Tanshinol ameliorates CCl4-induced liver fibrosis in rats through the regulation of Nrf2/HO-1 and NF-κB/IκBα signaling pathway

Calcitriol Inhibits NaAsO2 Triggered Hepatic Stellate Cells Activation and Extracellular Matrix Oversecretion by Activating Nrf2 Signaling Pathway Through Vitamin D Receptor

Previous studies, including our own, have demonstrated that arsenic exposure can induce liver fibrosis, while the underlying mechanism remains unclear and there is currently no effective pharmacological intervention available. Recent research has demonstrated that vitamin D supplementation can ameliorate liver fibrosis caused by various etiologies, potentially through modulation of the Nrf2 signaling pathways. However, it remains unclear whether vitamin D intervention can mitigate arsenic-caused liver fibrosis. As is known hepatic stellate cells (HSCs) activation and extracellular matrix (ECM) deposition are pivotal in the pathogenesis of liver fibrosis. In this study, we investigated the intervention effect of calcitriol (a form of active vitamin D) on arsenite-triggered Lx-2 cells (a human hepatic stellate cell line) activation and ECM oversecretion. Additionally, we also elucidated the role and mechanism of Nrf2 antioxidant signaling pathway. Our results demonstrated that calcitriol intervention significantly inhibits Lx-2 cell activation and ECM oversecretion induced by arsenite exposure. Additionally, calcitriol activates Nrf2 and its downstream antioxidant enzyme expression in Lx-2 cells, thereby reducing ROS overproduction caused by arsenite exposure. Further investigation reveals that calcitriol activates the Nrf2 signaling pathway and inhibits arsenite-triggered Lx-2 cell activation and ECM oversecretion by targeting vitamin D receptor (VDR). In conclusion, this study has demonstrated that vitamin D intervention can effectively inhibit HSC activation and ECM oversecretion triggered by arsenite exposure through its antioxidant activity. This provides a novel strategy for targeted nutritional intervention in the treatment of arsenic-induced liver fibrosis.

Solid lipid nanoparticle: A potent vehicle of the kaempferol for brain delivery through the blood-brain barrier in the focal cerebral ischemic rat

Kaempferol is major flavonoid present in Convolvulus pluricaulis. This phytochemical protects the brain against oxidative stress, neuro-inflammation, neurotoxicity, neurodegeneration and cerebral ischemia induced neuronal destruction. Kaempferol is poorly water soluble. Our study proved that solid lipid nanoparticles (SLNs) were efficient carrier of kaempferol through blood-brain barrier (BBB). Kaempferol was incorporated into SLNs prepared from stearic acid with polysorbate 80 by the process of ultrasonication. Mean particle size and zeta potential of kaempferol loaded solid lipid nanoparticles (K-SLNs) were 451.2 nm and -15.0 mV. Atomic force microscopy showed that K-SLNs were spherical in shape. Fourier transformed infrared microscopy (FTIR) showed that both stearic acid and kaempferol were present in K-SLNs. X-ray diffraction (XRD) and differential scanning calorimetry (DSC) revealed that the matrices of K-SLNs were in untidy crystalline state. Entraptment efficiency of K-SLNs was 84.92%. In-vitro drug release percentage was 93.24%. Kaempferol loaded solid lipid nanoparticles (K-SLNs) showed controlled release profile. In-vitro uptake study showed significant efficiency of K-SLNs to cross blood-brain barrier (BBB). After oral administration into the focal cerebral ischemic rat, accumulation of fluorescent labeled K-SLNs was observed in the brain cortex which confirmed its penetrability into the brain. It significantly decreased the neurological deficit, infarct volume and level of reactive oxygen species (ROS) and decreased the level of pro-inflammatory mediators like NF-κB and p-STAT3. Damaged neurons and brain texture were improved. This study indicated increased bioavailability of kaempferol into the brain tissue through SLNs formulation.

Tanshinol ameliorates imiquimod-induced psoriasis by inhibiting M1 macrophage polarization through suppression of the notch signaling pathway

BACKGROUND

Psoriasis is a common immune-related chronic inflammatory skin disease, often accompanied by significant itching, and once diseased, the course of the disease lasts for most of the lifetime. Tanshinol (TAN) is an active ingredient of Salvia miltiorrhiza, which possesses pharmacological effects such as anti-inflammatory and antioxidant properties. However, the effects of TAN on psoriasis have not been widely reported. Therefore, the aim of this study was to investigate the therapeutic effects and mechanisms of TAN in psoriasis.

METHODS

An imiquimod (IMQ)-induced psoriasis mouse model was constructed and treated with different doses of TAN to observe the changes in skin lesion phenotype, macrophage polarization, inflammation and Notch signaling pathway in mice. Further removal of macrophages or inhibition or activation of Notch signaling pathway was performed to examine the changes in skin lesion phenotype, macrophage polarization, inflammation and Notch signaling pathway in mice. In addition, in vitro experiments verified that TAN regulates RAW264.7 macrophage polarization and cytokine secretion through the Notch pathway.

RESULTS

The results showed that TAN alleviated IMQ-induced skin lesions and pathological phenotypes in psoriasis mice and inhibited Notch signaling pathway and M1-type macrophage polarization. Moreover, macrophage clearance and Notch signaling pathway activation inhibited the effect of TAN on psoriasis. Further in vitro experiments showed that Notch agonists reversed the effects of TAN on macrophage polarization and inflammatory cytokines.

CONCLUSIONS

Collectively, these findings suggest that TAN may exert a therapeutic effect on psoriasis by inhibiting the Notch signaling pathway and thus M1-type macrophage polarization.

Yinhuang granule alleviates carbon tetrachloride-induced liver fibrosis in mice and its mechanism

BACKGROUND

Liver fibrosis is a formidable global medical challenge, with no effective clinical treatment currently available. Yinhuang granule (YHG) is a proprietary Chinese medicine comprising Scutellariae Radix and Lonicerae Japonicae Flos. It is frequently used for upper respiratory tract infections, pharyngitis, as well as acute and chronic tonsillitis.

AIM

To investigate the potential of YHG in alleviating carbon tetrachloride (CCl4)-induced liver fibrosis in mice.

METHODS

To induce a hepatic fibrosis model in mice, this study involved intraperitoneal injections of 2 mL/kg of CCl4 twice a week for 4 wk. Meanwhile, liver fibrosis mice in the low dose of YHG (0.4 g/kg) and high dose of YHG (0.8 g/kg) groups were orally administered YHG once a day for 4 wk. Serum alanine/aspartate aminotransferase (ALT/AST) activity and liver hydroxyproline content were detected. Sirius red and Masson's trichrome staining assay were conducted. Real-time polymerase chain reaction, western-blot and enzyme-linked immunosorbent assay were conducted. Liver glutathione content, superoxide dismutase activity level, reactive oxygen species and protein carbonylation amount were detected.

RESULTS

The administration of YHG ameliorated hepatocellular injury in CCl4-treated mice, as reflected by decreased serum ALT/AST activity and improved liver histological evaluation. YHG also attenuated liver fibrosis, evident through reduced liver hydroxyproline content, improvements in Sirius red and Masson's trichrome staining, and lowered serum hyaluronic acid levels. Furthermore, YHG hindered the activation of hepatic stellate cells (HSCs) and ameliorated oxidative stress injury and inflammation in liver from CCl4-treated mice. YHG prompted the nuclear accumulation of nuclear factor erythroid 2-related factor 2 (Nrf2) and upregulated the expression of Nrf2-dependent downstream antioxidant genes. In addition, YHG promoted mitochondrial biogenesis in liver from CCl4-treated mice, as demonstrated by increased liver adenosine triphosphate content, mitochondrial DNA levels, and the expression of peroxisome proliferator-activated receptor gamma coactivator 1 alpha and nuclear respiratory factor 1.

CONCLUSION

YHG effectively attenuates CCl4-induced liver fibrosis in mice by inhibiting the activation of HSCs, reducing inflammation, alleviating liver oxidative stress damage through Nrf2 activation, and promoting liver mitochondrial biogenesis.

Isobavachalcone attenuates liver fibrosis via activation of the Nrf2/HO-1 pathway in rats

Liver fibrosis, a progression of chronic liver disease, is a significant concern worldwide due to the lack of effective treatment modalities. Recent studies have shown that natural products play a crucial role in preventing and treating liver fibrosis. Isobavachalcone (IBC) is a chalcone compound with anti-inflammatory, antioxidant, and anti-cancer properties. However, its potential antifibrotic effects remain to be elucidated. This study aimed to investigate the antifibrotic effects of IBC on liver fibrosis and its underlying mechanisms in rats. The results showed that IBC significantly ameliorated the pathological damage and collagen deposition in liver tissues; it also reduced the levels of hydroxyproline (HYP), alanine aminotransferase (ALT), and aspartate aminotransferase (AST). In addition, IBC activated Nuclear factor E2-associated factor 2/Hemeoxygenase-1 (Nrf2/HO-1) signaling, leading to the nuclear translocation of Nrf2. This translocation subsequently increased the levels of superoxide dismutase (SOD) and glutathione (GSH) and decreased the levels of malondialdehyde (MDA) and reactive oxygen species (ROS), thereby alleviating oxidative stress-induced damage. Moreover, it inhibited the expression of nuclear factor kappa B (NF-κB), which further reduced the levels of downstream inflammatory factors, such as tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and IL-1 beta (IL-1β), thereby suppressing the activation of HSCs and weakening liver fibrosis. In HSC-T6 cell experiments, changes observed in inflammatory responses, oxidative stress indicators, and protein expression were consistent with the in vivo results. Furthermore, the Nrf2 inhibitor (ML385) attenuated the effect of IBC on inhibiting the activation of quiescent HSCs. Consequently, IBC could alleviate liver fibrosis by activating Nrf2/ HO-1 signaling.

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.

Establishment of a Spontaneous Liver Fibrosis Model in NOD/SCID Mice Induced by Natural Aging

Liver fibrosis, a critical pathological feature of chronic liver diseases, arises from a multitude of pathogenic factors. Consequently, establishing an appropriate animal model to simulate liver fibrosis holds immense significance for comprehending its underlying pathogenesis. Despite the numerous methodologies available for generating liver fibrosis models, they often deviate substantially from the spontaneous age-related liver fibrosis process. In this study, compared with young (12 weeks) and middle-aged NOD/SCID mice (32 weeks), there were a large number of fibrous septum and collagen in the liver tissue of old NOD/SCID mice (43 weeks, 43 W). Immunohistochemical analysis unequivocally indicated heightened α-SMA content within the liver tissue of the 43 W mice, thereby underscoring aging's role in triggering the epithelial-to-mesenchymal transition. In addition, SA-β-gal staining as well as P21 expression were increased, and SIRT1 and SIRT3 expression were decreased in 43 W mice. A comprehensive evaluation encompassing transmission electron microscopy and fluorescence quantitative analysis elucidated compromised mitochondrial function and reduced antioxidant capacity in hepatocytes of the 43 W mice. Furthermore, the aging process activated the pro-fibrotic TGF-β-SMAD pathway, concurrently inducing hepatocellular inflammation. The results of the present study not only validate the successful construction of a spontaneous liver fibrosis mouse model through natural aging induction but also provide initial insights into the mechanisms underpinning age-induced liver fibrosis.

Progress on traditional Chinese medicine in improving hepatic fibrosis through inhibiting oxidative stress

Hepatic fibrosis is a common pathological process that occurs in the development of various chronic liver diseases into cirrhosis and liver cancer, characterized by excessive deposition of the extracellular matrix. In the past, hepatic fibrosis was thought to be a static and irreversible pathological process. In recent years, with the rapid development of molecular biology and the continuous in-depth study of the liver at the microscopic level, more and more evidence has shown that hepatic fibrosis is a dynamic and reversible process. Therefore, it is particularly important to find an effective, simple, and inexpensive method for its prevention and treatment. Traditional Chinese medicine (TCM) occupies an important position in the treatment of hepatic fibrosis due to its advantages of low adverse reactions, low cost, and multi-target effectiveness. A large number of research results have shown that TCM monomers, single herbal extracts, and TCM formulas play important roles in the prevention and treatment of hepatic fibrosis. Oxidative stress (OS) is one of the key factors in the occurrence and development of hepatic fibrosis. Therefore, this article reviews the progress in the understanding of the mechanisms of TCM monomers, single herbal extracts, and TCM formulas in preventing and treating hepatic fibrosis by inhibiting OS in recent years, in order to provide a reference and basis for drug therapy of hepatic fibrosis.

6-Hydroxy-2,2,4-trimethyl-1,2-dihydroquinoline Demonstrates Anti-Inflammatory Properties and Reduces Oxidative Stress in Acetaminophen-Induced Liver Injury in Rats

We examined the effects of 6-hydroxy-2,2,4-trimethyl-1,2-dihydroquinoline on markers of liver injury, oxidative status, and the extent of inflammatory and apoptotic processes in rats with acetaminophen-induced liver damage. The administration of acetaminophen caused the accumulation of 8-hydroxy-2-deoxyguanosine and 8-isoprostane in the liver and serum, as well as an increase in biochemiluminescence indicators. Oxidative stress resulted in the activation of pro-inflammatory cytokine and NF-κB factor mRNA synthesis and increased levels of immunoglobulin G, along with higher activities of caspase-3, caspase-8, and caspase-9. The administration of acetaminophen also resulted in the development of oxidative stress, leading to a decrease in the level of reduced glutathione and an imbalance in the function of antioxidant enzymes. This study discovered that 6-hydroxy-2,2,4-trimethyl-1,2-dihydroquinoline reduced oxidative stress by its antioxidant activity, hence reducing the level of pro-inflammatory cytokine and NF-κB mRNA, as well as decreasing the concentration of immunoglobulin G. These changes resulted in a reduction in the activity of caspase-8 and caspase-9, which are involved in the activation of ligand-induced and mitochondrial pathways of apoptosis and inhibited the effector caspase-3. In addition, 6-hydroxy-2,2,4-trimethyl-1,2-dihydroquinoline promoted the normalization of antioxidant system function in animals treated with acetaminophen. As a result, the compound being tested alleviated inflammation and apoptosis by decreasing oxidative stress, which led to improved liver marker indices and ameliorated histopathological alterations.

Human-Induced Hepatocytes-Derived Extracellular Vesicles Ameliorated Liver Fibrosis in Mice Via Suppression of TGF-β1/Smad Signaling and Activation of Nrf2/HO-1 Signaling

Liver fibrosis is a wound-healing response caused by persistent liver injury and often occurs in chronic liver diseases. Effective treatments for liver fibrosis are still pending. Recent studies have revealed that extracellular vesicles (EVs) derived from primary hepatocytes (Hep-EVs) have therapeutic potential for multiple liver diseases. However, Hep-EVs are difficult to manufacture in bulk because of the limited sources of primary hepatocytes. Human-induced hepatocytes (hiHep) are hepatocyte-like cells that can expand in vitro, and their cell culture supernatant is thus an almost unlimited resource for EVs. This study aimed to investigate the potential therapeutic effects of EVs derived from hiHeps. hiHep-EVs inhibited the expression of inflammatory genes and the secretion of inflammation-related cytokines, and suppressed the activation of hepatic stellate cells by inhibiting the transforming growth factor (TGF)-β1/Smad signaling pathway. The anti-inflammatory and antifibrotic effects of hiHep-EVs were similar to those of mesenchymal stem cell-EVs. Furthermore, the administration of hiHep-EVs ameliorated oxidative stress, inflammation, and fibrosis in a CCl4-induced liver fibrosis mouse model. The expression of α smooth muscle actin, collagen I, and collagen III was reduced, which may be attributed to the regulation of matrix metalloproteinase (MMP)-9, tissue inhibitor of metalloproteinases (TIMP)-1, and TIMP-2 by hiHep-EVs, and the protein expression of Nrf2, HO-1, and NQO1 was increased. Taken together, our results suggested that hiHep-EVs alleviated liver fibrosis by activating the Nrf2/HO-1 signaling pathway and inhibiting the TGF-β1/Smad signaling pathway. This study revealed the hepatoprotective effect of hiHep-EVs, and provided a new approach to treating liver fibrosis.

Therapeutic potential and mechanism of Chinese herbal medicines in treating fibrotic liver disease

Liver fibrosis is a pathological condition characterized by replacement of normal liver tissue with scar tissue, and also the leading cause of liver-related death worldwide. During the treatment of liver fibrosis, in addition to antiviral therapy or removal of inducers, there remains a lack of specific and effective treatment strategies. For thousands of years, Chinese herbal medicines (CHMs) have been widely used to treat liver fibrosis in clinical setting. CHMs are effective for liver fibrosis, though its mechanisms of action are unclear. In recent years, many studies have attempted to determine the possible mechanisms of action of CHMs in treating liver fibrosis. There have been substantial improvements in the experimental investigation of CHMs which have greatly promoted the understanding of anti-liver fibrosis mechanisms. In this review, the role of CHMs in the treatment of liver fibrosis is described, based on studies over the past decade, which has addressed the various mechanisms and signaling pathways that mediate therapeutic efficacy. Among them, inhibition of stellate cell activation is identified as the most common mechanism. This article provides insights into the research direction of CHMs, in order to expand its clinical application range and improve its effectiveness.

Dietary Polyphenols Remodel DNA Methylation Patterns of NRF2 in Chronic Disease

The nuclear factor erythroid 2-related factor 2 (NRF2) is a transcription factor crucial in regulating cellular homeostasis and apoptosis. The NRF2 gene has been implicated in various biological activities, including antioxidant, anti-inflammatory, and anticancer properties. NRF2 can be regulated genetically and epigenetically at the transcriptional, post-transcriptional, and translational levels. Although DNA methylation is one of the critical biological processes vital for gene expression, sometimes, anomalous methylation patterns result in the dysregulation of genes and consequent diseases and disorders. Several studies have reported promoter hypermethylation downregulated NRF2 expression and its downstream targets. In contrast to the unalterable nature of genetic patterns, epigenetic changes can be reversed, opening up new possibilities in developing therapies for various metabolic disorders and diseases. This review discusses the current state of the NRF2-mediated antioxidative and chemopreventive activities of several natural phytochemicals, including sulforaphane, resveratrol, curcumin, luteolin, corosolic acid, apigenin, and most other compounds that have been found to activate NRF2. This epigenetic reversal of hypermethylated NRF2 states provides new opportunities for research into dietary phytochemistry that affects the human epigenome and the possibility for cutting-edge approaches to target NRF2-mediated signaling to prevent chronic disorders.

Swietenine inhibited oxidative stress through AKT/Nrf2/HO-1 signal pathways and the liver-protective effect in T2DM mice: In vivo and in vitro study

Swietenia macrophylla King, belongs to the Meliaceae family, is a valuable medicinal plant and its fruits have been processed commercially to a variety of health foods. The seeds have long been known for their ethnomedicinal significance against these diseases. Swietenine (Swi) was isolated from S. macrophylla and could ameliorate inflammation and oxidative stress. In this study, HepG2 cells induced by H₂ O₂ were used to construct oxidative stress model in vitro. The aim of this study was to investigate the protective effect of Swi on H₂ O₂ induced oxidative injury in HepG2 cells and its molecular mechanism, and to explore the effect of Swi on liver injury in db/db mice and its possible mechanism. The results showed that Swi significantly inhibited HepG2 cells viability and reduced oxidative damage in a dose-dependent manner as evidenced by a range of biochemical analysis and immunoblotting study. Moreover, it induced the protein and mRNA expression of HO-1 together with its upstream mediator Nrf2 and activated the phosphorylation of AKT in HepG2 cells. LY294002, a PI3K/AKT inhibitor, significantly suppressed the Nrf2 nuclear translocation and HO-1 expression in H₂ O₂ induced HepG2 cells treated with Swi. In addition, RNA interference with Nrf2 significantly reduced the expression level of Nrf2 and HO-1 in the nucleus. Swi has a significant protective effect on cell damage in H₂ O₂ induced HepG2 cells by increasing the antioxidant capacity which is achieved through the AKT/Nrf2/HO-1 pathway. Additionally, in vivo, Swi could protect the liver of type 2 diabetic mice by improving lipid deposition in liver tissue and inhibiting oxidative stress. These findings indicated that Swi can be a promising dietary agent to improve type 2 diabetes.

Ginseng polysaccharide reduces autoimmune hepatitis inflammatory response by inhibiting PI3K/AKT and TLRs/NF-κB signaling pathways

BACKGROUND

Ginseng polysaccharides (GP) have been found to exhibit significant immune regulatory effects, making them a promising candidate for treating immune-related diseases. However, their mechanism of action in immune liver injury is not yet clear. The innovation of this study lies in exploring the mechanism of action of ginseng polysaccharides (GP) in immune liver injury. While GP has been previously identified for its immune regulatory effects, this study aims to provide a clearer understanding of its therapeutic potential for immune-related liver diseases.

PURPOSE

The purpose of this study is to characterize low molecular weight gingeng polysaccharides (LGP), investigate their effect on ConA-induced autoimmune hepatitis (AIH), and identify their potential molecular mechanisms.

METHODS

LGP was extracted and purified using water-alcohol precipitation, DEAE-52 cellulose column, and Sephadex G200. And its structure was analyzed. It was then evaluated for anti-inflammatory and hepatoprotective effects in ConA-induced cells and mice, assessing cellular viability and inflammation with Cell Counting Kit-8 (CCK-8), Reverse Transcription-polymerase Chain Reaction (RT-PCR), and Western Blot, and hepatic injury, inflammation, and apoptosis with various biochemical and staining methods.

RESULTS

LGP is a polysaccharide composed of glucose (Glu), galactose (Gal), and arabinose (Ara), with a molar ratio of 12.9:1.6:1.0. LGP has a low crystallinity amorphous powder structure and is free from impurities. LGP enhances cell viability and reduces inflammatory factors in ConA-induced RAW264.7 cells and inhibits inflammation and hepatocyte apoptosis in ConA-induced mice. LGP inhibits Phosphoinositide 3-kinase/protein kinase B (PI3K/AKT) and Toll-like receptors/Nuclear factor kappa B (TLRs/NF-κB) signaling pathways in vitro and in vivo to treat AIH.

CONCLUSIONS

LGP was successfully extracted and purified, exhibiting potential as a treatment for ConA-induced autoimmune hepatitis due to its ability to inhibit the PI3K/AKT and TLRs/NF-κB signaling pathways and protect liver cells from damage.

Synergistic effect of Rosemary and Lemon extractions on some physiological and biochemical parameters of CCl4-Stressed male rats

This study was carried out to examine the preventive impact of marine extracts of rosemary and lemon individually or together in adult-male rats with liver injury induced by carbon tetrachloride. The extracts were prepared and tested on 40 male rats distributed into groups by collecting blood samples and conducting some hematological and biochemical parameters. CCl4-induced significant increases in the weight of the liver and heart, while rosemary and lemon extracts alone were not able to restore the liver weight, but the effect was in the synergy. As well, the extracts alone or in combination had a significant impact on reducing heart weight. Additionally, CCl4 caused a substantial reduction in RBC, Hb, PCV, MCV, MCHC and lymphocytes, whereas WBC, monocyte and granulocyte increased. While extracts exhibited an enhancement in these parameters, the best effect was when the two extracts were used together. The biochemical parameters indicated high significance in glucose, AST, ALT and triglycerides; however, total protein, albumin, cholesterol and T-AOC decreased compared to the control group. Both rosemary and lemon worked to restore and remove the oxidative effect. Keywords: Rosemary(A plant that grows in mountainous regions), Lemon, Carbon tetrachloride, Stress, Rats.

Salvianolic acid A suppresses CCl4-induced liver fibrosis through regulating the Nrf2/HO-1, NF-κB/IκBα, p38 MAPK, and JAK1/STAT3 signaling pathways

Salvianolic acid A (SA-A), a water-soluble compound extracted from traditional Chinese herb Radix Salvia miltiorrhiza, has anti-fibrotic effects on carbon tetrachloride (CCl₄)-induced liver fibrosis. However, the underlying molecular mechanism remains unclear. Thus, this study aimed to elucidate the molecular mechanism underlying the anti-fibrotic effects of SA-A on CCl₄-induced liver fibrosis in mice. All mice (except control group) were intraperitoneally administered CCl₄ dissolved in peanut oil to induce liver fibrosis. Treatment groups were then gavaged with SA-A (20 or 40 mg/kg). The liver function index; liver fibrosis index; and superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione peroxidase (GSH-Px) levels were determined. Furthermore, histopathological changes in liver tissues were observed via hematoxylin-eosin and Masson's trichrome staining. The expression of α-smooth muscle actin (α-SMA) and collagen I was detected using immunofluorescence, and the mRNA levels of inflammatory factors were determined using quantitative polymerase chain reaction. Finally, western blotting and immunofluorescence were used to determine the expression levels of proteins related to Nrf2/HO-1, NF-κB/IκBα, p38 MAPK, and JAK1/STAT3 signaling pathways. The results showed that SA-A could ameliorate CCl₄-induced liver injury and liver fibrosis, improve morphology, and alleviate collagen deposition in the fibrotic liver. Moreover, SA-A could regulate the Nrf2/HO-1, NF-κB/IκBα, p38 MAPK, and JAK1/STAT3 signaling pathways; increase the levels of SOD and GSH-Px; and decrease MDA level in the fibrotic liver. Collectively, our study findings indicate that SA-A is effective in preventing liver fibrosis in mice by inhibiting inflammation and oxidative stress via regulating the Nrf2/HO-1, NF-κB/IκBα, p38 MAPK, and JAK1/STAT3 signaling pathways.

A novel mechanistic approach for the anti-fibrotic potential of rupatadine in rat liver via amendment of PAF/NF-ĸB p65/TGF-β1 and hedgehog/HIF-1α/VEGF trajectories

Hepatic fibrosis is one of the major worldwide health concerns which requires tremendous research due to the limited outcomes of the current therapies. The present study was designed to assess, for the first time, the potential therapeutic effect of rupatadine (RUP) in diethylnitrosamine (DEN)-induced liver fibrosis and to explore its possible mechanistic actions. For the induction of hepatic fibrosis, rats were treated with DEN (100 mg/kg, i.p.) once weekly for 6 consecutive weeks, and on the 6th week, RUP (4 mg/kg/day, p.o.) was administered for 4 weeks. Treatment with RUP ameliorated changes in body weights, liver indices, liver function enzymes, and histopathological alterations induced by DEN. Besides, RUP amended oxidative stress, which led to the inhibition of PAF/NF-κB p65-induced inflammation, and, subsequently, prevention of TGF-β1 elevation and HSCs activation as indicated by reduced α-SMA expression and collagen deposition. Moreover, RUP exerted significant anti-fibrotic and anti-angiogenic effects by suppressing Hh and HIF-1α/VEGF signaling pathways. Our results highlight, for the first time, a promising anti-fibrotic potential of RUP in rat liver. The molecular mechanisms underlying this effect involve the attenuation of PAF/NF-κB p65/TGF-β1 and Hh pathways and, subsequently, the pathological angiogenesis (HIF-1α/VEGF).

Protective effect of acrocarpus fraxinifolius extract against hepatic fibrosis induced by Gamma irradiation and carbon tetrachloride in albino rats

PURPOSE

Liver fibrosis is considered as one of the ultimate outcomes of chronic liver disorders, characterized by outrageous cell proliferation and abnormal deposition of extracellular matrix, resulting in sever pathological distortions in the architecture and performance of liver tissues. The present study aimed to investigate the protective properties of aqueous methanol extract of Acrocarpus fraxinifolius leaves (AFL) against liver fibrosis induced by dual toxicity of γ-irradiation and carbon tetrachloride (CCl₄) in rats.

METHODS

The animals were exposed to 2 Gy irradiation once/week concurrently with intraperitoneal administration of CCl₄ (0.2 mL/100 g body weight) for seven weeks. Afterwards, liver toxicity and fibrosis were assessed biochemically at cellular and molecular as well as histopathological levels.

RESULTS

The livers of intoxicated rats showed distinct structural and functional changes, compared with the normal rats. The administration of AFL (500 mg/kg, p.o) significantly ameliorated the histopathological manifestations of fibrotic liver evidenced by mitigated steatosis progression, necrosis, fibrotic septa, apoptotic bodies, and immunochistochemical studies of alpha-smooth muscle actin. Also, AFL increased the final body weight, total protein, albumin levels and albumin/globulin ratio. While, the absolute liver weight, liver enzymes, total cholesterol and triglycerides were reduced. A significant modulation was observed in hydroxyproline, transforming growth factor-β and collagen-1expression. Furthermore, AFL exerted a direct effect on liver fibrosis by promoting extracellular matrix degradation via overexpression of the tissue inhibitor metalloproteinase-1, coupled with decease of metalloproteinase-9 activity.

CONCLUSIONS

Our findings suggested that AFL effectively improved the architecture of fibrotic liver and modified the biochemical markers of liver fibrosis.

Hepatoprotective effects of norgalanthamine on carbon tetrachloride induced-hepatotoxicity in mice

Norgalanthamine is a major component of Crinum asiaticum var. japonicum that exhibits several biological activities. This study evaluated the anti-inflammatory and anti-oxidative properties of norgalanthamine in mice with carbon tetrachloride (CCl₄)-induced liver injury. Norgalanthamine (1 and 10 mg/kg) was orally administered to mice for 7 or 14 days, after which liver injury was induced by CCl₄ (1.5 ml/kg, i.p.). The vehicle and positive controls consisted of phosphate-buffered saline and silymarin (100 mg/kg), respectively. In CCl₄-injured mice, norgalanthamine pretreatment significantly reversed the increases in serum alanine aminotransferase, aspartate aminotransferase, and total bilirubin levels, and the decrease in the serum glucose level. In the liver, norgalanthamine restored the activities of the antioxidant enzymes superoxide dismutase and catalase, while reducing lipid accumulation and, concurrently, the expression of genes involved in lipid synthesis, including peroxisome proliferator-activated receptor γ and adipocyte protein-2. Norgalanthamine also ameliorated inflammation by down-regulating the expression of the pro-inflammatory mediators, TNF-α, IL-1β, and MCP-1, and up-regulating the Nrf2/HO-1 pathway. In addition, norgalanthamine decreased collagen deposition in liver tissue as shown on picrosirius red staining by down-regulating expression of the fibrosis-related genes αSMA and fibronectin. Collectively, these findings imply that norgalanthamine mitigates CCl₄-induced hepatic injury by increasing anti-oxidative activity, down-regulating pro-inflammatory mediators and fibrosis-related genes in the liver.HighlightsNorgalanthamine ameliorated the hepatotoxicity after CCl₄ injury.Norgalanthamine suppressed the activation of Kupffer cells and macrophages.Norgalanthamine down-regulated pro-inflammatory mediators.Norgalanthamine increased anti-oxidative activity via the Nrf2/HO-1 pathway.Norgalanthamine downregulated fibrosis-related genes in the liver.

Nuclear factor erythroid 2-related factor 2-mediated signaling and metabolic associated fatty liver disease

Oxidative stress is a key driver in the development and progression of several diseases, including metabolic associated fatty liver disease (MAFLD). This condition includes a wide spectrum of pathological injuries, extending from simple steatosis to inflammation, fibrosis, cirrhosis, and hepatocellular carcinoma. Excessive buildup of lipids in the liver is strictly related to oxidative stress in MAFLD, progressing to liver fibrosis and cirrhosis. The nuclear factor erythroid 2-related factor 2 (NRF2) is a master regulator of redox homeostasis. NRF2 plays an important role for cellular protection by inducing the expression of genes related to antioxidant, anti-inflammatory, and cytoprotective response. Consistent evidence demonstrates that NRF2 is involved in every step of MAFLD deve-lopment, from simple steatosis to inflammation, advanced fibrosis, and ini-tiation/progression of hepatocellular carcinoma. NRF2 activators regulate lipid metabolism and oxidative stress alleviating the fatty liver disease by inducing the expression of cytoprotective genes. Thus, modulating NRF2 activation is crucial not only in understanding specific mechanisms underlying MAFLD progression but also to characterize effective therapeutic strategies. This review outlined the current knowledge on the effects of NRF2 pathway, modulators, and mechanisms involved in the therapeutic implications of liver steatosis, inflammation, and fibrosis in MAFLD.

The beneficial effects of traditional Chinese medicine on antioxidative status and inflammatory cytokines expression in the liver of piglets

Oxidative stress and inflammation seriously affected the growth and development of piglets. Traditional Chinese medicine (TCM) prescriptions has been used to prevent various diseases of piglets, including anti-inflammatory and antioxidant. Here, we identified the effects of Xiao-Jian-Zhong-Tang (XJZT) and Jingsananli-sepsis (JJS) on the oxidative stress and inflammatory in the liver of piglets. The piglets were fed with the basal diet (Control group), basal diet affixed with 10 g/kg XJZT (TCM I group), and basal diet affixed with 3 g/kg JJS (TCM II group), respectively. The serum was gathered on days 30 and 60 and the liver samples were also collected on day 60. Results showed that the TCM I and TCM II markedly increased the activities of the glutathione peroxidase (GSH-Px) and total antioxidant capacity (T-AOC), and reduced the levels of malonaldehyde (MDA), TNF-α, IL-6, and IL-8 in serum. In addition, compared to the control group, Nrf2, SOD-1, NQO-1, and HO-1 mRNA expression levels and the protein levels of Nrf2 and HO-1 were significantly increased while NF-κB, TNF-α, IL-6, and IL-8 mRNA expression levels and the phosphorylation levels of NF-κB and IκB-α were decreased in TCM I and TCM II groups. Collectively, these findings suggested that TCM I and TCM II could enhance anti-oxidative and anti-inflammatory capabilities in the liver of piglets via the Nrf2/NF-κB pathway, providing a basis for the functional exploration of TCM prescriptions.

Salvia miltiorrhiza in thorax and abdomainal organ fibrosis: A review of its pharmacology

Organ fibrosis is a common pathological change that finally results in organ failure, which involves the destruction of parenchyma cells, the activation of mesenchymal cells and the imbalance of immunological cells. In recent years, although some breakthroughs have been made in understanding the pathogenesis and therapeutics of organ fibrosis, no registered drugs could directly target the fibrotic process, which constitutes a major biomedical challenge. Salvia miltiorrhiza (SM) is a well-known medicinal plant in China, which has been widely applied because of its pharmacological effects on anti-oxidative, anti-myocardial infarction, anti-fibrotic, anti-inflammatory, and anti-neoplastic properties. Accumulated evidence suggested that SM played critical roles against organ fibrosis in vivo and in vitro experiments by its multiple biological compounds. In this review, we discussed the recent advances on the phytochemistry and pharmacological mechanisms of SM and its active ingredients in liver, lung, kidney, and heart fibrosis, which might help to promote the treatment of fibrotic diseases in thorax and abdomainal viscera in clinic.

Synthesis and preparation of vitamin A coupled butein-loaded solid lipid nanoparticles for liver fibrosis therapy in rats

The development of a therapeutic system for hepatic fibrosis has become a research hotspot to date. Butein, a simple chalcone derivative, displays anti-fibrotic effects through different pathways. However, impurities, low solubility, and low concentration in the target tissue hinder therapy with herbal ingredients. Hepatic stellate cells (HSCs), the vitamin A (VA) storage cells, as the main contributors to liver fibrogenesis, are not readily accessible to drugs owing to their anatomical location. Targeted delivery of therapeutics to the activated HSCs is therefore critical for successful treatment. For these reasons, the current study aimed at increasing butein delivery to the liver. Hence, high purity butein was synthesized in three steps. A novel VA-Myrj52 ester conjugate was also synthesized using all-trans retinoic acid and a hydrophilic emulsifier (Myrj52) as a targeting agent. Next, butein was encapsulated inside the novel VA-modified solid lipid nanoparticles (VA-SLNs) and studied in vitro and in vivo. According to our evaluations, negatively charged SLNs with a mean diameter of 150 nm and entrapment efficacy of 75 % were successful in liver fibrosis amelioration. Intraperitoneal (i.p.) injection of VA-SLNs in fibrotic rats, for four weeks long, reduced serum AST and ALT by 58% (P, 0.001) and 72% (P, 0.05), respectively, concerning the CCl₄ group. Additionally, histologic damage score decline and normalization of tissue oxidative stress markers collectively confirmed the efficacy of formulations in hepatic fibrosis and kidney damage amelioration.

Is human umbilical cord mesenchymal stem cell-derived conditioned medium effective against oxidative and inflammatory status in CCl4- induced acute liver injury?

INTRODUCTION

Acute liver injury (ALI) is diagnosed by detection of elevated liver enzymes within six months after liver damage. Mesenchymal stem cells (MSCs) have recently been considered a beneficial strategy for treating various diseases due to holding secretory factors. Therapeutic effects of human umbilical cord MSCs-derived conditioned medium (hMSC-CM) were evaluated on CCl₄-induced ALI.

MATERIALS AND METHODS

Twenty-four male Wistar rats were divided into groups including N (received saline), ALI (received CCl₄), RPMI (received CCl₄ and RPMI medium), and ALI-CM (received CCl₄ and hMSC-CM) groups. The expression of TNF-α and TGFβ-1 genes was evaluated with qPCR. Hepatic levels of TNF-α and TGF-β were measured by ELISA. Total antioxidant capacity (TAC), total oxidant status (TOS), malondialdehyde (MDA), glutathione peroxidase (GPx) activity, and catalase (CAT) activity were also assayed. Hematoxylin-eosin (H&E), Masson's trichrome, reticulin, and Periodic Acid-Schiff (PAS) stainings were conducted to evaluate tissue lesions.

RESULTS

CCl₄ increased expression of TNF-α and TGF-1β at both mRNA and protein levels, while hMSC-CM decreased these parameters in the ALI-CM group. TAC levels significantly decreased in the ALI group, and CCl₄ increased TOS and MDA levels compared with the N group. hMSC-CM treatment led to the return of these parameters to their baseline levels. GPx and CAT activity in the ALI group were significantly lower than in the N group and hMSC-CM reduced these parameters to the baseline in the ALI-CM group. hMSC-CM modulated CCl₄-induced tissue lesions.

CONCLUSION

The present study suggests hMSC-CM probably improves CCl₄-induced ALI through its antioxidant and anti-inflammatory effects.

Lipophilic Constituents in Salvia miltiorrhiza Inhibit Activation of the Hepatic Stellate Cells by Suppressing the JAK1/STAT3 Signaling Pathway: A Network Pharmacology Study and Experimental Validation

Liver fibrosis is currently a global health challenge with no approved therapy, with the activation of hepatic stellate cells being a principal factor. Lipophilic constituents in Salvia miltiorrhiza (LS) have been reported to improve liver function and reduce the indicators of liver fibrosis for patients with chronic hepatitis B induced hepatic fibrosis. However, the pharmacological mechanisms of LS on liver fibrosis have not been clarified. In this study, 71 active compounds, 342 potential target proteins and 22 signaling pathways of LS were identified through a network pharmacology strategy. Through text mining and data analysis, the JAK1/STAT3 signaling pathway was representatively selected for further experimental validation. We firstly confirmed the protective effect of LS on liver fibrosis in vivo by animal experiments. Hepatic stellate cells, which proliferated and displayed a fibroblast-like morphology similar to activated primary stellate cells, were applied to evaluate its underlying mechanisms. The results showed that LS could inhibit the cell viability, promote the cell apoptosis, decrease the expression of liver fibrosis markers, and downregulate the JAK1/STAT3 signaling pathway. These results demonstrated that LS could exert anti-liver-fibrosis effects by inhibiting the activation of HSCs and regulating the JAK1/STAT3 signaling pathway, which is expected to benefit its clinical application.

Lyophyllum decastes fruiting body polysaccharide alleviates acute liver injury by activating the Nrf2 signaling pathway

Polysaccharides have high antioxidant, hypoglycemic, hypolipidemic, hepatoprotective, anti-tumor, and anticancer activities. In this study, the ability of the Lyophyllum decastes fruiting body polysaccharide (LDFP) to protect against CCl₄-induced acute liver injury in mice by activating the Nrf2 pathway was studied. LDFP can inhibit the activity of ALT, AST, TC, TG, tumor necrosis factor (TNF-α), and interleukin-6 (IL-6) in serum; significantly improve the inflammatory state of the liver; increase the activity of superoxide dismutase (SOD) and the glutathione (GSH) content; decrease the malondialdehyde (MDA) content; alleviate the toxicity caused by reactive oxygen species; and alleviate liver injury. Immunohistochemistry and western blot showed that LDFP can activate the Nrf2 pathway, up-regulate the expression of Nrf2, down-regulate the expression of Keap1, and increase the expression of the anti-oxidation factors HO-1 and CuZn-SOD. At the same time, it was found that the expression of the transcription factors TLR-4 and NF-κB were decreased in the NF-κB signaling pathway, the synthesis and secretion of the pro-inflammatory factors IL-6 and TNF-α were decreased consequently. These results suggest that LDFP protects the liver by activating the Nrf2 pathway and reducing the inflammatory response. Generally, the results of this study could be used to aid the development of hepatoprotective products and their application.

Modified Lipid Nanocapsules for Targeted Tanshinone IIA Delivery in Liver Fibrosis

Introduction

Liver fibrosis represents a serious global disease with no approved treatment. Tanshinone IIA (TSIIA) is a phytomedicine with documented activity in treating many hepatic disorders. TSIIA has been reported to have potent anti-inflammatory and antioxidant properties. It can also induce apoptosis for activated hepatic stellate cells, and is thereby considered as a promising herbal remedy for treating fibrotic liver. However, its poor aqueous solubility, short half-life, exposure to the first-pass effect, and low concentration reaching targeted cells constitute the major barriers hindering its effective therapeutic potential. Therefore, this work aimed at enhancing TSIIA systemic bioavailability together with achieving active targeting potential to fibrotic liver via its incorporation into novel modified lipid nanocapsules (LNCs).

Methods

Blank and TSIIA-loaded LNCs modified with either hyaluronate sodium or phosphatidyl serine were successfully prepared, optimized, and characterized both in vitro and in vivo.

Results

The developed LNCs showed good colloidal properties (size ≤100 nm and PDI ≤0.2), high drug-entrapment efficiency (>97%) with sustained-release profile for 24 hours, high storage stability up to 6 months, and good in vitro serum stability. After a single intraperitoneal injection, the administered LNCs exhibited a 2.4-fold significant increase in AUC_0–∞ compared with the TSIIA suspension (p≤0.01). Biodistribution-study results proved the liver-targeting ability of the prepared modified LNCs, with a significant ~1.5-fold increase in hepatic accumulation compared with the unmodified formulation (p≤0.05). Moreover, the modified formulations had an improved antifibrotic effect compared with both unmodified LNCs and TSIIA suspension, as evidenced by the results of biochemical and histopathological evaluation.

Conclusion

The modified TSIIA-LNCs could be regarded as promising novel targeted nanomedicines for effective management of liver fibrosis.

Astragaloside IV inhibits hepatocellular carcinoma by continually suppressing the development of fibrosis and regulating pSmad3C/3L and Nrf2/HO-1 pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Astragalus is a medicinal herb used in China for the prevention and treatment of diseases such as diabetes and cancer. As one of the main active ingredients of astragalus, Astragaloside IV (AS-IV) has a wide range of pharmacological effects, including anti-inflammation and anti-cancer effects.

AIM OF THE STUDY

Different phosphorylated forms of Smad3 differentially regulate the progression of hepatic carcinoma. The phosphorylation of the COOH-terminal of Smad3 (pSmad3C) and activation of the Nrf2/HO-1 pathway inhibits hepatic carcinoma, while phosphorylation of the linker region of Smad3 (pSmad3L) promotes progression. Thus, pSmad3C/3L and Nrf2/HO-1 pathways are potential targets for drug of anti-cancer development. AS-IV is anti-apoptotic and can inhibit hepatocellular carcinoma cell (HCC) proliferation, invasion, and tumor growth in nude mice. However, it is not clear whether AS-IV has a therapeutic effect on inhibiting the progression of primary liver cancer by regulating the pSmad3C/3L and Nrf2/HO-1 pathway. The purpose of this study is to investigate whether AS-IV inhibits hepatocellular carcinoma by regulating pSmad3C/3L and Nrf2/HO-1 pathway.

MATERIALS AND METHODS

primary liver cancer in mice induced by DEN/CCl₄/C₂H₅OH (DCC) and HSC-T6/HepG2 cell models activated by TGF-β₁ was investigated for the mechanisms of AS-IV. In vivo assays included liver biopsy, histopathology and post-mortem analysis included immunohistochemistry, immunofluorescent, and Western blotting analysis, and in vitro assays included immunofluorescent, and Western blotting analysis.

RESULTS

AS-IV significantly inhibited the development of primary liver cancer, reflecting improved liver biopsy, histopathology. The incidence and multiplicity of primary liver cancer were markedly decreased by AS-IV treatment at the 20th week. AS-IV had observable effects on the TGF-β₁/Smad and Nrf2/HO-1 expression in vivo, especially up-regulated pSmad3C, pNrf2, HO-1, and NQO1, while it down-regulated pSmad2C, pSmad2L, pSmad3L, PAI-1, and α-SMA at the 12th week and the 20th week. Furthermore, in vitro analysis further confirmed that AS-IV regulated the expression of pSmad3C/3L and Nrf2/HO-1 pathway in HSC-T6 and HepG2 cells activated by TGF-β₁.

CONCLUSION

AS-IV administration delays the occurrence of primary liver cancer by continually suppressing the development of fibrosis, the mechanism of the therapeutic effect involving the regulation of the pSmad3C/3L and Nrf2/HO-1 pathways, especially in regulation reversibility and antagonism of pSmad3C and pSmad3L and promoting the phosphorylation of Nrf2.

Modulation of vascular contraction via soluble guanylate cyclase signaling in a novel ex vivo method using rat precision-cut liver slices

Fibrotic processes in the liver of non-alcoholic steatohepatitis (NASH) patients cause microcirculatory dysfunction in the organ which increases blood vessel resistance and causes portal hypertension. Assessing blood vessel function in the liver is challenging, necessitating the development of novel methods in normal and fibrotic tissue that allow for drug screening and translation toward pre-clinical settings. Cultures of precision cut liver slices (PCLS) from normal and fibrotic rat livers were used for blood vessel function analysis. Live recording of vessel diameter was used to assess the response to endothelin-1, serotonin and soluble guanylate cyclase (sGC) activation. A cascade of contraction and relaxation events in response to serotonin, endothelin-1, Ketanserin and sGC activity could be established using vessel diameter analysis of rat PCLS. Both the sGC activator BI 703704 and the sGC stimulator Riociguat prevented serotonin-induced contraction in PCLS from naive rats. By contrast, PCLS cultures from the rat CCl4 NASH model were only responsive to the sGC activator, thus establishing that the sGC enzyme is rendered non-responsive to nitric oxide under oxidative stress found in fibrotic livers. The role of the sGC pathway for vessel relaxation of fibrotic liver tissue was identified in our model. The obtained data shows that the inhibitory capacities on vessel contraction of sGC compounds can be translated to published preclinical data. Altogether, this novel ex vivo PCLS method allows for the differentiation of drug candidates and the translation of therapeutic approaches towards the clinical use.

Polyphenol-rich leaf of Aphanamixis polystachya averts liver inflammation, fibrogenesis and oxidative stress in ovariectomized Long-Evans rats

Aphanamixis polystachya (Wall.) R.Parker, locally known as Pithraj, is a medicinal herb having enormous traditional applications. However, the scientific rationale underlying the ethnomedicinal claims was not well-founded. The current investigation aimed to explore the mechanistic insights of protective effects of ethanol extract of A. polystachya leaf (PT), given orally, on the chemical-intoxicated hepatic inflammation and fibrosis in Long-Evans female overiectomized rats. The GC-MS and HPLC-DAD analysis of PT revealed the presence of several bioactive metabolites, including polyphenolic compounds. Catechin hydrate, caffeic acid, syringic acid, epicatechin and p-coumaric acid have been identified and quantified in the ethanol extract of PT leaf. Intoxication with CCl₄ developed the oxidative stress, fibrosis and inflammation in liver of rats. Moreover, thiobarbituric acid reactive substances (TBARS), nitric oxide (NO), advanced protein oxidation product (APOP) level were found increased; whereas superoxide dismutase (SOD) and catalase activities in the plasma and liver were decreased in CCl₄ administered rats. Treatment with PT prominently mitigated the oxidative stress (TBARS, NO, APOP), and inflammatory (MPO) markers and improved the endogenous antioxidant enzymes (catalase and SOD) activities in CCl₄-intoxicated rats. Additionally, histological assessment confirmed the clear manifestation of inflammation and fibrosis in the liver of CCl₄-intoxicated rats, which was prevented by PT and silymarin treatment. In conclusion, PT treatment may protect the liver in CCl₄-administered rats, probably by mitigating oxidative stress, inflammation and fibrosis, and also augmenting the function of the antioxidant enzymes.

Propolis nanoparticles modulate the inflammatory and apoptotic pathways in carbon tetrachloride-induced liver fibrosis and nephropathy in rats

This study assessed the use of emulsion-produced propolis nanoparticles for treating carbon tetrachloride (CCl4 )-induced liver fibrosis and nephropathy on albino rat model. The evaluation of hepatotoxicity, nephrotoxicity, and the treatment outcomes involved biochemical investigations of blood samples as well as molecular analysis, and histopathological assessment for liver and kidney tissue samples. CCl4 treatment caused elevated biochemical indicators of hepatotoxic and nephrotoxic effects as detected by liver and kidney functions tests, which improved gradually with propolis nanoparticles treatment. The molecular studies showed an increase in transforming growth factor β (TGF-β), Nephrin, and Caspase-9, while Bcl-2 levels dropped in both liver and kidney tissue samples; such changes were normalized after treatment. The histological findings confirm both biochemical and molecular studies. Our results indicated that propolis nanoparticles had an anti-inflammatory effect as proved by decreased expression of TGF-β in liver tissue and Nephrin in kidney tissue. The propolis nanoparticles showed an anti-apoptotic effect on liver and kidney tissue increasing the expression of Bcl-2 and decreasing the expression of Caspase-9.

Citronellal ameliorates doxorubicin-induced hepatotoxicity via antioxidative stress, antiapoptosis, and proangiogenesis in rats

Doxorubicin (DOX) is a very effective broad-spectrum anticancer drug, yet its clinical application is badly restricted due to its serious side effects. Citronellal (CT), a specialized metabolite of plants found in Cymbopogon spp., is proved to exhibit many beneficial properties. In the current study, we intended to investigate the effect of CT on DOX-induced hepatotoxicity in rats. Rats were treated with CT (200 mg/kg b.w./day orally), and given DOX (2.5 mg/kg b.w./week, intraperitoneally) to induce hepatotoxicity for six consecutive weeks. The results showed that CT administration could attenuate the DOX-induced pathological changes of liver tissues and ameliorated the inappropriate alteration of liver function biomarkers (serum glutamic aspartate aminotransferase, glutamic pyruvic transaminase, and albumin) in serum and oxidative stress parameters (malondialdehyde, superoxide dismutase, and reduced glutathione) in the liver. Moreover, CT mitigated the Bax/Bcl-2 ratio and caspase-3 expression to inhibit cell apoptosis. Further study indicated that CT therapy could enhance the protein levels of p-PI3K, p-Akt, and CD31 in the liver. These results demonstrate that CT can ameliorate DOX-induced hepatotoxicity in rats mediated by antioxidative stress, antiapoptosis, and proangiogenesis.

The role of WNT/β-catenin signaling pathway and glutamine metabolism in the pathogenesis of CCl4-induced liver fibrosis: Repositioning of niclosamide and concerns about lithium

BACKGROUND

Liver fibrosis is a serious health problem which may lead to advanced liver cirrhosis and hepatocellular carcinoma.

OBJECTIVE

The present study aimed to investigate the role of Wnt/β-catenin signaling pathway and glutamine aminohydrolase enzyme (l-glutaminase) in the pathogenesis of liver fibrosis and the potential benefits of niclosamide in treating liver fibrosis.

METHODS

Ninety male Albino rats were divided into 6 equal groups (n = 15) as follows: a normal control group (NC), CCl₄-only treated group (Fib.) which received 1 mg/kg CCl₄ two times weekly, niclosamide-treated group (Niclo.) which received 5 mg/kg of niclosamide one time daily, lithium chloride-treated group (LiCl) which received 100 mg/kg of LiCl one time daily, niclosamide-and-CCl₄-treated group (Niclo. + Fib.) which received same doses of niclosamide and CCl₄ given to other groups, and finally lithium chloride-and-CCl₄-treated rat group (LiCl + Fib.) which received same doses of LiCl and CCl₄ given to other groups. All treatments were administered orally for 8 weeks. Liver tissue was assessed for l-hydroxyproline, beta-catenin (β-catenin), l-glutaminase activity, as well as the gene expression of transforming growth factor beta-1 (TGF-β1) and Dishevelled-2 (Dvl2). Histopathological and immunohistochemical analyses of alpha smooth muscle actin α-SMA were performed. Serum alanine transaminase (ALT), aspartate transaminase (AST), and total bilirubin were measured.

RESULTS

The group of niclosamide-and-CCl₄-treated rats showed a significant decrease in total bilirubin, ALT and AST, β-catenin, l-hydroxyproline, l-glutaminase activity, and gene expression of TGF-β1 and Dvl2. Moreover, the liver tissue in this group of rats showed mild α-SMA reactivity compared with the rats treated with CCl₄ only (fibrosis group). On the other hand, lithium chloride-and-CCl₄-treated rats showed a significant increase in liver indices, TGF-β1 expression, β-catenin, l-hydroxyproline, and l-glutaminase activity with severe α-SMA reactivity and apoptosis in the liver tissue.

CONCLUSIONS

Niclosamide protected rats against liver fibrosis by inhibiting the Wnt/β-catenin pathway and glutaminolysis.

Improved hepatoprotective activity of Beta vulgaris L. leaf extract loaded self-nanoemulsifying drug delivery system (SNEDDS): in vitro and in vivo evaluation

OBJECTIVE

Beta vulgaris L. (beetroot) is a vegetable plant rich in phytochemical compounds such as phenolic acids, carotenoids and flavonoids. The objective of the current study is the development and optimization of self-nanoemulsifying drug delivery systems (SNEDDSs) to enhance the hepatoprotective activity of beet leaf (BL) extract.

METHODS

Total flavonoids content was estimated in the BL extract and its solubility was evaluated in various vehicles to select proper component combinations. Pseudo-ternary phase diagrams were constructed employing olive, linseed, castor and sesame oils (oil phase), Tween^® 20 (Tw20) and Tween^® 80 (Tw80) (surfactants (SAs)) as well as dimethyl sulfoxide (DMSO) and propylene glycol (PG) (co-surfactants (Co-SAs)). Optimization of formulations from the phase diagrams took place through testing their thermodynamic stability, dispersibility and robustness to dilution.

RESULTS

Four optimized BL-SNEDDS formulations, comprising linseed oil or olive oil, Tw80 and DMSO at two SA/Co-SA ratios (2:1 or 3:1) were chosen. They exhibited high cloud point and percentage transmittance values with spherical morphology of mean droplet sizes ranging from 14.67 to 16.06 nm and monodisperse distribution with negatively charged zeta potential < -9.51 mV. The in vitro release profiles of the optimized formulations in pH 1.2 and 6.8 were nearly similar, with a non-Fickian release mechanism. In vivo evaluation of BL-SNEDDSs hepatoprotective activity in a thioacetamide-induced hepatotoxicity rat model depicted promoted liver functions, inflammatory markers and histopathological findings, most prominently in the group treated by F7.

CONCLUSION

The results indicate that SNEDDS, as a nanocarrier system, has potential to improve the hepatoprotective activity of the BL extract.

Crocin attenuates CCl4-induced liver fibrosis via PPAR-γ mediated modulation of inflammation and fibrogenesis in rats

BACKGROUND

Liver fibrosis is a chronic pathological condition with a leading cause of liver-related mortality worldwide. In the present study, we have evaluated the antifibrotic effect of crocin, a carotenoid present in the stigma of Crocus sativus, and also explored its putative mechanism of action.

METHODS

Liver fibrosis was induced by intraperitoneal administration of 30% carbon tetrachloride (CCl₄). The crocin was administered orally at 20, 40 and 80 mg/kg body weight along with CCl₄ up to 8 weeks.

RESULTS

Chronic exposure to CCl₄ resulted in elevated levels of liver enzymes and reduced cytochrome P450 2E1 (CYP2E1) activity in the liver. The liver tissue showed cellular swelling, vacuolization, necrosis, infiltration of inflammatory cells and fibrotic changes. The crocin treatment significantly lowered the levels of liver enzymes in serum and improved the liver CYP2E1 mRNA levels. The pathological changes in the liver were also lowered by crocin treatment. The level of pro-inflammatory cytokines, nuclear factor-kappa B, interleukin-6 and tumor necrosis factor α and fibrogenic factor, transforming growth factor β, and α-smooth muscle actin were elevated by the CCl₄ in the liver tissue. However, crocin treatment at different doses significantly reduced the expression of these factors. The increased caspase 3/7 activity was also lowered by crocin. CCl₄ administration decreased the expression of peroxisome proliferator-activated receptor γ (PPAR-γ) in liver tissue. The improved PPAR-γ expression in the liver by crocin treatment indicates its role in the therapeutic effect of crocin.

CONCLUSIONS

Crocin attenuated the various events in the progression of liver fibrosis via PPAR-γ mediated modulation of inflammatory and fibrogenic pathways.

Hepatoprotective effect of total flavonoids of Mallotus apelta (Lour.) Muell.Arg. leaf against carbon tetrachloride-induced liver fibrosis in rats via modulation of TGF-β1/Smad and NF-κB signaling pathways

ETHNOPHARMACOLOGICAL RELEVANCE

The Mallotus apelta (Lour.) Muell.Arg. is a well-known traditional Chinese medicine (TCM) used for anti-inflammatory, hemostasis and chronic hepatitis.

AIM

The purpose of this study was to explore the antifibrotic effect of total flavonoids of Mallotus apelta leaf (TFM) and its potential mechanism.

METHODS

Hepatic fibrosis was induced by carbon tetrachloride (CCl₄) in rats. The CCl₄-induced rats received intragastric administration of colchicine (0.2 mg/kg per day), TFM (25, 50, 100 mg/kg per day) and the equal vehicle was given to normal rats. Pathological evaluation in hepatic tissue were examined by hematoxylin and eosin (HE) staining. And the levels of serum biochemical parameters were detected by automatic biochemical analysis. Meanwhile, the collagen deposition in liver was observed by staining with Masson's trichrome. Collagenic parameters and inflammatory factors were measured by enzyme-linked immunosorbent assay (ELISA) kits. Additionally, corresponding assay kit was used to estimate the antioxidant enzyme and lipid peroxidation. In order to explore the potential mechanism of anti-fibrotic effects in TFM, the expressions of liver fibrosis related gene and protein were analyzed by real-time quantitative reverse transcription polymerase chain reaction (RT-PCR) and Western blot.

RESULTS

The CCl₄-induced hepatic fibrosis were inhibited dose-dependently in rats by TFM. The results showed that the key hallmarks of liver injury including aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), albumin (ALB) and total protein (TP) in the serum were reversed in CCl₄-induced hepatic fibrosis rats which were treated by TFM. Furthermore, TFM significantly alleviates collagen accumulation and reduces the contents of hydroxyproline (Hyp), Type III precollagen (PC-III), collagen I (Col I), hyaluronic acid (HA) and laminin (LN). RT-PCR and Western blot results showed that TFM markedly inhibits liver fibrosis hallmark factor α-smooth muscle actin (α-SMA) expressions in CCl₄-induced hepatic fibrosis rats. Moreover, TFM alleviated the oxidative stress and lipid peroxidation in rats induced by CCl₄. TFM also attenuated the pro-inflammatory cytokines including interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) via inhibiting nuclear factor-κB (NF-κB) activation. Meanwhile, transforming growth factor-β1 (TGF-β1)/Smad signaling pathway was inhibited by TFM treatment.

CONCLUSIONS

TFM can alleviate CCl₄-induced hepatic fibrosis in rats, which potential mechanism may be due to its ability of reducing ECM accumulation, improving antioxidant and regulating TGF-β1/Smad signaling pathways and NF-κB-dependent inflammatory response.

Kaempferol Protects Against Cerebral Ischemia Reperfusion Injury Through Intervening Oxidative and Inflammatory Stress Induced Apoptosis

The aim of this research is to investigate the potential neuro-protective effect of kaempferol which with anti-oxidant, anti-inflammatory, and immune modulatory properties, and understand the effect of kaempferol on reducing cerebral ischemia reperfusion (I/R) injury in vivo. Male adult Sprague Dawley (SD) rats were pretreated with kaempferol for one week via gavage before cerebral I/R injury operation. We found that kaempferol treatment can reduce the cerebral infarct volume and neurological score after cerebral I/R. Rats were sacrificed after 24 h reperfusion. We observed that kaempferol improved the arrangement, distribution, and morphological structure of neurons, as well as attenuated cell apoptosis in brain tissue via hematoxylin and eosin (H&E) staining, Nissl staining and TUNEL staining. Superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione peroxidase (GSH) kit analysis, enzyme-linked immunosorbent (ELISA) assay, real-time PCR, Western blot, and immunohistochemical examination indicated that kaempferol mitigated oxidative and inflammatory stress via regulating the expression of proteins, p-Akt, p-GSK-3β, nuclear factor erythroid2-related factor 2 (Nrf-2), and p-NF-κB during cerebral I/R, thus increasing the activity of SOD and GSH, meanwhile decreasing the content of MDA in serum and brain tissue, as well as restoring the expression levels of tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β), and IL-6 in vivo. Taken together, this study suggested that kaempferol protects against cerebral I/R induced brain damage. The possible mechanism is related with inhibiting oxidative and inflammatory stress induced apoptosis.

Tanshinol A Ameliorates Triton-1339W-Induced Hyperlipidemia and Liver Injury in C57BL/6J Mice by Regulating mRNA Expression of Lipemic-Oxidative Injury Genes

Tanshinol A, which is derived from a traditional Chinese herbal Radix Salviae Miltiorrhizae is indicative of a hypolipidemic candidate. Therefore, we aim to validate its hypolipidemic activity of tanshinol A and explore its mechanism in triton-1339W-induced hyperlipidemic mice model, which possess multiply pathogenesis for endogenous lipid metabolism disorder. Experimental hyperlipidemia mice are treated with or without tanshinol A (i.g. 40, 20, 10 mg/kg), and blood and liver tissue were collected for validating its hypolipidemic and hepatic protective effect, and hepatic mRNA expression profile, which was associated with lipid metabolism dysfunction and liver injury, was detected by RT-qPCR. As results show, triton-1339W-induced abnormal of serum TC, TAG, HDL-C, LDL-C, SOD, MDA, GOT, and GPT is remarkably attenuated by tanshinol A. In pathological experiment, triton-1339W-induced hepatocellular ballooning degeneration, irregular central vein congestion, and inflammation infiltration are alleviated by tanshinol A. Correspondingly, hepatic mRNA expression of Atf4, Fgf21, Vldlr, Nqo1, Pdk4, and Angptl4, which are genes regulating lipemic-oxidative injury, are significantly increased by tanshinol A by 2~6 fold. Abcg5, Cd36, and Apob, which are responsible for cholesterol metabolism, are mildly upregulated. Noticeably, triton-1339W-suppressed expressions of Ptgs2/Il10, which are genes responsible for acute inflammation resolution in liver injury, are remarkably increased by tanshinol A. Conclusively, tanshinol A exerted hypolipidemic effect and hepatoprotective effect through restoring triton-1339W-suppressed mRNA expression, which may be involved in Atf4/Fgf21/Vldlr and Ptgs2/Il-10 signaling pathways.

Connective tissue growth factor in hepatocytes is elevated by carbon tetrachloride via STAT3 activation

Carbon tetrachloride (CCl4) is widely used to induce hepatic fibrosis. Therapeutic agents alleviate hepatic fibrosis by inhibiting signal transducer and activator of transcription 3 (STAT3) activation. To understand the direct effects of CCl4 on STAT3 expression in the liver, the present study incubated cultured hepatocytes expressing connective tissue growth factor (CTGF) with CCl4. Rats exposed to CCl4 for 8 weeks exhibited hepatic fibrosis, which was confirmed through the assessment of plasma biomarkers. Isolated liver samples were used to determine the protein levels of CTGF and STAT3 using western blotting. In addition, STAT3 expression was silenced in α mouse liver 12 (AML‑12) cells using small interfering RNA transfection. In addition, a pharmacological inhibitor, stattic, was used to inhibit STAT3 expression. The incubation of AML‑12 cells with CCl4 induced a dose‑dependent increase in CTGF expression and STAT3 activation. Notably, silymarin, an extract from milk thistle, inhibited these changes in AML‑12 cells and the antioxidant tiron produced similar effects. Silencing of STAT3 reduced the CTGF expression promoted by CCl4 in the hepatocytes. Additionally, similar to tiron, stattic inhibited CTGF expression induced by CCl4. In conclusion, CCl4 may activate STAT3 through oxidative stress to promote CTGF expression, which is one of the main factors contributing to the risk of hepatic fibrosis.

Metabolomics combined with network pharmacology exploration reveals the modulatory properties of Astragali Radix extract in the treatment of liver fibrosis

Background

Astragali Radix (AR) is widely-used for improving liver fibrosis, but, the mechanism of action has not been systematically explained. This study aims to investigate the mechanism of AR intervention in liver fibrosis based on comprehensive metabolomics combined with network pharmacology approach.

Materials and methods

UPLC–Q-TOF/MS based metabolomics technique was used to explore the specific metabolites and possible pathways of AR affecting the pathological process of liver fibrosis. Network pharmacology analysis was introduced to explore the key targets of AR regarding the mechanisms on liver fibrosis.

Results

AR significantly reduced the levels of ALT, AST and AKP in serum, and improved pathological characteristics. Metabolomics analysis showed that the therapeutic effect of AR was mainly related to the regulation of nine metabolites, including sphingosine, 6-keto-prostaglandin F1a, LysoPC (O-18:0), 3-dehydrosphinganine, 5,6-epoxy-8,11,14-eicosatrienoic acid, leukotriene C4, taurochenodesoxycholic acid, LysoPC (18:1 (9Z)) and 2-acetyl-1-alkyl-sn-glycero-3-phosphocholine. Pathway analysis indicated that the treatment of AR on liver fibrosis was related to arachidonic acid metabolism, ether lipid metabolism, sphingolipid metabolism, glycerophospholipid metabolism and primary bile acid biosynthesis. Validation of the key targets by network pharmacology analysis of potential metabolic markers showed that AR significantly down-regulated the expression of CYP1B1 and up-regulated the expression of CYP1A2 and PCYT1A.

Conclusion

Metabolomics combined with network pharmacology was used for the first time to clarify that the treatment of AR on liver fibrosis, which is related to the regulation of arachidonic acid metabolism and ether lipid metabolism by modulating the expression of CYP1A2, CYP1B1 and PCYT1A. And the integrated approach can provide new strategies and ideas for the study of molecular mechanisms of traditional Chinese medicines in the treatment of liver fibrosis.

A network pharmacology-based study on the anti-hepatoma effect of Radix Salviae Miltiorrhizae

BACKGROUND

Radix Salviae Miltiorrhizae (RSM), a well-known traditional Chinese medicine, has been shown to inhibit tumorigenesis in various human cancers. However, the anticancer effects of RSM on human hepatocellular carcinoma (HCC) and the underlying mechanisms of action remain to be fully elucidated.

METHODS

In this study, we aimed to elucidate the underlying molecular mechanisms of RSM in the treatment of HCC using a network pharmacology approach. In vivo and in vitro experiments were also performed to validate the therapeutic effects of RSM on HCC.

RESULTS

In total, 62 active compounds from RSM and 72 HCC-related targets were identified through network pharmacological analysis. RSM was found to play a critical role in HCC via multiple targets and pathways, especially the EGFR and PI3K/AKT signaling pathways. In addition, RSM was found to suppress HCC cell proliferation, and impair cancer cell migration and invasion in vitro. Flow cytometry analysis revealed that RSM induced cell cycle G2/M arrest and apoptosis, and western blot analysis showed that RSM up-regulated the expression of BAX and down-regulated the expression of Bcl-2 in MHCC97-H and HepG2 cells. Furthermore, RSM administration down-regulated the expression of EGFR, PI3K, and p-AKT proteins, whereas the total AKT level was not altered. Finally, the results of our in vivo experiments confirmed the therapeutic effects of RSM on HCC in nude mice.

CONCLUSIONS

We provide an integrative network pharmacology approach, in combination with in vitro and in vivo experiments, to illustrate the underlying therapeutic mechanisms of RSM action on HCC.

Salvianolic acid A attenuates CCl4-induced liver fibrosis by regulating the PI3K/AKT/mTOR, Bcl-2/Bax and caspase-3/cleaved caspase-3 signaling pathways

Background: Liver fibrosis occurs due to chronic liver disease due to multiple pathophysiological causes. The main causes for this condition are chronic alcohol abuse, nonalcoholic steatohepatitis, and infection due to hepatitis C virus. Currently, there is more and more information available about the molecular as well as cellular mechanisms, which play a role in the advancement of liver fibrosis. However, there is still no effective therapy against it.

Purpose: In order to find an effective treatment against liver fibrosis, our study explored whether salvianolic acid A (SA-A), a traditional Chinese medicine extracted from the plant Danshen, could effectively inhibit the liver fibrosis, which is induced by CCl₄ in vivo.

Methods: The effects of SA-A were evaluated by assessing the parameters related to liver fibrosis such as body weight, histological changes, and biochemical parameters. Thereafter, the related protein or gene levels of P13K/AKT/mTOR, Bcl-2/Bax and caspase-3/cleaved caspase-3 signaling pathways were determined by western blotting, real-time PCR or immunohistochemistry staining.

Results: According to the results of our study, SA-A could reduce liver fibrosis by inhibiting liver function, liver fibrosis index, collagen deposition, and improving the degree of liver fibrosis in rats. Mechanistically, the PI3K/AKT/mTOR signaling cascade was inhibited by SA-A to prevent the stimulation of hepatic stellate cell, as well as the synthesis of extracellular matrix, and regulated Bcl-2/Bax and caspase-3/cleaved caspase-3 signaling pathways to prevent hepatocyte apoptosis.

Conclusion: The novel findings of this study suggested that SA-A could reduce liver fibrosis and the molecular mechanisms behind it are closely associated with the regulation of PI3K/AKT/mTOR, Bcl-2/Bax and caspase-3/cleaved caspase-3 signaling pathways.

Salvianolic acid B protects against ANIT-induced cholestatic liver injury through regulating bile acid transporters and enzymes, and NF-κB/IκB and MAPK pathways

The purpose of this study was to investigate the pharmacological effects of salvianolic acid B (SA-B) on α-naphthylisothiocyanate (ANIT)-induced cholestatic liver injury with the focus on bile acid homeostasis and anti-inflammatory pathways. Rats were randomly assigned into four groups. The control group was given normal saline (i.p.) for 7 consecutive days and on the 5th day was given the vehicle (i.g.). Model group was treated with normal saline (i.p.) for 7 days and administrated with ANIT (75 mg/kg, i.g.) on the 5th day. The SA-B groups were treated with SA-B (15 mg/kg and 30 mg/kg, i.p.) for 7 consecutive days as well as ANIT (75 mg/kg, i.g.) on the 5th day. We found that the serum levels of ALT, γ-GT, TBA, and other liver function indexes were found to be lower in the SA-B treatment groups than in the model group. SA-B also upregulated the transporters and enzymes involved in bile acid homeostasis such as Bsep, Oatp2, and Cyp3a2 in rats and BSEP, CYP3A4, and OATP2 in human cell lines. Moreover, SA-B suppressed NF-κB translocation into the nucleus, inhibited phosphorylation of p38 and JNK, and inhibited inflammation markers including IL-1β, IL-6, TGF-β, TNF-α, and COX-2 to extenuate cholestatic liver injury both in vivo and vitro. Taken together, our findings suggest that anti-cholestatic effects of SA-B may be associated with its ability to regulate NF-κB/IκB and MAPK inflammatory signaling pathways to inhibit inflammation and regulate transporters and enzymes to maintain bile acid homeostasis.

[Exendin-4 alleviates oxidative stress and liver fibrosis by activating Nrf2/HO-1 in streptozotocin-induced diabetic mice]

OBJECTIVE

To investigate the effects of exendin-4 on hepatic lipid metabolism, fibrosis and oxidative stress in mice with streptozotocin (STZ)-induced diabetes and explore the underlying mechanisms.

METHODS

C57BL/6J mice were fed with high-fat diet (HFD) for 4 weeks and received intraperitoneal injections of 120 mg/kg STZ to induce diabetes. After successful modeling, the mice were randomized into diabetic control group and exendin-4 treatment group (DM+E4), and in the latter group, the mice were given a daily dose of 1 nmol/kg of exendin-4 for 8 weeks. The changes in the body weight (BW) and random blood glucose (RBG) in the mice were recorded. The mRNA expressions of the genes related with liver lipid metabolism, fibrosis and oxidative stress were analyzed using RT-PCR, and the structural changes of the liver tissues were observed with HE, Sirius red and oil red O staining; the expressions of TGF-β1, Nrf2 and HO-1 proteins in the liver tissues were detected using Western blotting.

RESULTS

The diabetic mice showed significantly higher RBG levels and BW with obvious lipid deposition, fibrosis and oxidative stress in the liver as compared with the normal control mice (P &lt; 0.001). Exendin-4 treatment of the diabetic mice did not significantly lessened liver lipid deposition but obviously reduced the levels of RBG and TG (P &lt; 0.05), lowered the expression levels of liver fibrosis-related genes TGF-β, α-SMA and Col-Ⅰ (P &lt; 0.05), increased the expression levels of the antioxidant genes Nrf2, HO-1 and GPX4 (P &lt; 0.01), and enhanced the protein expressions of Nrf2 and HO-1 in the liver tissues (P &lt; 0.01).

CONCLUSIONS

Exendin-4 improves liver fibrosis and oxidative stress in diabetic mice by activating Nrf2/HO-1 pathway without significantly reducing liver lipid deposition.