Neorogioltriol and Related Diterpenes from the Red Alga Laurencia Inhibit Inflammatory Bowel Disease in Mice by Suppressing M1 and Promoting M2-Like Macrophage Responses

Marine Pharmacology in 2019-2021: Marine Compounds with Antibacterial, Antidiabetic, Antifungal, Anti-Inflammatory, Antiprotozoal, Antituberculosis and Antiviral Activities; Affecting the Immune and Nervous Systems, and Other Miscellaneous Mechanisms of Action

The current 2019-2021 marine pharmacology literature review provides a continuation of previous reviews covering the period 1998 to 2018. Preclinical marine pharmacology research during 2019-2021 was published by researchers in 42 countries and contributed novel mechanism-of-action pharmacology for 171 structurally characterized marine compounds. The peer-reviewed marine natural product pharmacology literature reported antibacterial, antifungal, antiprotozoal, antituberculosis, and antiviral mechanism-of-action studies for 49 compounds, 87 compounds with antidiabetic and anti-inflammatory activities that also affected the immune and nervous system, while another group of 51 compounds demonstrated novel miscellaneous mechanisms of action, which upon further investigation, may contribute to several pharmacological classes. Thus, in 2019-2021, a very active preclinical marine natural product pharmacology pipeline provided novel mechanisms of action as well as new lead chemistry for the clinical marine pharmaceutical pipeline targeting the therapy of several disease categories.

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.

Approaches of marine compounds and relevant immune mediators in Autism Spectrum Disorder: Opportunities and challenges

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder that affects social skills, language, communication, and behavioral skills, significantly impacting the individual's quality of life. Recently, numerous works have centered on the connections between the immune and central nervous systems and the influence of neuroinflammation on autism symptomatology. Marine natural products are considered as important alternative sources of different types of compounds, including polysaccharides, polyphenols, sterols, carotenoids, terpenoids and, alkaloids. These compounds present anti-inflammatory, neuroprotective and immunomodulatory activities, exhibiting a potential for the treatment of many diseases. Although many studies address the marine compounds in the modulation of inflammatory mediators, there is a gap regarding their use in the regulation of the immune system in ASD. Thus, this review aims to provide a better understanding regarding cytokines, chemokines, growth factors and immune responses in ASD, as well as the potential of bioactive marine compounds in the immune regulation in ASD. We expect that this review would contribute to the development of therapeutic alternatives for controlling immune mediators and inflammation in ASD.

Marine algae: A treasure trove of bioactive anti-inflammatory compounds

This comprehensive review examines the diverse classes of pharmacologically active compounds found in marine algae and their promising anti-inflammatory effects. The review covers various classes of anti-inflammatory compounds sourced from marine algae, including phenolic compounds, flavonoids, terpenoids, caretenoids, alkaloids, phlorotannins, bromophenols, amino acids, peptides, proteins, polysaccharides, and fatty acids. The anti-inflammatory activities of marine algae-derived compounds have been extensively investigated using in vitro and in vivo models, demonstrating their ability to inhibit pro-inflammatory mediators, such as cytokines, chemokines, and enzymes involved in inflammation. Moreover, marine algae-derived compounds have exhibited immunomodulatory properties, regulating immune cell functions and attenuating inflammatory responses. Specific examples of compounds with notable anti-inflammatory activities are highlighted. This review provides valuable insights for researchers in the field of marine anti-inflammatory pharmacology and emphasizes the need for further research to harness the pharmacological benefits of marine algae-derived compounds for the development of effective and safe therapeutic agents.

Artificially induced in situ macrophage polarization: An emerging cellular therapy for immuno-inflammatory diseases

Macrophages are the mature form of monocytes that have high plasticity and can shift from one phenotype to another by the process of macrophage polarization. Macrophage has several vital pharmacological tasks like eliminating microorganism invasion, clearing dead cells, causing inflammation, repairing damaged tissues, etc. The function of macrophages is based on their phenotype. M1 macrophages are mostly responsible for the body's immune responses and M2 macrophages have healing properties. Inappropriate activation of any one of the phenotypes often leads to ROS-induced tissue damage and affects wound healing and angiogenesis. Therefore, maintaining tissue macrophage homeostasis is necessary. Studies are being done to find techniques for macrophage polarization. But, the process of macrophage polarization is very complex as it involves multiple signalling pathways involving innate immunity. Thus, identifying the right pathways for macrophage polarization is essential to apply the polarizing technique for the treatment of various inflammatory diseases where macrophage physiology influences the disease pathology. In this review, we highlighted the various techniques so far used to change macrophage plasticity. We believe that soon macrophage targeting therapeutics will hit the market for the management of inflammatory disease. Hence this review will help macrophage researchers choose suitable methods and materials/agents to polarize macrophages artificially in various disease models.

Anti-Inflammatory Effects of Bioactive Compounds from Seaweeds, Bryozoans, Jellyfish, Shellfish and Peanut Worms

Inflammation is a defense mechanism of the body in response to harmful stimuli such as pathogens, damaged cells, toxic compounds or radiation. However, chronic inflammation plays an important role in the pathogenesis of a variety of diseases. Multiple anti-inflammatory drugs are currently available for the treatment of inflammation, but all exhibit less efficacy. This drives the search for new anti-inflammatory compounds focusing on natural resources. Marine organisms produce a broad spectrum of bioactive compounds with anti-inflammatory activities. Several are considered as lead compounds for development into drugs. Anti-inflammatory compounds have been extracted from algae, corals, seaweeds and other marine organisms. We previously reviewed anti-inflammatory compounds, as well as crude extracts isolated from echinoderms such as sea cucumbers, sea urchins and starfish. In the present review, we evaluate the anti-inflammatory effects of compounds from other marine organisms, including macroalgae (seaweeds), marine angiosperms (seagrasses), medusozoa (jellyfish), bryozoans (moss animals), mollusks (shellfish) and peanut worms. We also present a review of the molecular mechanisms of the anti-inflammatory activity of these compounds. Our objective in this review is to provide an overview of the current state of research on anti-inflammatory compounds from marine sources and the prospects for their translation into novel anti-inflammatory drugs.

Investigating anti-inflammatory actions of marine algal compound against lipoxygenase concentrating on therapeutic applications through computational approach

Inflammation is the preliminary response given to any possible harmful stimuli including infections, injury or stress by immune system where neutrophils and macrophages gets activated and produces mediators, such as nitric oxide and cytokines that serves as biomarkers of inflammation. Lipoxygenases are enzymes that peroxidises lipids and are involved in the pathogenesis of several diseases including inflammatory diseases. These are oxidative enzymes comprising a non-heme iron atom in active site and are convoluted in inflammatory reactions. Fucoidan is sulphated polysaccharide that has numerous pharmacological implications. Implications of fucoidan on inflammatory diseases are still an objective of rigorous research. Therefore, this study focusses on investigating lipoxygenase inhibitory activities of fucoidan. The mechanism of lipoxygenase inhibitory activities of fucoidan was studied via molecular docking and molecular dynamics simulations. The docking score produced by the binding of the fucoidan to the lipoxygenase was - 6.69 kcal/mol whereas, the docking score in case of Aspirin and Zileuton were -5.8 kcal/mol and -7.0 kcal/mol and it was found that fucoidan makes hydrogen bonds with lipoxygenase protein through polar amino acid glutamine at GLN 514. The results obtained from molecular dynamics simulations proposed the development of a stable complex between fucoidan and lipoxygenase due to the establishment of favourable interactions with amino acid residues and indicated efficient results when compared with Aspirin and Zileuton. This study suggested that fucoidan had anti-inflammatory potentials and thus can be used as a promising drug candidate against inflammation.Communicated by Ramaswamy H. Sarma.

Terpenes: Modulating anti-inflammatory signaling in inflammatory bowel disease

Inflammatory Bowel Disease (IBD) are autoimmune diseases characterized by chronic intestinal inflammation. Considered a western disease, IBD incidence in newly developed countries is skyrocketing. Accordingly, global prevalence is steadily increasing. There are two major IBD phenotypes, ulcerative colitis (UC) and Crohn's disease (CD). UC manifests as uninterrupted inflammation localized in the colon and rectum. Meanwhile, CD presents as interrupted inflammation that can occur throughout the digestive tract. As a result, therapeutics have focused on anti-inflammatory approaches for its treatment. Unfortunately, only 50% of patients benefit from current Food and Drug Administration approved treatments, and all are associated with serious adverse effects. Thus, there is a need for safer and novel therapeutics to increase the efficacy in this population. One aspect that is critical in understanding IBD is how food and phytochemicals therein may be associated with modifying the pathogenesis of IBD. A variety of retrospective and prospective studies, and clinical trials have shown benefits of plant-rich diets on the prevention and symptomatic improvement of IBD. The Mediterranean diet is rich in vegetables, fruits, legumes, and herbs; and characterized by the abundance of anti-inflammatory phytochemicals. An understudied phytochemical class enriched in this diet is terpenes; isoprene-based molecules are widely available in Mediterranean herbs and citrus fruits. Various terpenes have been evaluated in different IBD models. However, some present contradictory or inconclusive results. Therefore, in this review we evaluated preclinical studies of terpenes modulating basic inflammatory signaling related to IBD.

Rugulopteryx-Derived Spatane, Secospatane, Prenylcubebane and Prenylkelsoane Diterpenoids as Inhibitors of Nitric Oxide Production

This study aimed to evaluate the anti-inflammatory potential of the different classes of diterpenoids produced by algae of the genus Rugulopteryx. First, sixteen diterpenoids (1-16), including spatane, secospatane, prenylcubebane, and prenylkelsoane metabolites, were isolated from the extract of the alga Rugulopteryx okamurae collected at the southwestern Spanish coasts. Eight of the isolated diterpenoids are new compounds whose structures were determined by spectroscopic means: the spatanes okaspatols A-D (1-4); the secospatane rugukamural D (8); the prenylcubebanes okacubols A (13) and B (14); and okamurol A (16), which exhibits an unusual diterpenoid skeleton featuring a kelsoane-type tricyclic nucleus. Second, anti-inflammatory assays were performed on microglial cells Bv.2 and macrophage cells RAW 264.7. Compounds 1, 3, 6, 12, and 16 caused significant inhibition of the NO overproduction induced by LPS in Bv.2 cells, and compounds 3, 5, 12, 14, and 16 significantly decreased levels of NO in LPS-stimulated RAW 264.7 cells. The most active compound was okaspatol C (3), which completely suppressed the effects of LPS stimulation, both in Bv.2 and in RAW 264.7 cells.

Effects of the Antioxidant Quercetin in an Experimental Model of Ulcerative Colitis in Mice

Background and Objectives: Quercetin, a member of the flavanol family found in many fruits, vegetables, leaves and grains has been found to have a wide range of biological effects on human physiology. The aim of this study was to investigate the effects of quercetin, when administered orally in the form of the water-soluble inclusion complex with hydroxypropyl-b-cyclodextrin (Que-HP-β-CD), in an experimental model of ulcerative colitis in mice. Materials and Methods: Animals received either Dextran Sodium Sulphate (DSS), to induce colitis, + Que-HP-β-CD (Group A), DSS alone (Group B) or no intervention (control, Group C) for 7 days. All animals were weighed daily, and evaluation of colitis was performed using the Disease Activity Index (DAI). On day 7 a blood sample was taken from all animals, they were then euthanised, the large intestine was measured, and histological and immunochemical analyses were performed. Results: The DAI demonstrated an increase over time for the groups receiving DSS (Groups A and B) compared with the control group (Group C), with a significant degree of protection being observed in the group that also received quercetin (Group A): The DAI over time slope for Group B was higher than that for Group A by 0.26 points/day (95% Cl 0.20−0.33, p < 0.01). Weight calculations and immunohistochemistry results validated the DAI findings. Conclusions: In conclusion, the administration of quercetin in an ulcerative colitis model in mice presents a therapeutic/prophylactic potential that warrants further investigation.

Interleukin-34 deficiency aggravates development of colitis and colitis-associated cancer in mice

BACKGROUND

Although expression of interleukin (IL)-34 is upregulated in active ulcerative colitis (UC), the molecular function and underlying mechanism are largely unclear.

AIM

To investigate the function of IL-34 in acute colitis, in a wound healing model and in colitis-associated cancer in IL-34-deficient mice.

METHODS

Colitis was induced by administration of dextran sodium sulfate (DSS), and carcinogenesis was induced by azoxymethane (AOM). Whether the impact of IL-34 on colitis was dependent on macrophages was validated by depletion of macrophages in a murine model. The association between IL-34 expression and epithelial proliferation was studied in patients with active UC.

RESULTS

IL-34 deficiency aggravated murine colitis in acute colitis and in wound healing phase. The effect of IL-34 on experimental colitis was not dependent on macrophage differentiation and polarization. IL-34-deficient mice developed more tumors than wild-type mice following administration of AOM and DSS. No significant difference was shown in degree of cellular differentiation in tumors between wild-type and IL-34-deficient mice. IL-34 was dramatically increased in the active UC patients as previously reported. More importantly, expression of IL-34 was positively correlated with epithelial cell proliferation in patients with UC.

CONCLUSION

IL-34 deficiency exacerbates colonic inflammation and accelerates colitis-associated carcinogenesis in mice. It might be served as a potential therapeutic target in UC.

Macroalgae Specialized Metabolites: Evidence for Their Anti-Inflammatory Health Benefits

Inflammation is an organism's response to chemical or physical injury. It is split into acute and chronic inflammation and is the last, most significant cause of death worldwide. Nowadays, according to the World Health Organization (WHO), the greatest threat to human health is chronic disease. Worldwide, three out of five people die from chronic inflammatory diseases such as stroke, chronic respiratory diseases, heart disorders, and cancer. Nowadays, anti-inflammatory drugs (steroidal and non-steroidal, enzyme inhibitors that are essential in the inflammatory process, and receptor antagonists, among others) have been considered as promising treatments to be explored. However, there remains a significant proportion of patients who show poor or incomplete responses to these treatments or experience associated severe side effects. Seaweeds represent a valuable resource of bioactive compounds associated with anti-inflammatory effects and offer great potential for the development of new anti-inflammatory drugs. This review presents an overview of specialized metabolites isolated from seaweeds with in situ and in vivo anti-inflammatory properties. Phlorotannins, carotenoids, sterols, alkaloids, and polyunsaturated fatty acids present significant anti-inflammatory effects given that some of them are involved directly or indirectly in several inflammatory pathways. The majority of the isolated compounds inhibit the pro-inflammatory mediators/cytokines. Studies have suggested an excellent selectivity of chromene nucleus towards inducible pro-inflammatory COX-2 than its constitutive isoform COX-1. Additional research is needed to understand the mechanisms of action of seaweed's compounds in inflammation, given the production of sustainable and healthier anti-inflammatory agents.

Variation in the Efficacy of Anti-Ulcerative Colitis Treatments Reveals the Conflict Between Precipitating Compatibility of Traditional Chinese Medicine and Modern Technology: A Case of Scutellaria-Coptis

Scutellariae and Coptidis compose a classical drug pair applied in clinical practice to dispel heat, dryness, and dampness, and they are also precipitation compatible drug pairs. With modern technology, Scutellaria-Coptis is mostly prepared by decocting its components separately, while in the traditional method, it is predominantly prepared as a combined decoction. The present study investigated the effects and mechanisms of separate and combined application of Scutellaria-Coptis decoction on ulcerative colitis (UC) in mice induced by the administration of dextran sulfate sodium (DSS). Changes in body weight, colon length, and Disease Activity Index scores were also evaluated. Hematoxylin and eosin staining and other methods were used to evaluate the overall condition of animals in each group. Intestinal microflora was analyzed using 16S rRNA sequencing, while colon inflammation and antioxidant capacity were evaluated based on the levels of interleukin-6 (IL-6), IL-10, IL-1β, tumor necrosis factor-α, superoxide dismutase, malondialdehyde, and reduced glutathione. The results revealed that Scutellaria-Coptis significantly relieved colon inflammation in mice, and the combined decoction of Scutellaria-Coptis exerted a significant effect on UC. Notably, the protective effect of Scutellaria-Coptis against colon inflammation was weakened when the antibiotic mixture was partially consumed by the gut microbiota. The results of 16S rRNA sequencing showed that the group treated with combined decoction of Scutellaria-Coptis exhibited a higher intestinal microbial diversity and intestinal flora composition than the separated decoction group. Treatment of mice with UC by administering Scutellaria-Coptis decoction through intestinal flora removal (ABX) and fecal microbial transplantation (FMT) was closely associated with intestinal flora composition. In conclusion, Scutellaria-Coptis can relieve UC with an excellent effect especially when taken as a combined decoction, alleviating colon inflammation incurred by intestinal microbes to a certain extent.

Recent advancement on development of drug-induced macrophage polarization in control of human diseases

Macrophages, an important part of human immune system, possess a high plasticity and heterogeneity (macrophage polarization) as classically activated macrophages (M1) and alternatively activated macrophages (M2), which exert pro-inflammatory/anti-tumor and anti-inflammatory/pro-tumor effects, respectively. Thus, drug development in induction of macrophage polarization could be used to treat different human diseases. This review summarizes the recent advancement on modulation of macrophage polarization and its related molecular mechanisms induced by a number of agents. Research on the anti-inflammatory drugs to regulate the macrophage polarization accounts for a large proportion in the field and types of diseases investigated could include atherosclerosis, enteritis, nephritis, and the nervous system and skeletal diseases, while study of the anti-tumor agents to modify macrophage polarization is a novel area of research. Future study of the molecular mechanisms by which the different agents regulate the macrophage polarization could lead to an effective control of various human diseases, including inflammation and cancers.

Collagen-Containing Fish Sidestream-Derived Protein Hydrolysates Support Skin Repair via Chemokine Induction

Restoring homeostasis following tissue damage requires a dynamic and tightly orchestrated sequence of molecular and cellular events that ensure repair and healing. It is well established that nutrition directly affects skin homeostasis, while malnutrition causes impaired tissue healing. In this study, we utilized fish sidestream-derived protein hydrolysates including fish collagen as dietary supplements, and investigated their effect on the skin repair process using a murine model of cutaneous wound healing. We explored potential differences in wound closure and histological morphology between diet groups, and analyzed the expression and production of factors that participate in different stages of the repair process. Dietary supplementation with fish sidestream-derived collagen alone (Collagen), or in combination with a protein hydrolysate derived from salmon heads (HSH), resulted in accelerated healing. Chemical analysis of the tested extracts revealed that Collagen had the highest protein content and that HSH contained the great amount of zinc, known to support immune responses. Indeed, tissues from mice fed with collagen-containing supplements exhibited an increase in the expression levels of chemokines, important for the recruitment of immune cells into the damaged wound region. Moreover, expression of a potent angiogenic factor, vascular endothelial growth factor-A (VEGF-A), was elevated followed by enhanced collagen deposition. Our findings suggest that a 5%-supplemented diet with marine collagen-enriched supplements promotes tissue repair in the model of cutaneous wound healing, proposing a novel health-promoting use of fish sidestreams.

Fish Sidestream-Derived Protein Hydrolysates Suppress DSS-Induced Colitis by Modulating Intestinal Inflammation in Mice

Inflammatory bowel disease is characterized by extensive intestinal inflammation, and therapies against the disease target suppression of the inflammatory cascade. Nutrition has been closely linked to the development and suppression of inflammatory bowel disease, which to a large extent is attributed to the complex immunomodulatory properties of nutrients. Diets containing fish have been suggested to promote health and suppress inflammatory diseases. Even though most of the health-promoting properties of fish-derived nutrients are attributed to fish oil, the potential health-promoting properties of fish protein have not been investigated. Fish sidestreams contain large amounts of proteins, currently unexploited, with potential anti-inflammatory properties, and may possess additional benefits through bioactive peptides and free amino acids. In this project, we utilized fish protein hydrolysates, based on mackerel and salmon heads and backbones, as well as flounder skin collagen. Mice fed with a diet supplemented with different fish sidestream-derived protein hydrolysates (5% w/w) were exposed to the model of DSS-induced colitis. The results show that dietary supplements containing protein hydrolysates from salmon heads suppressed chemically-induced colitis development as determined by colon length and pro-inflammatory cytokine production. To evaluate colitis severity, we measured the expression of different pro-inflammatory cytokines and chemokines and found that the same supplement suppressed the pro-inflammatory cytokines IL-6 and TNFα and the chemokines Cxcl1 and Ccl3. We also assessed the levels of the anti-inflammatory cytokines IL-10 and Tgfb and found that selected protein hydrolysates induced their expression. Our findings demonstrate that protein hydrolysates derived from fish sidestreams possess anti-inflammatory properties in the model of DSS-induced colitis, providing a novel underexplored source of health-promoting dietary supplements.

Analysis of interleukin-1 receptor associated kinase-3 (IRAK3) function in modulating expression of inflammatory markers in cell culture models: A systematic review and meta-analysis

BACKGROUND

IRAK3 is a critical modulator of inflammation in innate immunity. IRAK3 is associated with many inflammatory diseases, including sepsis, and is required in endotoxin tolerance to maintain homeostasis of inflammation. The impact of IRAK3 on inflammatory markers such as nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), tumour necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in cell culture models remains controversial.

OBJECTIVE

To analyse temporal effects of IRAK3 on inflammatory markers after one- or two-challenge interventions in cell culture models.

METHODS

A systematic search was performed to identify in vitro cell studies reporting outcome measures of expression of IRAK3 and inflammatory markers. Meta-analyses were performed where sufficient data were available. Comparisons of outcome measures were performed between different cell lines and human and mouse primary cells.

RESULTS

The literature search identified 7766 studies for screening. After screening titles, abstracts and full-texts, a total of 89 studies were included in the systematic review.

CONCLUSIONS

The review identifies significant effects of IRAK3 on decreasing NF-κB DNA binding activity in cell lines, TNF-α protein level at intermediate time intervals (4h-15h) in cell lines or at long term intervals (16h-48h) in mouse primary cells following one-challenge. The patterns of TNF-α protein expression in human cell lines and human primary cells in response to one-challenge are more similar than in mouse primary cells. Meta-analyses confirm a negative correlation between IRAK3 and inflammatory cytokine (IL-6 and TNF-α) expression after two-challenges.

Mitochondrial metabolism in regulating macrophage polarization: an emerging regulator of metabolic inflammatory diseases

As a major type of immune cells with heterogeneity and plasticity, macrophages are classically divided into inflammatory (M1) and alternative/anti-inflammatory (M2) types and play a crucial role in the progress of the inflammatory diseases. Recent studies have shown that metabolism is an important determinant of macrophage phenotype. Mitochondria, one of the most important compartments involving cell metabolism, are closely associated with the regulation of cell functions. In most types of cell, mitochondrial oxidative phosphorylation (OXPHOS) is the primary mode of cellular energy production. However, mitochondrial OXPHOS is inhibited in activated M1 macrophages, rendering them unable to be converted into M2 phenotype. Thus, mitochondrial metabolism is a crucial regulator in macrophage functions. This review summarizes the roles of mitochondria in macrophage polarization and analyzes the molecular mechanisms underlying mitochondrial metabolism and function, which may provide new approaches for the treatment of metabolic inflammatory diseases.

TRAF3 promotes ROS production and pyroptosis by targeting ULK1 ubiquitination in macrophages

Disrupted mitochondrial function and reactive oxygen species (ROS) generation cause cellular damage and oxidative stress-induced macrophage inflammatory cell death. It remains unclear how mitochondrial dysfunction relates to inflammasome activation and pyroptotic cell death. In this study, we demonstrated that tumor necrosis factor receptor-associated factor 3 (TRAF3) regulates mitochondrial ROS production and promotes TLR agonist LPS plus nigericin (LPS/Ng)-induced inflammasome and pyroptosis in mouse primary macrophages and human monocyte THP-1 cells. Co-IP assays confirmed that TRAF3 forms a complex with TRAF2 and cIAP1 and mediates ubiquitin and degradation of Unc-51 like autophagy activating kinase 1 (ULK1). Moreover, knockdown of ULK1 in THP-1 cells significantly promoted LPS/Ng-induced inflammasome by activating caspase 1 and mature IL-1β. Apoptosis inducing factor (AIF) translocation from mitochondrial to nuclear was observed in ULK1-deficient THP-1 cells under LPS/Ng stimulation, which mediates LPS/Ng-induced cell death in ULK1 deficient macrophages. In conclusion, this study identified a novel role of TRAF3 in regulation of ULK1 ubiquitination and inflammasome signaling and provided molecular mechanisms by which ubiquitination of ULK1 controls mitochondrial ROS production, inflammasome activity, and AIF-dependent pyroptosis.

Seaweed Secondary Metabolites with Beneficial Health Effects: An Overview of Successes in In Vivo Studies and Clinical Trials

Macroalgae are increasingly viewed as a source of secondary metabolites with great potential for the development of new drugs. In this development, in vitro studies are only the first step in a long process, while in vivo studies and clinical trials are the most revealing stages of the true potential and limitations that a given metabolite may have as a new drug. This literature review aims to give a critical overview of the secondary metabolites that reveal the most interesting results in these two steps. Phlorotannins show great pharmaceutical potential in in vivo models and, among the several examples, the anti-dyslipidemia activity of dieckol must be highlighted because it was more effective than lovastatin in an in vivo model. The IRLIIVLMPILMA tridecapeptide that exhibits an in vivo level of activity similar to the hypotensive clinical drug captopril should still be stressed, as well as griffithsin which showed such stunning results over a variety of animal models and which will probably move onto clinical trials soon. Regarding clinical trials, studies with pure algal metabolites are scarce, limited to those carried out with kahalalide F and fucoxanthin. The majority of clinical trials currently aim to ascertain the effect of algae consumption, as extracts or fractions, on obesity and diabetes.

Thuwalallenes A-E and Thuwalenynes A-C: New C15 Acetogenins with Anti-Inflammatory Activity from a Saudi Arabian Red Sea Laurencia sp

Thuwalallenes A-E (1-3, 5 and 8) and thuwalenynes A-C (4, 6, 7), new C₁₅ acetogenins featuring uncommon ring systems, along with cis-maneonene D (9), thyrsiferol (10) and 23-acetyl-thyrsiferol (11) were isolated from the organic extract of a population of the red alga Laurencia sp., collected at Rose Reef off the village of Thuwal in the Red Sea waters of the Kingdom of Saudi Arabia. The structure elucidation of the isolated natural products was based on extensive analysis of their spectroscopic data. Compounds 1-6, 8, 10 and 11 were evaluated for their anti-inflammatory activity by quantifying nitric oxide (NO) release in response to TLR4 stimulation in macrophages. Besides compound 4 that did not exhibit any activity, all other tested metabolites inhibited NO production from activated macrophages. Among them, thyrsiferol (10) and 23-acetylthyrsiferol (11) displayed activity with IC₅₀ values in the low nM scale without cytotoxicity.