Ameliorative effect of dieckol-enriched extraction from Laminaria japonica on hepatic steatosis induced by a high-fat diet via β-oxidation pathway in ICR mice

Chinese herbal medicines: The modulator of nonalcoholic fatty liver disease targeting oxidative stress

ETHNOPHARMACOLOGICAL RELEVANCE

Plants are a natural treasure trove; their secondary metabolites participate in several pharmacological processes, making them a crucial component in the synthesis of novel pharmaceuticals and serving as a reserve resource foundation in this process. Nonalcoholic fatty liver disease (NAFLD) is associated with the risk of progression to hepatitis and liver cancer. The "Treatise on Febrile Diseases," "Compendium of Materia Medica," and "Thousand Golden Prescriptions" have listed herbal remedies to treat liver diseases.

AIM OF THE REVIEW

Chinese herbal medicines have been widely used for the prevention and treatment of NAFLD owing to their efficacy and low side effects. The production of reactive oxygen species (ROS) during NAFLD, and the impact and potential mechanism of ROS on the pathogenesis of NAFLD are discussed in this review. Furthermore, common foods and herbs that can be used to prevent NAFLD, as well as the structure-activity relationships and potential mechanisms, are discussed.

METHODS

Web of Science, PubMed, CNKI database, Google Scholar, and WanFang database were searched for natural products that have been used to treat or prevent NAFLD in the past five years. The primary search was performed using the following keywords in different combinations in full articles: NAFLD, herb, natural products, medicine, and ROS. More than 400 research papers and review articles were found and analyzed in this review.

RESULTS

By classifying and discussing the literature, we obtained 86 herbaceous plants, 28 of which were derived from food and 58 from Chinese herbal medicines. The mechanism of NAFLD was proposed through experimental studies on thirteen natural compounds (quercetin, hesperidin, rutin, curcumin, resveratrol, epigallocatechin-3-gallate, salvianolic acid B, paeoniflorin, ginsenoside Rg1, ursolic acid, berberine, honokiol, emodin). The occurrence and progression of NAFLD could be prevented by natural antioxidants through several pathways to prevent ROS accumulation and reduce hepatic cell injuries caused by excessive ROS.

CONCLUSION

This review summarizes the natural products and routinely used herbs (prescription) in the prevention and treatment of NAFLD. Firstly, the mechanisms by which natural products improve NAFLD through antioxidant pathways are elucidated. Secondly, the potential of traditional Chinese medicine theory in improving NAFLD is discussed, highlighting the safety of food-medicine homology and the broader clinical potential of multi-component formulations in improving NAFLD. Aiming to provide theoretical basis for the prevention and treatment of NAFLD.

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.

The Effect of Laminaria japonica on Metabolic Syndrome: A Systematic Review of Its Efficacy and Mechanism of Action

Metabolic syndrome (MetS) is a medical condition characterized by abdominal obesity, insulin resistance, high blood pressure, and hyperlipidemia. An increase in the incidence of MetS provokes an escalation in health care costs and a downturn in quality of life. However, there is currently no cure for MetS, and the absence of immediate treatment for MetS has prompted the development of novel therapies. In accordance with recent studies, the brown seaweed Laminaria japonica (LJP) has anti-inflammatory and antioxidant properties, and so forth. LJP contains bioactive compounds used as food globally, and it has been used as a medicine in East Asian countries. We conducted a systematic review to examine whether LJP could potentially be a useful therapeutic drug for MetS. The following databases were searched from initiation to September 2021: PubMed, Web of Science, EMBASE, and Cochrane Central Register of Controlled Trials Library. Clinical trials and in vivo studies evaluating the effects of LJP on MetS were included. LJP reduces the oxidative stress-related lipid mechanisms, inflammatory cytokines and macrophage-related chemokines, muscle cell proliferation, and migration. Bioactive-glucosidase inhibitors reduce diabetic complications, a therapeutic target in obesity and type 2 diabetes. In obesity, LJP increases AMP-activated protein kinase and decreases acetyl-CoA carboxylase. Based on our findings, we suggest that LJP could treat MetS, as it has pharmacological effects on MetS.

Seaweed-Derived Phlorotannins: A Review of Multiple Biological Roles and Action Mechanisms

Phlorotannins are a group of phenolic secondary metabolites isolated from a variety of brown algal species belonging to the Fucaceae, Sargassaceae, and Alariaceae families. The isolation of phlorotannins from various algal species has received a lot of interest owing to the fact that they have a range of biological features and are very biocompatible in their applications. Phlorotannins have a wide range of therapeutic biological actions, including antimicrobial, antidiabetic, antioxidant, anticancer, anti-inflammatory, anti-adipogenesis, and numerous other biomedical applications. The current review has extensively addressed the application of phlorotannins, which have been extensively investigated for the above-mentioned biological action and the underlying mechanism of action. Furthermore, the current review offers many ways to use phlorotannins to avoid certain downsides, such as low stability. This review article will assist the scientific community in investigating the greater biological significance of phlorotannins and developing innovative techniques for treating both infectious and non-infectious diseases in humans.

Dieckol: a brown algal phlorotannin with biological potential

Dieckol [C36H22O18], is a naturally occurring phlorotannin found in some brown algal species. Dieckol is gaining more attention in the scientific community for its potential biological activities. It has been exhibited a broad spectrum of therapeutic functions including anti-bacterial, anti-cancer, anti-oxidant, anti-aging, anti-diabetic, neuroprotective, and other medicinal applications. Distinct emphasis has been given to extraction, purification, and biomedical applications of dieckol. This critical review comprises of in vitro, in vivo, and in silico biological properties of dieckol. An attempt has been made to evaluate the effectiveness, therapeutical application, and mechanism of dieckol against various diseases. The pharmacological significance, current status and the dosage of multifunctional dieckol and its mechanisms have been discussed in this review. Dieckol plays an important role in apoptosis induction via inhibiting the PI3K, AKT, mTOR and FAK signaling molecules. Dieckol remarkably inhibited the lipid accumulation in high fat diet induced animal models. Dieckol, a multifaceted compound will be beneficial in attenuating the action of various diseases and it could be a potential pharmaceutical and nutraceutical compound. Therefore, the combined effects of dieckol with existing drugs and natural compounds will be studied in future to optimize its benefits. Besides limited information on the toxicological action and dosage administration of dieckol on the human was reported to date. Overall, dieckol is a prospective health-promoting compound for the development of a novel drug against numerous diseases.

Dieckol-Attenuated High-Fat Diet Induced Muscle Atrophy by Modulating Muscular Deposition of Lipid Droplets

An excessive fat diet induces intramuscular fat deposition that accumulates as a form of lipid droplet (LD) and leads to lipotoxicity, including muscle atrophy or decreasing muscle strength. Lipotoxicity depends on the number of LDs, subcellular distribution (intermyofibrillar, IMF, LDs or subsarcolemmal, SS), and fiber type-specific differences (type I or type II fiber) as well as the size of LD. Ecklonia cava extracts (ECE), which is known to increase peroxisome proliferator-activated receptor alpha (PPAR-α), which leads to decreasing expression level of perilipin2 (PLIN2). PLIN2 is involved in modulating the size of LDs. This study shows that ECE and dieckol could decrease PLIN2 expression and decrease the size and number of LDs in the muscle of high-fat diet (HF)-fed animals and lead to attenuating muscle atrophy. Expression level of PPAR-α was decreased, and PLIN2 was increased by HF. ECE and dieckol increased PPAR-α expression and decreased PLIN2. The diameter of LDs was increased in high-fat diet condition, and it was decreased by ECE or dieckol treatment. The number of LDs in type II fibers/total LDs was increased by HF and it was decreased by ECE or dieckol. The SS LDs were increased, and IMF LDs were decreased by HF. ECE or dieckol decreased SS LDs and increased IMF LDs. The ECE or dieckol attenuated the upregulation of muscle atrophy-related genes including Murf1, Atrogin-1, and p53 by HF. ECE or dieckol increased the cross-sectional area of the muscle fibers and grip strength, which were decreased by HF. In conclusion, ECE or dieckol decreased the size of LDs and modulated the contribution of LDs to less toxic ones by decreasing PLIN2 expression and thus attenuated muscle atrophy and strength, which were induced by HF.

Dieckol attenuates the nociception and inflammatory responses in different nociceptive and inflammatory induced mice model

Pain is the common indicator of inflammatory ailments and traumatic tissue injuries. The dieckol is an important therapeutic compound, which present in many seaweeds. The present research work was planned to assess the anti-inflammatory and anti-nociceptive actions of dieckol by using animal model. The anti-nociceptive action of dieckol was investigated by acetic acid triggered writhing, formalin provoked nociception, tail immersion test, hot-plate methods and the anti-inflammatory effects was explored by carrageenan triggered paw edema method. In the present investigation the administration of dieckol was remarkably suppressed and inhibited the acetic acid-provoked writhing, formalin-triggered nociception, tail immersion test, hot plate-provoked nociception in the experimental animals. The dieckol was significantly (p < 0.05) inhibited the carrageenan-triggered inflammation, leukocyte infiltration and diminished the formation of pro-inflammatory regulators in the experimental animals. Altogether, the dieckol was showed a potent anti-nociceptive and anti-inflammatory activity.

Dieckol Decreases Caloric Intake and Attenuates Nonalcoholic Fatty Liver Disease and Hepatic Lymphatic Vessel Dysfunction in High-Fat-Diet-Fed Mice

Increased inflammation is the main pathophysiology of nonalcoholic fatty liver disease (NAFLD). Inflammation affects lymphatic vessel function that contributes to the removal of immune cells or macromolecules. Dysfunctional lymphatic vessels with decreased permeability are present in NAFLD. High-fat diet (HFD) is known to increase body weight, food intake, and inflammation in the liver. Previously, it was reported that Ecklonia cava extracts (ECE) decreased food intake or weight gain, and low-calorie diet and weight loss is known as a treatment for NAFLD. In this study, the effects of ECE and dieckol (DK)-which is one component of ECE that decreases inflammation and increases lymphangiogenesis and lymphatic drainage by controlling lymphatic permeability in high-fat diet (HFD)-fed mice-on weight gain and food intake were investigated. ECE and DK decreased weight gain and food intake in the HFD-fed mice. NAFLD activities such as steatosis, lobular inflammation, and ballooning were increased by HFD and attenuated by ECE and DK. The expression of inflammatory cytokines such as IL-6 and TNF-α and infiltration of M1 macrophages were increased by HFD, and they were decreased by ECE or DK. The signaling pathways of lymphangiogenesis, VEGFR-3, PI3K/pAKT, and pERK were decreased by HFD, and they were restored by either ECE or DK. The expression of VE-cadherin (which represents lymphatic junctional function) was increased by HFD, although it was restored by either ECE or DK. In conclusion, ECE and DK attenuated NAFLD by decreasing weight gain and food intake, decreasing inflammation, and increasing lymphangiogenesis, as well as modulating lymphatic vessel permeability.

Polyphenols in the prevention and treatment of non-alcoholic fatty liver disease: An update of preclinical and clinical studies

BACKGROUND & AIMS

The prevention and treatment of non-alcoholic fatty liver disease (NAFLD) has become one of the most urgent problems to be solved. To date, only a lifestyle modification related to diet and physical activity is considered for these patients. Polyphenols are a group of plant natural products that when regularly consumed has been related to a reduction in the risk of several metabolic disorders associated with NAFLD. In this study, we aimed to present an overview of the relationship between polyphenols and NAFLD with current approaches.

METHODS

We performed a comprehensive literature search for articles on polyphenols and NAFLD published in English between January 2018 to August 2020. Keywords included in this review: "Phenolic" OR "Polyphenol" AND "Non-Alcoholic Fatty Liver Disease". The editorials, communications and conference abstracts were excluded.

RESULTS

Different polyphenols decreased the pro-inflammatory cytokines in both serum and liver that contribute to a decrease in fatty liver dysfunction. Additionally, polyphenols may improve the regulation of adipokines and prevent hepatic steatosis. According to human clinical studies, polyphenols are promising for NAFLD patients and associated diseases that lead to NAFLD.

CONCLUSION

Preclinical and clinical studies suggest that various polyphenols could prevent steatosis and its progression to non-alcoholic steatohepatitis, as well as ameliorate NAFLD. However, more clinical studies are needed to confirm this hypothesis.

Attenuating Effects of Dieckol on High-Fat Diet-Induced Nonalcoholic Fatty Liver Disease by Decreasing the NLRP3 Inflammasome and Pyroptosis

Nonalcoholic fatty liver disease (NAFLD), which promotes serious health problems, is related to the increase in the nucleotide-binding oligomerization domain-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome and pyroptosis by a high-fat diet (HFD). Whether dieckol (DK), a component of Ecklonia cava extracts (ECE), attenuated NAFLD in an HFD-induced NAFLD animal model was evaluated. The expression of high mobility group box 1/Toll-like receptor 4/nuclear factor-κB, which initiated the NLRP3 inflammasome, was increased in the liver of HFD-fed animals and significantly decreased with ECE or DK administration. The expression of NLRP3/ASC/caspase-1, which are components of the NLRP3 inflammasome, and the number of pyroptotic cells were increased by HFD and decreased with ECE or DK administration. The accumulation of triglycerides and free fatty acids in the liver was increased by HFD and decreased with ECE or DK administration. The histological NAFLD score was increased by HFD and decreased with ECE or DK administration. The expression of lipogenic genes (FASN, SREBP-2, PPARγ, and FABP4) increased and that of lipolytic genes (PPARα, CPT1A, ATGL, and HSL) was decreased by HFD and attenuated with ECE or DK administration. In conclusion, ECE or DK attenuated NAFLD by decreasing the NLRP3 inflammasome and pyroptosis.

Chemopreventive effect of dieckol against 7,12-dimethylbenz(a)anthracene induced skin carcinogenesis model by modulatory influence on biochemical and antioxidant biomarkers

Skin cancer is the commonly found type, which contributes to 40% of whole cancer incidences worldwide. Dieckol is an active compound occurs in the marine algae with many biological benefits. In this exploration, we intended to investigate the therapeutic potency of dieckol against the 7,12-dimethylbenz(a)anthracene (DMBA)-triggered skin carcinogenesis in mice. The skin cancer was stimulated to the animals via injecting the 25 μg of DMBA in 100 μL of acetone in shaved dorsal portion along with the 30 mg/kg of dieckol supplementation for 25 week. The antioxidant enzymes and phase-I and -II detoxifying enzymes in the test animals were inspected via standard protocols. Pro-inflammatory markers (IL-6, IL-1β, and TNF-α) level was examined via ELISA kits and the expression of inflammatory molecular markers like p-NF-ƙB, IƙBα and p-IƙBα were studied through western blotting. The expression status of pro- and anti-apoptotic proteins (p53, Bax, Bcl-2, caspase-3, caspase-9, COX-2, TGF-β1) was investigated via real-time polymerase chain reaction (RT-PCR). Our results revealed that the 30 mg/kg of dieckol supplementation noticeably regained the body and liver weight and also diminished the tumor incidence in the DMBA-incited animals. Dieckol treatment exhibited an enhanced antioxidants (SOD, CAT, GPx, and GSH) and reduced phase-I enzymes Cyt-p450 and Cyt-b5 in the DMBA-induced animals. Dieckol also diminished the pro-inflammatory modulators like IL-6, IL-1β and TNF-α. Western blotting result evidenced that the dieckol was inhibited the IƙB/NF-ƙB signaling pathway. RT-PCR study proved the enhanced expression of pro-apoptotic protein (p53, Bax, caspase-3 and -9) in the dieckol treated animals. Histological study also confirmed the therapeutic benefits of Dieckol. Altogether with these findings, it was clear that the dieckol has appreciably allayed the DMBA activated skin tumorigenesis in the mice and it could be a promising agent to treat the human skin cancer in future.

Marine bioactive compound dieckol induces apoptosis and inhibits the growth of human pancreatic cancer cells PANC-1

Pancreatic cancer, which threatens the global population, is a very aggressive disease with an increased mortality rate. Regarding the types of cancer, pancreatic cancer is prone to display significant resistance to conventional therapy, therefore there 5-year survival rate is only 2% to 9%. Bioactive metabolites of marine algae such as polysaccharides, chitin, carternoids, and sterols possess immense pharmacological properties and tend to be promising alternatives for cancer treatment. Dieckol is one such polyphenolic bioactive compound extracted from brown algae Ecklonia cava, which is proven to possess antioxidant, anti-inflammatory, antibacterial, antidiabetic properties. Therefore in the present study, we analyzed the anticancer property of dieckol on PANC-1 pancreatic carcinoma cells. The cytotoxicity property of dieckol against PANC-1 cells was assessed with 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide assay, and cell morphological analysis. The generation of reactive oxygen species by dieckol on PANC-1 was analyzed with DCFH-DA staining and confirmed by quantifying antioxidants levels in untreated and dieckol-treated PANC-1 cells. The induction of apoptosis was further evaluated with different staining techniques such as Rhodamine 123 staining, acridine orange/ethidium bromide staining, DAPI staining, propidium iodide staining and was confirmed by estimating the protein expression of apoptotic genes, Bax and Bcl2. Cell adhesion assay and estimation of inflammatory cytokines were performed to detect the inhibitory effect of dieckol against cancer cell progression. It is further confirmed by analyzing cancer cell progression proteins, that is, proliferating cell nuclear antigen and cyclin D1 expressions in untreated and dieckol-treated PANC-1 cells. Our overall results authentically prove dieckol persuasively induces apoptosis and inhibits the progression of human pancreatic cancer cells in vitro, suggesting dieckol as a potent marine-based phytochemical to treat pancreatic cancer.

Structural basis of quinolone derivatives, inhibition of type I and II topoisomerases and inquiry into the relevance of bioactivity in odd or even branches with molecular docking study

The structural modification of quinolone derivatives has been a hot spot in recent years, especially the modification of the N-1 position, which is the part that this article focuses on. In this paper, series of synthesized quinoline quaternary ammonium salts with odd and even carbon number alkyl groups in N-1 position were used to explain the influence of the alkyl side chain on activity. With respect to all the recently synthesized twenty products, the biological activity results exhibited significant antitumor and antibacterial activity with obvious differences in the target alkyliodine substituted compounds and the antibacterial activities apparently had the prominent odd-carbon number predominance. Compound 8-((4-(benzyloxy)phenyl)amino)-7-(ethoxycarbonyl)-5-propyl-[1,3]dioxolo[4,5-g]quinolin-5-ium (4d) was found to be the most potent derivative with IC₅₀ values of 4 ± 0.88, 4 ± 0.42, 14±1.96, and 32±3.66 against A-549, Hela, SGC-7901, and L-02 cells, respectively, stronger than the positive control 5-FU and MTX. Furthermore, it had the most potent bacterial inhibitory activity of MIC value against E. coli (ATCC 29213) and Staphylococcus aureus (ATCC 8739) at 3.125 nmol mL⁻¹. With respect to molecular simulations, in order to illustrate the possible mechanism of the difference between the series of compounds in the even or odd carbon chain alkyliodine substitution, this paper simulated the conceivable mode and explained the main interactions. Finally, we could find that the position and proportion of hydrogen bonds and other interactions in each series were regarded as the main reasons for this difference in activity.

The protective mechanisms of macroalgae Laminaria japonica consumption against lipid metabolism disorders in high-fat diet-induced hyperlipidemic rats

Macroalgae Laminaria japonica (MLJ) has been reported to exhibit various biological activities including improving immunity, anti-aging, anti-tumor, anti-atherosclerosis and anti-diabetic, but the protective mechanisms of MLJ consumption against non-alcoholic fatty liver disease (NAFLD) associated with hyperlipidemia remain poorly understood. This study demonstrated that MLJ consumption prevented high-fat diet (HFD)-induced NAFLD associated with hyperlipidemia in a rat model, and improved hyperlipidemia-related parameters, e.g. serum and hepatic lipid profiles. Moreover, histological analysis showed that MLJ reduced lipid deposition in adipocytes and hepatocytes compared with the HFD group. Such beneficial effects may be associated with the modulation of the intestinal microbiota, especially some key microbial phylotypes involved in lipid metabolism homeostasis. The underlying protective mechanisms of MLJ consumption against HFD-induced NAFLD associated with hyperlipidemia were also studied by ultra-high performance liquid chromatography with quadruple-time of flight mass spectrometry (UPLC-QTOF/MS)-based liver metabolomics coupled with pathway analysis. The metabolic pathway enrichment analysis of the differentially abundant hepatic metabolites indicated that primary bile acid biosynthesis metabolism and cysteine and methionine metabolism were the two main metabolic pathways altered by MLJ consumption when compared with the model group. The analysis of the transcription levels of liver-related genes by RT-qPCR and the expressions of liver-related proteins by immunohistochemistry (IHC) showed that MLJ consumption could regulate the levels of mRNA transcription and protein expression related to hepatic lipid metabolism. In short, this study indicates that MLJ could be developed as functional food supplement for the prevention or treatment of NAFLD associated with hyperlipidemia.

Optimization of betacyanins from agricultural by-products using pressurized hot water extraction for antioxidant and in vitro oleic acid-induced steatohepatitis inhibitory activity

Pressurized hot water extraction (PHWE) is proposed to recover betacyanins from agricultural by-products (pitaya fruits peels (PFP), red beet stalks (RBS), and cactus pear peels (CPP)). The extraction yield of betacyanins was optimized by response surface methodology. The optimal PHWE conditions were attained and the actual yields of betacyanins under optimal conditions were well matched with the predicted yields. In addition, betacyanin pigment compositions as well as superoxide anion scavenging activity of individual betacyanins extract (BE) produced in optimal PHWE conditions were characterized by HPLC-ESI/MSⁿ and cyclic voltammetry. Furthermore, the inhibitory activity of three BEs on oleic acid-induced steatohepatitis in cellular model was comparatively investigated. The results showed that unlike PFP, RBS, and CPP presented excellent efficacy in decreasing intracellular triglyceride and reactive oxygen species, inhibiting the release of alanine aminotransferase and aspartate aminotransferase as well as regulating fatty acid synthase and carnitine palmitoyltransferase 1 mRNAs expression. Practical applications In this study, PHWE, is firstly proposed for the enhancement of the extraction of betacyanins from three agricultural by-products. Betacyanin-rich extracts by PHWE method exhibit excellent activities in inhibition of ROS and regulation of lipid metabolism in hepatic cells. It suggests that PHWE has a strong potentiality in keeping bioactivity of BEs, which is significant for the production of betacyanins functional foods.