Hepatoprotective effect of a fucoidan extract from Sargassum fluitans Borgesen against CCl4-induced toxicity in rats

Medicinal herbs and their metabolites with biological potential to protect and combat liver toxicity and its disorders: A review

The liver is an essential organ that helps the body with immunity, metabolism, and detoxification, among other functions. Worldwide, liver illnesses are a leading cause of mortality and disability. There are few effective treatment choices, but they frequently have unfavorable side effects. Investigating the potential of medicinal plants and their bioactive phytoconstituents in the prevention and treatment of liver disorders has gained more attention in recent years. An assessment of the hepatoprotective potential of medicinal plants and their bioactive secondary metabolites is the goal of this thorough review paper. To determine their hepatoprotective activity, these plants were tested against liver toxicity artificially induced in rats, mice and rabbits by chemical agents such as carbon tetrachloride (CCl4), paracetamol (PCM), thioacetamide (TAA), N-nitrosodiethylamine, d-galactosamine/lipopolysaccharide, antitubercular medicines (rifampin, isoniazid) and alcohol. To find pertinent research publications published between 1989 and 2022, a comprehensive search of electronic bibliographic databases (including Web of Science, SpringerLink, ScienceDirect, Google Scholar, PubMed, Scopus, and others) was carried out. The investigation comprised 203 plant species from 81 families in total. A thorough discussion was mentioned regarding the hepatoprotective qualities of plants belonging to several families, such as Fabaceae, Asteraceae, Lamiaceae, and Euphorbiaceae. The plant groups Asteraceae and Fabaceae were the most frequently shown to have hepatoprotective properties. The phytochemical constituents namely flavonoids, phenolic compounds, and alkaloids exhibited the highest frequency of hepatoprotective action. Also, some possible mechanism of action of some active constituents from medicinal plants was discussed in brief which were found in some studies. In summary, the information on medicinal plants and their potentially hepatoprotective bioactive phytoconstituents has been consolidated in this review which emphasizes the importance of further research to explore the efficacy and safety of these natural remedies for various liver ailments.

Bilobalide attenuates lipopolysaccharide‑induced HepG2 cell injury by inhibiting TLR4‑NF‑κB signaling via the PI3K/Akt pathway

Inflammation is involved in the pathological process underlying a number of liver diseases. Bilobalide (BB) is a natural compound from Ginkgo biloba leaves that was recently demonstrated to exert hepatoprotective effects by inhibiting oxidative stress in the liver cancer cell line HepG2. The anti-inflammatory activity of BB has been reported in recent studies. The major objective of the present study was to investigate whether BB could attenuate inflammation-associated cell damage. HepG2 cells were cultured with lipopolysaccharide (LPS) and BB, and cell damage was evaluated by measuring cell viability using MTT assay. The activity of the NF-κB signaling pathway was assessed by measuring the levels of IκBα, NF-κB p65, phosphorylated (p)-IκBα, p-p65, p65 DNA-binding activity and inflammatory cytokines IL-1β, IL-6 and TNF-α. A toll-like receptor (TLR)4 inhibitor (CLI-095) was used to detect the involvement of TLR4 in cell injury caused by LPS. In addition, the PI3K/Akt inhibitor LY294002 was applied to explore the involvement of the PI3K/Akt axis in mediating the effects of BB. The results demonstrated that LPS induced HepG2 cell injury. LPS also elevated the levels of p-IκBα, p-p65, p65 DNA-binding activity and inflammatory cytokines. However, CLI-095 significantly attenuated the LPS-induced cell damage and inhibited the activation of NF-κB signaling. BB also dose-dependently attenuated the LPS-induced cell damage, activation of NF-κB signaling and TLR4 overexpression. Furthermore, it was observed that LY294002 diminished the cytoprotective effects of BB on cell injury, TLR4 expression and NF-κB activation. These findings indicated that BB could attenuate LPS-induced inflammatory injury to HepG2 cells by regulating TLR4-NF-κB signaling.

Baicalein attenuates bleomycin-induced lung fibroblast senescence and lung fibrosis through restoration of Sirt3 expression

CONTEXT

Fibroblast senescence was reported to contribute to the pathological development of idiopathic pulmonary fibrosis (IPF), and baicalein is reported to attenuate IPF.

OBJECTIVE

This study explores whether baicalein attenuates lung fibrosis by regulating lung fibroblast senescence.

MATERIALS AND METHODS

Institute of Cancer Research (ICR) mice were randomly assigned to control, bleomycin (BLM), baicalein and BLM + baicalein groups. Lung fibrosis was established by a single intratracheal dose of BLM (3 mg/kg). The baicalein group received baicalein orally (100 mg/kg/day). Sirtuin 3 (Sirt3) siRNA (50 μg) was injected through the tail vein once a week for 2 weeks to explore its effect on the anti-pulmonary fibrosis of baicalein.

RESULTS

BLM-treated mice exhibited obvious lung fibrosis and fibroblast senescence by showing increased levels of collagen deposition (27.29% vs. 4.14%), hydroxyproline (208.05 vs. 40.16 ng/mg), collagen I (25.18 vs. 9.15 μg/mg), p53, p21, p16, MCP-1, PAI-1, TNF-α, MMP-10 and MMP-12 in lung tissues, which were attenuated by baicalein. Baicalein also mitigated BLM-mediated activation of TGF-β1/Smad signalling pathway. Baicalein restored the BLM-induced downregulation of Sirt3 expression in lung tissues and silencing of Sirt3 abolished the inhibitory role of baicalein against BLM-induced lung fibrosis, fibroblast senescence and activation of TGF-β1/Smad signalling pathway.

CONCLUSIONS

Baicalein preserved the BLM-induced downregulation of lung Sirt3 expression, and thus the suppression of TGF-β1/Smad signalling pathway and lung fibrosis, which might provide an experimental basis for treatment of IPF.

Fucoidan alleviates the hepatorenal syndrome through inhibition organic solute transporter α/β to reduce bile acids reabsorption

The high levels of bile acids are a critical factor in hepatorenal syndrome. Organic solute transporter α/β (Ostα/β) participate in bile acids reabsorption in the kidney. Fucoidan has the great potential in protecting against liver and kidney injury. However, whether Ostα/β increase bile acids reabsorption in bile duct ligature (BDL)-induced hepatorenal syndrome and the blockade of fucoidan are still not clear. Male mice that received BDL were given to fucoidan (at 12.5, 25 and 50 ​mg/kg) through intraperitoneal injection once daily for three weeks. The serum, liver and kidney samples of these experimental mice were collected to carry out biochemical, pathological and Western blot analysis. In this study, fucoidan significantly lowered serum activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), decreased serum levels of uric acid, creatinine and uric nitrogen, restored the deregulation of the renal urate transporter 1 (URAT1), organic anion transporter 1 (OAT1), and organic cation/carnitine transporter 1/2 (OCTN1/2), consistence with alleviation BDL-induced liver and kidney dysfunction, inflammation and fibrosis in mice. Furthermore, fucoidan significantly hampered Ostα/β and reduced bile acids reabsorption in BDL-induced mice, protected against AML12 and HK-2 ​cells injury in vitro. These results demonstrate that fucoidan alleviates BDL-induced hepatorenal syndrome through inhibition Ostα/β to reduce bile acids reabsorption in mice. Therefore, suppression of Ostα/β by fucoidan may be a novel strategy for attenuating hepatorenal syndrome.

Bioactive Compounds from Brown Algae Alleviate Nonalcoholic Fatty Liver Disease: An Extensive Review

Nonalcoholic fatty liver disease (NAFLD) is one of the most prevalent chronic liver diseases. The increasing NAFLD incidences are associated with unhealthy lifestyles. Currently, there are no effective therapeutic options for NAFLD. Thus, there is a need to develop safe, efficient, and economic treatment options for NAFLD. Brown algae, which are edible, contain abundant bioactive compounds, including polysaccharides and phlorotannins. They have been shown to ameliorate insulin resistance, as well as hepatic steatosis, and all of these biological functions can potentially alleviate NAFLD. Accumulating reports have shown that increasing dietary consumption of brown algae reduces the risk for NAFLD development. In this review, we summarized the animal experiments and clinical proof of brown algae and their bioactive compounds for NAFLD treatment within the past decade. Our findings show possible avenues for further research into the pathophysiology of NAFLD and brown algae therapy.

A Review on Fucoidan Structure, Extraction Techniques, and Its Role as an Immunomodulatory Agent

Functional ingredients for human health have recently become the focus of research. One such potentially versatile therapeutic component is fucose-containing sulfated polysaccharides (FCSPs), referred to as fucoidans. The exploitation of marine brown algae provides a rich source of FCSPs because of their role as a structural component of the cell wall. Fucoidans are characterized by a sulfated fucose backbone. However, the structural characterization of FCSPs is impeded by their structural diversity, molecular weight, and complexity. The extraction and purification conditions significantly influence the yield and structural alterations. Inflammation is the preliminary response to potentially injurious inducements, and it is of the utmost importance for modulation in the proper direction. Improper manipulation and/or continuous stimuli could have detrimental effects in the long run. The web of immune responses mediated through multiple modulatory/cell signaling components can be addressed through functional ingredients, benefiting patients with no side effects. In this review, we attempted to address the involvement of FCSPs in the stimulation/downregulation of immune response cell signaling. The structural complexity and its foremost influential factor, extraction techniques, have also attracted attention, with concise details on the structural implications of bioactivity.

Anti-Dengue Activity of ZnO Nanoparticles of Crude Fucoidan from Brown Seaweed S.marginatum

Dengue fever is a rapidly spreading infection that affects people all over the tropics and subtropics, posing a significant public health threat. The brown seaweed Stoechospermum marginatum was found all over the world, from South Africa (Indian Ocean) to Australia (Pacific Ocean), among other places. In India, it is only available along the coast of the Bay of Bengal, which is a small region. Various metal oxides were proved to be successful in the formation of nanoparticles and zinc is one among them. In this present study, an attempt was made to study the anti-dengue activity of green synthesized zinc oxide nanoparticles of crude fucoidan isolated from brown seaweed S. marginatum. The fucoidan was isolated from the seaweed by acid extraction method and then characterized by UV, HPLC, and Fourier Transform Infra-Red (FT-IR) Spectroscopy. Then it was biosynthesized into ZnO nanoparticles and characterized by SEM-EDAX analysis. The results showed the formation of fucoidans and SEM studies showed the crystalline nature of the synthesized nanoparticles. The size of nanoparticles was in the range of 80-126 nm. The synthesized nanoparticles were tested with the C6/36 cell line and it was shown 99.09% of anti-dengue activity against the tested cell line. As an antiviral agent, the ZnO nanoparticles of fucoidans have been shown to be an excellent lead molecule for the treatment of dengue fever.

Antifibrotic effect of brown algae-derived fucoidans on osteoarthritic fibroblast-like synoviocytes

Synovial fibrosis is a pathological process which contributes to joint pain and stiffness in several musculoskeletal disorders. Fucoidans, sulfated polysaccharides found in brown algae, have recently emerged as promising therapeutic agents. Despite the increasing amount of evidence suggesting the protective role of fucoidans in different experimental approaches of human fibrotic disorders, the effect of these sulfated polysaccharides on synovial fibrosis has not been investigated yet. By an in vitro experimental approach in fibroblast-like synoviocytes, we detected that fucoidans inhibit their differentiation into myofibroblasts with tumor cell-like characteristics and restore apoptosis. Composition and structure of fucoidan appear to be critical for the detected activity. Furthermore, protective effects of these sulfated polysaccharides are mediated by upregulation of nitric oxide production and modulation of TGF-β/smad pathway. Altogether, our results support the use of fucoidans as therapeutic compounds in the treatment of the fibrotic processes involved in rheumatic pathologies.

Health benefits and potential applications of fucoidan (FCD) extracted from brown seaweeds in aquaculture: An updated review

Nowadays, the application of immunomodulators in aquaculture has become of an urgent need because of high incidence of fish and shrimp diseases. For a long time, researchers have paid great interest to find suitable, relatively economical, and environmentally safe immunostimulant products to be used either as feed or water additives to boost immunity and increase the resistance of fish and shrimp against the challenging pathogens. Probiotics, prebiotics, synbiotics, phytobiotics, herbal extracts, microalgae, macroalgae, and essential oils have been extensively evaluated. Brown seaweeds (Phaeophyceae) are a large group of multi-cellular macroalgae that are widely distributed in marine aquatic environments. They are abundant in several bioactive sulfated polysaccharides known as fucoidan (FCD). Research studies demonstrated the beneficial functions of FCD in human medicine because of its immunomodulating, antioxidant, anti-allergic, antitumor, antiviral, anti-inflammatory, and hepatoprotective effects. In aquaculture, several researchers have tested the benefits and potential applications of FCD in aquafeed. This literature review provides an updated information and key references of research studies that focused principally on using FCD in aquaculture. Its effects on growth, intestinal health, antioxidant capacity, and immune responses of several finfish and shellfish species will be discussed. This review paper will also highlight the potential efficacy and mechanisms of FCD in the modulation of toxicity signs and increasing the resistance of fish and shrimp against bacterial and viral infections. Hence, this contribution will be valuable to maintain aquaculture sustainability and to improve the health and welfare of farmed fish and shrimp.

Fucoidan Modulated Oxidative Stress and Caspase-3 mRNA Expression Induced by Sulfoxaflor in the Brain of Mice

The current study aimed to investigate the role of fucoidan in the oxidative and apoptotic effects of sulfoxaflor, a neonicotinoid sulfoximine insecticide, in the brain of Swiss albino mice (Mus musculus). Sulfoxaflor and fucoidan were administered to mice at doses of 15 mg/kg/day (1/50 oral LD50) and 50 mg/kg/day, respectively, by oral gavage for 24 h or 7 days. The tGSH, TBARS and protein levels, and GPx, GR, and GST enzyme activities were determined by spectrophotometric methods. Caspase-3 gene expression level was determined by RT-PCR. Data analysis showed that brains of sulfoxaflor-treated mice exhibited higher TBARS levels; GPx, GR, and GST enzyme activities; and caspase-3 expression levels, as well as lower levels of tGSH. Co-administration of fucoidan and sulfoxaflor reduced the TBARS levels, increased tGSH levels, and increased GPx, GR, and GST enzyme activities. Fucoidan also decreased the sulfoxaflor-induced up-regulation of caspase-3 mRNA expression. Results of the present study showed that sulfoxaflor caused oxidative stress by inducing lipid peroxidation and altering GSH-dependent antioxidants in the brain of mice. In addition, sulfoxaflor may trigger apoptotic cell death shown by the up-regulation of caspase-3. Fucoidan treatment modulated all the aforementioned alterations in the brain of mice. It was concluded that fucoidan might have antioxidant effects that support the GSH-dependent antioxidant system and can play a modulator role in oxidative stress and caspase-3 expression in the brain of sulfoxaflor treated-mice.

Fucoidan supplementation modulates hepato-renal oxidative stress and DNA damage induced by aflatoxin B1 intoxication in rats

Aflatoxins are a common food contaminant of global concern. Aflatoxin B₁ (AFB₁) intoxication is associated with serious health hazards. Recently, fucoidan (FUC) has gained much attention from pharmaceutical industry due to its promising therapeutic effects. The impacts of FUC on AFB₁-induced liver and kidney injures have not been sufficiently addressed. This research was conducted to evaluate the ameliorative effect of FUC in AFB1-induced hepatorenal toxicity model in rats over 14 days. Five groups were assigned; control, FUC (200 mg/kg/day, orally), AFB₁ (50 μg/kg, i.p.), and AFB₁ plus a low or high dose of FUC. AFB₁ induced marked hepatorenal injury elucidated by substantial alterations in biochemical tests and histological pictures. The oxidative distress instigated by AFB₁ enhanced production of malondialdehyde (MDA) and nitric oxide (NO) along with reduction in the reduced-glutathione (GSH), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and catalase (CAT) activities. DNA damage in the liver and kidney tissues has been demonstrated by overexpression of proliferating cell nuclear antigen (PCNA). Unambiguously, FUC consumption alleviates the AFB₁-induced mitochondrial dysfunction, oxidative harm, and apoptosis. These ameliorated effects are proposed to be attributed to fucoidan's antioxidant and anti-apoptotic activities. Our results recommend FUC supplementation to food because it exerts both preventive and therapeutic effects against AFB₁-induced toxicity.

Current developments in the oral drug delivery of fucoidan

Fucoidan is well known to have various biological functions and is often investigated for pharmaceutical applications. Several studies have been conducted on clinical applications of fucoidan in recent years, especially regarding its oral drug delivery. Although fucoidan has shown promising results in various dosage forms, its potential applications as a dietary supplement have been demonstrated, and recent studies show that oral administration of fucoidan is preferred. However, the focus on the oral delivery of fucoidan in recent studies has caused its potency in therapy to be understudied. This review aims to provide results on the promising fucoidan activity by oral administration with in vivo studies. In addition to using it as an active ingredient, the utilization of fucoidan as an excipient in oral drug delivery systems will be discussed. An overview of fucoidan administration by oral delivery in recent promising studies will provide a direction for further investigations in clinical applications, particularly for fucoidan, which has a broad spectrum of bioactive properties.

The Structural Characteristics of Seaweed Polysaccharides and Their Application in Gel Drug Delivery Systems

In recent years, researchers across various fields have shown a keen interest in the exploitation of biocompatible natural polymer materials, especially the development and application of seaweed polysaccharides. Seaweed polysaccharides are a multi-component mixture composed of one or more monosaccharides, which have the functions of being anti-virus, anti-tumor, anti-mutation, anti-radiation and enhancing immunity. These biological activities allow them to be applied in various controllable and sustained anti-inflammatory and anticancer drug delivery systems, such as seaweed polysaccharide-based nanoparticles, microspheres and gels, etc. This review summarizes the advantages of alginic acid, carrageenan and other seaweed polysaccharides, and focuses on their application in gel drug delivery systems (such as nanogels, microgels and hydrogels). In addition, recent literature reports and applications of seaweed polysaccharides are also discussed.

Fucoidan: Biological Activity in Liver Diseases

Fucoidan is a type of polysaccharide rich in sulfuric acid groups and is mainly found in brown algae. Due to its extensive biological activities, such as anticoagulant, antitumor, antithrombotic, antiviral, anti-oxidant and enhancing immune function, fucoidan has gradually become a research hotspot. Under the scientific guidance of modern medical theory, fucoidan and its mechanism in oxidative stress, carbohydrate and lipid metabolism, inflammatory response, tumor proliferation, and metastasis have become a new research direction and an important basis as an effective liver protection drug. In this paper, we discuss the important role of fucoidan in viral hepatitis, liver fibrosis, liver cancer, nonalcoholic fatty liver and liver injury induced by drugs and ischemia and briefly discuss its underlying mechanism. We supplement the theoretical basis for its clinical application and provide effective targets for the development of follow-up dominant drugs.

Immunomodulatory and Anti-Inflammatory Effects of Fucoidan: A Review

Inflammation is the initial response of the immune system to potentially harmful stimuli (e.g., injury, stress, and infections). The process involves activation of macrophages and neutrophils, which produce mediators, such as nitric oxide (NO), prostaglandin E2 (PGE2), pro-inflammatory and anti-inflammatory cytokines. The pro-inflammatory cytokines interleukin-1β (IL-1β), interleukin 6 (IL-6), and tumor necrosis factor-α (TNF-α) are considered as biomarkers of inflammation. Even though it occurs as a physiological defense mechanism, its involvement in the pathogenesis of various diseases is reported. Rheumatoid arthritis, inflammatory bowel disease, Alzheimer's disease, and cardiovascular diseases are only a part of the diseases, in which pathogenesis the chronic inflammation is involved. Fucoidans are complex polysaccharides from brown seaweeds and some marine invertebrates, composed mainly of L-fucose and sulfate ester groups and minor amounts of neutral monosaccharides and uronic acids. Algae-derived fucoidans are studied intensively during the last years regarding their multiple biological activities and possible therapeutic potential. However, the source, species, molecular weight, composition, and structure of the polysaccharides, as well as the route of administration of fucoidans, could be crucial for their effects. Fucoidan is reported to act on different stages of the inflammatory process: (i) blocking of lymphocyte adhesion and invasion, (ii) inhibition of multiple enzymes, and (iii) induction of apoptosis. In this review, we focused on the immunemodulating and anti-inflammatory effects of fucoidans derived from macroalgae and the models used for their evaluation. Additional insights on the molecular structure of the compound are included.

Potential Beneficial Actions of Fucoidan in Brain and Liver Injury, Disease, and Intoxication-Potential Implication of Sirtuins

Increased interest in natural antioxidants has brought to light the fucoidans (sulfated polysaccharides present in brown marine algae) as highly valued nutrients as well as effective and safe therapeutics against several diseases. Based on their satisfactory in vitro antioxidant potency, researchers have identified this molecule as an efficient remedy for neuropathological as well as metabolic disorders. Some of this therapeutic activity is accomplished by upregulation of cytoprotective molecular pathways capable of restoring the enzymatic antioxidant activity and normal mitochondrial functions. Sirtuin-3 has been discovered as a key player for achieving the neuroprotective role of fucoidan by managing these pathways, whose ultimate goal is retrieving the entirety of the antioxidant response and preventing apoptosis of neurons, thereby averting neurodegeneration and brain injuries. Another pathway whereby fucoidan exerts neuroprotective capabilities is by interactions with P-selectin on endothelial cells, thereby preventing macrophages from entering the brain proper. Furthermore, beneficial influences of fucoidan have been established in hepatocytes after xenobiotic induced liver injury by decreasing transaminase leakage and autophagy as well as obtaining optimal levels of intracellular fiber, which ultimately prevents fibrosis. The hepatoprotective role of this marine polysaccharide also includes a sirtuin, namely sirtuin-1 overexpression, which alleviates obesity and insulin resistance through suppression of hyperglycemia, reducing inflammation and stimulation of enzymatic antioxidant response. While fucoidan is very effective in animal models for brain injury and neuronal degeneration, in general, it is accepted that fucoidan shows somewhat limited potency in liver. Thus far, it has been used in large doses for treatment of acute liver injuries. Thus, it appears that further optimization of fucoidan derivatives may establish enhanced versatility for treatments of various disorders, in addition to brain injury and disease.

Pharmacological and natural products diversity of the brown algae genus Sargassum

Sargassum (F. Sargassaceae) is an important seaweed excessively distributed in tropical and subtropical regions.