Resveratrol attenuates the progress of liver fibrosis via the Akt/nuclear factor-κB pathways

Comprehensive and critical view on the anti-inflammatory and immunomodulatory role of natural phenolic antioxidants

The immune response encompasses innate and adaptive immunity, each with distinct and specific activities. The innate immune system is constituted by phagocytic cells, macrophages, monocytes and neutrophils, the cascade system, and different classes of receptors such as toll-like receptors that are exploited by the innate immune cells. The adaptive immune system is antigen-specific, encompassing memory lymphocytes and the corresponding specific receptors. Inflammation is understood as an activation of different signaling pathways such as toll-like receptors or nuclear factor kappa-light-chain-enhancer of activated B cells, with an increase in nitric oxide, inflammatory cytokines and chemokines. Increased oxidative stress has been identified as main source of chronic inflammation. Phenolic antioxidants modulate the activities of lymphocytes and macrophages by impacting cytokines and nitric oxide release, exerting anti-inflammatory effect. The nuclear-factor kappa-light-chain-enhancer of activated B cells signaling pathway and the mitogen-activated protein kinase pathway are targeted, alongside an increase in nuclear factor erythroid 2-related factor mediated antioxidant response, triggering the activity of antioxidant enzymes. The inhibitive potential on phospholipase A2, cyclooxygenase and lipoxygenase in the arachidonic acid pathway, and the subsequent reduction in prostaglandin and leukotriene generation, reveals the potential of phenolics as inflammation antagonists. The immunomodulative potential encompasses the capacity to interfere with proinflammatory cytokine synthesis and with the expression of the corresponding genes. A diet rich in antioxidants can result in prevention of inflammation-related pathologies. More investigations are necessary to establish the role of these antioxidants in therapy. The appropriate delivery system and the prooxidant effects exhibited at large doses, or in the presence of heavy metal cations should be regarded.

Human diet-derived polyphenolic compounds and hepatic diseases: From therapeutic mechanisms to clinical utilization

This review focuses on the potential ameliorative effects of polyphenolic compounds derived from human diet on hepatic diseases. It discusses the molecular mechanisms and recent advancements in clinical applications. Edible polyphenols have been found to play a therapeutic role, particularly in liver injury, liver fibrosis, NAFLD/NASH, and HCC. In the regulation of liver injury, polyphenols exhibit anti-inflammatory and antioxidant effects, primarily targeting the TGF-β, NF-κB/TLR4, PI3K/AKT, and Nrf2/HO-1 signaling pathways. In the regulation of liver fibrosis, polyphenolic compounds effectively reverse the fibrotic process by inhibiting the activation of hepatic stellate cells (HSC). Furthermore, polyphenolic compounds show efficacy against NAFLD/NASH by inhibiting lipid oxidation and accumulation, mediated through the AMPK, SIRT, and PPARγ pathways. Moreover, several polyphenolic compounds exhibit anti-HCC activity by suppressing tumor cell proliferation and metastasis. This inhibition primarily involves blocking Akt and Wnt signaling, as well as inhibiting the epithelial-mesenchymal transition (EMT). Additionally, clinical trials and nutritional evidence support the notion that certain polyphenols can improve liver disease and associated metabolic disorders. However, further fundamental research and clinical trials are warranted to validate the efficacy of dietary polyphenols.

Recent Advances in Research on Active Compounds Against Hepatic Fibrosis

BACKGROUND

Almost all chronic liver diseases cause fibrosis, which can lead to cirrhosis and eventually liver cancer. Liver fibrosis is now considered to be a reversible pathophysiological process and suppression of fibrosis is necessary to prevent liver cancer. At present, no specific drugs have been found that have hepatic anti-fibrotic activity.

OBJECTIVE

The research progress of anti-hepatic fibrosis compounds in recent ten years was reviewed to provide a reference for the design and development of anti-hepatic fibrosis drugs.

METHODS

According to the structure of the compounds, they are divided into monocyclic compounds, fused-heterocyclic compounds, and acyclic compounds.

RESULTS

In this article, the natural products and synthetic compounds with anti-fibrotic activity in recent ten years were reviewed, with emphasis on their pharmacological activity and structure-activity relationship (SAR).

CONCLUSION

Most of these compounds are natural active products and their derivatives, and there are few researches on synthetic compounds and SAR studies on natural product.

Phytobioactive compounds as therapeutic agents for human diseases: A review

Phytobioactive compounds are plant secondary metabolites and bioactive compounds abundantly present in medicinal plants and have remarkable therapeutic potential. Oxidative stress and antibiotic resistance are major causes of present-day ailments such as diabetes, atherosclerosis, cardiovascular disorders, cancer, and inflammation. The data for this review were collected from Google Scholar, PubMed, Directory of Open Access Journals (DOAJ), and Science Direct by using keywords: "Medicinal plants, Phytobioactive compounds, Polyphenols, Alkaloids, Carotenoids etc." Several studies have reported the pharmacological and therapeutic potential of the phytobioactives. Polyphenols, alkaloids, terpenes, and polysaccharides isolated from medicinal plants showed remarkable antioxidant, anticancer, cytotoxic, anti-inflammatory, cardioprotective, hepatoprotective, immunomodulatory, neuroprotective, and antidiabetic activities. This literature review was planned to provide comprehensive insight into the biopharmacological and therapeutic potential of phytobioactive compounds. The techniques used for the extraction and isolation of phytobioactive compounds, and bioassays required for their biological activities such as antioxidant, antimicrobial, anti-inflammatory, and cytotoxic activities, have been discussed. Characterization techniques for the structural elucidation of phytobioactive compounds such as HPLC, TLC, FTIR, GC-MS/MS, and NMR have also been discussed. This review concludes that phytobioactive compounds may be used as potential alternative to synthetic compounds as therapeutic agents for the treatment of various diseases.

Resveratrol inhibits TGF-β1-induced fibrotic effects in human pterygium fibroblasts

BACKGROUND

Resveratrol is a polyphenolic phytoalexin which has the properties of anti-oxidant, anti-inflammatory and anti-fibrotic effects. The aim of this study was to investigate the anti-fibrotic effects of resveratrol in primary human pterygium fibroblasts (HPFs) and elucidate the underlying mechanisms.

METHOD

Profibrotic activation was induced by transforming growth factor-beta1 (TGF-β1). The expression of profibrotic markers, including type 1 collagen (COL1), α-smooth muscle actin (α-SMA), and fibronectin, were detected by western blot and quantitative real-time-PCR after treatment with various concentrations of resveratrol in HPFs to investigate the anti-fibrotic effects. Relative signaling pathways downstream of TGF-β1 were detected by Western blot to assess the underlying mechanism. Cell viability and apoptosis were assessed using CCK-8 assay and flow cytometry to evaluate proliferation and drug-induced cytotoxicity. Cell migration and contractile phenotype were detected through wound healing assay and collagen gel contraction assay.

RESULTS

The expression of α-SMA, FN and COL1 induced by TGF-β1 were suppressed by treatment with resveratrol in dose-dependent manner. The Smad3, mitogen-activated protein kinase (p38 MAPK) and phosphatidylinositol-3-kinase (PI3K) / protein kinase B (AKT) pathways were activated by TGF-β1, while resveratrol attenuated those pathways. Resveratrol also inhibited cellular proliferation, migration and contractile phenotype, and induced apoptosis in HPFs.

CONCLUSIONS

Resveratrol inhibit TGF-β1-induced myofibroblast activation and extra cellular matrix synthesis in HPFs, at least partly, by regulating the TGF-β/Smad3, p38 MAPK and PI3K/AKT pathways.

Disease-associated regulation of gene expression by resveratrol: Special focus on the PI3K/AKT signaling pathway

Resveratrol (3,5,4′-trihydroxy-trans-stilbene) is a natural phenol that is present in the skin of the grape, blueberry, raspberry, mulberry, and peanut. This substance is synthesized in these plants following injury or exposure to pathogens. Resveratrol is used as a dietary supplement for a long time and its effects have been assessed in animal models of human disorders. It has potential beneficial effects in diverse pathological conditions such as diabetes mellitus, obesity, hypertension, neoplastic conditions, Alzheimer's disease, and cardiovascular disorders. Notably, resveratrol has been found to affect the expression of several genes including cytokine coding genes, caspases, matrix metalloproteinases, adhesion molecules, and growth factors. Moreover, it can modulate the activity of several signaling pathways such as PI3K/AKT, Wnt, NF-κB, and Notch pathways. In the current review, we summarize the results of studies that reported modulatory effects of resveratrol on the expression of genes and the activity of signaling pathways. We explain these results in two distinct sections of non-neoplastic and neoplastic conditions.

Resveratrol ameliorates liver fibrosis induced by nonpathogenic Staphylococcus in BALB/c mice through inhibiting its growth

Background

The altered gut microbiota is implicated in the pathogenesis of liver fibrosis. Resveratrol is a candidate for the treatment of liver fibrosis, which could ameliorate the dysregulation of gut microbiota in mice. This study aimed to clarify the role and mechanism of resveratrol in gut microbiota during liver fibrosis.

Methods

A mouse model of liver fibrosis induced by CCl₄ was conducted to assess the effect of resveratrol on liver fibrosis. The changes of gut microbiota in liver fibrotic mice after resveratrol intervention were assessed using 16S ribosomal RNA sequencing. The mechanism of the gut microbiota dysregulation in liver fibrosis was investigated by Sirius red staining, immunohistochemical assay, bacterial translocation (BT), EUB338 fluorescence in situ hybridization, immunofluorescence, trans-epithelial electrical resistance analysis and paracellular permeability analysis.

Results

Resveratrol relieved CCl₄-induced liver fibrosis. Besides, resveratrol restrained the gut microbiota Staphylococcus_lentus and Staphylococcus_xylosus in the liver fibrotic mice, and the Staphylococcus_xylosus and Staphylococcus_lentus facilitated the occurrence of BT and the cultures of them enhanced the permeability of intestine. The in vivo assay corroborated that the excessive Staphylococcus_xylosus and Staphylococcus_lentus canceled the protecting effect of resveratrol on liver fibrosis, and Staphylococcus_xylosus or Staphylococcus_lentus alone had a limited impact on the liver injury of normal mice.

Conclusion

Resveratrol ameliorated liver fibrosis by restraining the growth of Staphylococcus_xylosus and Staphylococcus_lentus.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10020-022-00463-y.

Research progress of natural products interfering with cell signaling pathway in liver fibrosis

Liver cirrhosis and hepatocellular carcinoma are the late stage of liver fibrosis. How to early use drugs to intervene in liver fibrosis is a prerequisite for the reversal of liver fibrosis. This paper mainly introduces a cell signaling transduction pathway in liver fibrosis and the intervention of natural products in order to provide theoretical basis for the treatment of liver fibrosis.

The Protective Effects of Zornia diphylla (L.) Pers. Against Acute Liver Injury Induced by Carbon Tetrachloride in Mice

Background:Zornia diphylla (L.) Pers. (ZDP) is a traditional Chinese herbal medicine that has been used for several decades to treat patients with liver diseases. Whether ZDP is best administered as a single agent or adjunctive therapy has yet to be determined as does the mechanism whereby it exerts its effects on antagonizing acute liver injury (ALI).

Aim of the study: To investigate the protective effects of ZDP on ALI induced by carbon tetrachloride (CCl₄) and the potential underlying mechanisms.

Materials and Methods: Sixty adult mice were randomized into six study groups (n = 10/group). Three groups were treated with different concentrations of ZDP (2.5, 1.25, 0.625 g/kg), one with bifendate (0.0075 g/kg) alone (positive control) and one with physiologic saline (normal, negative control). All groups were treated for 14 days. Two hours after the last administration, the normal group received an intraperitoneal injection of peanut oil, and the other five groups received an intraperitoneal injection of an equal dose of CCl₄ peanut oil solution. At 24 h, the liver index, histology and serum or tissue levels and/or protein expression of aspartate aminotransferase (AST), alanine aminotransferase (ALT), total bilirubin (TBIL), alkaline phosphatase (ALP), superoxide dismutase (SOD), malondialdehyde (MDA), catalase (CAT), glutathione (GSH), Akt, phosphorylated Akt (p-Akt), nuclear factor kappa B p65 (NF-κB p65), inhibitor of NF-κB α (IκB-α), interleukin-1 β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor α (TNF-α), E-cadherin and vimentin were determined.

Results: Compared to the model controls, the degree of inflammatory cell infiltration and hepatocyte injury of liver tissue was relieved in the bifendate and three ZDP groups; liver index in the ZDP (2.5, 1.25 g/kg) groups and serum liver function indices in the ZDP (2.5, 1.25 and 0.625 g/kg) groups were decreased; antioxidants SOD, CAT and GSH in liver tissue were increased but the lipid peroxidation index MDA was decreased; protein expression of inflammatory cytokines Akt, p-Akt, NF-κB p65, IκB-α, IL-1β, IL-6 and TNF-α in the liver was ameliorated, and E-cadherin expression was increased. The results of liver histopathology also showed that ZDP had a significant effect on ALI.

Conclusion: ZDP has obvious protective effects on CCl₄-induced ALI as a single therapy and appears to act by inhibiting oxidation, reducing the release of inflammatory factors and promoting hepatocyte repair.

Resveratrol Inhibits Hepatic Stellate Cell Activation via the Hippo Pathway

Liver fibrosis, which results from chronic liver injury due to factors such as chronic alcohol consumption, hepatitis virus infections, and immune attacks, is marked by excessive deposition of extracellular matrix (ECM). Resveratrol (Res), a polyphenol phytoalexin, has been demonstrated to show anti-inflammatory, antioxidative, antiproliferative, and chemopreventive activities. In recent years, Res has been found to inhibit liver fibrosis. Enhanced Hippo pathway activation has also been reported to inhibit tumor progression and liver fibrosis. In the present study, the role of the Hippo pathway in mediating the effects of Res on hepatic stellate cells (HSCs) was examined. We found that Res significantly suppresses HSC proliferation, reducing the cell index. Res induced HSC inactivation, reducing collagen deposition and α-smooth muscle actin (α-SMA) expression. In addition, Res contributed to HSC apoptosis, upregulating Bax and downregulating Bcl-2 expression. Notably, the Hippo pathway was involved in the Res-mediated suppression of HSC activation. Res enhanced the activation of the Hippo pathway and reduced yes-associated protein (YAP) and transcriptional coactivator with the PDZ-binding motif (TAZ) expression. Interestingly, the YAP overexpression inhibited Res-induced HSC inactivation and apoptosis. In conclusion, these results demonstrate that Res inhibits HSC activation, at least in part, via the Hippo pathway. The present study indicates a new antifibrotic mechanism of Res and provides novel insights into Hippo-mediated HSC apoptosis and HSC activation in liver fibrosis.

Preparation, Characterization, and In Vitro/In Vivo Evaluation of 3-O-β-D-Galactosylated Resveratrol-Loaded Polydopamine Nanoparticles

3-O-β-D-galactosylated resveratrol (Gal-Res) was synthesized from resveratrol (Res) and 3-O-β-D-galactose (Gal) in our previous study. In order to improve the pH sensitivity and bioavailability of Gal-Res, Gal-Res nanoparticles (Gal-Res NPs) were prepared using polydopamine (PDA) as a drug carrier. The drug loading (DL %) and entrapment efficiency (EE %) of Gal-Res NPs were 46.80% and 88.06%. The average particle size, polydispersity index (PDI), and Zeta potential of Gal-Res NPs were 179.38 ± 2.83 nm, 0.129 ± 0.013, and - 28.05 ± 0.36 mV, respectively. The transmission electron microscope (TEM) showed that Gal-Res NPs had uniform spherical morphology. Compared with the fast release of raw Gal-Res, the in vitro release of Gal-Res NPs was slow and pH-sensitive. The results of the blood vessel irritation and hemolysis test demonstrated that Gal-Res NPs had good hemocompatibility. The pharmacokinetics study in rats showed that area under the curve of plasma drug concentration time (AUC_0→600) and half-life (t_1/2) of Gal-Res NPs were enhanced 1.82-fold and 2.19-fold higher than those of raw Gal-Res. The in vivo biodistribution results showed that Gal-Res NPs were more distributed in liver tissue than Gal-Res. Gal-Res NPs with high bioavailability and liver accumulation were hopeful drug delivery systems (DDS) to treat liver diseases.

Pulmonary fibrosis: Therapeutic and mechanistic insights into the role of phytochemicals

Pulmonary fibrosis (PF) is the devastating consequence of various inflammatory diseases of the lung. PF leads to a reduction of lung function, respiratory failure, and death. Several molecular pathways are involved in PF, such as inflammatory cytokines including tumor necrosis factor α (TNFα), tumor necrosis factor β1 (TNFβ1), interleukin 6 (IL-6), and interleukin 4 (IL-4), reactive oxygen species, matrix metalloproteases, and transforming growth factor-beta (TGF-β). Targeting these processes involved in the progression of PF is essential for the treatment of this disease. Natural products, including plant extracts and active compound that directly target the processes involved in PF, could be suitable therapeutic options with less adverse effects. In the present study, we reviewed the protective effects and the therapeutic role of various bioactive compounds from plants in PF management.

Roles and mechanisms of NRG1 in modulating the pathogenesis of NAFLD through ErbB3 signaling in hepatocytes (NRG1 modulates NAFLD through ErbB3 signaling)

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is an emerging chronic liver disease. However, the underlying mechanisms remained poorly understood. Neuregulin (NRG) family participate in energy metabolism, and might be related to NAFLD.

METHODS

L02 cells were exposed to oleic acid to establish a cellular model of NAFLD. We analyzed the NAFLD cells with NRG1 and subsequent ErbB3 siRNA treatment. Cellular total lipid was stained by Oil Red O, while triglyceride content and inflammation markers were measured by enzymatic kits. The expressions of down-stream molecules were evaluated by western blot.

RESULTS

In vitro, NRG1 could alleviate the steatosis of NAFLD, and inhibit the expression of IL-6 and TNF-α. The downregulation of ErbB3 aggravated steatosis, improved the levels of triglyceride, IL-6 and TNF-α in NRG1-treated NAFLD. Moreover, NRG1 treatment up-regulated ErbB3 phosphorylation, and increased the expression of PI3K and phosphorylation-AKT. When NRG1-treated NAFLD cells were transfected with ErbB3 siRNA, the expressions of ErbB3, p-ErbB3, p-AKT and PI3K were all reduced.

CONCLUSION

NRG1 might play a protective role in the pathogenesis of NAFLD through ErbB3 phosphorylation to modulate the activation of PI3K-AKT pathway. The findings will expand the understanding of the mechanisms of NAFLD, and provide potential therapeutic targets.

Anti-Inflammatory Action and Mechanisms of Resveratrol

Resveratrol (3,4',5-trihy- droxystilbene), a natural phytoalexin polyphenol, exhibits anti-oxidant, anti-inflammatory, and anti-carcinogenic properties. This phytoalexin is well-absorbed and rapidly and extensively metabolized in the body. Inflammation is an adaptive response, which could be triggered by various danger signals, such as invasion by microorganisms or tissue injury. In this review, the anti-inflammatory activity and the mechanism of resveratrol modulates the inflammatory response are examined. Multiple experimental studies that illustrate regulatory mechanisms and the immunomodulatory function of resveratrol both in vivo and in vitro. The data acquired from those studies are discussed.

A Comprehensive Review of Natural Products against Liver Fibrosis: Flavonoids, Quinones, Lignans, Phenols, and Acids

Liver fibrosis resulting from continuous long-term hepatic damage represents a heavy burden worldwide. Liver fibrosis is recognized as a complicated pathogenic mechanism with extracellular matrix (ECM) accumulation and hepatic stellate cell (HSC) activation. A series of drugs demonstrate significant antifibrotic activity in vitro and in vivo. No specific agents with ideally clinical efficacy for liver fibrosis treatment have been developed. In this review, we summarized the antifibrotic effects and molecular mechanisms of 29 kinds of common natural products. The mechanism of these compounds is correlated with anti-inflammatory, antiapoptotic, and antifibrotic activities. Moreover, parenchymal hepatic cell survival, HSC deactivation, and ECM degradation by interfering with multiple targets and signaling pathways are also involved in the antifibrotic effects of these compounds. However, there remain two bottlenecks for clinical breakthroughs. The low bioavailability of natural products should be improved, and the combined application of two or more compounds should be investigated for more prominent pharmacological effects. In summary, exploration on natural products against liver fibrosis is becoming increasingly extensive. Therefore, natural products are potential resources for the development of agents to treat liver fibrosis.

Additive Effect of Resveratrol on Astrocyte Swelling Post-exposure to Ammonia, Ischemia and Trauma In Vitro

Swelling of astrocytes represents a major component of the brain edema associated with many neurological conditions, including acute hepatic encephalopathy (AHE), traumatic brain injury (TBI) and ischemia. It has previously been reported that exposure of cultured astrocytes to ammonia (a factor strongly implicated in the pathogenesis of AHE), oxygen/glucose deprivation, or to direct mechanical trauma results in an increase in cell swelling. Since dietary polyphenols have been shown to exert a protective effect against cell injury, we examined whether resveratrol (RSV, 3,5,4'-trihydroxy-trans-stilbene, a stilbenoid phenol), has a protective effect on astrocyte swelling following its exposure to ammonia, oxygen-glucose deprivation (OGD), or trauma in vitro. Ammonia increased astrocyte swelling, and pre- or post-treatment of astrocytes with 10 and 25 µM RSV displayed an additive effect, while 5 µM did not prevent the effect of ammonia. However, pre-treatment of astrocytes with 25 µM RSV slightly, but significantly, reduced the trauma-induced astrocyte swelling at earlier time points (3 h), while post-treatment had no significant effect on the trauma-induced cell swelling at the 3 h time point. Instead, pre- or post-treatment of astrocytes with 25 µM RSV had an additive effect on trauma-induced astrocyte swelling. Further, pre- or post-treatment of astrocytes with 5 or 10 µM RSV had no significant effect on trauma-induced astrocyte swelling. When 5 or 10 µM RSV were added prior to, or during the process of OGD, as well as post-OGD, it caused a slight, but not statistically significant decline in cell swelling. However, when 25 µM RSV was added during the process of OGD, as well as after the cells were returned to normal condition (90 min period), such treatment showed an additive effect on the OGD-induced astrocyte swelling. Noteworthy, a higher concentration of RSV (25 µM) exhibited an additive effect on levels of phosphorylated forms of ERK1/2, and p38^MAPK, as well as an increased activity of the Na⁺-K⁺-Cl^- co-transporter-1 (NKCC1), factors known to induce astrocytes swelling, when the cells were treated with ammonia or after trauma or ischemia. Further, inhibition of ERK1/2, and p38^MAPK diminished the RSV-induced exacerbation of cell swelling post-ammonia, trauma and OGD treatment. These findings strongly suggest that treatment of cultured astrocytes with RSV enhanced the ammonia, ischemia and trauma-induced cell swelling, likely through the exacerbation of intercellular signaling kinases and ion transporters. Accordingly, caution should be exercised when using RSV for the treatment of these neurological conditions, especially when brain edema is also suspected.

Improvement of Mitochondrial Activity and Fibrosis by Resveratrol Treatment in Mice with Schistosoma japonicum Infection

Schistosomiasis caused by Schistosoma japonicum is a major parasitic disease in the People's Republic of China. Liver fibrosis is the main pathological mechanism of schistosomiasis, and it is also the major lesion. The common drug used for its treatment, praziquantel (PZQ), does not have a marked effect on liver fibrosis. Resveratrol (RSV), which is an antioxidant, improves mitochondrial function and also attenuates liver fibrosis. The combination of PZQ and RSV has been found to have a synergistic antischistosomal effect on Schistosoma mansoni; additionally, the activity of PZQ is enhanced in the presence of RSV. Here, we examine the therapeutic effects of RSV on the S. japonicum infection in a mouse model, and we investigate RSV as a novel therapeutic agent for mitochondrial function and schistosomiasis-associated liver fibrosis (SSLF). Mitochondrial membrane potential was examined using flow cytometry analysis. The expression of the mitochondrial biogenesis genes PGC-α and fibrosis-associated genes collagen I, collagen III and α-SMA were examined using western blot analysis. Fibrosis-associated histological changes were examined using Masson trichrome staining. Additionally, the effects of RSV on S. japonicum adult worms were examined using scanning electron microscopy and transmission electron microscopy. RSV treatment improved mitochondrial function by increasing membrane potential and increasing PGC-α expression (mitochondrial biogenesis). Further, RSV attenuated liver injury, including liver scarring, by decreasing collagen deposition and the extent of fibrosis, based on the decrease in expression of the fibrosis-related genes. RSV also decreased the adult worm count and caused considerable physical damage to the worm. These results indicate that RSV upregulates mitochondrial biogenesis and inhibits fibrosis. RSV may have potential as a therapeutic target for the treatment of fibrosis in schistosomiasis.

Orally administered resveratrol enhances the therapeutic effect of autologous transplanted adipose-derived stem cells on rats with diabetic hepatopathy

Stem cell therapy is a promising treatment for hepatopathy due to diabetes mellitus (DM); oral resveratrol treatment exhibits protective effects. We investigated whether protective effects could be produced in liver of diabetic rats receiving autologous adipose-derived stem cell transplantation (ADSC) plus oral resveratrol administration. Male rats were divided into four groups: sham group; streptozotocin induced DM group; DM + ADSC group, in which DM rats were treated with 10⁶ stem cells/rat; and DM + R + ADSC group, in which DM rats were treated with ADSC and oral resveratrol. The DM group exhibited apoptosis, inflammation and fibrosis, whereas Sirt-1 and survival signaling were suppressed. Pathological conditions other than survival signaling were improved in the DM + ADSC group. All pathological conditions were improved in the DM + R + ADSC group. Also, the oxidative stress level in the blood was reduced in the DM + R + ADSC group compared to the sham group. Oral resveratrol administration appears to reduce oxidative damage and enhances survival signaling in diabetic liver. The therapeutic response in the DM + R + ADSC group was better than in the DM + ADSC group.

Synthesis, cytotoxicity and liver targeting of 3-O-β-D-Galactosylated Resveratrol

OBJECTIVES

Resveratrol (Res), a naturally occurring polyphenol, has shown pharmacological activities in treatment of liver diseases. However, the application of Res was limited by its poor bioavailability and liver targeting. Herein, 3-O-β-D-Galactosylated Resveratrol (Gal-Res) was synthesized by structural modification of Res to enhance bioavailability and liver targeting.

METHODS

The Gal-Res was characterized by IR, ¹ H-NMR spectra and MS. The in vitro antitumour experiments, in vivo pharmacokinetics and biodistribution studies were evaluated.

RESULTS

Gal-Res was successfully synthesized in our study. Compared to Res, Gal-Res resulted in enhanced cytotoxicity in HepG2 cells. After intravenous injection of normal SD rats, Gal-Res significantly improved the bioavailability of Res and the C_max and AUC_0-t of Gal-Res were 3.186 and 3.929 time than that of Res. In addition, in the study of liver targeting, the relative uptake rate (R_e ) of Gal-Res in the liver (2.006) is the largest. The drug targeting efficiency (T_e ; 38.924%) of Gal-Res was greater than that of Res. These showed that Gal-Res could significantly improve the distribution ability of Res in liver.

CONCLUSIONS

On the whole, Gal-Res increased cellular uptake to HepG2 cells, bioavailability and liver targeting, providing its future clinical application in the treatment of liver diseases.

Resveratrol prevents liver fibrosis via two possible pathways: Modulation of alpha fetoprotein transcriptional levels and normalization of protein kinase C responses

OBJECTIVE:

Liver fibrosis is a global health problem that causes approximately 1.4 million deaths per year. It is associated with inflammation, oxidative stress, necrosis and ends with cirrhosis, liver cancer, or liver failure. Therefore, the present study was constructed to investigate the protective effect of resveratrol (RVT) on liver fibrosis, focusing on the possible involvement of alpha 1-fetoprotein and protein kinase C signaling.

MATERIALS AND METHODS:

Rats received thioacetamide (TAA) (200 mg/kg, intraperitoneal) twice weekly, for 4 successive weeks to induce liver fibrosis. RVT (30 mg/kg, per os) and vehicle were administered orally for 1 month before and another month during TAA intoxication. Body weights and mortality rate were assessed during the experiment. Liver functions and protein concentration were determined in serum, while liver tissues were analyzed for oxidative and fibrotic biomarkers. Moreover, histological examinations were performed to liver biopsies.

RESULTS:

RVT prevented the debility of TAA; liver functions including alanine aminotransferase, aspartate aminotransferase, bilirubin, and albumin were also protected. RVT prevented TAA oxidative stress, and normal liver contents of malondialdehyde and reduced glutathione were markedly preserved. In addition, RVT abolished the stimulant effect of TAA to fibrosis markers and conserved normal liver contents of nuclear factor kappa B, hydroxyproline, and alpha fetoprotein. Histological examinations indicated normal liver architecture in RVT-administered rats as compared to their TAA-administered peers.

CONCLUSION:

RVT was able to enhance liver functions, prevent oxidative stress, and eliminate liver fibrosis. Hence, the present data highlight the therapeutic potential of RVT as a protective agent against liver fibrosis.

Oxidative stress is bane in chronic liver diseases: Clinical and experimental perspective

Oxidative stress plays an important role in the pathogenesis of various chronic liver diseases (CLD) and increasing evidence have confirmed the contributory role of oxidative stress in the pathogenesis of drugs and chemical-induced CLD. Chronic liver injury is manifested as necrosis, cholestasis, fibrosis, and cirrhosis. Chronic administration of anti-tubercular, anti-retroviral, immunosuppressive drugs is reported to induce free radical generation during their biotransformation in the liver. Further, these reactive intermediates are said to induce profibrogenic cytokines, several inflammatory markers, collagen synthesis during the progression of hepatic fibrosis. Oxidative stress and free radicals are reported to induce activation and proliferation of hepatic stellate cells in the injured liver leading to the progression of CLD. Hence, to counteract or to scavenge these reactive intermediates, several plant-derived antioxidant principles have been effectively employed against oxidative stress and came out with promising results in human and experimental models of CLD. This review summarizes the relationships between oxidative stress and different liver pathogenesis induced by drugs and xenobiotics, focusing upon different chronic liver injury induced by alcohol, antitubercular drugs and hyperactivity of antiretroviral drugs in HIV patients, viral hepatitis infection induced oxidative stress.

The Potential and Action Mechanism of Polyphenols in the Treatment of Liver Diseases

Liver disease, involving a wide range of liver pathologies from fatty liver, hepatitis, and fibrosis to cirrhosis and hepatocellular carcinoma, is a serious health problem worldwide. In recent years, many natural foods and herbs with abundant phytochemicals have been proposed as health supplementation for patients with hepatic disorders. As an important category of phytochemicals, natural polyphenols have attracted increasing attention as potential agents for the prevention and treatment of liver diseases. The striking capacities in remitting oxidative stress, lipid metabolism, insulin resistance, and inflammation put polyphenols in the spotlight for the therapies of liver diseases. It has been reported that many polyphenols from a wide range of foods and herbs exert therapeutic effects on liver injuries via complicated mechanisms. Therefore, it is necessary to have a systematical review to sort out current researches to help better understand the potentials of polyphenols in liver diseases. In this review, we aim to summarize and update the existing evidence of natural polyphenols in the treatment of various liver diseases by in vitro, in vivo, and clinical studies, while special attention is paid to the action mechanisms.

A Comparison of the Effectiveness of Silibinin and Resveratrol in Preventing Alpha-Amanitin-Induced Hepatotoxicity

Amanita phalloides species mushrooms containing alpha-amanitin (α-AMA) are responsible for the majority of fatal mushroom intoxications and can lead to severe poisonings resulting in hepatotoxicity and acute hepatic failure. Existing antidotes, such as silibinin, are not sufficiently effective in the prevention and/or resolution of α-AMA-induced hepatotoxicity. We investigated the effects of resveratrol on α-AMA-induced hepatotoxicity and compared with silibinin, a known antidote using in vivo and in vitro toxicity models. In the in vivo protocol, resveratrol (30 mg/kg) was given simultaneously with α-AMA (α-AMA + SR) or 12 (α-AMA + 12R) or 24 (α-AMA + 24R) hr after α-AMA administration. Silibinin (5 mg/kg) (α-AMA + Sil) and normal saline (α-AMA + NS) were given simultaneously with α-AMA. We found that liver transaminase levels in α-AMA + SR and α-AMA + 12R groups and histomorphologic injury score in the α-AMA + SR, α-AMA + 12R, α-AMA + 24R and α-AMA + Sil groups were significantly lower than that of the α-AMA + NS group. Resveratrol decreased mononuclear cell infiltration, necrosis and active caspase-3 immunopositivity in the liver. In the in vitro protocol, the effects of resveratrol and silibinin were evaluated in a reduction in cell viability induced by α-AMA in THLE-2 and THLE-3 hepatocytes. Neither resveratrol nor silibinin was found to be effective in increasing cell viability decreased by α-AMA + NS. As a conclusion, resveratrol was found to be effective in α-AMA-induced hepatotoxicity with its anti-inflammatory properties in in vivo conditions. It is a promising compound with the potential for use in the treatment of hepatotoxicity associated with Amanita phalloides type mushroom poisonings.

Resveratrol as a potential therapeutic drug for respiratory system diseases

Respiratory system diseases are common and major ailments that seriously endanger human health. Resveratrol, a polyphenolic phytoalexin, is considered an anti-inflammatory, antioxidant, and anticancer agent. Thanks to its wide range of biological activities, resveratrol has become a hotspot in many fields, including respiratory system diseases. Indeed, research has demonstrated that resveratrol is helpful to relieve pulmonary function in the general population. Meanwhile, growing evidence indicates that resveratrol plays a protective role in respiratory system diseases. This review aimed to summarize the main protective effects of resveratrol in respiratory system diseases, including its anti-inflammatory, antiapoptotic, antioxidant, antifibrotic, antihypertensive, and anticancer activities. We found that resveratrol plays a protective role in the respiratory system through a variety of mechanisms, and so it may become a new drug for the treatment of respiratory system diseases.

Food components with antifibrotic activity and implications in prevention of liver disease

Increasing prevalence of nonalcoholic fatty liver disease (NAFLD) in parallel with the obesity epidemic has been a major public health concern. NAFLD is the most common chronic liver disease in the United States, ranging from fatty liver to steatohepatitis, fibrosis and cirrhosis in the liver. In response to chronic liver injury, fibrogenesis in the liver occurs as a protective response; however, prolonged and dysregulated fibrogenesis can lead to liver fibrosis, which can further progress to cirrhosis and eventually hepatocellular carcinoma. Interplay of hepatocytes, macrophages and hepatic stellate cells (HSCs) in the hepatic inflammatory and oxidative milieu is critical for the development of NAFLD. In particular, HSCs play a major role in the production of extracellular matrix proteins. Studies have demonstrated that bioactive food components and natural products, including astaxanthin, curcumin, blueberry, silymarin, coffee, vitamin C, vitamin E, vitamin D, resveratrol, quercetin and epigallocatechin-3-gallate, have antifibrotic effects in the liver. This review summarizes current knowledge of the mechanistic insight into the antifibrotic actions of the aforementioned bioactive food components.

Immunity and Fibrogenesis: The Role of Th17/IL-17 Axis in HBV and HCV-induced Chronic Hepatitis and Progression to Cirrhosis

Cirrhosis is a common final pathway for most chronic liver diseases; representing an increasing burden worldwide and is associated with increased morbidity and mortality. Current evidence has shown that, after an initial injury, the immune response has a significant participation in the ongoing damage, and progression from chronic viral hepatitis (CVH) to cirrhosis, driving the activation and maintenance of main fibrogenic pathways. Among immune deregulations, those related to the subtype 17 of T helper lymphocytes (Th17)/interleukin-17 (IL-17) axis have been recognized as key immunopathological and prognostic elements in patients with CVH. The Th17/IL-17 axis has been found involved in several points of fibrogenesis chain from the activation of stellate cells, increased expression of profibrotic factors as TGF-β, promotion of the myofibroblastic or epithelial–mesenchymal transition, stimulation of the synthesis of collagen, and induction of imbalance between matrix metalloproteinases and tissue inhibitors of metalloproteinases (TIMPs). It also promotes the recruitment of inflammatory cells and increases the expression of proinflammatory cytokines such as IL-6 and IL-23. So, the Th17/IL-17 axis is simultaneously the fuel and the flame of a sustained proinflammatory and profibrotic environment. This work aims to present the immunopathologic and prognostic role of the Th17/IL-17 axis and related pathways in fibrogenesis and progression to cirrhosis in patients with liver disease due to hepatitis B virus (HBV) and hepatitis C virus (HCV).

Hepatitis C virus-induced CCL5 secretion from macrophages activates hepatic stellate cells

Hepatitis C virus (HCV)-mediated chronic liver disease is a serious health problem around the world and often causes fibrosis/cirrhosis and hepatocellular carcinoma. The mechanism of liver disease progression during HCV infection is still unclear, although inflammation is believed to be an important player in disease pathogenesis. We previously reported that macrophages including Kupffer cells exposed to HCV induce proinflammatory cytokines. These secreted cytokines may activate hepatic stellate cells (HSCs) toward fibrosis. In this study, we examined crosstalk between macrophages and HSCs following HCV infection. Primary human HSCs and immortalized HSCs (LX2 cells) were incubated with conditioned medium derived from HCV-exposed human macrophages. Expression of inflammasome and fibrosis-related genes in these cells was examined, with increased expression of inflammatory (NLR family pyrin domain containing 3, interleukins 1β and 6, and cysteine-cysteine chemokine ligand 5 [CCL5]) and profibrogenic (transforming growth factor β1, collagen type 4 alpha 1, matrix metalloproteinase 2, and alpha-smooth muscle actin) markers. Further investigation suggested that CCL5, secreted from HCV-exposed macrophages, activates inflammasome and fibrosis markers in HSCs and that neutralizing antibody to CCL5 inhibited activation.

CONCLUSION

Together, our results demonstrate that human macrophages exposed to HCV induce CCL5 secretion, which plays a significant role in hepatic inflammation and fibrosis. (Hepatology 2017;66:746-757).

Extracts of Salvia-Nelumbinis Naturalis Ameliorate Nonalcoholic Steatohepatitis via Inhibiting Gut-Derived Endotoxin Mediated TLR4/NF-κB Activation

Nonalcoholic steatohepatitis (NASH) is featured by the presence of hepatic steatosis combined with inflammation and hepatocellular injury. Gut-derived endotoxin plays a crucial role in the pathogenesis of NASH. Salvia-Nelumbinis naturalis (SNN), a formula of Traditional Chinese Medicine, has been identified to be effective for NASH, but the mechanisms were not thoroughly explored. In the present study, a NASH model was generated using C57BL/6 mice fed a high fat diet (HFD) supplemented periodically with dextran sulfate sodium (DSS) in drinking water for 12 weeks. Mice fed HFD alone (without DSS) or chow diet were used as controls. The NASH mice were given the SNN extracts in the following 4 weeks, while control mice were provided with saline. Mice fed HFD developed steatosis, and DSS supplementation resulted in NASH. The SNN extracts significantly improved metabolic disorders including obesity, dyslipidemia, and liver steatosis and reduced hepatic inflammation, circulating tumor necrosis factor-α (TNF-α), and lipopolysaccharide (LPS) levels. The beneficial effect of the SNN extracts was associated with restoration of intestinal conditions (microbiota, integrity of intestinal barrier) and inhibition of TLR4/NF-κB activation. These results suggest that the SNN extracts ameliorate NASH progression, possibly through blocking endotoxin related TLR4/NF-κB activation.