Metformin modulates autophagic pathway in renal fibrosis induced by carbon tetrachloride in adult male albino rats

BACKGROUNDS

Chronic kidney disease (CKD) is a global public health problem. All progressive chronic kidney disease (CKD) is characterized by tubulointerstitial fibrosis. Exposure to high concentrations of carbon tetrachloride (including vapor) can destroy the kidneys. Autophagy played an important role in maintaining the homeostasis of organs. Impaired autophagy was frequently associated with renal damage and fibrosis. Recent data suggests that metformin protects against a variety of kidney disorders.

AIM

To investigate the protective role of metformin on carbon tetrachloride induced renal damage via autophagy pathway.

MATERIALS AND METHODS

Forty adult male albino rats were divided into four equal groups (10 rats, each); Group 1: control group. Group 2: olive oil group received olive oil 1.5 mg/kg twice weekly S.C for 12 weeks. Group 3: The ccl4 group, the rats were received ccl4 1.5 mg/kg twice weekly S.C for 12 weeks. Group 4: CCL4 and Metformin group received concomitant treatment of CCL4, 1.5 mg/kg twice weekly S.C and 100 mg/kg/day Metformin orally for 12 weeks. After sacrifice, kidneys were taken from all animal groups and processed for light and electron microscopy, immunological studies and biochemical tests. Statistical analysis was done.

RESULTS

Administration of ccl4 resulted in histopathological changes in the kidney tissue in the form of areas of tissue destruction, inflammatory cell infiltration, congestion and fibrosis. Ultrastructurally, irregular thickening of GBM was observed. Improvement was noticed with concomitant treatment of ccl4 with metformin.

CONCLUSION

Metformin administration can modulate histological and biochemical effects in the renal tissue induced by of ccl4.

Boldine protects against carbon tetrachloride-induced chronic liver injury by regulating NF-κB signaling pathway

Sustained liver injuries predominantly promote oxidative stress and inflammation that lead to the progression of chronic liver disease (CLD), including fibrosis, cirrhosis, and hepatocellular carcinoma. Boldine, an alkaloid isolated from Peumus boldus, has been shown to have antioxidant and anti-inflammatory effects. Currently, there is no definitive treatment option available for CLD. Therefore, we investigated the hepatoprotective effect of boldine against carbon tetrachloride (CCl4 )-induced chronic liver injury in rats. CCl4 (2 mL/kg., b.w., i.p.) was administered twice weekly for 5 weeks to induce chronic liver injury in rats. Separate groups of rats were given boldine (20 mg/kg b.w., and 40 mg/kg b.w.) and silymarin (100 mg/kg b.w.) orally, daily. Serum transaminases, lipid peroxidation, and antioxidant levels were measured, and nuclear factor-κB (NF-κB), tumor necrosis factor-α (TNF-α), cyclooxygenase-2 (cox-2), interleukin-1 β (IL-1β), and α-smooth muscle actin (α-SMA) gene and protein expressions were evaluated. CCl4 administration increased liver marker enzymes of hepatotoxicity in serum and oxidative stress markers, inflammatory genes and α-smooth muscle actin expression in liver tissue. Boldine concurrent treatment suppressed CCl4 -induced elevation of transaminase levels in serum, restored enzymic and non-enzymic antioxidants, and downregulated NF-κB, TNF-α, Cox-2 and IL-1β expressions, thereby suppressing hepatic inflammation. Boldine administration also repressed α-SMA expression. The results of this study demonstrate the antioxidant, anti-inflammatory, and antifibrotic properties of boldine, and it can be a potential therapeutic candidate in the treatment of CLD.

Attenuation of carbon tetrachloride-induced nephrotoxicity by gum Arabic extract via modulating cellular redox state, NF-κB pathway, and KIM-1

The current study investigated the ameliorating impact of GA water extract (GAE) on CCl4-induced nephrotoxicity in renal cells and tissue by comparing its effectiveness with the Ketosteril (Ks) drug in restoring oxidative stress and necroinflammation. The cell morphology, necrosis, and redox state were evaluated in Vero cells. The influence of GAE on CCl4-induced oxidative stress, inflammation, and necrosis was examined in rats. The predicted inhibitory mechanism of GAE phenolic constituents against COX-2 and iNOS was also studied. The results revealed that GAE contains crucial types of phenolic acids, which are associated with its antiradical activities. GAE improved CCl4-induced Vero cell damage and restored renal architecture damage, total antioxidant capacity, ROS, TBARS, NO, GSH, GPX, SOD, and MPO in rats. GAE downregulated the gene expression of renal NF-κB, TNF-α, iNOS, and COX-2, as well as kidney injury molecule-1 (KIM-1) in rats. The GAE improved blood urea, creatinine, cholesterol, and reducing power. The computational analysis revealed the competitive inhibitory mechanism of selected phenolic composites of GAE on COX-2 and iNOS activities. The GAE exhibited higher potency than Ks in most of the studied parameters, as observed by the heatmap plots. Thus, GAE is a promising extract for the treatment of kidney toxicity.

Therapeutic benefit of oregano oil in the acute idiosyncratic hepatotoxicity induced by carbon tetrachloride in rats: Adverse effects of high dose of oreganum

Toxicity caused by carbon tetrachloride (CCl4) can lead to serious liver injury. The aim of the study is to investigate the protective effects of oregano oil (Origanum minutiflorum extract oil) against CCl4-induced liver injury. Two doses of oregano oil were used in the experiment: a low dose (LD; 20 mg/kg) and a high dose (HD; 60 mg/kg) during 2 weeks. CCl4 caused severe liver damage, nucleolus destruction in hepatocytes and cytogenetic changes in the nucleus. Indirectly, CCl4 causes decreased protein synthesis and significantly high creatinine and urea values. Hematological disorders have been recorded, such as decreased RBC and hemoglobin concentration, increased WBC and deformability of the erythrocyte membrane. Both doses of oregano oil had protective effects. Improved protein synthesis and high globulins level, creatinine and urea were found in both groups. Cytogenetic changes in the nucleus of hepatocytes were reduced. A high dose of oregano oil had maximal protective effects for RBC, but a very weak effect on hemoglobin synthesis. Also, WBC and lymphocyte values were low. Origanum stimulates protein synthesis and recovery of hepatocytes after liver injury, reduces the deformability of the erythrocyte membrane. High doses of oregano oil decreased WBC and lymphocytes which may lead to a weakening of the immune response. However, high doses are more effective against severe platelet aggregation than low doses, suggesting an effective treatment against thrombocytosis.

Therapeutic Potential of Diosgenin in Amelioration of Carbon Tetrachloride-Induced Murine Liver Injury

Diosgenin is a sapogenin with antidiabetic, antioxidant, and anti-inflammatory properties. The current study investigated whether diosgenin could ameliorate carbon tetrachloride (CCL4)-induced liver injury. To cause liver injury, CCL4 was injected intraperitoneally twice a week for 8 weeks. Daily oral administration of diosgenin at doses of 20, 40, and 80 mg/kg was started one day before CCL4 injection and continued for 8 weeks. Finally, serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and also albumin were assessed. Catalase and superoxide dismutase (SOD) activities in addition to glutathione (GSH) and malondialdehyde (MDA) levels were also quantified in the liver homogenate and routine histological evaluation was also conducted. Elevated serum levels of liver enzymes and decreased serum level of albumin caused by CCL4 were significantly restored following diosgenin administration at doses of 40 and 80 mg/kg. Long-term administration of CCL4 increased inflammatory and apoptotic factors such as IL-1β, caspase 3, TNF-α, and IL-6 and decreased SOD and catalase activities as well as GSH level in liver homogenates; while MDA level was increased. Treatment with diosgenin increased SOD and catalase activities and GSH levels in the liver of injured animals. In addition, liver MDA, IL-1β, caspase 3, TNF-α, and IL-6 level or activity decreased by diosgenin treatment. Additionally, diosgenin aptly prevented aberrant liver histological changes. According to obtained results, diosgenin can dose-dependently diminish CCl4-induced liver functional deficits and histological changes in a dose-dependent manner, possibly due to its antioxidant and anti-inflammation properties, and its beneficial effect is comparable to known hepatoprotective agent silymarin.

Dietary rice bran attenuates hepatic stellate cell activation and liver fibrosis in mice through enhancing antioxidant ability

Various endogenous and exogenous stimuli can result in an inflammatory response and collagen deposition in the liver, which affect liver function and increase the risk of developing liver cirrhosis and cancer. Rice bran, the main by-product of rice milling, contains various nutrients which possess hepatoprotective activities. In this study, we investigated the effects of rice bran on carbon tetrachloride (CCl4)-induced liver fibrosis in mice. Mice were fed a rice-bran-containing diet (10% rice bran w/w) or a standard diet with or without an injection of 20% CCl4 to induce liver fibrosis. Our results showed that feeding a rice-bran-containing diet could alleviate CCl4-induced liver damage, collagen deposition, and expressions of fibrosis-related genes, including α-smooth muscle actin (α-SMA), collagen 1a2 (COL1A2), and transforming growth factor-β (TGF-β) in liver tissues. Moreover, consumption of rice bran enhanced phase II detoxification and antioxidant gene expressions, including Gsta3, Gstp1, Catalase, SOD1, SOD2, and SOD3. Treatment with γ-oryzanol, the major bioactive compound in rice bran, decreased the sensitivity of hepatic stellate cells (HSCs) to TGF-β1-induced α-SMA, COL1A2, and phosphorylated smad2 expressions. In conclusion, a rice-bran-containing diet may have beneficial effects on liver fibrogenesis through increased antioxidant and detoxification activities. γ-Oryzanol, the major bioactive compound of rice bran, can inhibit activation of HSCs.

Redox-sensitive high-mobility group box-1 isoforms contribute to liver fibrosis progression and resolution in mice

BACKGROUND & AIMS

High-mobility group box-1 (HMGB1) significantly increases and undergoes post-translational modifications (PTMs) in response to liver injury. Since oxidative stress plays a major role in liver fibrosis and induces PTMs in proteins, we hypothesized that redox-sensitive HMGB1 isoforms contribute to liver fibrosis progression and resolution.

METHODS

We used ESI-LC-MS (electrospray ionization-liquid chromatography-mass spectrometry) to study PTMs of HMGB1 during fibrosis progression and resolution. Conditional knockout mice were used for functional analyses.

RESULTS

We identified that disulfide ([O]) and sulfonated ([SO3]) HMGB1 increase during carbon tetrachloride-induced liver fibrosis progression, however, while [O] HMGB1 declines, [SO3] HMGB1 drops but remains, during fibrosis resolution. Conditional knockout of Hmgb1 revealed that production of [O] and [SO3] HMGB1 occurs mostly in hepatocytes. Co-injection of [O] HMGB1 worsens carbon tetrachloride-induced liver fibrosis more than co-injection of [H] HMGB1. Conversely, ablation of [O] Hmgb1 in hepatocytes reduces liver fibrosis. Moreover, ablation of the receptor for advanced-glycation end-products (Rage) reveals that the profibrogenic effect of [O] HMGB1 is mediated by RAGE signaling in hepatic stellate cells (HSCs). Notably, injection of [SO3] HMGB1 accelerates fibrosis resolution due to RAGE-dependent stimulation of HSC apoptosis. Importantly, gene signatures activated by redox-sensitive HMGB1 isoforms in mice, classify patients with fibrosis according to fibrosis and inflammation scores.

CONCLUSION

Dynamic changes in hepatocyte-derived [O] and [SO3] HMGB1 signal through RAGE-dependent mechanisms on HSCs to drive their profibrogenic phenotype and fate, contributing to progression and resolution of liver fibrosis.

IMPACT AND IMPLICATIONS

Since oxidative stress plays a major role in liver fibrosis and induces post-translational modifications of proteins, we hypothesized that redox-sensitive HMGB1 isoforms contribute to liver fibrosis progression and resolution. This study is significant because a rise in [H] HMGB1 could flag 'patient at risk', the presence of [O] HMGB1 could suggest 'disease in progress or active scarring', while the appearance of [SO3] HMGB1 could point at 'resolution under way'. The latter could be used as a readout for response to pharmacological intervention with anti-fibrotic agents.

Protective effect of chicory and/or artichoke leaves extracts on carbon tetrachloride and gamma-irradiation-induced chronic nephrotoxicity in rats

The prevalence of chronic kidney disease (CKD) is in progress that causes kidney failure, leading to global problems. This manuscript investigated the nephroprotective effects of chicory (CLE) and/or artichoke (ALE) leaves extracts on carbon tetrachloride (CCl4 ) and gamma-irradiation (Rad)-induced chronic nephrotoxicity in rats. Rats were divided into 10 groups (10 animals/group): group 1: control, groups 2-7 rats were treated with CLE, ALE, CLE/ALE, CCl4 , Rad, and CCl4 /Rad, respectively. Groups 8 to 10, rats were intoxicated with CCl4 /Rad, and treated with CLE, ALE, and CLE/ALE extracts, respectively, for 4 weeks. The data demonstrated that CCl4 administration or Rad exposure induced high levels of urea and creatinine, with low levels of total protein and albumin in the serum. However, high levels of malondialdehyde (MDA), nitric oxide (NO), hydrogen peroxide (H2 O2 ), some pro-inflammatory markers such as interleukins (IL-1β, IL-2, IL-6), TNF-α, NF-κB, the fibrotic marker; TGF-β1, calcium, and copper, low contents of reduced glutathione (GSH), iron, and zinc, and suppression of the antioxidant enzymes' activity, superoxide dismutase (SOD), and catalase (CAT) were observed. In addition, the Wnt and β-catenin protein expression ratios were up-regulated in the kidney tissues of the CCl4 , and Rad intoxicated animals. However, the combined treatment CCl4 /Rad augmented these measurements. On the other hand, CLE, ALE, and CLE/ALE treatments demonstrated nephroprotection in the kidney tissues of CCl4 /Rad intoxicated animals, in the order of CLE/ALE>ALE>CLE by ameliorating the investigated parameters. Kidney tissues' histopathological examinations confirmed these results. In conclusion, CLE and/or ALE demonstrated nephroprotection against CCl4 /Rad co-toxicity mediated by down-regulation of renal Wnt/β-catenin protein expressions.

Oral delivery of aescin-loaded gelatin nanoparticles ameliorates carbon tetrachloride-induced hepatotoxicity in Wistar rats

AIM

The liver plays a crucial role in biotransformation but it is susceptible to chemical-induced damage, known as hepatotoxicity. Traditional therapies for protecting the liver face significant challenges, including poor bioavailability, off-target effects, adverse reactions, drug breakdown, and inadequate uptake. These issues emphasize the need for precise, targeted therapeutic approaches against hepatotoxicity.

MATERIALS AND METHODS

The objective of our research was to develop a customized, biocompatible, and biodegradable nanodrug delivery system for hepatoprotection. We chose collagen hydrolyzed protein, or gelatin, as the base material and utilized solvent evaporation and nanoprecipitation methods to create nanoparticles with size ranging from 130 to 155 nm. The resulting nanoparticles exhibited a spherical and smooth surface, as confirmed by scanning and transmission electron microscopy.

KEY FINDINGS

Bioactive aescin (AES), into these gelatin nanoparticles (AES-loaded gel NPs), we tested these nanoparticles using a hepatotoxicity model. The results were indicating a significant reduction in the levels of key biomolecules, including NF-κB, iNOS, BAX, and COX-2 and decreased serum levels of enzymes ALT and AST. This reduction correlated with a notable alleviation in the severity of hepatotoxicity. Furthermore, the treatment with AES-loaded gel NPs resulted in the downregulation of several inflammatory and liver-specific biomarkers, including nitrite, MPO, TNF-α, and IL-6.

SIGNIFICANCE

In summary, our study demonstrates that the AES-loaded gel NPs were markedly more effective in mitigating experimental hepatotoxicity when compared to the free aescin. The nanoparticles exhibited a propensity for suppressing liver damage, showcasing the potential of this targeted therapeutic approach for safeguarding the liver from harmful chemical insults.

Selenizing chitooligosaccharide with site-selective modification to alleviate acute liver injury in vivo

Two selenized chitooligosaccharide (O-Se-COS and N,O-Se-COS) with different sites modification were synthesized to alleviate liver injury in vivo. Comparing to traditional COS, both selenized COS exhibited enhanced reducibility as well as antioxidant capacity in vitro. Furthermore, O-Se-COS demonstrated superior efficacy in reducing intracellular reactive oxygen species (ROS) and mitochondrial damage compared to N,O-Se-COS as its enhanced cellular uptake by the positive/negative charge interactions. Two mechanisms were proposed to explained these results: one is to enhance the enzymatic activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), which effectively scavenge free radicals; the other is to down-regulate intracellular cytochrome P450 (CYP2E1) levels, inhibiting carbon tetrachloride (CCl4)-induced peroxidation damage. In vivo studies further demonstrated the effective alleviation of CCl4-induced liver injury by selenized COS, with therapeutic efficacy observed in the following order: O-Se-COS > N,O-Se-COS > COS. Finally, hemolysis and histological tests confirmed the biosafety of both selenized COS. Taken together, these finding demonstrated that selenium has the potential to improve the biological activity of COS, and precise selenylation was more conducive to achieving the synergistic effect where 1 + 1>2.

Oleuropein, a phenolic component of Olea europaea L. ameliorates CCl4-induced liver injury in rats through the regulation of oxidative stress and inflammation

OBJECTIVE

This study aimed to assess the hepatoprotective role of oleuropein (Olp), a phenolic compound found in olive, against carbon tetrachloride (CCl4)-induced liver damage in rats.

MATERIALS AND METHODS

The research involved male albino rats, which received intraperitoneal injections of 100 mg/kg b.w. of oleuropein for 8 consecutive weeks before being subjected to carbon tetrachloride (CCl4) at a dosage of 1.0 ml/kg b.w. Changes induced by CCl4 in antioxidant and inflammatory marker levels were assessed using ELISA assay kits. Moreover, CCl4-induced liver tissue architecture alteration, fibrosis, and expression pattern of protein were evaluated by performing H&E, Sirius red, Masson trichrome, and immunohistochemistry staining.

RESULTS

Increased serum transaminases and massive hepatic damage were observed by this liver toxicant. The hepatic injury was further evidenced by a significant decrease in antioxidant enzyme activity [superoxide dismutase (SOD), glutathione peroxidase (GPx), Glutathione (GSH) and Total Antioxidant Capacity (T-AOC)]. The administration of CCl4 resulted in an increased inflammatory response, which was measured by C-reactive protein, interleukin-6, as well as tumor necrosis factor-alpha. Olp as a curative regimen led to significant attenuation in the inflammatory response and oxidative/nitrosative stress. This polyphenol treatment improved the hepatic tissue architecture and decreased fibrosis. In the CCl4 treatment group, the expression pattern of IL-6 protein was high, whereas expression was decreased after Olp, as evidenced by immunohistochemistry staining.

CONCLUSIONS

The study suggests that oleuropein treatment has the potential to reduce liver damage caused by CCl4 induction by inhibiting oxidative stress and inflammation and maintaining liver tissue architecture. This could make it a promising treatment option for liver pathogenesis.

The hepatoprotective potentials of Olea europaea L. leaves against carbon tetrachloride-induced hepatic injury in rats

OBJECTIVE

To examine the therapeutic effects of Olea europaea L. leaves extract on carbon tetrachloride-induced liver injury in rats.

Methods

The experimental study was conducted at the Department of Physiology, University of Karachi, Karachi, in July 2021, and comprised Albino Wistar male rats weighing 180-220gm. The animals were divided into control group I, carbon tetrachloride group II, Olea europaea L. + carbon tetrachloride group III and Olea europaea L. group IV. In Vitro model of hepatic toxicity was developed by carbon tetrachloride. A daily dose of 50mg/kg of aqueous extract of olive leaves was administered orally and 0.8ml/kg of carbon tetrachloride was administered twice a week subcutaneously for 28 days. On the 29th day, the animals were sacrificed, and tested for hepatic enzymes, lipid peroxidation markers and histopathology. Data was analysed using SPSS 20.

RESULTS

Of the 24 rats, 6(25%) were in each of the 4 groups. Alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase and total bilirubin levels were significantly reduced (p<0.05) in group II whereas, 4- hydroxynonenal, isoprostane and malondialdehyde levels were significantly increased (p<0.05). However, total antioxidant level increased significantly (p<0.05) in group III compared to group II. Histopathology showed severe liver damage in group II and mild damage in group III.

Conclusion

Olea europaea L. leaves extract was found to have profound hepatoprotective effects.

Early detection of liver injuries by the Serum enhanced binding test sensitive to albumin post-transcriptional modifications

Early and sensitive biomarkers of liver dysfunction and drug-induced liver injury (DILI) are still needed, both for patient care and drug development. We developed the Serum Enhanced Binding (SEB) test to reveal post-transcriptional modifications (PTMs) of human serum albumin resulting from hepatocyte dysfunctions and further evaluated its performance in an animal model. The SEB test consists in spiking serum ex-vivo with ligands having specific binding sites related to the most relevant albumin PTMs and measuring their unbound fraction. To explore the hypothesis that albumin PTMs occur early during liver injury and can also be detected by the SEB test, we induced hepatotoxicity in male albino Wistar rats by administering high daily doses of ethanol and CCl4 over several days. Blood was collected for characterization and quantification of albumin isoforms by high-resolution mass spectrometry, for classical biochemical analyses as well as to apply the SEB test. In the exposed rats, the appearance of albumin isoforms paralleled the positivity of the SEB test ligands and histological injuries. These were observed as early as D3 in the Ethanol and CCl4 groups, whereas the classical liver tests (ALT, AST, PAL) significantly increased only at D7. The behavior of several ligands was supported by structural and molecular simulation analysis. The SEB test and albumin isoforms revealed hepatocyte damage early, before the current biochemical biomarkers. The SEB test should be easier to implement in the clinics than albumin isoform profiling.

On a deterministic mathematical model which efficiently predicts the protective effect of a plant extract mixture in cirrhotic rats

In this work, we propose a mathematical model that describes liver evolution and concentrations of alanine aminotransferase and aspartate aminotransferase in a group of rats damaged with carbon tetrachloride. Carbon tetrachloride was employed to induce cirrhosis. A second groups damaged with carbon tetrachloride was exposed simultaneously a plant extract as hepatoprotective agent. The model reproduces the data obtained in the experiment reported in [Rev. Cub. Plant. Med. 22(1), 2017], and predicts that using the plants extract helps to get a better natural recovery after the treatment. Computer simulations show that the extract reduces the damage velocity but does not avoid it entirely. The present paper is the first report in the literature in which a mathematical model reliably predicts the protective effect of a plant extract mixture in rats with cirrhosis disease. The results reported in this manuscript could be used in the future to help in fighting cirrhotic conditions in humans, though more experimental and mathematical work is required in that case.

Serum α-SMA is a potential noninvasive biomarker of liver fibrosis

The severity of fibrosis is central to the therapeutic course for patients with chronic liver disease; therefore, early detection of liver fibrosis is critical for timely therapeutic interventions. Liver biopsy is the gold standard for the diagnosis of liver fibrosis; however, it is contraindicated in several pathological conditions. Activated hepatic stellate cells (HSCs) are the main cells for fibrotic tissue synthesis, such as that of alpha-smooth muscle actin (α-SMA). This study aimed to determine whether serum α-SMA levels are a suitable noninvasive, sensitive, and reliable liver fibrosis marker. Fibrosis was induced in male Wistar rats via chronic CCl4 administration. Fibrosis was determined in the liver tissues by quantifying the hydroxyproline content and visualized using Masson's trichrome staining. Rats chronically administered CCl4 exhibited a progressive increment in the hepatic collagen content, as well as both hepatic and serum α-SMA levels in a time-dependent manner. Moreover, serum levels of α-SMA significantly correlated with hepatic α-SMA levels (p ≤ 0.001), as well as with the severity of liver fibrosis (p ≤ 0.001). These findings suggest that increased levels of serum α-SMA can be considered a potential reliable and noninvasive biomarker for early liver fibrosis.

Aging aggravates liver fibrosis through downregulated hepatocyte SIRT1-induced liver sinusoidal endothelial cell dysfunction

BACKGROUND

Aging increases the susceptibility to chronic liver diseases and hastens liver fibrosis deterioration, but the underlying mechanisms remain partially understood. The aim of this study was to investigate the effect of aging and chronic liver diseases on hepatocyte Sirtuin 1 (SIRT1) and LSECs and their contribution to liver fibrosis pathogeneses.

METHODS

Young (8-12 wk) and aged (18-20 mo) mice were subjected to carbon tetrachloride-induced liver fibrosis. Primary HSCs and LSECs were isolated and cocultured for in vitro experiments. Liver tissues and blood samples from healthy controls and patients with liver fibrosis were analyzed.

RESULTS

Downregulated hepatocytes SIRT1 in aged mice increased high mobility group box 1 acetylation, cytoplasmic translocation, and extracellular secretion, causing LSECs dysfunction by means of the toll-like receptor 4/AK strain transforming (AKT)/endothelial nitric oxide synthase pathway, ultimately activating HSCs and increasing susceptibility to liver injury and fibrosis. Adeno-associated virus-mediated overexpression of SIRT1 in hepatocytes suppressed the abovementioned alterations and attenuated carbon tetrachloride-induced liver injury and fibrosis in liver fibrosis mice, and there were no significant differences in liver injury and fibrosis indicators between young and aged mice after SIRT1 overexpression treatment. In vitro experiments demonstrated that SIRT1 overexpression and endothelial nitric oxide synthase agonist YC-1 improved LSECs function and inhibited HSCs activation, mediated by nitric oxide. Similarly, downregulated hepatocytes SIRT1 and LSECs dysfunction were observed in the livers of aged individuals compared to young individuals and were more pronounced in aged patients with liver fibrosis.

CONCLUSIONS

Aging aggravates liver fibrosis through downregulated hepatocytes SIRT1-induced LSECs dysfunction, providing a prospective curative approach for preventing and treating liver fibrosis.

A Mouse Model of Non-Alcoholic Steatohepatitis and Hepatocellular Carcinoma Induced by Western Diet and Carbon Tetrachloride

Non-alcoholic steatohepatitis (NASH) is a severe form of non-alcoholic fatty liver disease (NAFLD). Obesity is a known risk factor of NASH, which, in turn, increases the risk of developing cirrhosis (liver scarring) and hepatocellular carcinoma (HCC). In addition to being a potentially life-threatening condition, public health concerns surrounding NASH are amplified by the lack of FDA-approved treatments. Although various preclinical models reflecting both the histopathology and the pathophysiological progression of human NASH exist, most of these models are diet-based and require 6-13 months for NASH symptom manifestation. Here, we describe a simple and rapid-progression model of NASH and NASH-driven HCC in mice. Mice received a western diet equivalent (WD; i.e., a high-fat, high-fructose, and high-cholesterol diet), high-sugar water (23.1 g/L fructose and 18.9 g/L glucose), and weekly intraperitoneal injections of carbon tetrachloride (CCl4) at a dose of 0.2 μL/g of body weight. The resulting phenotype, consisting in liver fibrosis and HCC, appeared within 24 weeks of diet/treatment initiation and presented similar histological and transcriptomic features as human NASH and NASH-driven HCC, thereby supporting the adequacy of this preclinical model for the development and evaluation of drugs that can prevent or reverse these diseases.

Multi-omics reveals deoxycholic acid modulates bile acid metabolism via the gut microbiota to antagonize carbon tetrachloride-induced chronic liver injury

Deoxycholic acid (DCA) serves essential functions in both physiological and pathological liver processes; nevertheless, the relationship among DCA, gut microbiota, and metabolism in chronic liver injury remain insufficiently understood. The primary objective of this study is to elucidate the potential of DCA in ameliorating chronic liver injury and evaluate its regulatory effect on gut microbiota and metabolism via a comprehensive multi-omics approach. Our study found that DCA supplementation caused significant changes in the composition of gut microbiota, which were essential for its antagonistic effect against CCl4-induced chronic liver injury. When gut microbiota was depleted with antibiotics, the observed protective efficacy of DCA against chronic liver injury became noticeably attenuated. Mechanistically, we discovered that DCA regulates the metabolism of bile acids (BAs), including 3-epi DCA, Apo-CA, and its isomers 12-KLCA and 7-KLCA, IHDCA, and DCA, by promoting the growth of A.muciniphila in gut microbiota. This might lead to the inhibition of the IL-17 and TNF inflammatory signaling pathway, thereby effectively countering CCl4-induced chronic liver injury. This study illustrates that the enrichment of A. muciniphila in the gut microbiota, mediated by DCA, enhances the production of secondary bile acids, thereby mitigating chronic liver injury induced by CCl4. The underlying mechanism may involve the inhibition of hepatic IL-17 and TNF signaling pathways. These findings propose a promising approach to alleviate chronic liver injury by modulating both the gut microbiota and bile acids metabolism.

Dimethyl Bisphenolate Ameliorates Carbon Tetrachloride-Induced Liver Injury by Regulating Oxidative Stress-Related Genes

Liver disease accounts for millions of deaths per year all over the world due to complications from cirrhosis and liver injury. In this study, a novel compound, dimethyl bisphenolate (DMB), was synthesized to investigate its role in ameliorating carbon tetrachloride (CCl4)-induced liver injury through the regulation of oxidative stress-related genes. The structure of DMB was confirmed based on its hydrogen spectrum and mass spectrometry. DMB significantly reduced the high levels of ALT, AST, DBIL, TBIL, ALP, and LDH in a dose-dependent manner in the sera of CCl4-treated rats. The protective effects of DMB on biochemical indicators were similar to those of silymarin. The ROS fluorescence intensity increased in CCl4-treated cells but significantly weakened in DMB-treated cells compared with the controls. DMB significantly increased the content of oxidative stress-related GSH, Nrf2, and GCLC dose-dependently but reduced MDA levels in CCl4-treated cells or the liver tissues of CCl4-treated rats. Moreover, DMB treatment decreased the expression levels of P53 and Bax but increased those of Bcl2. In summary, DMB demonstrated protective effects on CCl4-induced liver injury by regulating oxidative stress-related genes.

Fate tracking reveals differences between Reelin+ hepatic stellate cells (HSCs) and Desmin+ HSCs in activation, migration and proliferation

The activation of hepatic stellate cells (HSCs) is the main cause of liver fibrogenesis in response to different etiologies of chronic liver injuries. HSCs are heterogeneous, but the lack of specific markers to distinguish different HSC subset hinders the development of targeted therapy for liver fibrosis. In this study, we aim to reveal new HSC subsets by cell fate tracking. We constructed a novel ReelinCreERT2 transgenic mouse model to track the fate of cells expressing Reelin and their progeny (Reelin+ cells). And we investigated the property of Reelin+ cells, such as differentiation and proliferation, in hepatotoxic (carbon tetrachloride; CCl4 ) or cholestatic (bile duct ligation; BDL) liver injury models by immunohistochemistry. Our study revealed that Reelin+ cells were a new HSC subset. In terms of activation, migration, and proliferation, Reelin+ HSCs displayed different properties from Desmin+ HSCs (total HSCs) in cholestatic liver injury model but shared similar properties to total HSCs in hepatotoxic liver injury model. Besides, we did not find evidence that Reelin+ HSCs transdifferentiated into hepatocytes or cholangiocytes through mesenchymal-epithelial transition (MET). In this study, our genetic cell fate tracking data reveal that ReelinCreERT2-labelled cells are a new HSC subset, which provides new insights into targeted therapy for liver fibrosis.

The application of a novel platform of multiparametric magnetic resonance imaging in a bioenvironmental toxic carbon tetrachloride-induced mouse model of liver fibrosis

The use of multiparametric magnetic resonance imaging (MRI) to distinguish complex histopathological changes in liver fibrosis has not yet been systematically established. The purpose of this study is to gauge the efficacy of a cutting-edge MRI platform for evaluating ecotoxicologically hazardous carbon tetrachloride (CCl4) induced liver fibrosis, while also scrutinizing the relationship between MRI and its histopathological features. Thirty-six mice were randomly divided into 6 groups, each with 6 mice. Control mice received an intraperitoneal injection of olive oil, while the experimental mice received different doses of intraperitoneal injection of CCl4. Both sets underwent this process twice per week over a duration of 5 weeks. MRI measurements encompassed T1WI, T2WI, T1 mapping, T2 mapping, T2* mapping. Liver fibrosis and inflammation were assessed and classified using Metavir and activity scoring systems. CCl4 successfully induced liver fibrosis in mice, showing an increasing extent of liver fibrosis and liver function damage with the increasing dosage of CCl4. Compared with the control group, T1, ΔT1, and T2 in the experimental group were considerably elevated (P < 0.05) than those in the control group. Spearman's correlation showed that the correlation of Native T1 and △T1 with fibrosis (r = 0.712, 0.678) was better than with inflammation (r = 0.688, 0.536). T2 correlation with inflammation (r = 0.803) was superior to fibrosis (r = 0.568). ROC analysis showed that the AUC of Native T1 was highest (0.906), followed by ΔT1 (0.852), while the AUC increased to 0.945 when all relevant MRI parameters were combined. T1 is the most potent MRI parameter for evaluating CCl4-induced liver fibrosis, followed by ΔT1. Meanwhile, T2 may not be suitable for evaluating liver fibrosis but is more suitable for evaluating liver inflammation.

Saffron reduces the liver fibrosis in mice by inhibiting the JAK/STAT3 pathway

PURPOSE

Chronic inflammation in the liver is a key trigger for liver injury and fibrosis in various liver diseases. Given the anti-inflammatory and antioxidant effects of Saffron, this study aimed to investigate the pharmacological effects of Saffron on hepatic inflammation and fibrosis.

METHODS

The mice model of hepatic fibrosis was constructed using CCl4, and Saffron was administered at low (10 mg/kg) and high (20 mg/kg) doses by gavage. Then, the changes in liver function, liver inflammation and fibrosis markers were evaluated. The effects and mechanisms of Saffron on hepatic stellate cells were further investigated in in-vitro experiments.

RESULTS

Saffron improved liver function, reduced liver inflammation and attenuated liver fibrosis in a dose-dependent manner in hepatic fibrosis mice. Furthermore, Western blotting showed that Saffron significantly inhibited JAK/STAT3 phosphorylation in fibrotic livers.

CONCLUSIONS

Saffron can attenuate liver fibrosis by inhibiting the JAK/STAT3 pathway and the activation of hepatic stellate cell, providing a theoretical basis for the development of new anti-fibrotic drugs.

Hepatocellular Brg1 promotes CCl4-induced liver inflammation, ECM accumulation and fibrosis in mice

INTRODUCTION

Hepatic fibrosis is a progressive pathological process involving the exhaustion of hepatocellular regenerative capacity and ultimately leading to the development of cirrhosis and even hepatocellular carcinoma. Brg1, the core subunit of the SWI/SNF chromatin-remodeling complex, was recently identified as important for liver regeneration. This study investigates the role of Brg1 in hepatic fibrosis development.

METHODS

Hepatocyte-specific Brg1 knockout mice were generated and injected with carbon tetrachloride (CCl4) for 4, 6, 8, and 12 weeks to induce liver fibrosis. Afterwards, liver fibrosis and liver damage were assessed.

RESULTS

Brg1 expression was significantly increased in the fibrotic liver tissue of wild-type mice, as compared to that of untreated wild-type mice. The livers of the Brg1 knockout animals showed reduced liver inflammation, extracellular matrix accumulation, and liver fibrosis. TNF-α and NF-κB-mediated inflammatory response was reduced in Brg1 knockout animals.

CONCLUSION

Brg1 promotes the progression of liver fibrosis in mice and may therefore be used as a potential therapeutic target for treating patients with liver fibrosis due to chronic injury.

Sex Drives Functional Changes in the Progression and Regression of Liver Fibrosis

Liver fibrosis is a common and reversible feature of liver damage associated with many chronic liver diseases, and its onset is influenced by sex. In this study, we investigated the mechanisms of liver fibrosis and regeneration, focusing on understanding the mechanistic gaps between females and males. We injected increasing doses of carbon tetrachloride into female and male mice and maintained them for a washout period of eight weeks to allow for liver regeneration. We found that male mice were more prone to developing severe liver fibrosis as a consequence of early chronic liver damage, supported by the recruitment of a large number of Ly6Chigh MoMφs and neutrophils. Although prolonged liver damage exacerbated the fibrosis in mice of both sexes, activated HSCs and Ly6Chigh MoMφs were more numerous and active in the livers of female mice than those of male mice. After eight weeks of washout, only fibrotic females reported no activated HSCs, and a phenotype switching of Ly6Chigh MoMφs to anti-fibrogenic Ly6Clow MoMφs. The early stages of liver fibrosis mostly affected males rather than females, while long-term chronic liver damage was not influenced by sex, at least for liver fibrosis. Liver repair and regeneration were more efficient in females than in males.

ADAMTS12 is a stromal modulator in chronic liver disease

Adamalysins, a family of metalloproteinases containing a disintegrin and metalloproteinases (ADAMs) and ADAM with thrombospondin motifs (ADAMTSs), belong to the matrisome and play important roles in various biological and pathological processes, such as development, immunity and cancer. Using a liver cancer dataset from the International Cancer Genome Consortium, we developed an extensive in silico screening that identified a cluster of adamalysins co-expressed in livers from patients with hepatocellular carcinoma (HCC). Within this cluster, ADAMTS12 expression was highly associated with recurrence risk and poorly differentiated HCC signatures. We showed that ADAMTS12 was expressed in the stromal cells of the tumor and adjacent fibrotic tissues of HCC patients, and more specifically in activated stellate cells. Using a mouse model of carbon tetrachloride-induced liver injury, we showed that Adamts12 was strongly and transiently expressed after a 24 h acute treatment, and that fibrosis was exacerbated in Adamts12-null mice submitted to carbon tetrachloride-induced chronic liver injury. Using the HSC-derived LX-2 cell line, we showed that silencing of ADAMTS12 resulted in profound changes of the gene expression program. In particular, genes previously reported to be induced upon HSC activation, such as PAI-1, were mostly down-regulated following ADAMTS12 knock-down. The phenotype of these cells was changed to a less differentiated state, showing an altered actin network and decreased nuclear spreading. These phenotypic changes, together with the down-regulation of PAI-1, were offset by TGF-β treatment. The present study thus identifies ADAMTS12 as a modulator of HSC differentiation, and a new player in chronic liver disease.

Cakes fortified with papaya seeds effectively protects against CCl4-induced immunotoxicity

Maintaining a robust immune system and safeguarding the liver from toxins are crucial for overall health. The study aimed to investigate the immunostimulant effects of papaya seed-enriched cakes (CPS) in countering carbon tetrachloride (CCl4)-induced immunocytotoxicity in rats (n = 48). The rats were divided into six groups (8 each): a control group (Group 1), rats fed cakes containing 15% papaya seeds (Group 2 - CPS), rats exposed only to CCl4 (Group 3 - CCl4), rats injected with CCl4 and administered silymarin (Group 4 - CCl4 + S), rats receiving both CCl4 and cakes with papaya seeds (Group 5 - CCl4 + CPS), and rats receiving both CCl4 and silymarin with papaya seed-enriched cakes (Group 6 - CCl4 + CPS + S). HPLC analysis of papaya seeds revealed the presence of ten polyphenol compounds, with quercetin, apigenin, and catechin identified as major flavonoids, along with pyrogallol, ellagic, and gallic acid as predominant phenolic acids. These compounds displayed potent antioxidant activity, attributed to the seeds' high total phenolic and flavonoid content. The administration of CCl4 significantly affected hematological parameters, liver enzymes, hepatic oxidative stress, levels of TNF-α, IL-6, IgG, as well as IgM. However, rats fed with CPS exhibited mitigation of CCl4-induced toxic effects on hematological parameters and hepatotoxicity. CPS consumption enhanced the antioxidant system, improved inflammatory markers, and immune parameters, restoring them to normal levels. Histopathological analysis confirmed CPS's ability to reduce CCl4-induced hepatocellular necrosis. Immunohistochemical assessment further revealed reduced immunoreactivity against cleaved caspase-3 expression and increased COX2 immunoreactivity, indicating hepatocellular regeneration in CPS. The combination of CPS and silymarin demonstrated even more notable improvements, suggesting augmented protective impacts against CCl4-induced immunosuppression and hepatotoxicity. In conclusion, CPS exhibited antioxidant properties and effectively protected against CCl4-induced immunotoxicity and hepatotoxicity, with additional benefits observed when combined with silymarin. These findings emphasize the potential health advantages of incorporating papaya seeds into food products, promoting immune system health, and safeguarding against liver damage induced by hazardous agents like CCl4.

Hydronidone ameliorates liver fibrosis by inhibiting activation of hepatic stellate cells via Smad7-mediated degradation of TGFβRI

BACKGROUND AND PURPOSE

Liver fibrosis is a wound-healing reaction that eventually leads to cirrhosis. Hydronidone is a new pyridine derivative with the potential to treat liver fibrosis. In this study, we explored the antifibrotic effects of hydronidone and its potential mode of action.

METHODS

The anti-hepatic fibrosis effects of hydronidone were studied in carbon tetrachloride (CCl4 )- and 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC)- induced animal liver fibrosis. The antifibrotic mechanisms of hydronidone were investigated in hepatic stellate cells (HSCs). The antifibrotic effect of hydronidone was further tested after Smad7 knockdown in HSCs in mouse models of fibrosis.

RESULTS

In animal models, hydronidone attenuated liver damage and collagen accumulation, and reduced the expression of fibrosis-related genes. Hydronidone decreased the expression of fibrotic genes in HSCs. Impressively, hydronidone significantly upregulated Smad7 expression and promoted the degradation of transforming growth factor β receptor I (TGFβRI) in HSCs and thus inhibited the TGFβ-Smad signalling pathway. Specific knockdown of Smad7 in HSCs in vivo blocked the antifibrotic effect of hydronidone.

CONCLUSION

Hydronidone ameliorates liver fibrosis by inhibiting HSCs activation via Smad7-mediated TGFβRI degradation. Hydronidone is a potential drug candidate for the treatment of liver fibrosis.

MFAP2 promotes HSCs activation through FBN1/TGF-β/Smad3 pathway

Liver fibrosis is a chronic inflammatory process characterized by the accumulation of extracellular matrix (ECM), which contributes to cirrhosis and hepatocellular carcinoma. Increasing evidence suggests that the activation of hepatic stellate cells (HSCs) under an inflammatory state leads to the secretion of collagens, which can cause cirrhosis. In this study, we analysed data from the Gene Expression Omnibus (GEO) databases to identify differentially expressed genes (DEGs) between quiescent and fibrotic HSCs. We found that Microfibril Associated Protein 2 (MFAP2) was elevated in carbon tetrachloride (CCl4)-induced liver fibrosis and Transforming Growth Factor-Beta 1 (TGF-β1)-activated HSCs. Knockdown of MFAP2 inhibited HSC proliferation and partially attenuated TGF-β-stimulated fibrogenesis markers. Bioinformatics analysis revealed that Fibrillin-1 (FBN1) was correlated with MFAP2, and the expression of FBN1 was significantly upregulated after MFAP2 overexpression. Silencing MFAP2 partially attenuated the activation of HSCs by inhibiting HSC proliferation and decreasing collagen deposits. In vitro results showed that the inhibition of MFAP2 alleviated hepatic fibrosis by inhibiting the activation and inducing the apoptosis of active HSCs in a CCl4-induced mouse model. In conclusion, our results suggest that MFAP2 is a potential target for the clinical treatment of liver fibrosis.

Unaltered hepatic wound healing response in male rats with ancestral liver injury

The possibility that ancestral environmental exposure could result in adaptive inherited effects in mammals has been long debated. Numerous rodent models of transgenerational responses to various environmental factors have been published but due to technical, operational and resource burden, most still await independent confirmation. A previous study reported multigenerational epigenetic adaptation of the hepatic wound healing response upon exposure to the hepatotoxicant carbon tetrachloride (CCl4) in male rats. Here, we comprehensively investigate the transgenerational effects by repeating the original CCl4 multigenerational study with increased power, pedigree tracing, F2 dose-response and suitable randomization schemes. Detailed pathology evaluations do not support adaptive phenotypic suppression of the hepatic wound healing response or a greater fitness of F2 animals with ancestral liver injury exposure. However, transcriptomic analyses identified genes whose expression correlates with ancestral liver injury, although the biological relevance of this apparent transgenerational transmission at the molecular level remains to be determined. This work overall highlights the need for independent evaluation of transgenerational epigenetic inheritance paradigms in mammals.

Longitudinal Study of Cirrhosis Development in STAM and carbon tetrachloride Mouse Models Using Fourier Transform Infrared Spectral Imaging

Animal models of cirrhosis are of great interest to investigate the pathological process leading to the final stage of cirrhosis. The aim of this study was to analyze the different steps involved in the progressive development of cirrhosis using Fourier transform infrared spectral histology in 2 mouse models of cirrhosis, the STAM model of metabolic cirrhosis, and the carbon tetrachloride-induced cirrhosis model. Formalin-fixed, paraffin-embedded liver samples were obtained from 3 mice at 5 time points in each model to analyze the course of hepatic lesions up to the formation of cirrhosis. For each time point, adjacent 3-μm-thick liver sections were obtained for histologic stains and spectral histology. Fourier transform infrared acquisitions of liver sections were performed at projected pixel sizes of 25 μm × 25 μm and 6.25 μm × 6.25 μm. Spectral images were then preprocessed with an extended multiplicative signal correction and analyzed with common k-means clustering, including all stages in each model. In both models, the 2- and 4-class common k-means clustering in the 1000 to 1350 cm-1 range showed that spectral classes characterized by higher absorbance peaks of glycogen were predominant at baseline, then decreased markedly in early stages of hepatic damage, and almost disappeared in cirrhotic tissues. Concomitantly, spectral classes characterized by higher absorbance peaks of nucleic acids became progressively predominant during the course of hepatic lesions. These results were confirmed using k-means clustering on the peaks of interest identified for glycogen and nucleic acid content. Our study showed that the glycogen depletion previously described at the stage of cirrhosis is an early event in the pathological process, independently of the cause of cirrhosis. In addition, there was a progressive increase in the nucleic acid content, which may be linked to increased proliferation and polyploidy in response to cellular lesions.

Metabolomics study of the hepatoprotective effect of total flavonoids of Mallotus apelta leaf in carbon tetrachloride-induced liver fibrosis in rats

Mallotus apelta leaf, recorded in the quality standard of Yao Medicinal Material in Guangxi Zhuang autonomous region, is commonly used in the treatment of liver diseases. Total flavonoids of M. apelta leaf (TFM) had good anti-fibrosis activity, but the anti-fibrosis mechanism of TFM is still unclear. Nuclear magnetic resonance technology was used to study the dynamic changes of urine metabolites in CCl4 -induced liver fibrosis before and after TFM treatment. Ingenuity Path Analysis (IPA) was used to find potential target genes for TFM to improve liver fibrosis and verify the expression of target genes by real-time fluorescent quantitative PCR and Western blotting. TFM can significantly reduce serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) levels, improve liver steatosis and reduce inflammation; in urine metabolomics, a total of seven potential biomarkers were found, mainly involving two metabolic pathways; IPA analysis showed that TNF may be a potential target for TFM to improve liver fibrosis induced by CCl4 in rats. This study found that TNF may be a potential target gene for TFM treatment of liver fibrosis, and shows that the anti-fibrosis mechanism of TFM could improve liver fibrosis by regulating the tricarboxylic acid cycle and subtaurine metabolism.

The Dual Therapeutic Potential of Ottelione A on Carbon Tetrachloride-induced Hepatic Toxicity in Mice

BACKGROUND

Some herbal natural products play an important role in protecting organisms from the toxic effect of some xenobiotics. The present study was designed to evaluate the potential therapeutic effects of Ottelione A (OTTE) against carbon tetrachloride(CCl4)-induced toxicity in mice.

METHODS

Adult male Swiss albino mice were divided into six groups: group I was used as a normal control received olive oil; group II received DMSO; group III received OTTE; group IV received CCl4 in olive oil, (injected i.p) 3 times/week for 6 weeks; group V received the same CCl4 regimen as group IV followed by OTTE injected for 15 days, and group VI first received OTTE injected for 15 days followed by the same CCl4 regimen as group IV. Some biochemical and histological parameters were investigated.

RESULTS

Our results showed that the administration of CCl4 caused hepatotoxicity, as monitored by the significant increase in biochemical parameters concerning the olive oil group. Treatment with OTTE appeare d to be effective against hepatotoxic and liver changes induced by CCl4, as evidenced by the improvement of the same parameters.

CONCLUSION

Ottelione A (OTTE) has good antioxidant and therapeutic properties, which can help in preventing CCl4-induced hepatotoxicity in both pre-treatment and post-treatment modes.

Mitochondrial oxidative stress regulates LonP1-TDP-43 pathway and rises mitochondrial damage in carbon tetrachloride-induced liver fibrosis

Carbon tetrachloride (CCl4)-mediated liver damage has been well recognized, but the sources and mechanisms of mitochondrial damage during this progress still remain poorly understood. Accumulating evidence has revealed that LonP1-TDP-43 pathway affect proper mitochondrial integrity and function in neurodegenerative diseases. The current study aims to investigate whether mitochondrial oxidative stress regulate LonP1-TDP-43 pathway and the possible roles of this pathway in CCl4-driven liver fibrosis. We found that TDP-43 interacted with LonP1 in chronic CCl4 exposure-induced hepatic fibrogenesis. Moreover, CCl4 led to deficiency of LonP1 and excessive accumulation of TDP-43 on mitochondria. Particularly, the gene correlation analysis for liver fibrosis patients RNA sequencing (RNA-seq) results (GSE159676) showed an obvious negative correlation between LonP1 and TDP-43. By contrast, MitoQ enhanced the occurrence of mitochondrial unfolded protein response (mtUPR), especially the activation of LonP1 after CCl4 treatment. Importantly, mitochondrial antioxidant also promoted the degradation of TDP-43 and alleviated mitochondrial damage. In addition, our results showed that CCl4 induced the release of mitochondrial DNA (mtDNA) and effectively elevated cGAS-STING-mediated immune response, which can be inhibited by MitoQ. Finally, MitoQ prevented CCl4-induced liver fibrosis. Together, our study revealed that LonP1-TDP-43 pathway mediated by mitochondrial oxidative stress participated in the progress of CCl4-drived liver fibrosis. Therefore, mitigating or reversing mitochondrial damage through targeting LonP1-TDP-43 pathway may serve as a promising therapeutic strategy for CCl4 exposure-induced liver diseases.

An in vivo and in silico evaluation of the hepatoprotective potential of Gynura procumbens: A promising agent for combating hepatotoxicity

INTRODUCTION

The liver, the most important metabolic organ of the body, performs a wide variety of vital functions. Hepatic cell injury occurs by the activation of reactive oxygen species (ROS) that are generated by carbon tetrachloride (CCl4), xenobiotics, and other toxic substances through cytochrome P450-dependent steps resulting from the covalent bond formation with lipoproteins and nucleic acids. Observing the urgent state of hepatotoxic patients worldwide, different medicinal plants and their properties can be explored to combat such free radical damage to the liver. In vivo and in silico studies were designed and conducted to evaluate the antioxidant and hepatoprotective properties of Gynura procumbens in rats.

MATERIALS AND METHODS

Gynura procumbens leaves were collected and extracted using 70% ethanol. The required chemicals CCl4, standard drug (silymarin), and blood serum analysis kits were stocked. The in vivo tests were performed in 140 healthy Wister albino rats of either sex under well-controlled parameters divided into 14 groups, strictly maintaining Institutional Animal Ethics Committee (IEAC) protocols. For the histopathology study, 10% buffered neutral formalin was used for organ preservation. Later the specimens were studied under a fluorescence microscope. In silico molecular docking and absorption, distribution, metabolism, excretion, and toxicity (ADMET) studies were performed, and the results were analyzed statistically.

RESULTS AND DISCUSSION

Gynura procumbens partially negate the deleterious effect of carbon tetrachloride on normal weight gain in rats. The elevated level of serum glutamate pyruvate transaminase (SGPT), serum glutamate oxaloacetate transaminase (SGOT), alkaline phosphatase (ALP), creatinine, LDH, total cholesterol (TC), low-density lipoprotein (LDL), triglycerides (TG), malondialdehyde (MDA), deoxyribonucleic acid (DNA) fragmentation ranges, gamma-glutamyl transferase (γ-GT) in CCl4 treated groups were decreased by both standard drug silymarin and G. procumbens leaf extract. We have found significant & highly significant changes statistically for different doses, here p<0.05 & p<0.01, respectively. On the other hand, G. procumbens and silymarin displayed Statistically significant (p<0.05) and high significant(p<0.01) increased levels of HDL, CAT SOD (here p<0.05 & p<0.01 for different doses) when the treatment groups were compared with the disease control group. Because the therapeutic activity imparted by plants and drugs accelerates the movement of the disturbed pathophysiological state toward the healthy state. In the molecular docking analysis, G. procumbens phytoconstituents performed poorly against transforming growth factor-beta 1 (TGF-β1) compared to the control drug silymarin. In contrast, 26 phytoconstituents scored better than the control bezafibrate against peroxisome proliferator-activated receptor alpha (PPAR-α). The top scoring compounds for both macromolecules were observed to form stable complexes in the molecular dynamics simulations. Flavonoids and phenolic compounds performed better than other constituents in providing hepatoprotective activity. It can, thus, be inferred that the extract of G. procumbens showed good hepatoprotective properties in rats.

Hepatodamianol as hepatoprotective constituent of Turnera diffusa

It is well known that liver diseases are a major health problem and that there is a lack of hepatoprotective agents. Turnera diffusa (damiana) is a plant with a widespread distribution in México, which has many traditional uses, including the treatment of hepatic illnesses. Based on the bioassay-guided fractionation of a methanolic extract obtained from the aerial part of T. diffusa, we purified and identified a compound called hepatodamianol (1). This C-glycoside exhibited a four times greater hepatoprotective effect than the widely used hepatoprotective agent silibinin against carbon tetrachloride damage in an in vitro model using HepG2 cells. Hepatodamianol produced no cytotoxic effects and it exhibited a high antioxidant capacity. Therefore, hepatodamianol is a good candidate compound for testing as a hepatoprotective agent in a preclinical trial.

Reparative and Antioxidant Effects of New Analogues of Immunomodulator Thymogen in Experimental Model of Liver Damage

We studied the reparative and antioxidant effects of Thymogen and its new structural analogues obtained by binding amino acid D-Ala to the N- or C-end of the peptide molecule in acute toxic hepatopathy. Intragastric administration of carbon tetrachloride for 5 days caused the development of fat degeneration of hepatocytes, a decrease in catalase activity, and an increase in malondialdehyde concentration. Administration of peptides suppressed oxidative peroxidation and stimulated reparative regeneration of hepatocytes; Thymogen analogues produced more pronounced hepatotropic and antioxidant effects than Thymogen. Inclusion of D-Ala enhanced the effect of Thymogen on the processes of regeneration in hepatocytes and the antioxidant effect under conditions of acute carbon tetrachloride hepatopathy. The highest efficiency was achieved when the amino acid was added to the C-end of the molecule.

Hydroxyurea attenuates hepatic stellate cell proliferation in vitro and liver fibrogenesis in vivo

Liver fibrosis results from excessive proliferation of, and collagen production by hepatic stellate cells (HSCs) that is caused by chronic liver injury. No drugs are available to cure liver fibrosis. Hydroxyurea is an anti-proliferative drug that is used in benign and malignant disorders. Here, we studied the effect of hydroxyurea on primary HSCs and its anti-fibrotic effect in the CCl4 mouse model of liver fibrosis. Primary rat HSCs were cultured in the absence or presence of hydroxyurea (0.1-1.0 mmol/L). CCl4 or vehicle was administered to C57BL/6/J mice for 4 weeks, with or without hydroxyurea (100 mg/kg/day) co-treatment. We used real-time cell proliferation analysis, Oil Red O (lipid droplet) staining, immunohistochemistry, Acridine Orange staining (apoptosis), Sytox green staining (necrosis), RT-qPCR, ELISA, and Western Blotting for analysis. Hydroxyurea dose-dependently suppressed lipid droplet-loss and mRNA levels of Col1α1 and Acta2 in transdifferentiating HSCs. In fully-activated HSCs, hydroxyurea dose-dependently attenuated PCNA protein levels and BrdU incorporation, but did not reverse Col1α1 and Acta2 mRNA expression. Hydroxyurea did not induce apoptosis or necrosis in HSCs or hepatocytes. Hydroxyurea suppressed accumulation of desmin-positive HSCs and hepatic collagen deposition after CCl4 treatment. CCl4 -induced regenerative hepatocyte proliferation, Col1α1 and Acta2 mRNA expression and α-SMA protein levels were not affected. This study demonstrates that hydroxyurea inhibits HSC proliferation in vitro and attenuates early development of liver fibrosis in vivo, while preserving hepatocyte regeneration after toxic insults by CCl4. Thus, hydroxyurea may have therapeutic value against liver fibrosis.

Liver fibrotic development is reduced through inflammation prevention by an adenosine derivative compound

BACKGROUND

Liver fibrosis is a global health problem, and studying its development provides important information to address its treatment. Here, we characterized the effects of an adenosine compound (IFC-305) on preventing fibrosis and liver inflammation.

METHODS

We studied the impact of IFC-305 on a carbon tetrachloride-induced liver fibrosis model in Wistar male rats at 4, 6, and 8 weeks. The effects were characterized by liver tissue histology, macrophages identification by flow cytometry with CD163+/CD11b/c+ antibodies, hepatic and plasmatic cytokine levels employing MILLIPLEX MAP and ELISA, Col1a1 and Il6 gene expression by RTqPCR, lipoperoxidation by TBARS reaction, and reactive oxygen species using 2'-7'dichlorofluorescin diacetate.

RESULTS

CCl4-induced liver fibrosis and inflammation were significantly reduced in rats treated with IFC-305 at 6 and 8 weeks. In addition, we observed diminished expression of Col1a1; a decrease in the inflammatory cytokines IL-1β, IL-6, MCP-1, TNF-α, and IL-4 a; reduction in inflammatory macrophages; inhibition of lipoperoxidation; and ROS production in Kupffer cells.

CONCLUSION

This study showed that IFC-305 can inhibit liver fibrosis establishment by regulating the immune response during CCl4-induced damage. The immunomodulatory action of IFC-305 supports its use as a potential therapeutic strategy for preventing liver fibrosis.

Lycopene improves autophagy and attenuates carbon tetrachloride-induced hepatic fibrosis in rats

AIM

To evaluate the effect of lycopene on carbon tetrachloride (CCl4)-induced hepatic fibrosis and elucidate the underlying mechanism.

METHODS

Male rats were randomly assigned to the control group, CCl4 group, and lycopene group. The CCl4 group was intraperitoneally injected with CCl4 twice per week for 12 weeks to induce hepatic fibrosis. The control group was intraperitoneally injected with olive oil. Lycopene was orally administered during CCl4 treatment. Body weight and liver weight were recorded. Liver function was assessed. Biomarkers of oxidative stress and inflammatory factors were measured. Histological changes and collagen expression were evaluated. The expression of TGF-β1, α-SMA, HO-1, SIRT 1, REDD1, SHP2, P62, and LC3 in the liver was determined, as well as the levels of phosphorylated NF-κB and IκB α.

RESULTS

Lycopene significantly reduced the liver/body weight ratio, and AST (P=0.001) and ALT levels (P=0.009). It also significantly increased CAT and SOD activities (P<0.001) and decreased MDA content (P<0.001), IL-6 (P<0.001), and TNF-α (P=0.001). Histological analysis demonstrated that lycopene improved lobular architecture and decreased collagen expression. It also decreased the expression of TGF-β1, α-SMA, P62, and SHP2, and increased the ratio of LC3 II/I, as well as Beclin 1 and REDD1 expression. In addition, it reduced NF-κB and IκB-α phosphorylation, and elevated the levels of HO-1, SIRT 1, and PGC 1α.

CONCLUSION

Lycopene attenuates CCl4-induced hepatic fibrosis because of its effect on autophagy by reducing oxidative stress and inflammation.

Evaluation of the carcinogenicity of carbon tetrachloride

Carbon tetrachloride (CCl4) has been extensively used and reported to produce toxicity, most notably involving the liver. Carbon tetrachloride metabolism involves CYP450-mediated bioactivation to trichloromethyl and trichloromethyl peroxy radicals, which are capable of macromolecular interaction with cell components including lipids and proteins. Radical interaction with lipids produces lipid peroxidation which can mediate cellular damage leading to cell death. Chronic exposure with CCl4 a rodent hepatic carcinogen with a mode of action (MOA) exhibits the following key events: 1) metabolic activation; 2) hepatocellular toxicity and cell death; 3) consequent regenerative increased cell proliferation; and 4) hepatocellular proliferative lesions (foci, adenomas, carcinomas). The induction of rodent hepatic tumors is dependent upon the dose (concentration and exposure duration) of CCl4, with tumors only occurring at cytotoxic exposure levels. Adrenal benign pheochromocytomas were also increased in mice at high CCl4 exposures; however, these tumors are not of relevant importance to human cancer risk. Few epidemiology studies that have been performed on CCl4, do not provide credible evidence of enhanced risk of occurrence of liver or adrenal cancers, but these studies have serious flaws limiting their usefulness for risk assessment. This manuscript summarizes the toxicity and carcinogenicity attributed to CCl4, specifically addressing MOA, dose-response, and human relevance.

Grb2-related adaptor protein GRAP is a novel regulator of liver fibrosis

AIMS

Excessive liver fibrosis is frequently observed in chronic liver diseases and associated with decline of liver functions. Hepatic stellate cells (HSCs) are considered the principal mediator of liver fibrosis by trans-differentiating into myofibroblasts. In the present study we investigated the role of Grb2-related adaptor protein (GRAP) in HSC activation and liver fibrosis.

METHODS AND MATERIALS

Liver fibrosis was induced by carbon tetrachloride (CCl4) injection. Gene expression was examined by quantitative PCR. Cell proliferation was evaluated by EdU incorporation. DNA-protein interaction was examined by chromatin immunoprecipitation (ChIP).

KEY FINDINGS

GRAP expression was up-regulated during HSC-myofibroblast transition both in vivo and in vitro. Mechanistically, serum response factor (SRF) and myocardin-related transcription factor A (MRTF-A) formed a complex to bind to the GRAP promoter and activate GRAP transcription. Small interfering RNA (siRNA) mediated GRAP silencing blocked HSC-myofibroblast transition in vitro. Importantly, adeno-associated virus 6 (AAV6) mediated GRAP knockdown in myofibroblasts attenuated liver fibrosis in mice. Of note, inhibition of ERK signaling abrogated enhancement of HSC-myofibroblast transition by GRAP over-expression.

SIGNIFICANCE

Our data suggest that GRAP, possibly via ERK activation, regulates HSC-myofibroblast transition and contributes to liver fibrosis. Screening for small-molecule GRAP inhibitors may yield novel therapeutic solutions against liver fibrosis.

Neuroblastoma RAS viral oncogene homolog (N-RAS) deficiency aggravates liver injury and fibrosis

Progressive hepatic damage and fibrosis are major features of chronic liver diseases of different etiology, yet the underlying molecular mechanisms remain to be fully defined. N-RAS, a member of the RAS family of small guanine nucleotide-binding proteins also encompassing the highly homologous H-RAS and K-RAS isoforms, was previously reported to modulate cell death and renal fibrosis; however, its role in liver damage and fibrogenesis remains unknown. Here, we approached this question by using N-RAS deficient (N-RAS-/-) mice and two experimental models of liver injury and fibrosis, namely carbon tetrachloride (CCl4) intoxication and bile duct ligation (BDL). In wild-type (N-RAS+/+) mice both hepatotoxic procedures augmented N-RAS expression in the liver. Compared to N-RAS+/+ counterparts, N-RAS-/- mice subjected to either CCl4 or BDL showed exacerbated liver injury and fibrosis, which was associated with enhanced hepatic stellate cell (HSC) activation and leukocyte infiltration in the damaged liver. At the molecular level, after CCl4 or BDL, N-RAS-/- livers exhibited augmented expression of necroptotic death markers along with JNK1/2 hyperactivation. In line with this, N-RAS ablation in a human hepatocytic cell line resulted in enhanced activation of JNK and necroptosis mediators in response to cell death stimuli. Of note, loss of hepatic N-RAS expression was characteristic of chronic liver disease patients with fibrosis. Collectively, our study unveils a novel role for N-RAS as a negative controller of the progression of liver injury and fibrogenesis, by critically downregulating signaling pathways leading to hepatocyte necroptosis. Furthermore, it suggests that N-RAS may be of potential clinical value as prognostic biomarker of progressive fibrotic liver damage, or as a novel therapeutic target for the treatment of chronic liver disease.

Hepatoprotective potential of Anagallis arvensis (L.) extract against carbon tetrachloride (CCl4)-induced hepatic injury and oxidative stress in rabbits

Anagallis arvensis L. has several health benefits, such as it is an effective remedy for epileptic disorders, leprosy, rheumatism, and hepatic and renal dysfunctions. However, scientific evidence of the plant against liver disease is not reported so far. Thus, the aim of the present study was to highlight the hepatoprotective and hepatocurative effect of extract on hepatic injury induced by carbon tetrachloride (CCl4). The extract was investigated for its effect on hematological parameters, liver enzymes regulation, and anti-oxidant markers (SOD & CAT). In addition, histopathological investigations were performed. This extract displayed significant reversion of WBCs, RBCs, platelets count, hemoglobin, ALT, AST, ALP and albumin levels towards the normal level as compared with control. Therefore, there was significant rise in level of SOD and CAT in both groups (hepatocurative and protective). Furthermore, histological investigation demonstrated the preventive effect. The presence of alkaloids, carbohydrates, protein, phenolic compounds, tannins and saponins in the extract was confirmed by the preliminary phytochemical studies. Thus, based on all these facts, it can be concluded that Anagallis arvensis extract has restorative capability against CCl4-induced hepatotoxicity and could be used as the hepatocurative and hepatoprotective agent, which could be attributed to the reported secondary metabolites.

Effect of mycophenolate mofetil alleviates carbon tetrachloride-induced liver fibrosis in mice

OBJECTIVES

Hepatic fibrosis is a serious pathological consequence of chronic liver disease. Mycophenolate mofetil (MMF) is a commonly used immunosuppressant after organ transplant. However, the relationship between MMF and hepatic fibrosis remains unclear. This study aims to explore the effect of MMF on hepatic fibrosis in mice and the potential mechanism.

METHODS

A total of 24 mice (male, 8-week old, C57BL/6) were randomly divided into a control group, a MMF group, a carbon tetrachloride (CCl4) group and a CCl4+MMF group (n=6 in each group). After the mice were sacrificed, the serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were detected. The liver tissues were taken up for Masson staining and collagen I (COL1) immunohistochemistry. The levels of transforming growth factor-β1 (TGF-β1) and α-smooth muscle actin (α-SMA) were detected by Western blotting. Finally, the levels of mRNA for TGF-β1, α-SMA, and COL1 were detected using real-time PCR.

RESULTS

Compared with the CCl4 group, the ALT and AST levels were lower (both P<0.05), the degree of liver fibrosis was alleviated, and the deposition of COL1 in the liver was significantly decreased (P<0.01) in the CCl4+MMF group. Compared with the CCl4 group, the protein expression levels of TGF-β1 and α-SMA were significantly decreased (both P<0.05) and the relative expression levels of TGF-β1, α-SMA and COL1 mRNA in the liver were significantly decreased (all P<0.05) in the CCl4+MMF.

CONCLUSIONS

MMF could reduce CCl4-induced hepatic fibrosis, which might be related to the inhibition of TGF-β1. This study is expected to provide a target for the treatment of hepatic fibrosis.

Cell atlas of CCl 4-induced progressive liver fibrosis reveals stage-specific responses

Chronic liver injury leads to progressive liver fibrosis and ultimately cirrhosis, a major cause of morbidity and mortality worldwide. However, there are currently no effective anti-fibrotic therapies available, especially for late-stage patients, which is partly attributed to the major knowledge gap regarding liver cell heterogeneity and cell-specific responses in different fibrosis stages. To reveal the multicellular networks regulating mammalian liver fibrosis from mild to severe phenotypes, we generated a single-nucleus transcriptomic atlas encompassing 49 919 nuclei corresponding to all main liver cell types at different stages of murine carbon tetrachloride (CCl 4)-induced progressive liver fibrosis. Integrative analysis distinguished the sequential responses to injury of hepatocytes, hepatic stellate cells and endothelial cells. Moreover, we reconstructed cell-cell interactions and gene regulatory networks implicated in these processes. These integrative analyses uncovered previously overlooked aspects of hepatocyte proliferation exhaustion and disrupted pericentral metabolic functions, dysfunction for clearance by apoptosis of activated hepatic stellate cells, accumulation of pro-fibrotic signals, and the switch from an anti-angiogenic to a pro-angiogenic program during CCl 4-induced progressive liver fibrosis. Our dataset thus constitutes a useful resource for understanding the molecular basis of progressive liver fibrosis using a relevant animal model.

Calcitriol attenuates liver fibrosis through hepatitis C virus nonstructural protein 3-transactivated protein 1-mediated TGF β1/Smad3 and NF-κB signaling pathways

BACKGROUND

Hepatic fibrosis is a serious condition, and the development of hepatic fibrosis can lead to a series of complications. However, the pathogenesis of hepatic fibrosis remains unclear, and effective therapy options are still lacking. Our group identified hepatitis C virus nonstructural protein 3-transactivated protein 1 (NS3TP1) by suppressive subtractive hybridization and bioinformatics analysis, but its role in diseases including hepatic fibrosis remains undefined. Therefore, additional studies on the function of NS3TP1 in hepatic fibrosis are urgently needed to provide new targets for treatment.

AIM

To elucidate the mechanism of NS3TP1 in hepatic fibrosis and the regulatory effects of calcitriol on NS3TP1.

METHODS

Twenty-four male C57BL/6 mice were randomized and separated into three groups, comprising the normal, fibrosis, and calcitriol treatment groups, and liver fibrosis was modeled by carbon tetrachloride (CCl₄). To evaluate the level of hepatic fibrosis in every group, serological and pathological examinations of the liver were conducted. TGF-β1 was administered to boost the in vitro cultivation of LX-2 cells. NS3TP1, α-smooth muscle actin (α-SMA), collagen I, and collagen III in every group were examined using a Western blot and real-time quantitative polymerase chain reaction. The activity of the transforming growth factor beta 1 (TGFβ1)/Smad3 and NF-κB signaling pathways in each group of cells transfected with pcDNA-NS3TP1 or siRNA-NS3TP1 was detected. The statistical analysis of the data was performed using the Student’s t test.

RESULTS

NS3TP1 promoted the activation, proliferation, and differentiation of hepatic stellate cells (HSCs) and enhanced hepatic fibrosis via the TGFβ1/Smad3 and NF-κB signaling pathways, as evidenced by the presence of α-SMA, collagen I, collagen III, p-smad3, and p-p65 in LX-2 cells, which were upregulated after NS3TP1 overexpression and downregulated after NS3TP1 interference. The proliferation of HSCs was lowered after NS3TP1 interference and elevated after NS3TP1 overexpression, as shown by the luciferase assay. NS3TP1 inhibited the apoptosis of HSCs. Moreover, both Smad3 and p65 could bind to NS3TP1, and p65 increased the promoter activity of NS3TP1, while NS3TP1 increased the promoter activity of TGFβ1 receptor I, as indicated by coimmunoprecipitation and luciferase assay results. Both in vivo and in vitro, treatment with calcitriol dramatically reduced the expression of NS3TP1. Calcitriol therapy-controlled HSCs activation, proliferation, and differentiation and substantially suppressed CCl₄-induced hepatic fibrosis in mice. Furthermore, calcitriol modulated the activities of the above signaling pathways via downregulation of NS3TP1.

CONCLUSION

Our results suggest that calcitriol may be employed as an adjuvant therapy for hepatic fibrosis and that NS3TP1 is a unique, prospective therapeutic target in hepatic fibrosis.

A novel type lavandulyl flavonoid from Sophora flavescens as potential anti-hepatic injury agent that inhibit TLR2/NF-κB signaling pathway

ETHNOPHARMACOLOGY RELEVANCE

Sophora flavescens Aiton, was a crucial source of Traditional Chinese Medicine (TCM) that has benefited human health for hundreds of years. Alkaloids and flavonoids were the major bioactive constituents from S. flavescens, which had been widely used for liver disease treatment in China. However, the liver-protective components of flavonoids from S. flavescens and their mechanism of action were not clear.

AIM OF THE STUDY

This work aimed to evaluate the in vitro hepatoprotective activities of 35 flavonoids from S. flavescens and screen active compounds. Furthermore, it was conducted to demonstrate the hepatoprotective effects of a new active compound (kurarinol A, 1) was isolated by authors and the ethyl acetate (EtOAc) extract form S. flavescens against carbon tetrachloride (CCl₄)-induced hepatic injury in Kunming (KM) mice, meanwhile revealed the potential mechanism.

MATERIALS AND METHODS

The 35 flavonoids from S. flavescens were co-incubated with HepG2 cells and treated with 0.35% CCl₄ for 6 h cell viability was measured by (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt) (MTS) assay. Then, in vivo animal experiments, the activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) in the serum were analyzed, the degree of hepatic injury was examined using hematoxylin-eosin (H&E) staining, the mRNA expression of Superoxide Dismutase 2 (SOD2), Nuclear factor E2-related factor 2 (Nrf2), heme oxygenase 1 (HO-1), Interleukin 6 (IL-6), Tumor Necrosis Factor-α (TNF-α), interleukin-1β (IL-1β), and the protein levels of nuclear factor-kappa B p65/p-p65 (NF-κB p65/p-p65), toll-like receptor 2 (TLR2), IL-1β and cyclooxygenase-2 (COX2) in hepatic tissues were detected.

RESULTS

The lavandulyl flavonoid (kurarinol A, 1) and the EtOAc extract from S. flavescens showed protective effects on CCl₄-injured HepG2 cells, increasing cell viability from 24.5% to 61.3% and 91.8%, respectively. What's more, we found that treatment with kurarinol A (1) and the EtOAc extract lead to a significant reduction in hepatotoxicity in response to acute CCl₄ exposure. Compared with the model group, experimental results exhibited kurarinol A (10 mg/kg, i.p.) and the EtOAc extract (300 mg/kg, i.p.) could decrease the levels of AST, ALT, ALP and tissue damage. Further mechanistic investigations revealed that up-regulated the mRNA expression of SOD2, Nrf2, OH-1 and down-regulated the IL-1β in liver tissues, respectively. Additionally, Western blot analyses elucidated that inhibition of IL-1β, TLR2, COX-2, NF-κB (p65/p-p65) via TLR2/NF-κB signaling pathway by kurarinol A and the EtOAc extract contribute to its hepatoprotective activity.

CONCLUSION

These findings demonstrated that the novel compound (kurarinol A, 1) possessed notable hepatoprotective activity against CCl₄. It was confirmed that kurarinol A had a certain effect on mice with liver damage induced by CCl₄, and its mechanism could be include inhibiting inflammation and reducing of oxidative stress reaction by regulating expression of related genes and proteins. Thus, kurarinol A could as a novel active agent that contributes to the hepatoprotective activity of S. flavescens for the treatment of live injury.

Study of ameliorative effect of Allium cepa essential oil and purple cabbage (Brassica Oleracea Var. Capitata F. Rubra) leaves extract on CCl4 induced nephrotoxicity in rats

In human body kidney pair acts as an essential excretory organ which keeps up the acid/base equalization. The onion and cabbage compounds play vital role as nephroprotective, because toxicity induced free radicals are neutralized by antioxidant substances present in onion (Allium Cepa) and cabbage (Brassica oleracea). This research helps to find which compound has better nephroprotective activity. In this study 25 albino rats were used as models for studying carbon tetrachloride induced nephrotoxicity. The rats were divided into 5 groups. Control group received no treatment, 2nd group got only CCl4, 3rd group received CCl4 and purple cabbage leaves extract, 4th group received CCl4 and onion oil (5 ml/kg) and 5th group received CCl4 and both onion essential oil and purple cabbage leaves extract. At 15th day, rats were euthanized, blood and kidney samples of all groups were collected for histopathology of kidney and serum testing, includes BUN, creatinine, albumin and electrolytes levels. CCl4 administration altered creatinine, albumin protein and blood urea nitrogen level of serum. It also changed the electrolytes' concentration in treated group animals as compared to control group rats. The extract of purple cabbage leaves and onion essential oil showed a protective effect against nephrotoxicity among treated groups of rats.

Profile of 5-HT2A receptor involved in signaling cascades associated to intracellular inflammation and apoptosis in hepatocytes and its role in carbon tetrachloride-induced hepatotoxicity

Previously, we found that the 5-HT_2A receptor plays a key role in cell injury. However, the mechanism by which the 5-HT_2A receptor mediates intracellular processes remains unclear. In this study, we aimed to clarify this intracellular process in hepatocyte LO2 cells and evaluate its role in CCl₄-induced hepatotoxicity in mice. In vitro, both the agonist and overexpression of 5-HT_2A receptor could promote 5-HT degradation by upregulating the expression of 5-HT synthases and monoamine oxidase-A (MAO-A) to cause overproduction of ROS in mitochondria. We refer to this as the activation of the 5-HT degradation system (5DS) axis, which leads to the phosphorylation of JNK, p38 MAPK, STAT3, and NF-κB; upregulation of Bax, cleaved-caspase3, and cleaved-caspase9; and downregulation of Bcl-2, followed by apoptosis and oversecretion of TNF-α and IL-1β in cells. This phenomenon could be markedly blocked by the 5-HT_2A receptor antagonist, MAO-A inhibitor, or gene-silencing MAO-A. Through protein kinases C epsilon (PKCε) agonist treatment and gene silencing of the PKCε and 5-HT_2A receptor, we demonstrated that the 5-HT_2A receptor controls 5-HT synthases and MAO-A expression via the PKCε pathway in cells. Unexpectedly, we discovered that PKCε-mediated phosphorylation of the AKT/mTOR pathway is also a consequence of the activation of the 5DS axis. Furthermore, we confirmed that the inhibition of the 5DS axis using the 5-HT_2A receptor antagonist could prevent hepatotoxicity induced by CCl₄ both in vitro and in vivo, inhibiting the aforementioned signaling cascades, inflammation, and apoptosis, and that the 5DS activation area overlapped the necrotic area of mouse liver. Taken together, we revealed a 5DS axis in hepatocytes that controls the signaling cascades associated with inflammation and apoptosis and confirmed its role in CCl₄-induced hepatotoxicity.

Effect of ADHI on hepatic stellate cell activation and liver fibrosis in mice

The relationship between alcohol dehydrogenase (ADH) and liver fibrosis has been studied, but the mechanism of ADH involvement in liver fibrosis remains unclear. The aim of the present study was to explore the role of ADHI, the classical liver ADH, in hepatic stellate cell (HSC) activation and the effect of 4-methylpyrazole (4-MP), an ADH inhibitor, on liver fibrosis induced by carbon tetrachloride (CCl₄) in mice. The results showed that overexpression of ADHI significantly increases proliferation, migration, adhesion and invasion rates of HSC-T6 cells as compared with controls. When HSC-T6 cells were activated by ethanol, TGF-β1 or LPS, the expression of ADHI was elevated significantly (P < 0.05). Overexpression of ADHI significantly increased the levels of COL1A1 and α-SMA, markers of HSC activation. Moreover, the expression of COL1A1 and α-SMA was decreased significantly by transfection of ADHI siRNA (P < 0.01). In a liver fibrosis mouse model ADH activity increased significantly and was highest in the 3rd week. The activity of ADH in the liver was correlated with its activity in the serum (P < 0.05). 4-MP significantly decreased ADH activity and ameliorated liver injury, and ADH activity was positively correlated with the Ishak score of liver fibrosis. In conclusion, ADHI plays an important role in the activation of HSC, and inhibition of ADH ameliorates liver fibrosis in mice.