis. With preconditioned media, HDFs also displayed oxidative stress; however, the increase in the sub-G₁ phase was insignificant compared with HaCaT. LMF dose-dependently regulated the NF-κB/MAPK signaling in HaCaT. Furthermore, significant downregulation in NF-κB/MAPK signaling, as well as inflammatory cytokines, tissue inhibitors of metalloproteinases, matrix metalloproteinases, and reduction in relative elastase and collagenase activities related to the extracellular matrix degeneration were observed in HDFs with a preconditioned media treatment. Therefore, we concluded that HDFs were protected from inflammation by preconditioned media. Continued research on tissue culture and in vivo studies may reveal the therapeutic potential of LMF.

Sulforaphene Attenuates Cutibacterium acnes-Induced Inflammation

Acne is a chronic inflammatory disease of the sebaceous gland attached to the hair follicles. Cutibacterium acnes is a major cause of inflammation caused by acne. It is well known that C. acnes secretes a lipolytic enzyme to break down lipids in sebum, and free fatty acids produced at this time accelerate the inflammatory reaction. There are several drugs used to treat acne; however, each one has various side effects. According to previous studies, sulforaphene (SFEN) has several functions associated with lipid metabolism, brain function, and antibacterial and anti-inflammatory activities. In this study, we examined the effects of SFEN on bacterial growth and inflammatory cytokine production induced by C. acnes. The results revealed that SFEN reduced the growth of C. acnes and inhibited proinflammatory cytokines in C. acnes-treated HaCaT keratinocytes through inhibiting NF-κB-related pathways. In addition, SFEN regulated the expression level of IL-1α, a representative pro-inflammatory cytokine expressed in co-cultured HaCaT keratinocytes and THP-1 monocytes induced by C. acnes. In conclusion, SFEN showed antibacterial activity against C. acnes and controlled the inflammatory response on keratinocytes and monocytes. This finding means that SFEN has potential as both a cosmetic material for acne prevention and a pharmaceutical material for acne treatment.

Ethyl Acetate Extract of Marine Algae, Halymenia durvillei, Provides Photoprotection against UV-Exposure in L929 and HaCaT Cells

Halymenia durvillei is a red alga distributed along the coasts of Southeast Asian countries including Thailand. Previous studies have shown that an ethyl acetate fraction of H. durvillei (HDEA), containing major compounds including n-hexadecanoic acid, 2-butyl-5-hexyloctahydro-1H-indene, 3-(hydroxyacetyl) indole and indole-3-carboxylic acid, possesses high antioxidant and anti-lung cancer activities. The present study demonstrated that HDEA could protect mouse skin fibroblasts (L929) and human immortalized keratinocytes (HaCaT) against photoaging due to ultraviolet A and B (UVA and UVB) by reducing intracellular reactive oxygen species (ROS) and expressions of matrix metalloproteinases (MMP1 and MMP3), as well as increasing Nrf2 nuclear translocation, upregulations of mRNA transcripts of antioxidant enzymes, including superoxide dismutase (SOD), heme oxygenase (HMOX) and glutathione S-transferase pi1 (GSTP1), and procollagen synthesis. The results indicate that HDEA has the potential to protect skin cells from UV irradiation through the activation of the Nrf2 pathway, which leads to decreasing intracellular ROS and MMP production, along with the restoration of skin collagen.

3-Bromo-4,5-dihydroxybenzaldehyde Isolated from Polysiphonia morrowii Suppresses TNF-α/IFN-γ-Stimulated Inflammation and Deterioration of Skin Barrier in HaCaT Keratinocytes

Polysiphonia morrowii is a well-known red alga that has promising pharmacological characteristics. The current study evaluates the protective effect of 3-bromo-4,5-dihydroxybenzaldehyde (BDB) isolated from P. morrowii on tumor necrosis factor (TNF)-α/interferon (IFN)-γ-stimulated inflammation and skin barrier deterioration in HaCaT keratinocytes. The anti-inflammatory effect of BDB in TNF-α/IFN-γ-stimulated HaCaT keratinocytes is evaluated by investigating nuclear factor kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) pathways, inflammatory cytokines, and chemokines. Further, the interaction between BDB and the skin barrier functions in stimulated HaCaT keratinocytes is investigated. The findings of the study reveal that BDB dose-dependently increases cell viability while decreasing intracellular reactive oxygen species (ROS) production. BDB downregulates the expression of inflammatory cytokines, interleukin (IL)-6, -8, -13, IFN-γ, TNF-α, and chemokines, Eotaxin, macrophage-derived chemokine (MDC), regulated on activation, normal T cells expressed and secreted (RANTES), and thymus and activation-regulated chemokine (TARC) by modulating the MAPK and NF-κB signaling pathways in TNF-α/IFN-γ-stimulated HaCaT keratinocytes. Furthermore, BDB increases the production of skin hydration proteins and tight junction proteins in stimulated HaCaT keratinocytes by preserving skin moisturization and tight junction stability. These findings imply that BDB exhibits a protective ability against inflammation and deterioration of skin barrier via suppressing the expression of inflammatory signaling in TNF-α/IFN-γ-stimulated HaCaT keratinocytes.

Fucosterol Isolated from Dietary Brown Alga Sargassum horneri Protects TNF-α/IFN-γ-Stimulated Human Dermal Fibroblasts via Regulating Nrf2/HO-1 and NF-κB/MAPK Pathways

Sargassum horneri is a well-known edible brown alga that is widely abundant in the sea near China, Korea, and Japan and has a wide range of bioactive compounds. Fucosterol (FST), which is a renowned secondary metabolite in brown algae, was extracted from S. horneri to 70% ethanol, isolated via high-performance liquid chromatography (HPLC), followed by the immiscible liquid-liquid separation, and its structure was confirmed by NMR spectroscopy. The present study was undertaken to investigate the effects of FST against oxidative stress, inflammation, and its mechanism of action in tumor necrosis factor (TNF)-α/interferon (IFN)-γ-stimulated human dermal fibroblast (HDF). FST was biocompatible with HDF cells up to the 120 μM dosage. TNF-α/IFN-γ stimulation significantly decreased HDF viability by notably increasing reactive oxygen species (ROS) production. FST dose-dependently decreased the intracellular ROS production in HDFs. Western blot analysis confirmed a significant increment of nuclear factor erythroid 2-related factor 2 (Nrf2)/ heme oxygenase-1 (HO-1) involvement in FST-treated HDF cells. In addition, the downregulation of inflammatory mediators, molecules related to connective tissue degradation, and tissue inhibitors of metalloproteinases were identified. TNF-α/IFN-γ stimulation in HDF cells increased the phosphorylation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) mediators, and its phosphorylation was reduced with the treatment of FST in a dose-dependent manner. Results obtained from western blot analysis of the NF-κB nuclear translocation were supported by immunocytochemistry results. Collectively, the outcomes suggested that FST significantly upregulates the Nrf2/HO-1 signaling and regulates NF-κB/MAPK signaling pathways to minimize the inflammatory responses in TNF-α/IFN-γ-stimulated HDF cells.

ACSL4 is overexpressed in psoriasis and enhances inflammatory responses by activating ferroptosis

More and more studies have shown that ferroptosis is closely related to the progression of various diseases, but the significance of ferroptosis in psoriasis is still rarely explored. The detection of plasma and psoriatic lesions found that the contents of MDA and ROS were significantly increased, while the contents of SOD and GSH were significantly decreased, and the trend of increase or decrease in patients with progressive psoriasis was more obvious. The expression of ACSL4, a key regulator of ferroptosis, was significantly increased in psoriatic lesions and further up-regulated in patients with progressive psoriasis. ACSL4 expression was positively correlated with PASI score and the expression levels of inflammatory cytokines (TNF-α, IL-6, IL-8 and IL-17a), and linear regression analysis showed that high expression of ACSL4 in psoriatic lesions was associated with higher PASI score. Both ferroptosis inducer Erastin and IFN-γ/TNF-α significantly induced ferroptosis, inhibited keratinocyte viability, promoted the accumulation of MDA, ROS and Fe²⁺, and enhanced ACSL4, TNF-α, IL-6 and IL-8 expression. When ferroptosis inhibitor Ferrostatin-1 was added to inhibit ferroptosis, the up-regulation trends of MDA, ROS, Fe²⁺, ACSL4, TNF-α, IL-6 and IL-8 were significantly inhibited, and inhibition of ACSL4 expression also had a similar effect. Apoptosis inhibitor Z-VAD-FMK could also attenuate the pro-inflammatory effect of IFN-γ/TNF-α, and Fer-1 plus Z-VAD-FMK further inhibited the expression of inflammatory cytokines. Thus, ferroptosis is significantly activated during the progression of psoriasis and promotes inflammatory responses by upregulating ACSL4 expression. This discovery will provide new targets for clinical detection, prevention and treatment of psoriasis.

Impacts of Oxidative Stress and PI3K/AKT/mTOR on Metabolism and the Future Direction of Investigating Fucoidan-Modulated Metabolism

The critical factors for regulating cancer metabolism are oxidative stress and phosphoinositide-3-kinase/AKT serine-threonine kinase/mechanistic target of the rapamycin kinase (PI3K/AKT/mTOR). However, the metabolic impacts of oxidative stress and PI3K/AKT/mTOR on individual mechanisms such as glycolysis (Warburg effect), pentose phosphate pathway (PPP), fatty acid synthesis, tricarboxylic acid cycle (TCA) cycle, glutaminolysis, and oxidative phosphorylation (OXPHOS) are complicated. Therefore, this review summarizes the individual and interacting functions of oxidative stress and PI3K/AKT/mTOR on metabolism. Moreover, natural products providing oxidative stress and PI3K/AKT/mTOR modulating effects have anticancer potential. Using the example of brown algae-derived fucoidan, the roles of oxidative stress and PI3K/AKT/mTOR were summarized, although their potential functions within diverse metabolisms were rarely investigated. We propose a potential application that fucoidan may regulate oxidative stress and PI3K/AKT/mTOR signaling to modulate their associated metabolic regulations. This review sheds light on understanding the impacts of oxidative stress and PI3K/AKT/mTOR on metabolism and the future direction of metabolism-based cancer therapy of fucoidan.