Marine bioactives: pharmacological properties and potential applications against inflammatory diseases

Fucoxanthin supplemented combinatorial treatment accelerates diabetic wound healing in rats by targeting hypermethylation of Ang-1 promoter via DNMT-1 inhibition

It has been widely established that DNA methyl transferase 1 has a role in the epigenetic regulation of numerous complications including diabetes and inhibition of the same is widely being seen as a potential therapeutic mechanism to treat these complications. Fucoxanthin is a carotenoid that has widely been reported to have a wealth of biological functions. Fucoxanthin is believed to be involved in a broad spectrum of pathways to produce anti-cancer, anti-obesity and antioxidant effects. In this study, fucoxanthin was encapsulated within myristic acid and BSA particles. These particles were tested for their physicochemical properties and fucoxanthin encapsulated within these particles exhibited superior thermal and storage stability. In-vitro digestion tests were carried out further confirming the ability of the encapsulation process to enhance the biological activity of fucoxanthin. The efficacy of fucoxanthin encapsulated particles were evaluated at in-vivo level using diabetic wound models in wistar rats. Fucoxanthin when delivered as an oral supplement in combination with linseed polysaccharide gel as wound dressing managed to significantly accelerate wound healing progression when compared with control and treatment groups. Fucoxanthin when delivered orally also managed to significantly inhibit DNA methyl transferase 1 leading to Angiopoietin 1 upregulation eventually resulting in accelerated wound healing.

Algal bioactive compounds: A review on their characteristics and medicinal properties

Bioactive compounds derived from marine algae drawn increasing interest in pharmaceuticals, nutraceuticals, and cosmetics due to their wide range of therapeutic properties. These natural molecules, which include polysaccharides, polyphenols, phlorotannins, carotenoids, and pigments, exhibit potent antioxidant, antimicrobial, anti-inflammatory, antiviral, and antitumor activities. Algal bioactives are safer and more sustainable options for drug discovery since they often have less negative effects than synthesized compounds. This review highlights the structural diversity of algal biomolecules and their mechanisms of action, with emphasis on validated bioactivities supported by recent studies. It also critically examines challenges such as the low bioavailability of high-molecular-weight compounds like fucoidans, variability in metabolite production linked to environmental factors, and limitations in scalable extraction processes. Recent advances in nano-encapsulation, metabolic engineering, and eco-friendly extraction methods are explored as promising strategies to enhance bioavailability and industrial applicability. By integrating traditional knowledge with biotechnological innovations, this review underscores the underexploited potential of macroalgae in addressing chronic diseases and the urgent need for standardized protocols to facilitate the clinical translation of algal-derived bioactives.

Fucoxanthin ameliorates ulcerative colitis by maintaining the epithelial barrier via blocking JAK2/STAT3 signaling pathway

BACKGROUND

The clinical efficacies of Ulcerative colitis (UC) are far from satisfactory. Fucoxanthin (FUC) is a marine carotenoid that is abundant in seaweed and microalgae. It has been reported that FUC can possess anti-inflammatory and antioxidant. However, its mechanism and role in UC is yet to be clarified. This study aimed to investigate the protective effect and potential mechanism of FUC extracted from the diatom Phaeodactylum tricornutm on dextran sodium sulfate (DSS) -induced colitis.

METHODS

Animal UC model was induced by DSS and cellular model was established by TNF-α. Immunohistochemical staining, Western blot, RT-qPCR, and immunofluorescence were used to assess the inflammatory responses and epithelial barrier in vivo and in vitro models.

RESULTS

The results showed that FUC attenuates DSS-induced colitis by ameliorating the epithelial mucosal barrier. Moreover, FUC possessed antioxidant and anti-inflammatory effects on NCM460 cells. JAK/STAT activator RO8191 could reverse these changes.

CONCLUSION

FUC exerted anti-inflammatory and antioxidant effects via the JAK2/STAT3 signaling pathway, and served as a potential therapeutic agent for the treatment of UC.

Marine-Derived Bioactive Ingredients in Functional Foods for Aging: Nutritional and Therapeutic Perspectives

Aging is closely linked to various health challenges, including cardiovascular disease, metabolic disorders, and neurodegenerative conditions. This study emphasizes the critical role of bioactive compounds derived from marine sources, such as antioxidants, omega-3 fatty acids, vitamins, minerals, and polysaccharides, in addressing oxidative stress, inflammation, and metabolic disorders closely related to aging. Incorporating these materials into functional foods not only provides essential nutrients but also delivers therapeutic effects, thereby promoting healthy aging and mitigating age-related diseases. The growth of the global anti-aging market, particularly in North America, Europe, and Asia, underscores the significance of this study. This review systematically analyzes the current research, identifying key bioactive compounds, their mechanisms of action, and their potential health benefits, thus highlighting the broad applicability of marine-derived bioactive compounds to enhancing healthy aging and improving the quality of life of aging populations.

A comprehensive review of marine sponge metabolites, with emphasis on Neopetrosia sp

The secondary metabolites that marine sponges create are essential to the advancement of contemporary medicine and are often employed in clinical settings. Over the past five years, microbes associated with sponges have yielded the identification of 140 novel chemicals. Statistics show that most are derived from actinomycetes (bacteria) and ascomycotes (fungi). The aim of this study was to investigate the biological activity of metabolites from marine sponges. Chlocarbazomycins A-D, which are a group of novel chlorinated carbazole alkaloids isolated from the sponge Neopetrosia fennelliae KUFA 0811, exhibit antimicrobial, cytotoxic, and enzyme inhibitory activities. Recently, marine sponges of the genus Neopetrosia have attracted attention due to the unique chemical composition of the compounds they produce, including alkaloids of potential importance in drug discovery. Fridamycin H and fridamycin I are two novel type II polyketides synthesized by sponge-associated bacteria exhibit antitrypanosomal activity. Fintiamin, composed of amino acids and terpenoid moieties, shows affinity for the cannabinoid receptor CB 1. It was found that out of 27 species of Neopetrosia sponges, the chemical composition of only 9 species has been studied. These species mainly produce bioactive substances such as alkaloids, quinones, sterols, and terpenoids. The presence of motuporamines is a marker of the species Neopetrosia exigua. Terpenoids are specific markers of Neopetrosia vanilla species. Although recently discovered, secondary metabolites from marine sponges have been shown to have diverse biological activities, antimicrobial, antiviral, antibacterial, antimicrobial, antioxidant, antimalarial, and anticancer properties, providing many lead compounds for drug development. The data presented in this review on known and future natural products derived from sponges will further clarify the role and importance of microbes in marine sponges and trace the prospects of their applications, especially in medicine, cosmeceuticals, environmental protection, and manufacturing industries.

Inflammation in Metal-Induced Neurological Disorders and Neurodegenerative Diseases

Essential metals play critical roles in maintaining human health as they participate in various physiological activities. Nonetheless, both excessive accumulation and deficiency of these metals may result in neurotoxicity secondary to neuroinflammation and the activation of microglia and astrocytes. Activation of these cells can promote the release of pro-inflammatory cytokines. It is well known that neuroinflammation plays a critical role in metal-induced neurotoxicity as well as the development of neurological disorders, such as Alzheimer's disease (AD), Parkinson's disease (PD), and multiple sclerosis (MS). Initially seen as a defense mechanism, persistent inflammatory responses are now considered harmful. Astrocytes and microglia are key regulators of neuroinflammation in the central nervous system, and their excessive activation may induce sustained neuroinflammation. Therefore, in this review, we aim to emphasize the important role and molecular mechanisms underlying metal-induced neurotoxicity. Our objective is to raise the awareness on metal-induced neuroinflammation in neurological disorders. However, it is not only just neuroinflammation that different metals could induce; they can also cause harm to the nervous system through oxidative stress, apoptosis, and autophagy, to name a few. The primary pathophysiological mechanism by which these metals induce neurological disorders remains to be determined. In addition, given the various pathways through which individuals are exposed to metals, it is necessary to also consider the effects of co-exposure to multiple metals on neurological disorders.

Equisetin protects from atherosclerosis in vivo by binding to STAT3 and inhibiting its activity

Atherosclerosis is a chronic inflammatory vascular disease characterized by lipid metabolism disorder and lipid accumulation. Equisetin (EQST) is a hemiterpene compound isolated from fungus of marine sponge origin, which has antibacterial, anti-inflammatory, lipid-lowering, and weight loss effects. Whether EQST has anti-atherosclerotic activity has not been reported. In this study, we revealed that EQST displayed anti- atherosclerosis effects through inhibiting macrophage inflammatory response, lipid uptake and foam cell formation in vitro, and finally ameliorated high-fat diet (HFD)-induced atherosclerosis in AopE-/- mice in vivo. Mechanistically, EQST directly bound to STAT3 with high-affinity by forming hydrophobic bonds at GLN247 and GLN326 residues, as well as hydrogen bonds at ARG325 and THR346 residues. EQST interacted with STAT3 physically, and functionally inhibited the transcription activity of STAT3, thereby regulating atherosclerosis. Therefore, these results supports EQST as a candidate for developing anti-atherosclerosis therapeutic agent.

Seaweeds as Source of Bioactive Pigments with Neuroprotective and/or Anti-Neurodegenerative Activities: Astaxanthin and Fucoxanthin

The marine kingdom is an important source of a huge variety of scaffolds inspiring the design of new drugs. The complex molecules found in the oceans present a great challenge to organic and medicinal chemists. However, the wide variety of biological activities they can display is worth the effort. In this article, we present an overview of different seaweeds as potential sources of bioactive pigments with activity against neurodegenerative diseases, especially due to their neuroprotective effects. Along with a broad introduction to seaweed as a source of bioactive pigments, this review is especially focused on astaxanthin and fucoxanthin as potential neuroprotective and/or anti-neurodegenerative agents. PubMed and SciFinder were used as the main sources to search and select the most relevant scientific articles within the field.

Enemies or Allies? Hormetic and Apparent Non-Dose-Dependent Effects of Natural Bioactive Antioxidants in the Treatment of Inflammation

This review aims to analyze the emerging number of studies on biological media that describe the unexpected effects of different natural bioactive antioxidants. Hormetic effects, with a biphasic response depending on the dose, or activities that are apparently non-dose-dependent, have been described for compounds such as resveratrol, curcumin, ferulic acid or linoleic acid, among others. The analysis of the reported studies confirms the incidence of these types of effects, which should be taken into account by researchers, discarding initial interpretations of imprecise methodologies or measurements. The incidence of these types of effects should enhance research into the different mechanisms of action, particularly those studied in the field of basic research, that will help us understand the causes of these unusual behaviors, depending on the dose, such as the inactivation of the signaling pathways of the immune defense system. Antioxidative and anti-inflammatory activities in biological media should be addressed in ways that go beyond a mere statistical approach. In this work, some of the research pathways that may explain the understanding of these activities are revised, paying special attention to the ability of the selected bioactive compounds (curcumin, resveratrol, ferulic acid and linoleic acid) to form metal complexes and the activity of these complexes in biological media.

Hypoglycaemic Molecules for the Management of Diabetes Mellitus from Marine Sources

Diabetes mellitus (DM) is a chronic metabolic disorder recognized as a major health problem globally. A defective insulin activity contributes to the prevalence and expansion of DM. Treatment of DM is often hampered by limited options of conventional therapies and adverse effects associated with existing procedures. This has led to a spike in the exploration for potential therapeutic agents from various natural resources for clinical applications. The marine environment is a huge store of unexplored diversity of chemicals produced by a multitude of organisms. To date, marine microorganisms, microalgae, macroalgae, corals, sponges, and fishes have been evaluated for their anti-diabetic properties. The structural diversity of bioactive metabolites discovered has shown promising hypoglycaemic potential through in vitro and in vivo screenings via various mechanisms of action, such as PTP1B, α-glucosidase, α-amylase, β-glucosidase, and aldose reductase inhibition as well as PPAR alpha/gamma dual agonists activities. On the other hand, hypoglycaemic effect is also shown to be exerted through the balance of antioxidants and free radicals. This review highlights marine-derived chemicals with hypoglycaemic effects and their respective mechanisms of action in the management of DM in humans.

Anti-Inflammatory Effects of Marine Bioactive Compounds and Their Potential as Functional Food Ingredients in the Prevention and Treatment of Neuroinflammatory Disorders

Functional foods include enhanced, enriched, fortified, or whole foods that impart health benefits beyond their nutritional value, particularly when consumed as part of a varied diet on a regular basis at effective levels. Marine sources can serve as the sources of various healthy foods and numerous functional food ingredients with biological effects can be derived from these sources. Microalgae, macroalgae, crustaceans, fungi, bacteria fish, and fish by-products are the most common marine sources that can provide many potential functional food ingredients including phenolic compounds, proteins and peptides, and polysaccharides. Neuroinflammation is closely linked with the initiation and progression of various neurodegenerative diseases, including Alzheimer's disease, Huntington's disease, and Parkinson's disease. Activation of astrocytes and microglia is a defense mechanism of the brain to counter damaged tissues and detrimental pathogens, wherein their chronic activation triggers neuroinflammation that can further exacerbate or induce neurodegeneration. Currently, available therapeutic agents only provide symptomatic relief from these disorders and no therapies are available to stop or slow down the advancement of neurodegeneration. Thereffore, natural compounds that can exert a protective effect against these disorders have therapeutic potential. Numerous chemical compounds, including bioactive peptides, fatty acids, pigments, alkaloids, and polysaccharides, have already been isolated from marine sources that show anti-inflammatory properties, which can be effective in the treatment and prevention of neuroinflammatory disorders. The anti-inflammatory potential of marine-derived compounds as functional food ingredients in the prevention and treatment of neurological disorders is covered in this review.

Advances in Fucoxanthin Research for the Prevention and Treatment of Inflammation-Related Diseases

Owing to its unique structure and properties, fucoxanthin (FX), a carotenoid, has attracted significant attention. There have been numerous studies that demonstrate FX's anti-inflammatory, antioxidant, antitumor, and anti-obesity properties against inflammation-related diseases. There is no consensus, however, regarding the molecular mechanisms underlying this phenomenon. In this review, we summarize the potential health benefits of FX in inflammatory-related diseases, from the perspective of animal and cellular experiments, to provide insights for future research on FX. Previous work in our lab has demonstrated that FX remarkably decreased LPS-induced inflammation and improved survival in septic mice. Further investigation of the activity of FX against a wide range of diseases will require new approaches to uncover its molecular mechanism. This review will provide an outline of the current state of knowledge regarding FX application in the clinical setting and suggest future directions to implement FX as a therapeutic ingredient in pharmaceutical sciences in order to develop it into a treatment strategy against inflammation-associated disorders.

In Vivo Assessment of the Effects of Mono-Carrier Encapsulated Fucoxanthin Nanoparticles on Type 2 Diabetic C57 Mice and Their Oxidative Stress

Fucoxanthin (FX) is a carotenoid from a marine origin that has an important role in our health, especially in the regulation and alleviation of type 2 diabetes. Its specific molecular structure makes it very unstable, which greatly affects its delivery in the body. In this study, FX was encapsulated in a mono-carrier using a hydrolyzed zein to form a nanocomplex with a stable structure and chemical properties (FZNP). Its stability was demonstrated by characterization and the efficacy of FX before and after encapsulation in alleviating diabetes in mice, which was evaluated by in vivo experiments. FZNP reduced the level of fasting blood glucose and restored it to normal levels in T2DM mice, which was not caused by a decrease in food intake, and effectively reduced oxidative stress in the organism. Both FX and FZNP repaired the hepatocyte and pancreatic β-cell damage, increased serum SOD and reduced INS values significantly, upregulated PI3K-AKT genes as well as CaMK and GNAs expression in the pancreas. FZNP increased ADPN and GSH-PX values more significantly and it decreased serum HOMA-IR and MDA values, upregulated GLUT2 expression, promoted glucose transport in pancreatic and hepatocytes, regulated glucose metabolism and glycogen synthesis with much superior effects than FX.

The Role of Exosomes in Inflammatory Diseases and Tumor-Related Inflammation

Inflammation plays a decisive role in inducing tumorigenesis, promoting tumor development, tumor invasion and migration. The interaction of cancer cells with their surrounding stromal cells and inflammatory cells further forms an inflammatory tumor microenvironment (TME). The large number of cells present within the TME, such as mesenchymal stem cells (MSCs), macrophages, neutrophils, etc., play different roles in the changing TME. Exosomes, extracellular vesicles released by various types of cells, participate in a variety of inflammatory diseases and tumor-related inflammation. As an important communication medium between cells, exosomes continuously regulate the inflammatory microenvironment. In this review, we focused on the role of exosomes in inflammatory diseases and tumor-related inflammation. In addition, we also summarized the functions of exosomes released by various cells in inflammatory diseases and in the TME during the transformation of inflammatory diseases to tumors. We discussed in depth the potential of exosomes as targets and tools to treat inflammatory diseases and tumor-related inflammation.

Carotenoids from Marine Sources as a New Approach in Neuroplasticity Enhancement

An increasing number of people experience disorders related to the central nervous system (CNS). Thus, new forms of therapy, which may be helpful in repairing processes' enhancement and restoring declined brain functions, are constantly being sought. One of the most relevant physiological processes occurring in the brain for its entire life is neuroplasticity. It has tremendous significance concerning CNS disorders since neurological recovery mainly depends on restoring its structural and functional organization. The main factors contributing to nerve tissue damage are oxidative stress and inflammation. Hence, marine carotenoids, abundantly occurring in the aquatic environment, being potent antioxidant compounds, may play a pivotal role in nerve cell protection. Furthermore, recent results revealed another valuable characteristic of these compounds in CNS therapy. By inhibiting oxidative stress and neuroinflammation, carotenoids promote synaptogenesis and neurogenesis, consequently presenting neuroprotective activity. Therefore, this paper focuses on the carotenoids obtained from marine sources and their impact on neuroplasticity enhancement.

Bioactive Peptides: Synthesis, Sources, Applications, and Proposed Mechanisms of Action

Bioactive peptides are a group of biological molecules that are normally buried in the structure of parent proteins and become active after the cleavage of the proteins. Another group of peptides is actively produced and found in many microorganisms and the body of organisms. Today, many groups of bioactive peptides have been marketed chemically or recombinantly. This article reviews the various production methods and sources of these important/ubiquitous and useful biomolecules. Their applications, such as antimicrobial, antihypertensive, antioxidant activities, blood-lipid-lowering effect, opioid role, antiobesity, ability to bind minerals, antidiabetic, and antiaging effects, will be explored. The types of pathways proposed for bioactive applications will be in the next part of the article, and at the end, the future perspectives of bioactive peptides will be reviewed. Reading this article is recommended for researchers interested in various fields of physiology, microbiology, biochemistry, and nanotechnology and food industry professionals.

Marine-derived pipeline anticancer natural products: a review of their pharmacotherapeutic potential and molecular mechanisms

Background

Cancer is a complex and most widespread disease and its prevalence is increasing worldwide, more in countries that are witnessing urbanization and rapid industrialization changes. Although tremendous progress has been made, the interest in targeting cancer has grown rapidly every year. This review underscores the importance of preventive and therapeutic strategies.

Main text

Natural products (NPs) from various sources including plants have always played a crucial role in cancer treatment. In this growing list, numerous unique secondary metabolites from marine sources have added and gaining attention and became potential players in drug discovery and development for various biomedical applications. Many NPs found in nature that normally contain both pharmacological and biological activity employed in pharmaceutical industry predominantly in anticancer pharmaceuticals because of their enormous range of structure entities with unique functional groups that attract and inspire for the creation of several new drug leads through synthetic chemistry. Although terrestrial medicinal plants have been the focus for the development of NPs, however, in the last three decades, marine origins that include invertebrates, plants, algae, and bacteria have unearthed numerous novel pharmaceutical compounds, generally referred as marine NPs and are evolving continuously as discipline in the molecular targeted drug discovery with the inclusion of advanced screening tools which revolutionized and became the component of antitumor modern research.

Conclusions

This comprehensive review summarizes some important and interesting pipeline marine NPs such as Salinosporamide A, Dolastatin derivatives, Aplidine/plitidepsin (Aplidin®) and Coibamide A, their anticancer properties and describes their mechanisms of action (MoA) with their efficacy and clinical potential as they have attracted interest for potential use in the treatment of various types of cancers.

Marine Algae of the Genus Gracilaria as Multi Products Source for Different Biotechnological and Medical Applications

BACKGROUND

Gracilaria has been shown to be an important source of marine bioactive natural biomaterials and compounds. Although there are no enough patents used Gracilaria worldwide, the current study tries to put the Gracilaria on the spot for further important patents in the future.

OBJECTIVE

The current study investigates the pharmaceuticals and biochemical activity of Gracilaria because no previous studies have been carried out to examine the biochemical and pharmaceutical activates of Gracilaria from the Suez Canal of Egypt as an excellent source for bioactive compounds.

METHODS

Different advanced experimental models and analytical techniques, such as cytotoxicity, total antioxidant capacity, anticancer, and anti-inflammatory profiling were applied. The phytochemical analysis of different constituents was also carried out.

RESULTS

The mineral analysis revealed the presence of copper (188.3 ppm) and iron (10.07 ppm) in addition to a remarkable wealth of selenium and sulfur contents giving up to 36% of its dry mass. The elemental analysis showed high contents of sulfur and nitrogen compounds. The GCMS profiling showed varieties of different bioactive compounds, such as fatty acids, different types of carotenoids in addition to pigments, alkaloids, steroids. Many other compounds, such as carbohydrates and amino acids having antioxidant, anti-inflammatory, and antiviral activities, etc. were identified. The cytotoxicity activity of Gracilaria marine extract was very effective against cancerous cell lines and showed high ability as a potent antitumor due to their bioactive constituents. Specialized screening assays using two anticancer experimental models, i.e., PTK and SKH1 revealed 77.88% and 84.50% inhibition anticancer activity; respectively. The anti-inflammatory activities investigated using four different experimental models, i.e., COX1, COX2, IL6, and TNF resulted in 68%, 81.76%, 56.02% and 78.43% inhibition; respectively. Moreover, Gracilaria extracts showed potent anti-Alzheimer with all concentrations.

CONCLUSION

Gracilaria proved to be a multi-product source of marine natural products for different biotechnological applications. Our recommendation is to investigate the Gracilaria bioactive secondary metabolites in order to create and innovate in more patents from current important seaweeds (Gracilaria).

Dihydromyricetin Imbues Antiadipogenic Effects on 3T3-L1 Cells via Direct Interactions with 78-kDa Glucose-Regulated Protein

BACKGROUND

Obesity is among the most serious public health problems worldwide, with few safe pharmaceutical interventions. Natural products have become an important source of potential anti-obesity therapeutics. Dihydromyricetin (DHM) exerts antidiabetic effects. The biochemical target of DHM, however, has been unknown. It is crucial to identify the biochemical target of DHM for elucidating its physiological function and therapeutic value.

OBJECTIVES

The objective of this study was to identify the biochemical target of DHM.

METHODS

An abundant antiadipogenic flavanonol was extracted from the herbal plant Ampelopsis grossedentata through bioassay-guided fractionation and characterized with high-resolution LC-MS and 1H and 13C nuclear magnetic resonance. Antiadipogenic experiments were done with mouse 3T3-L1 preadipocytes. A biochemical target of the chemical of interest was identified with drug affinity responsive target stability assay. Direct interactions between the chemical of interest and the protein target in vitro were predicted with molecular docking and subsequently confirmed with surface plasmon resonance. Expression levels of peroxisome proliferator-activated receptor γ (PPARγ), which is associated with 78-kDa glucose-regulated protein (GRP78), were measured with real-time qPCR.

RESULTS

DHM was isolated, purified, and structurally characterized. Cellular studies showed that DHM notably reduced intracellular oil droplet formation in 3T3-L1 cells with a median effective concentration of 294 μM (i.e., 94 μg/mL). DHM targeted the ATP binding site of GRP78, which is associated with adipogenesis. An equilibrium dissociation constant between DHM and GRP78 was 21.8 μM. In 3T3-L1 cells upon treatment with DHM at 50 μM (i.e., 16 μg/mL), the expression level of PPARγ was downregulated to 53.9% of the solvent vehicle control's level.

CONCLUSIONS

DHM targets GRP78 in vitro. DHM is able to reduce lipid droplet formation in 3T3-L1 cells through a mode of action that is plausibly associated with direct interactions between GRP78 and DHM, which is a step forward in determining potential applications of DHM as an anti-obesity agent.

Anti-Angiogenetic Agents from the Sea: A New Potential Preventive and Therapeutic Wave?

Angiogenesis, generation of novel blood vessels from pre-existing ones, is a prerequisite for the physiological expansion, reparation, and functioning of body tissues and systems. However, it is also involved in some pathological inflammatory situations, such as oncologic and chronic degenerative disorders. The correct angiogenesis and neo-vascular response also accompanies wound healing, interaction with biocompatible materials, and tissue regeneration. In this respect, natural products deriving from terrestrial and marine plants/organisms may prevent and even cure various angiogenesis-dependent disorders. Bioactive natural compounds with antioxidant and anti-inflammatory activities could concur to maintain adequate vascularization and endothelial functions and inhibit angiogenesis, thus controlling tumor development. This review aims to illustrate the role of some marine-derived compounds as anti-angiogenetic agents.

Marine Algae as a Potential Source for Anti-diabetic Compounds - A Brief Review

BACKGROUND

Diabetes Mellitus (DM) is a major chronic metabolic disorder characterized by hyperglycemia that leads to several complications such as retinopathy, atherosclerosis, nephropathy, etc. In 2019, it was estimated that about 463 million people had diabetes, and it may increase up to 700 million in 2045. Marine macroalgae are the rich source of bioactive compounds for the treatment of diabetes mellitus.

OBJECTIVE

This review summarizes the recent epidemiology and possible use of marine macroalgae-derived bioactive compounds for the protection against chronic metabolic disease, diabetes mellitus and marine macroalgae as a nutraceutical supplement.

CONCLUSION

The present therapies available for diabetes treatment are oral medicines and insulin injections. But continuous use of synthetic medicines provides low therapeutic with many side effects. In continuing search of anti-diabetic drugs, marine macroalgae remain as a promising source with potent bioactivity. Among existing marine algae, red and brown algae are reported to show anti-diabetic activity. Hence, the present review focuses on the epidemiology, diabetes biomarkers and different secondary bioactive compounds present in marine macroalgae to treat diabetes mellitus.

Marine-Derived Biologically Active Compounds for the Potential Treatment of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic, systemic autoimmune disease with a prevalence rate of up to 1% and is significantly considered a common worldwide public health concern. Commercially, several traditional formulations are available to treat RA to some extent. However, these synthetic compounds exert toxicity and considerable side effects even at lower therapeutic concentrations. Considering the above-mentioned critiques, research is underway around the world in finding and exploiting potential alternatives. For instance, marine-derived biologically active compounds have gained much interest and are thus being extensively utilized to confront the confines of in practice counterparts, which have become ineffective for 21st-century medical settings. The utilization of naturally available bioactive compounds and their derivatives can minimize these synthetic compounds' problems to treat RA. Several marine-derived compounds exhibit anti-inflammatory and antioxidant properties and can be effectively used for therapeutic purposes against RA. The results of several studies ensured that the extraction of biologically active compounds from marine sources could provide a new and safe source for drug development against RA. Finally, current challenges, gaps, and future perspectives have been included in this review.

Bioactive Metabolites from Marine Algae as Potent Pharmacophores against Oxidative Stress-Associated Human Diseases: A Comprehensive Review

In addition to cancer and diabetes, inflammatory and ROS-related diseases represent one of the major health problems worldwide. Currently, several synthetic drugs are used to reduce oxidative stress; nevertheless, these approaches often have side effects. Therefore, to overcome these issues, the search for alternative therapies has gained importance in recent times. Natural bioactive compounds have represented, and they still do, an important source of drugs with high therapeutic efficacy. In the ''synthetic'' era, terrestrial and aquatic photosynthetic organisms have been shown to be an essential source of natural compounds, some of which might play a leading role in pharmaceutical drug development. Marine organisms constitute nearly half of the worldwide biodiversity. In the marine environment, algae, seaweeds, and seagrasses are the first reported sources of marine natural products for discovering novel pharmacophores. The algal bioactive compounds are a potential source of novel antioxidant and anticancer (through modulation of the cell cycle, metastasis, and apoptosis) compounds. Secondary metabolites in marine Algae, such as phenolic acids, flavonoids, and tannins, could have great therapeutic implications against several diseases. In this context, this review focuses on the diversity of functional compounds extracted from algae and their potential beneficial effects in fighting cancer, diabetes, and inflammatory diseases.

The preparation of (4H)-imidazol-4-ones and their application in the total synthesis of natural products

(4H)-Imidazol-4-ones are an important scaffold for a variety of applications, including natural products, medicine, agriculture, and other applications. Over the years, there have been a number of preparations published for the synthesis of imidazol-4-ones. This review discusses the progress made on the synthesis of imidazol-4-ones, and their application towards the total synthesis of a range of imidazol-4-one containing natural products. Emphasis is made on areas of the field that still need progress.

Hymenialdisine: A Marine Natural Product That Acts on Both Osteoblasts and Osteoclasts and Prevents Estrogen-Dependent Bone Loss in Mice

Excessive osteoclast (OC) activity together with relatively weak osteoblast (OB) function are strongly connected to osteolytic diseases, including osteoporosis, tumor-induced osteolysis, and inflammatory bone erosion. Very few natural products or compounds have been shown to exert therapeutic effects on both OCs and OBs, limiting the potential development of natural compounds for clinical application. Hymenialdisine (HMD) is a marine sponge-derived natural inhibitor of protein kinases with previously reported anti-osteoarthritis and anti-cancer properties. However, the roles of HMD in OCs, OBs, and osteoporosis have not yet been well established. Here, we found that HMD not only suppressed osteoclastogenesis but also promoted OB differentiation. HMD exerted dose-dependent inhibitory effects on RANKL-induced OC formation, bone resorption, and OC-specific gene expression. These strong inhibitory effects were achieved by blocking the NF-κB and MAPK signaling pathways, and NFATc1 expression. In addition, HMD potentially stimulated OB differentiation by activating alkaline phosphatase (ALP) and enhancing OB matrix mineralization. We found that HMD can activate the glycogen synthase kinase 3β (GSK-3β)/β-catenin/T-cell factor (TCF)/lymphoid enhancer factor (LEF) signaling pathway to upregulate Runx-2 expression, the main transcription factor in this pathway. Increased expression of Runx-2 was also correlated with expression of the OB-specific genes Col1a1 and osteocalcin (Ocn). Furthermore, we also evaluated the therapeutic potential of HMD in a female C57BL/6j mouse model of ovariectomy (OVX)-induced systematic bone loss. HMD showed a remarkable ability to prevent decreases in bone volume (BV/TV) and trabecular thickness (Tb.Th). In summary, HMD exerts notable effects in inhibiting OC-related osteolysis and enhancing OB-induced ossification, suggesting the potential application of HMD in osteoporosis treatment. © 2020 American Society for Bone and Mineral Research.

Antinociceptive and Anti-inflammatory Effects of Methanolic Extract of Laurencia caspica

Introduction: Seaweeds are valuable resources for the discovery of efficient and safe drugs for pain treatment. In the present investigation, we evaluated the antinociceptive and anti-inflammatory properties of, methanolic extract of Laurencia caspica, a red algae, in mice models. Methods: The analgesic effect of methanolic extract of L. caspica was assessed by hot-plate and acetic acid-induced writhing tests in male Swiss albino mice (weight = 20-25 g). The anti-inflammatory activity of methanolic extract of L. caspica was also evaluated by formalin-induced ear edema and xylene-induced paw edema tests. Results: The total flavonoid content of the extract was estimated as 0.0537 mg quercetin/g extract. Both first and second phases of the nociception were significantly inhibited at a dose of 120 mg/kg of methanolic extract of L. caspica. The observed anti-inflammatory effect was dose-dependent. Acetic acid-induced writhing test and hot plate test showed that the extract significantly reduced pain in all evaluated doses (15, 30, 60, and 120 mg/kg). The antinociceptive activity of the methanolic extract was significantly reduced by naloxone (4 mg/kg). Moreover, the extract significantly reduced paw edema at the dose of 120 mg/kg in all the animals. Conclusion: Methanolic extract of L. caspica exhibited central analgesic effect, as well as anti-inflammatory activity probably due to the presence of constituents like flavonoids and triterpenoids.

Fucoxanthin: A promising compound for human inflammation-related diseases

Fucoxanthin, a natural product of carotenoids, is a potential drug source obtained from marine algae. The special chemical structure of fucoxanthin has equipped it with a variety of biological activities. Several studies have indicated that fucoxanthin has a potential protective effect on a variety of inflammation-related diseases. This mechanism may be related to fucoxanthin's strong antioxidant capacity and gut microbiota regulation. The key molecules that require consideration include nuclear factor erythroid 2-related factor 2, Akt serine/threonine kinase/phosphatidylinositol-3-kinase, extracellular signal-regulated kinase, adenosine monophosphate (AMP)-dependent protein kinase, cAMP response element binding protein, and peroxisome proliferator-activated receptorγcoactivator-1α. The study summarizes the recent progress in the research based on the protective effect of fucoxanthin and its related molecular mechanism, in addition to the potential use of fucoxanthin as a promising compound for human inflammation-related diseases.

Use of Natural Products in Asthma Treatment

Asthma, a disease classified as a chronic inflammatory disorder induced by airway inflammation, is triggered by a genetic predisposition or antigen sensitization. Drugs currently used as therapies present disadvantages such as high cost and side effects, which compromise the treatment compliance. Alternatively, traditional medicine has reported the use of natural products as alternative or complementary treatment. The aim of this review was to summarize the knowledge reported in the literature about the use of natural products for asthma treatment. The search strategy included scientific studies published between January 2006 and December 2017, using the keywords "asthma," "treatment," and "natural products." The inclusion criteria were as follows: (i) studies that aimed at elucidating the antiasthmatic activity of natural-based compounds or extracts using laboratory experiments (in vitro and/or in vivo); and (ii) studies that suggested the use of natural products in asthma treatment by elucidation of its chemical composition. Studies that (i) did not report experimental data and (ii) manuscripts in languages other than English were excluded. Based on the findings from the literature search, aspects related to asthma physiopathology, epidemiology, and conventional treatment were discussed. Then, several studies reporting the effectiveness of natural products in the asthma treatment were presented, highlighting plants as the main source. Moreover, natural products from animals and microorganisms were also discussed and their high potential in the antiasthmatic therapy was emphasized. This review highlighted the importance of natural products as an alternative and/or complementary treatment source for asthma treatment, since they present reduced side effects and comparable effectiveness as the drugs currently used on treatment protocols.

Assessment of Body Composition and Nutritional Risks in Young Ballet Dancers - The Bioelectrical Impedance Analysis

BACKGROUND

Young ballet dancers are at risk of health issues associated with altered nutritional status and of relative energy deficiency in sport compared to the general population.

AIM

To evaluate the nutritional status and body composition in ballet dancers.

MATERIALS AND METHODS

The study group consisted of 40 young ballet dancers (mean age 19.97 years). Height and weight were measured and body mass index was calculated in all subjects (mean BMI value 19.79 kg/m², SD: 2.051). Body composition was estimated using the bioelectrical impedance method.

RESULTS

The dancers' fat-free mass was 47.33 kg (SD: 5.064) and, on the average, body fat represented the 15.92% (SD: 16.91) of their body weight.

CONCLUSIONS

Ballet dancers, who usually show significantly lower BMI values compared to the general population, also displayed body fat values under the suggested range. Some screening for altered nutritional status should be performed. In addition, education programs should be recommended in young ballet dancers, in order to inform about energy and nutrition requirements for health and training and to prevent malnutrition-related problems.

A Microbiological, Toxicological, and Biochemical Study of the Effects of Fucoxanthin, a Marine Carotenoid, on Mycobacterium tuberculosis and the Enzymes Implicated in Its Cell Wall: A Link Between Mycobacterial Infection and Autoimmune Diseases

This study explored the antitubercular properties of fucoxanthin, a marine carotenoid, against clinical isolates of Mycobacterium tuberculosis (Mtb). Two vital enzymes involved in Mtb cell wall biosynthesis, UDP-galactopyranose mutase (UGM) and arylamine-N-acetyltransferase (TBNAT), were selected as drug targets to reveal the mechanism underlying the antitubercular effect of fucoxanthin. The obtained results showed that fucoxanthin showed a clear bacteriostatic action against the all Mtb strains tested, with minimum inhibitory concentrations (MIC) ranging from 2.8 to 4.1 µM, along with a good degree of selectivity index (ranging from 6.1 to 8.9) based on cellular toxicity evaluation compared with standard drug isoniazid (INH). The potent inhibitory actions of fucoxanthin and standard uridine-5’-diphosphate against UGM were recorded to be 98.2% and 99.2%, respectively. TBNAT was potently inactivated by fucoxanthin (half maximal inhibitory concentration (IC₅₀) = 4.8 µM; 99.1% inhibition) as compared to INH (IC₅₀ = 5.9 µM; 97.4% inhibition). Further, molecular docking approaches were achieved to endorse and rationalize the biological findings along with envisaging structure-activity relationships. Since the clinical evidence of the last decade has confirmed the correlation between bacterial infections and autoimmune diseases, in this study we have discussed the linkage between infection with Mtb and autoimmune diseases based on previous clinical observations and animal studies. In conclusion, we propose that fucoxanthin could demonstrate great therapeutic value for the treatment of tuberculosis by acting on multiple targets through a bacteriostatic effect as well as by inhibiting UGM and TBNAT. Such outcomes may lead to avoiding or decreasing the susceptibility to autoimmune diseases associated with Mtb infection in a genetically susceptible host.

Protective Effects of Fucoxanthin against Alcoholic Liver Injury by Activation of Nrf2-Mediated Antioxidant Defense and Inhibition of TLR4-Mediated Inflammation

Fucoxanthin (Fx) is a natural extract from marine seaweed that has strong antioxidant activity and a variety of other bioactive effects. This study elucidated the protective mechanism of Fx on alcoholic liver injury. Administration of Fx was associated with lower pathological effects in liver tissue and lower serum marker concentrations for liver damage induced by alcohol. Fx also alleviated oxidative stress, and lowered the level of oxides and inflammation in liver tissue. Results indicate that Fx attenuated alcohol-induced oxidative lesions and inflammatory responses by activating the nuclear factor erythrocyte-2-related factor 2 (Nrf2)-mediated signaling pathway and down-regulating the expression of the toll-like receptor 4 (TLR4)-mediated nuclear factor-kappa B (NF-κB) signaling pathway, respectively. Our findings suggest that Fx can be developed as a potential nutraceutical for preventing alcohol-induced liver injury in the future.

Extreme environments: microbiology leading to specialized metabolites

The prevalence of multidrug-resistant microbial pathogens due to the continued misuse and overuse of antibiotics in agriculture and medicine is raising the prospect of a return to the preantibiotic days of medicine at the time of diminishing numbers of drug leads. The good news is that an increased understanding of the nature and extent of microbial diversity in natural habitats coupled with the application of new technologies in microbiology and chemistry is opening up new strategies in the search for new specialized products with therapeutic properties. This review explores the premise that harsh environmental conditions in extreme biomes, notably in deserts, permafrost soils and deep-sea sediments select for micro-organisms, especially actinobacteria, cyanobacteria and fungi, with the potential to synthesize new druggable molecules. There is evidence over the past decade that micro-organisms adapted to life in extreme habitats are a rich source of new specialized metabolites. Extreme habitats by their very nature tend to be fragile hence there is a need to conserve those known to be hot-spots of novel gifted micro-organisms needed to drive drug discovery campaigns and innovative biotechnology. This review also provides an overview of microbial-derived molecules and their biological activities focusing on the period from 2010 until 2018, over this time 186 novel structures were isolated from 129 representatives of microbial taxa recovered from extreme habitats.

Immunomodulatory and Antioxidant Activities of Sulfated Polysaccharides from Laminaria ochroleuca, Porphyra umbilicalis, and Gelidium corneum

Seaweeds of the genera Laminaria, Gelidium, and Porphyra have been used in both food and non-food industries due to their unique properties and characteristic biological activity. This study assesses the antioxidant activity and immunomodulatory properties of the acidic polysaccharides extracted from Laminaria ochroleuca, Porphyra umbilicalis, and Gelidium corneum collected in the Atlantic coast of Tarifa (Cadiz, Spain). The proliferation of murine cell line RAW 264 decreased with increasing concentration of polysaccharides of the three algal species. The highest both antioxidant (25.69 μmol TE g-1 DW) and immunomodulatory activities were observed in the sulfated polysaccharides of L. ochroleuca compared to that of P. umbilicalis and G. corneum. Sulfated polysaccharides of L. ochroleuca presented high potential anticancer activity in cell lines of human colon cancer HTC-116 (IC50 = 0.44 mg mL-1), human malignant melanoma G-361 (IC50 = 5.42 mg mL-1), breast adenocarcinoma human MCF-7 (IC50 = 8.32 mg mL-1), and human leukemia U-937 (IC50 = 3.72 mg mL-1). It is concluded that metabolites of L. ochroleuca can offer significant advantages for the pharmaceutical industry, particularly when macrophage activation is required.

Fucoxanthin-An Antibacterial Carotenoid

Fucoxanthin is a carotenoid produced by brown algae and diatoms. This compound has several biological properties such as antioxidant, anti-obesity, anti-diabetic, anticancer, and antimicrobial activities. Unfortunately, until now the latter effect has been poorly confirmed. The aim of this study was an evaluation of fucoxanthin activity against 20 bacterial species. Antimicrobial effect of fucoxanthin was determined by using the agar disc-diffusion and micro-dilution methods. The studied carotenoid acted against 13 bacteria growing in aerobic conditions. It was observed to have a significantly stronger impact on Gram-positive than Gram-negative bacteria. Mean zones of growth inhibition (ZOIs) for Gram-positive bacteria ranged between 9.0 and 12.2 mm, while for Gram-negative were from 7.2 to 10.2 mm. According to the agar disc-diffusion method, the highest activity of fucoxanthin was exhibited against Streptococcus agalactiae (mean ZOI 12.2 mm), Staphylococcus epidermidis (mean ZOI 11.2 mm), and Staphylococcus aureus (mean ZOI 11.0 mm), and in the microdilution test towards Streptococcus agalactiae with the minimal inhibitory concentration (MIC) of 62.5 µg/mL. On the other hand, fucoxanthin was not active against strict anaerobic bacteria.

Omega-3 Polyunsaturated Fatty Acids: Benefits and Endpoints in Sport

The influence of nutrition has the potential to substantially affect physical function and body metabolism. Particular attention has been focused on omega-3 polyunsaturated fatty acids (n-3 PUFAs), which can be found both in terrestrial features and in the marine world. They are responsible for numerous cellular functions, such as signaling, cell membrane fluidity, and structural maintenance. They also regulate the nervous system, blood pressure, hematic clotting, glucose tolerance, and inflammatory processes, which may be useful in all inflammatory conditions. Animal models and cell-based models show that n-3 PUFAs can influence skeletal muscle metabolism. Furthermore, recent human studies demonstrate that they can influence not only the exercise and the metabolic response of skeletal muscle, but also the functional response for a period of exercise training. In addition, their potential anti-inflammatory and antioxidant activity may provide health benefits and performance improvement especially in those who practice physical activity, due to their increased reactive oxygen production. This review highlights the importance of n-3 PUFAs in our diet, which focuses on their potential healthy effects in sport.

Food-Related Atrial Fibrillation? The Potential Role of Biogenic Amines in “Nutri-Arrhythmias” Genesis

Atrial fibrillation (AF) is the most common type of arrhythmia: a disorganized electrical atrial activity leading to irregular ventricular beats. Its most common risk factors include high blood pressure, congenital and valvular heart diseases, aging, heart failure and coronary heart diseases. Other risk factors include excessive alcohol intake, tobacco smoking, diabetes mellitus and thyrotoxicosis. However, many cases are not associated with any of these risk factors: probably, in these patients, immunological, functional and even dietary mechanisms may be responsible to induce cardiac arrhythmias. Several studies have focused on immunological and neurohumoral mechanisms; however, little information is available about the potential relationship between dietary patterns and atrial fibrillation episodes. This case report describes a potential correlation between biogenic amines in ingested food and recurrent atrial fibrillation onset in a 61-years old man in absence of a remarkable clinical history and of the most common risk factors. The nutritional team instituted a food protocol: a low calories diet and eliminating biogenic amines-rich foods. During the follow-up (16 months), there was a noticeable weight loss and no arrhythmic episodes happened again. This clinical case provides evidence for a possible new relationship between some kinds of food and heart conduction (defining the very novel field of arrhythmogenic foods and of “nutri-arrhythmias”), recognizing biogenic amines-rich foods abuse as the potential trigger and substrate for atrial fibrillation. Therefore, we suggested that clinical history in patients with new onset AF should also include questions concerning the ingestion of histamine-rich foodstuffs (or other amines-rich food) and alcohol consumption: their effects may result to be synergistic in the alteration of cardiac rhythm and may explain the recurrence of an unexplained atrial fibrillation.

Dietary polysaccharide-rich extract from Eucheuma cottonii modulates the inflammatory response and suppresses colonic injury on dextran sulfate sodium-induced colitis in mice

Inflammatory bowel disease (IBD) is a known medical burden in most developed countries and a significant cause of morbidity. The IBD label includes Crohn's disease (CD) and ulcerative colitis (UC). Pharmacological and surgical intervention are the two main management approaches for IBD. Some drugs have been developed for IBD therapy, but accessibility is limited due to high costs. Furthermore, these agents have demonstrated inactivity over long-term treatment courses. Therefore, an urgent need is present for new treatment options that are safe, able to sustain clinical remission, and improve mucosal gut healing. Seaweed has received much attention in the pharmacological field owing to its various biomedical properties, including the prolongation of blood clotting time, as well as antitumor, anti-inflammation, and antioxidant effects. This study therefore aimed to examine the effects of a dietary polysaccharide-rich extract obtained from Eucheuma cottonii (EC) on a model of colitis. Colitis was induced in male BALB/c mice by the administration of 2.5% (w/v) dextran sulfate sodium (DSS) for 7 days. DSS-induced mice were treated with either one of three different doses of EC extracts (0.35, 0.70, and 1.75 g/kg body weight) or curcumin as a positive control (0.10 g/kg). Mice were sacrificed post-treatment and blood samples were collected. The disease activity index (DAI) and inflammatory cytokine levels (tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, IL-10) were measured. After treatment for 7 days, EC extract administration protected against weight loss and decreased the colon weight per length ratio. EC extract administration also decreased pro-inflammatory cytokine expression, increased IL-10 levels, and reduced colonic damage. Therefore, a dietary polysaccharide-rich extract from E. cottonii reduced DSS-induced bowel inflammation, thereby becoming a promising candidate for the treatment of colitis.

Inhibitory effect of salvianolic acid on inflammatory mediators of rats with collagen-induced rheumatoid arthritis

The aim of this study was to investigate the inhibitory effect of salvianolic acid on inflammatory mediators of rats with collagen-induced rheumatoid arthritis (RA). Thirty rats were randomly divided into the normal control group, collagen-induced arthritis model group (CIA model group) and drug group (Salvianolic Acid-CIA group). In the model group, the CIA models were established through intradermal injection of collagen emulsion at the toes. At 3 weeks after the model establishment, grouped drug administration was conducted, of which salvianolic acid was given by gavage to Salvianolic Acid-CIA group. The degrees of joint swelling of each group of rats were recorded. Enzyme-linked immunosorbent assay (ELISA) was applied to detect the levels of relevant inflammatory mediators, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to measure the messenger RNA (mRNA) expression levels of serum necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and prostaglandin E2 (PGE2), and hematoxylin and eosin staining was utilized to detect the pathological characteristics of the synovial tissues. After the establishment of models, the ankle joint swelling degree of rats in the model group was more obvious compared with that in the normal control group (P<0.01). After 3 weeks of drug administration, the ankle joint swelling degree of rats in the Salvianolic Acid-CIA group was alleviated compared with that in the model group (P<0.05). The contents of TNF-α, IL-6 and PGE2 in Salvianolic Acid-CIA group were obviously lower than those in the model group (P<0.01). The mRNA expression levels of TNF-α, IL-6 and PGE2 in the Salvianolic Acid-CIA group were markedly lower than those in the model group. The hyperemia of rat synovial tissues in Salvianolic Acid-CIA group was obviously relieved compared with that in the CIA model group. In conclusion, the models of CIA rats are successfully established, and the results show salvianolic acid has an inhibitory effect on the RA of CIA model rats and can significantly inhibit the expression levels of relevant inflammatory mediators.

Cyanobacterial pigments: Perspectives and biotechnological approaches

Cyanobacteria are the oxygenic photosynthesis performing prokaryotes and show a connecting link between plastids of eukaryotic autotrophs and prokaryotes. A variety of pigments, like chlorophyll, carotenoids and phycobiliproteins which exhibit different colors are present in cyanobacteria. Increasing consciousness about the harmful effects of synthetic or chemical dyes encouraged people to give more preference towards the usage of natural products, such as plant or microbial-derived colors in food and cosmetics. That is why cyanobacteria are exploited as a source of natural colors and have high commercial value in many industries. This review mainly focuses on different cyanobacterial pigments, their applications and modern biotechnological approaches such as genetic engineering, systems biology to enhance the production of biopigments for their potential use in pharmaceuticals, food, research, and cosmetics industries.

Phyto-mediated synthesis of silver nanoparticles using fucoidan isolated from Spatoglossum asperum and assessment of antibacterial activities

The present study was aimed to investigate the antibacterial efficacy of fucoidan mediated silver nanoparticles (Fu-AgNPs) synthesized from Spatoglossum asperum. The synthesized Fu-AgNPs were characterized by UV-visible, Field emission - scanning electron microscope (FE-SEM), Tranmission electron microscope (TEM), X-ray diffraction (XRD), Selected area electron diffraction (SAED) pattern, Energy-dispersive X-ray spectroscopy (EDAX), Fourier transform infrared spectroscopy (FT-IR), Dynamic light scattering (DLS) and Zeta potential analysis. The UV-visible spectrum of Fu-AgNPs exhibited a characteristic surface plasmon resonance (SPR) peak at 440 nm. The electron microscopic results revealed that the nanoparticles were spherical to oval in shape and are found to be 20 to 46 nm. Altogether the X-ray diffraction analysis showed that the Fu-AgNPs were crystalline in nature. The FT-IR spectrum confirmed the existence of CC stretching vibration of aromatic compounds and sulfated groups of fucoidan plays a major role in the synthesis of Fu-AgNPs. The biosynthesized Fu-AgNPs shows potential antibacterial activity against Klebsiella pneumoniae in agar bioassay, disk diffusion, reactive oxygen species, protein leakage and confocal laser scanning microscopy assays. Furthermore, Artemia toxicity assay results showed less mortality (3.3 ± 0.8%) even at higher concentration of Fu-AgNPs. Therefore, Fu-AgNPs can be effectively used as an antibacterial agent in the pharmaceutical fields.

Neuroprotective role of fucoxanthin against cerebral ischemic/reperfusion injury through activation of Nrf2/HO-1 signaling

In the present study, an attempt was made to determine whether administration of fucoxanthin could attenuate cerebral ischemic/reperfusion (I/R) injury and its possible mechanisms using an in vivo middle cerebral artery occlusion (MCAO) model and an in vitro oxygen-glucose deprivation and reoxygenation (OGD/R) model. Fucoxanthin was intragastrically administrated in different doses (30 mg/kg, 60 mg/kg, and 90 mg/kg, respectively) to the rats 1 h before MCAO induction. The neurological function, infarct area and brain water content of rats were then evaluated. Rat cortical neuron were pretreated with different doses of fucoxanthin (5 μM, 10 μM, and 20 μM) and then subjected to OGD/R. Expression levels of proteins in the brain tissues and cultured cells were determined by western blotting. Our results demonstrated that fucoxanthin pretreatment improved the neurologic deficit score, lowered the infarct volume and reduced the expression of apoptosis-associated proteins in brain tissues. In addition, fucoxanthin also suppresses OGD/R-induced apoptosis and ROS accumulation in cultured neurons. Furthermore, we found that fucoxanthin could significantly activate the Nrf2/HO-1 signaling through inducing Nrf2 nuclear translocation with enhanced HO-1 expression, and Nrf2 knockdown obviously abrogated the beneficial role of fucoxanthin in OGD/R-treated neurons. These findings suggested that fucoxanthin could be exploited as a therapeutic target for protecting neurons from cerebral I/R injury.

Phytochemical Analysis and Evaluation of the Antioxidant, Anti-Inflammatory, and Antinociceptive Potential of Phlorotannin-Rich Fractions from Three Mediterranean Brown Seaweeds

Phlorotannins, phenolic compounds produced exclusively by seaweeds, have been reported to possess various pharmacological properties. However, there have been few works on these compounds from Mediterranean seaweeds. In this study, we investigated the phytochemical analysis and pharmacological potential of phlorotannin-rich fractions from three brown seaweeds collected along the Tunisia coast: Cystoseira sedoides (PHT-SED), Cladostephus spongeosis (PHT-CLAD), and Padina pavonica (PHT-PAD). Phytochemical determinations showed considerable differences in total phenolic content (TPC) and phlorotannin content (PHT). The highest TPC level (26.45 mg PGE/g dry material (Dm)) and PHT level (873.14 μg PGE/g Dm) were observed in C. sedoides. The antioxidant properties of these three fractions assessed by three different methods indicated that C. sedoides displayed the highest total antioxidant activity among the three species (71.30 mg GAE/g Dm), as well as the free radical scavenging activity with the lowest IC50 value in both DPPH (27.7 μg/mL) and ABTS (19.1 μg/mL) assays. Furthermore, the pharmacological screening of the anti-inflammatory potential of these fractions using in vivo models, in comparison to reference drugs, established a remarkable activity of PHT-SED at the dose of 100 mg/kg; the inhibition percentages of ear edema in mice model and paw edema in rats model were of 82.55 and 81.08%, respectively. The content of malondialdehyde (MDA) in liver tissues has been quantified, and PHT-SED was found to remarkably increase the lipid peroxidation in rat liver tissues. In addition, in two pain mice models, PHT-SED displayed a profound antinociceptive activity at 100 mg/kg and has proved a better analgesic activity when used in combination with the opioid drug, tramadol.

Antioxidative and anti-inflammatory pyranoids and isochromenyl analogues from Corbiculid bivalve clam, Villorita cyprinoides

Bivalve black clam, Villorita cyprinoides is traditional seafood in Southwestern coast of Arabian Sea. In this study, bioactivity-guided purification of ethyl acetate:methanol extract of black clam was carried out. Two irregular meroterpenoids {tetrahydro-3-methoxy-5-((E)-8,12-dimethyloct-8-enyl)-pyran-2-one (1) and dihydro-5-(8-(9,12-dihydro-8-methyl-11-propyl-2H-pyran-8-yl)-ethyl)-furan-2(3H)-one (2)} and two hexahydro-isochromenyl-meroterpenoids (3-4) were identified. The structures were characterized by detailed spectroscopy and their antioxidant/anti-inflammatory potentials were evaluated. Compound 2 registered significantly greater 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging ability (IC₅₀ <0.65 mg/mL) than other analogues (IC₅₀ ≥0.70 mg/mL). Ferrous ion (Fe²⁺) chelating ability was higher for 1-2 (IC₅₀ ∼0.84 mg/mL) than α-tocopherol (IC₅₀ 0.89 mg/mL). The 5-lipoxygenase inhibitory potential of furano-meroterpenoid analogue, 2 (IC₅₀ 0.76 mg/mL) was greater than other compounds (IC₅₀ >0.90 mg/mL). An optimum hydrophobic-hydrophilic balance of furano-meroterpenoid and lesser steric bulk manifested towards its greater bioactivities compared to other compounds. These anti-inflammatory and antioxidant leads could be used as potential functional food components.