Dose-Dependent Antifibrotic Effect of Chrysin on Regression of Liver Fibrosis: The Role in Extracellular Matrix Remodeling

Chrysin Directing an Enhanced Solubility through the Formation of a Supramolecular Cyclodextrin-Calixarene Drug Delivery System: A Potential Strategy in Antifibrotic Diabetes Therapeutics

Calixarene 0118 (OTX008) and chrysin (CHR) are promising molecules for the treatment of fibrosis and diabetes complications but require an effective delivery system to overcome their low solubility and bioavailability. Sulfobutylated β-cyclodextrin (SBECD) was evaluated for its ability to increase the solubility of CHR by forming a ternary complex with OTX008. The resulting increase in solubility and the mechanisms of complex formation were identified through phase-solubility studies, while dynamic light-scattering assessed the molecular associations within the CHR-OTX008-SBECD system. Nuclear magnetic resonance, differential scanning calorimetry, and computational studies elucidated the interactions at the molecular level, and cellular assays confirmed the system's biocompatibility. Combining SBECD with OTX008 enhances CHR solubility more than using SBECD alone by forming water-soluble molecular associates in a ternary complex. This aids in the solubilization and delivery of CHR and OTX008. Structural investigations revealed non-covalent interactions essential to complex formation, which showed no cytotoxicity in hyperglycemic in vitro conditions. A new ternary complex has been formulated to deliver promising antifibrotic agents for diabetic complications, featuring OTX008 as a key structural and pharmacological component.

Chrysin-based supramolecular cyclodextrin-calixarene drug delivery system: a novel approach for attenuating cardiac fibrosis in chronic diabetes

Introduction: Cardiac fibrosis is strongly induced by diabetic conditions. Both chrysin (CHR) and calixarene OTX008, a specific inhibitor of galectin 1 (Gal-1), seem able to reduce transforming growth factor beta (TGF-β)/SMAD pro-fibrotic pathways, but their use is limited to their low solubility. Therefore, we formulated a dual-action supramolecular system, combining CHR with sulfobutylated β-cyclodextrin (SBECD) and OTX008 (SBECD + OTX + CHR). Here we aimed to test the anti-fibrotic effects of SBECD + OTX + CHR in hyperglycemic H9c2 cardiomyocytes and in a mouse model of chronic diabetes. Methods: H9c2 cardiomyocytes were exposed to normal (NG, 5.5 mM) or high glucose (HG, 33 mM) for 48 h, then treated with SBECD + OTX + CHR (containing OTX008 0.75-1.25-2.5 µM) or the single compounds for 6 days. TGF-β/SMAD pathways, Mitogen-Activated Protein Kinases (MAPKs) and Gal-1 levels were assayed by Enzyme-Linked Immunosorbent Assays (ELISAs) or Real-Time Quantitative Reverse Transcription Polymerase chain reaction (qRT-PCR). Adult CD1 male mice received a single intraperitoneal (i.p.) administration of streptozotocin (STZ) at a dosage of 102 mg/kg body weight. From the second week of diabetes, mice received 2 times/week the following i.p. treatments: OTX (5 mg/kg)-SBECD; OTX (5 mg/kg)-SBECD-CHR, SBECD-CHR, SBECD. After a 22-week period of diabetes, mice were euthanized and cardiac tissue used for tissue staining, ELISA, qRT-PCR aimed to analyse TGF-β/SMAD, extracellular matrix (ECM) components and Gal-1. Results: In H9c2 cells exposed to HG, SBECD + OTX + CHR significantly ameliorated the damaged morphology and reduced TGF-β1, its receptors (TGFβR1 and TGFβR2), SMAD2/4, MAPKs and Gal-1. Accordingly, these markers were reduced also in cardiac tissue from chronic diabetes, in which an amelioration of cardiac remodeling and ECM was evident. In both settings, SBECD + OTX + CHR was the most effective treatment compared to the other ones. Conclusion: The CHR-based supramolecular SBECD-calixarene drug delivery system, by enhancing the solubility and the bioavailability of both CHR and calixarene OTX008, and by combining their effects, showed a strong anti-fibrotic activity in rat cardiomyocytes and in cardiac tissue from mice with chronic diabetes. Also an improved cardiac tissue remodeling was evident. Therefore, new drug delivery system, which could be considered as a novel putative therapeutic strategy for the treatment of diabetes-induced cardiac fibrosis.

Extracellular matrix turnover: phytochemicals target and modulate the dual role of matrix metalloproteinases (MMPs) in liver fibrosis

Extracellular matrix (ECM) resolution by matrix metalloproteinases (MMPs) is a well-documented mechanism. MMPs play a dual and complex role in modulating ECM degradation at different stages of liver fibrosis, depending on the timing and levels of their expression. Increased MMP-1 combats disease progression by cleaving the fibrillar ECM. Activated hepatic stellate cells (HSCs) increase expression of MMP-2, -9, and -13 in different chemicals-induced animal models, which may alleviate or worsen disease progression based on animal models and the stage of liver fibrosis. In the early stage, elevated expression of certain MMPs may damage surrounding tissue and activate HSCs, promoting fibrosis progression. At the later stage, downregulation of MMPs can facilitate ECM accumulation and disease progression. A number of phytochemicals modulate MMP activity and ECM turnover, alleviating disease progression. However, the effects of phytochemicals on the expression of different MMPs are variable and may depend on the disease models and stage, and the dosage, timing and duration of phytochemicals used in each study. Here, we review the most recent advances in the role of MMPs in the effects of phytochemicals on liver fibrogenesis, which indicates that further studies are warranted to confirm and define the potential clinical efficacy of these phytochemicals.

Vanillin augments liver regeneration effectively in Thioacetamide induced liver fibrosis rat model

AIMS

This study has been designed to investigate the role of vanillin either as prophylaxis or treatment in liver regeneration augmentation and liver fibrosis regression in thioacetamide (TAA) induced liver damage.

MATERIALS AND METHODS

Animals were injected with TAA to induce liver injury (200mg/kg twice weekly) for 8 weeks. In vanillin prophylaxis group; rats were administered vanillin (100 mg/Kg; IP, daily) from day 1 of TAA injection for 8 weeks. In vanillin treatment group; rats were confronted with the same dose of TAA injection for 8 weeks then treated with vanillin (100 mg/Kg, IP, daily) for 4 weeks. ALT, AST activities, serum albumin, hepatic GSH, MDA, HGF, VEGF, IL-6 and TNF-α levels were measured and also, MMP-2, TIMP-1 and cyclin D gene expression were determined. Liver sections were stained with H&E and Sirius red and immunostained for Ki-67 and α-SMA for histological and immunohistological changes analysis.

KEY FINDINGS

Vanillin improved liver function and histology. Also, showed a remarkable increase in hepatic HGF and VEGF level, and up-regulation of cyclin D1 expression accompanied by a significant up-regulation of MMP-2 and down- regulation of TIMP-1. All these effects were accompanied by TNF-α, IL-6 and oxidative stress significant attenuation.

SIGNIFICANCE

In conclusion, vanillin enhanced liver regeneration in TAA induced liver damage model; targeting growth factors (HGF, VEGF) and cellular proliferation marker cyclin D1. As well as stimulating fibrosis regression by inhibition of ECM accumulation and enhancing its degradation.

Complexation with Random Methyl-β-Cyclodextrin and (2-Hidroxypropyl)-β-Cyclodextrin Enhances In Vivo Anti-Fibrotic and Anti-Inflammatory Effects of Chrysin via the Inhibition of NF-κB and TGF-β1/Smad Signaling Pathways and Modulation of Hepatic Pro/Anti-Fibrotic miRNA

Chrysin (CHR) is a natural flavonoid with a wide range of pharmacological activities, including hepatoprotection, but poor water solubility. By including water-soluble hydroxypropyl (HPBCD) and randomly methylated (RAMEB) β-cyclodextrin, we aimed to increase its biodisponibility and the effectiveness of the antifibrotic effects of chrysin at oral administration. Liver fibrosis in mice was induced in 7 weeks by CCl₄ i.p. administration, and afterwards treated with 50 mg/kg of CHR-HPBCD, CHR-RAMEB, and free chrysin. CCl₄ administration increased hepatic inflammation (which was augmented by the upregulation of nuclear factor kappa-light-chain enhancer of activated B cells (NF-kB), tumor necrosis factor (TNF)-α, and interleukin 6 (IL-6) and induced fibrosis, as determined using histopathology and electron microscopy. These results were also confirmed by the upregulation of Collagen I (Col I) and matrix metalloproteinase (MMP) expression, which led to extracellular fibrotic matrix proliferation. Moreover, the immunopositivity of alpha-smooth muscle actin (a-SMA) in the CCl₄ group was evidence of hepatic stellate cell (HSC) activation. The main profibrotic pathway was activated, as confirmed by an increase in the transforming growth factor- β1 (TGF-β1) and Smad 2/3 expression, while Smad 7 expression was decreased. Treatment with CHR–HPBCD and CHR–RAMEB considerably reduced liver injury, attenuated inflammation, and decreased extracellular liver collagen deposits. CHR–RAMEB was determined to be the most active antifibrotic complex. We conclude that both nanocomplexes exert anti-inflammatory effects and antifibrotic effects in a considerably stronger manner than for free chrysin administration.

Chrysin mitigates bleomycin-induced pulmonary fibrosis in rats through regulating inflammation, oxidative stress, and hypoxia

Pulmonary fibrosis is a chronic condition characterized by fibroblast proliferation, and the infiltration of inflammatory cells that can initiate local tissue hypoxia. In this study the effect of chrysin (50 mg/kg/orally) in a model of bleomycin (BLM)-induced pulmonary fibrosis was studied. Chrysin managed to decrease mortality rate associated with BLM instillation and it managed to improve lung architecture and lung fibrosis by decreasing hydroxyproline content and transforming growth factor-β1 (TGF-β1) protein expression. Chrysin showed anti-inflammatory effect displayed by the decrease in inflammatory cells infiltrates, the decline in permeability of the alveolar/capillary barrier and the reduction in lactate dehydrogenase (LDH) activity. Chrysin demonstrated potent antioxidant effect by decreasing lipid peroxidation, increasing antioxidant defense mechanisms by increasing superoxide dismutase (SOD) activity and reduced glutathione (GSH) content. Additionally, the effect of chrysin on nitric oxide (NOx) content was assessed, where chrysin decreased NOx, increased the protein expression of endothelial nitric oxide synthase (eNOS), and decreased inducible nitric oxide synthase (iNOS) protein expression. Chrysin also succeeded in decreasing thioredoxin-interacting protein (TXNIP), the negative regulator of thioredoxin system, showing potent antioxidant effect. Finally, both tissue and bronchoalveolar lavage fluid contents of hypoxia inducible factor one alpha (HIF1α) were decreased by chrysin indicating that chrysin decreased local tissue hypoxia. In conclusion, this study exposed a possible proof that chrysin could mitigate pulmonary fibrosis induced by BLM through its anti-inflammatory, antioxidant, antifibrotic effects and its effect in alleviating hypoxia.

Nutraceutical Properties of Polyphenols against Liver Diseases

Current food tendencies, suboptimal dietary habits and a sedentary lifestyle are spreading metabolic disorders worldwide. Consequently, the prevalence of liver pathologies is increasing, as it is the main metabolic organ in the body. Chronic liver diseases, with non-alcoholic fatty liver disease (NAFLD) as the main cause, have an alarming prevalence of around 25% worldwide. Otherwise, the consumption of certain drugs leads to an acute liver failure (ALF), with drug-induced liver injury (DILI) as its main cause, or alcoholic liver disease (ALD). Although programs carried out by authorities are focused on improving dietary habits and lifestyle, the long-term compliance of the patient makes them difficult to follow. Thus, the supplementation with certain substances may represent a more easy-to-follow approach for patients. In this context, the consumption of polyphenol-rich food represents an attractive alternative as these compounds have been characterized to be effective in ameliorating liver pathologies. Despite of their structural diversity, certain similar characteristics allow to classify polyphenols in 5 groups: stilbenes, flavonoids, phenolic acids, lignans and curcuminoids. Herein, we have identified the most relevant compounds in each group and characterized their main sources. By this, authorities should encourage the consumption of polyphenol-rich products, as most of them are available in quotidian life, which might reduce the socioeconomical burden of liver diseases.

Complexation with Random Methyl-β-Cyclodextrin and (2-Hydroxypropyl)-β-Cyclodextrin Promotes Chrysin Effect and Potential for Liver Fibrosis Therapy

Liver fibrosis results from chronic liver injury and is characterized by the accumulation of extracellular matrix in excess driven by hepatic stellate cells (HSCs) activation. Chrysin (CHR) is a natural flavonoid that is limited by its low solubility to exert its anti-inflammatory, antioxidant and anti-fibrotic properties. The aim of this study was to investigate the biocompatibility of CHR complexes with two cyclodextrins (CDs)-(2-hydroxypropyl)-β-cyclodextrin (HPBCD) and random methyl-β-cyclodextrin (RAMEB), and their potential to induce anti-inflammatory, antioxidant and anti-fibrotic effects. Biocompatibility of the complexes was evaluated on Huh7 and LX2 cell lines: MTT and Live/Dead tests indicated the cell viability and an LDH test showed the cytotoxicity. Immunohistochemical staining of Nuclear Factor Kappa B (NF-κB) nuclear translocation was performed to evaluate the anti-inflammatory effect of the complexes. Oxygen Radical Absorbance assay, Superoxide Dismutase activity and Glutathione Peroxidase (GPx) assays indicated the antioxidant properties of the chrysin complexes. Finally, the complexes’ anti-fibrotic potential was evaluated at the protein and gene level of α-sma. In HSCs, CDs induced higher cytotoxicity correlated with lower cell viability than CHR–CD. The 1:1 CHR–RAMEB pretreatment avoided p65 translocation. The 1:2 CHR–RAMEB complex increased ORAC values, improved SOD activity and produced the highest stimulation of GPx activity. CHR–RAMEB reduced α-sma expression at lower concentration than CHR–HPBCD, proving to be more efficient. In conclusion, both CHR–CD complexes proved to be biocompatible, but CHR–RAMEB showed improved anti-inflammatory, antioxidant and anti-fibrotic effects that could recommend its further use in liver fibrosis treatment.

Anti-proliferative activity of A. Oxyphylla and its bioactive constituent nootkatone in colorectal cancer cells

Background

A. oxyphylla extract is known to possess a wide range of pharmacological activites. However, the molecular mechanism of A. oxyphylla and its bioactive compound nootkatone in colorectal cancer is unknown.

Methods

Our study aims to examine the role of A. oxyphylla and its bioactive compound nootkatone, in tumor suppression using several in vitro assays.

Results

Both A. oxyphylla extract and nootkatone exhibited antiproliferative activity in colorectal cancer cells. A. oxyphylla displayed antioxidant activity in colorectal cancer cells, likely mediated via induction of HO-1. Furthermore, expression of pro-apoptotic protein NAG-1 and cell proliferative protein cyclin D1 were increased and decreased respectively in the presence of A. oxyphylla. When examined for anticancer activity, nootkatone treatment resulted in the reduction of colony and spheroid formation. Correspondingly, nootkatone also led to increased NAG-1 expression and decreased cyclin D1 expression. The mechanism by which nootkatone suppresses cyclin D1 involves protein level regulation, whereas nootkatone increases NAG-1 expression at the transcriptional level. In addition to having PPARγ binding activity, nootkatone also increases EGR-1 expression which ultimately results in enhanced NAG-1 promoter activity.

Conclusion

In summary, our findings suggest that nootkatone is an anti-tumorigenic compound harboring antiproliferative and pro-apoptotic activity.

Alterations in the Transcriptional Profile of the Liver Tissue and the Therapeutic Effects of Propolis Extracts in Alcohol-induced Steatosis in Rats

The hepatoprotective effects of the ethanolic extracts of propolis (EEP) on alcohol-induced liver steatosis were investigated in Wistar rats. Chronic alcoholic fatty liver was induced by administration of 52% alcohol to male Wistar rats at the dose of 1% body weight for 7 weeks. Then animals were simultaneously treated with 50% ethanol solutions of EEP or normal saline at the dose of 0.1% body weight for 4 further weeks. Serological analyses and liver histopathology studies were performed to investigate the development of steatosis. Microarray analysis was conducted to investigate the alterations of hepatic gene expression profiling. Our results showed that 4-week treatment of EEP helped to restore the levels of various blood indices, liver function enzymes and the histopathology of liver tissue to normal levels. Results from the microarray analysis revealed that the hepatic expressions of genes involved in lipogenesis were significantly down-regulated by EEP treatment, while the transcriptional expressions of functional genes participating in fatty acids oxidation were markedly increased. The ability of EEP to reduce the negative effects of alcohol on liver makes propolis a potential natural product for the alternative treatment of alcoholic fatty liver.

Chronic consumption of the dietary polyphenol chrysin attenuates metabolic disease in fructose-fed rats

PURPOSE

Metabolic syndrome (MS) is a major public health issue worldwide and fructose consumption has been associated with MS development. Recently, we showed that the dietary polyphenol chrysin is an effective inhibitor of fructose uptake by human intestinal epithelial cells. Therefore, our aim was to investigate if chrysin interferes with the development of MS induced by fructose in an animal model.

METHODS

Adult male Sprague-Dawley rats (220-310 g) were randomly divided into four groups: (A) tap water (control), (B) tap water and a daily dose of chrysin (100 mg/kg) by oral administration (chrysin) (C) 10% fructose in tap water (fructose), and (D) 10% fructose in tap water and a daily dose of chrysin (100 mg/kg) by oral administration (fructose + chrysin). All groups were fed ad libitum with standard laboratory chow diet and dietary manipulation lasted 18 weeks.

RESULTS

Fructose-feeding for 18 weeks induced an increase in serum triacylglycerols, insulin and angiotensin II levels and in hepatic fibrosis and these changes did not occur in fructose + chrysin rats. Moreover, the increase in both systolic and diastolic blood pressure which was found in fructose-fed animals from week 14th onwards was not observed in fructose + chrysin animals. In contrast, the increase in energy consumption, liver/body, heart/body and right kidney/body weight ratios, serum proteins, serum leptin and liver triacylglycerols observed in fructose-fed rats was not affected by chrysin.

CONCLUSIONS

Chrysin was able to protect against some of the MS features induced by fructose-feeding.