NAMPT-mediated NAD+ biosynthesis suppresses activation of hepatic stellate cells and protects against CCl4-induced liver fibrosis in mice.

Background: Nicotinamide phosphoribosyltransferase (NAMPT) catalyzes the rate-limiting step in the salvage pathway of mammalian nicotinamide adenine dinucleotide (NAD+) biosynthesis. Through its NAD+-biosynthetic activity, NAMPT is able to regulate the development of hepatic steatosis and inflammation induced by diet or alcohol. However, the roles NAMPT plays in the development of liver fibrosis remain obscure. Purpose: To investigate the roles of NAMPT-mediated NAD+ biosynthesis in hepatic stellate cell (HSC) activation and liver fibrosis. Research Design: Realtime RT-PCR and western blot analyses were performed to analyze the expression of profibrogenic genes. Sirius red staining was conducted to examine the fibrosis in liver. Mouse liver fibrosis was induced by intraperitoneal injection of carbon tetrachloride (CCl4) 2 times a week for 6 weeks. Adenovirus-mediated NAMPT overexpression or nicotinamide mononucleotide (NMN) administration was carried out to study the effects of elevation of NAD+ levels on protecting CCl4-induced liver fibrosis in mice. LX2 cells or primary HSCs were used to study the role of NAMPT overexpression or NMN treatment in reducing profibrogenic gene expression in vitro. ResultsCCl4 administration suppresses NAMPT expression in liver and reduces hepatic NAD+ content. Tgfß1 treatment decreases intracellular NAD+ levels and NAMPT expression in LX2 cells. Adenovirus-mediated NAMPT overexpression augments liver NAD+ levels, inhibits HSC activation and alleviates CCl4-induced liver fibrosis in mice. Administration of NMN also suppresses HSC activation and protects against CCl4-induced liver fibrosis in mice. Conclusions: NAMPT-mediated NAD+ biosynthesis inhibits HSC activation and protects against CCl4-induced liver fibrosis.

Hepatoprotective effect of Spirulina platensis against carbon tetrachloride-induced liver injury in male rats.

OBJECTIVES: Spirulina platensis (SP) is an edible Cyanobacterium with ethnomedicinal significance. This study aims at evaluating the beneficial effect of SP against carbon tetrachloride (CCl4)-induced liver toxicity in male rats. METHODS: Rats received intraperitoneal injections of CCl4 (2 ml/kg body weight [b.w.] per every other day) for 40 days, alone or in combination with oral treatments of SP (400 mg/kg b.w. per day). KEY FINDINGS: SP attenuated haematological disturbances, serum liver markers, hepatic necrosis and inflammation, and dyslipidemia in CCl4-intoxicated rats. SP also reduced CCl4-induced oxidative stress by increasing the activities of antioxidant enzymes, such as glutathione peroxidase, superoxide dismutase and catalase and glutathione content, and inhibiting lipid peroxidation products and nitric oxide levels in the rat liver. Further investigations revealed that SP counteracted CCl4-induced increased hepatic levels of Ki-67 (a parameter of cell proliferation), interleukin-6, and tumour necrosis factor-alpha and cyclooxygenase-2 messenger RNA expression. Noticeably, the supplementation of SP restored the decrease of proapoptotic p53 protein levels in the liver of rats treated with CCl4. CONCLUSIONS: SP prevented liver damage in CCl4-treated rats via augmentation of antioxidant defense mechanisms and inhibition of inflammatory cytokines/mediators and antiproliferative effects.

In vivo studies on the ameliorative effect of coconut water against carbon tetrachloride induced toxicity in rats.

PURPOSE: Coconut water is used in folklore medicine for oral rehydration, treatment of childhood diarrhoea, gastroenteritis and cholera, and is also known to possess antioxidant properties. OBJECTIVE: In this study, we examined the ameliorative potentials of coconut water on carbon tetrachloride (CCl4) induced toxicity in rats. MATERIALS AND METHODS: Rats were randomly assigned into separate cages according to the sex of 5 groups. Groups 2-5 were intraperitoneally injected a single dose of 1 mL/kg CCl4 diluted in olive oil. Only 3, 4 and 5 were orally given 2, 4, 6 mL/kg coconut water respectively, whereas groups 1 and 2 received distilled water. RESULTS: Treatment with coconut water significantly (p < 0.05) increased red blood cell, packed cell volume, haemoglobin, high-density lipoprotein, glutathione, superoxide dismutase, catalase, total protein, and albumin compared to the negative control in both sexes of the rats. Furthermore, platelets, white blood cells, urea, low-density lipoprotein, triglyceride, total cholesterol, malondialdehyde, bilirubin, alkaline phosphatase, alanine and aspartate transaminases decreased significantly (p < 0.05) compared to the negative control in both male and female rats. CONCLUSION: Thus, coconut water supplementation may reverse CCl4 induced toxicity and distortions on haematological parameters, lipid profile and antioxidant enzymes, liver and kidney biomarkers in rats.

Zingiber roseum Rosc. rhizome: A rich source of hepatoprotective polyphenols.

Zingiber roseum is native to Bangladesh and widely used in folk medicine. This present study was designed to assess the ameliorative potential of Zingiber roseum rhizome extract in carbon tetrachloride (CCl4) induced hepatotoxicity in mice model. Seven phenolic compounds were identified and quantified by HPLC analysis in the plant extract, including quercetin, myricetin, catechin hydrate, trans-ferulic acid, trans-cinnamic acid, (-) epicatechin, and rosmarinic acid. Hepatotoxicity was induced by administrating a single intraperitoneal injection of CCl4 (10 mL/kg) on 7th day of treatment. The results revealed that plant extract at all doses (100, 200 and 400 mg/kg) significantly reduced (p < 0.05) the elevated serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) concentrations, and these effects were comparable to that of standard drug silymarin. Histopathological examination also revealed the evidence of recovery from CCL4 induced cellular damage when pretreated with Z. roseum rhizome extract. The in-vivo hepatoprotective effects were further investigated by the in-silico study of the aforementioned compounds with liver-protective enzymes such as superoxide dismutase (SOD), peroxiredoxin, and catalase. The strong binding affinities (ranging from -7.3359 to -9.111 KCal/mol) between the phenolic compounds (except trans-cinnamic acid) and oxidative stress enzymes inhibit ROS production during metabolism. The compounds were also found non-toxic in computational prediction, and a series of biological activities like antioxidant, anticarcinogen, cardio-protectant, hepato-protectant have been detected.

Hepatoprotective effect of linagliptin against liver fibrosis induced by carbon tetrachloride in mice.

The current study aimed to investigate linagliptin for its potential role in the prevention of liver fibrosis progression. Balb-C mice were randomly allocated into five groups (10 each): (i) control; (ii) mice were injected intraperitoneally with 50 µL carbon tetrachloride (CCl4) in corn oil in a dose of 0.6 µL/g three times per week for four weeks; (iii) linagliptin was administered orally in a daily dose of 10 mg/kg simultaneously with CCl4; (iv) silymarin was administered orally in a daily dose of 200 mg/kg concomitantly with CCl4; and (v) only linagliptin was administered. Hepatic injury was manifested in the CCl4 group by elevation of biochemical parameters (alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP)), and hepatic fibrosis was evident histopathologically by increased METAVIR score and immunostaining expression of alpha-smooth muscle actin (α-SMA), as well as increased liver tissue oxidative stress parameters, transforming growth factor-ß1 (TGF-ß1), and mammalian target of rapamycin (mTOR). Linagliptin was able to stop the progression of liver fibrosis, evident histopathologically with reduced METAVIR score and α-SMA expression. The possible mechanism may be via suppression of oxidative stress, TGF-ß1, and mTOR, which was associated with improvement of serum biochemical parameters ALT and AST. In conclusion, linagliptin might help to protect the liver against persistent injury-related consequences.

Hepatoprotection of pine nut polysaccharide via NRF2/ARE/MKP1/JNK signaling pathways against carbon tetrachloride-induced liver injury in mice.

Previously, we obtained a purified polysaccharide (PNP40c-1) from Pinus koraiensis pine nut and reported its protective effect on carbon tetrachloride (CCl4)-induced liver injury in vitro. The object of this study is to investigate its hepatoprotective activity in vivo and elucidate the mechanism underlying the hepatoprotection. PNP40c-1 effectively prevented the accumulation of serum liver injury biomarkers including alanine aminotransferase, aspartate aminotransferase, alkaline phpsphatase and total bilirubin stimulated by CCl4. The pathological changes in PNP40c-1-treated mice livers were also markedly ameliorated. Results showed that PNP40c-1 suppressed the production of reactive oxygen species (ROS) and lipid peroxidation, upregulated Nrf2/ARE pathway and enhanced the antioxidant capacity of hepatocytes. Furthermore, the reaction between Nrf2 and ARE promoted the generation of Mkp1, which inhibited the activation of JNK induced by CCl4, and suppressed hepatocytes apoptosis by regulating the protein expression of Bax, cleaved-Caspase-3 and Bcl2, exerting hepatoprotective activity. Taken together, upregulation of Nrf2/ARE pathway and suppression of JNK activation via Nrf2/ARE/Mkp1/JNK signaling pathways are the main mechanisms underlying the hepatoprotective effect of PNP40c-1 against CCl4-induced mice liver injury. These results indicated that PNP40c-1 has potential to serve as a hepatoprotective agent against chemical induced hepatotoxicity.

Blockade of periostin-dependent migration and adhesion by curcumol via inhibition of nuclear factor kappa B signaling in hepatic stellate cells.

OBJECTIVES: Curcumol, a guaiane-type sesquiterpenoid hemiketal extracted from the herb Rhizoma Curcumae, exhibits multiple-pharmacological activities. We previously reported that curcumol ameliorated hepatic fibrosis by inhibiting hepatic stellate cell (HSC) activation. In this study, we aimed to investigate the effect of curcumol on HSC migration and adhesion, and reveal its regulation mechanisms. MATERIALS AND METHODS: Cellular viability was determined by Cell Counting Kit-8. Cell migration was detected by boyden chamber and cell scratch experiment. Recombinant human periostin (rh POSTN) and adeno-associated viral (AAV)-GFP-periostin were used to achieve POSTN overexpression in vitro and in vivo, respectively. Nuclear factor kappa B (NF-κB)-p65 overexpression was achieved by using plasmid. ELISA was conducted to detect POSTN level. Immunohistochemistry, qRT-PCR, Western blotting, and immunofluorescence were performed to assess associated factor expression. RESULTS: Curcumol suppressed HSC migration and adhesion, and reduced the secretion and expression of POSTN. By gain of function POSTN in HSCs, using rh POSTN, we found that the inhibition of HSC migration and adhesion by curcumol depended on the decrease of POSTN. Besides, curcumol protection against chronic CCl4-caused hepatic fibrosis could be impaired by POSTN overexpression. Moreover, we showed that curcumol repressed NF-κB signaling and the production of pro-inflammatory factor. Importantly, curcumol down-regulation of POSTN was rescued by knock-in of NF-κB, as well as the inhibition of HSC migration and adhesion. CONCLUSION: These findings reveal the molecular mechanism of curcumol-reduced HSC migration and adhesion, by which points to the possibility of using curcumol based on NF-κB dependent POSTN for the treatment of fibrogenesis.

4-methylumbelliferone Prevents Liver Fibrosis by Affecting Hyaluronan Deposition, FSTL1 Expression and Cell Localization.

4-methylumbelliferone (4MU) is an inhibitor of hyaluronan deposition and an active substance of hymecromone, a choleretic and antispasmodic drug. 4MU reported to be anti-fibrotic in mouse models; however, precise mechanism of action still requires further investigation. Here we describe the cellular and molecular mechanisms of 4MU action on CCl4-induced liver fibrosis in mice using NGS transcriptome, Q-PCR and immunohistochemical analysis. Collagen and hyaluronan deposition were prevented by 4MU. The CCl4 stimulated expression of Col1a and αSMA were reduced, while the expression of the ECM catabolic gene Hyal1 was increased in the presence of 4MU. Bioinformatic analysis identified an activation of TGF-beta and Wnt/beta-catenin signaling pathways, and inhibition of the genes associated with lipid metabolism by CCL4 treatment, while 4MU restored key markers of these pathways to the control level. Immunohistochemical analysis reveals the suppression of hepatic stellate cells (HSCs) transdifferentiation to myofibroblasts by 4MU treatment. The drug affected the localization of HSCs and macrophages in the sites of fibrogenesis. CCl4 treatment induced the expression of FSTL1, which was downregulated by 4MU. Our results support the hypothesis that 4MU alleviates CCl4-induced liver fibrosis by reducing hyaluronan deposition and downregulating FSTL1 expression, accompanied by the suppression of HSC trans-differentiation and altered macrophage localization.

Protective effect of RNA interference targeting Ikkß on hepatic fibrosis in rats.

Nuclear factor-κB (NF-κB) is an important regulatory factor in cells. NF-κB has a wide range of biological activities. After activation, it participates in the transcription and regulation of many genes and plays a role in infection, inflammatory response, oxidative stress, cell multiplication, and apoptosis. The activation of the NF-κB signal pathway is dependent on the degradation of the IκB kinase ß (IKKß) complex. IKK ß is the key kinase in the NF-κB activation pathway. After inhibition, it can block the activation of NF-κB. IKKß is a key regulator of NF-κB activation, also an early regulator of inflammation in all stages of the immune response. This study aimed to investigate the effect of IKKß-siRNA lentivirus vector treatment for hepatic fibrosis of rats. An IKKß-siRNA expression plasmid was constructed and injected in the tail vein of rats. Then, IKKß-siRNA distribution in the liver was observed by immunofluorescence, and the quantitative polymerase chain reaction was used to detect inflammation-related and fibrosis-related factors. IKKß-siRNA lentiviruses could be delivered to the liver and significantly decrease carbon tetrachloride-induced hepatic fibrosis. Furthermore, serum transaminase levels significantly decreased, and inflammation-related and fibrosis-related factors decreased. IKKß-siRNA can be an effective method of anti-fibrosis gene therapy for liver fibrosis.

Protective Effects of Ammannia baccifera Against CCl4-Induced Oxidative Stress in Rats.

Ammannia baccifera Linn. is commonly used as a traditional medicine in India and China. The antioxidant potential of an ethanolic extract of A. baccifera (EEAB; 250 mg/kg and 500 mg/kg) was evaluated against CCL4-induced toxicity in rats. Antioxidant activity was assessed by measuring the enzymatic and non-enzymatic antioxidants. Phytochemical constituents of EEAB were also analyzed by using UHPLC-QTOF-MS. EEAB treatment markedly reduced CCl4 effects on lipid peroxidation, cholesterol, triacylglycerides, and protein carbonyls. It increased the levels of phospholipids, total sulfhydryl, and antioxidant enzymes, which were reduced by CCl4 intoxication. Treatment with EEAB significantly alleviated the CCl4 effect on non-enzymatic antioxidants. Isoenzyme pattern analyses revealed that significant alterations in superoxide dismutase (SOD1), glutathione peroxidase (GPx2, GPx3), and catalase (CAT) occurred in rats that were exposed to CCl4 and restored post EEAB treatment. Moreover, CCl4-induced down regulation of SOD, CAT, and GPx gene expression was conversely counteracted by EEAB. Its bioactivity may be due to its incorporation of major compounds, such as chlorogenic acid, quercetin, protocatechuic acid, lamioside, crocetin, and khayasin C. These results suggest that EEAB may be used as a potent antioxidant and hepatoprotective agent since it is a rich source of flavonoids and phenolic compounds.

Structural characterization and hepatoprotective activities of polysaccharides from the leaves of Toona sinensis (A. Juss) Roem.

Two polysaccharide fractions (TSP-1 and TSP-2) with molecular weights of 833.6 kDa and 81.6 kDa were isolated from Toona sinensis leaves (Meliaceae) by hot water extraction, DEAE Cellulose-52 chromatography and Sephacryl S-400 gel permeation chromatography. Structural analysis indicated that TSP-1 and TSP-2 consisted of Manp, GlcpA, Glcp, Galp, Xylp and Araf with different molar ratios. Methylation and NMR analysis revealed that the backbone of TSP-1 might consist of 1,6-linked-Glcp, 1,3,6-linked-Manp and 1,6-linked-Galp, while TSP-2 was mainly composed of 1,3,5-linked-Araf, 1,6-linked-Glcp, 1,4-linked-Xylp and 1,6-linked-Galp. Congo red assay indicated that TSP-1 and TSP-2 had no triple-helix structure, which was consistent with the results of AFM. In vivo hepatoprotective activity showed that TSP-1 and TSP-2 could improve CCl4-induced mice liver injury by reducing the activities of AST, ALT and the level of MDA, increasing the activities of SOD, GSH-Px, and CAT and the level of GSH in liver and decreasing the expression levels of TNF-α and IL-6 in liver. These results suggest that TSP-1 and TSP-2 have promising potential to serve as hepatoprotective agents.

Inhibition of activated factor X; a new pathway in ameliorating carbon tetrachloride-induced liver fibrosis in rats.

Activated factor X has a central role in the coagulation activation and also contributes to chronic inflammation and tissue fibrosis. In this study, rivaroxaban, a direct factor X inhibitor, attenuates liver fibrosis induced by carbon tetrachloride (CCl4 ). Male rats were randomly allocated into three groups: a control group, CCl 4 fibrotic group, and CCl 4 +rivaroxaban (5 mg/kg) group. Liver fibrosis was induced by subcutaneous injection of CCl 4 twice a week for 6 weeks. Rivaroxaban significantly restored the biochemical parameter including inflammatory and fibrosis markers with histopathological evidence using routine and Masson trichrome staining. It reduced also the expression of tissue factor, fibrin, transforming growth factor and α-smooth muscle actin in the liver tissues. This concludes that rivaroxaban attenuates liver injury caused by CCl 4 , at least in part by inhibiting coagulation and proinflammatory activation. In conclusion, rivaroxaban may be used for the management of liver fibrosis.

R. verniciflua and E. ulmoides Extract (ILF-RE) Protects against Chronic CCl4-Induced Liver Damage by Enhancing Antioxidation.

This study aimed to characterize the protective effects of R. verniciflua extract (ILF-R) and E. ulmoides extract (ILF-E), the combination called ILF-RE, against chronic CCl4-induced liver oxidative injury in rats, as well as to investigate the mechanism underlying hepatoprotection by ILF-RE against CCl4-induced hepatic dysfunction. Chronic hepatic stress was induced via intraperitoneal (IP) administration of a mixture of CCl4 (0.2 mL/100 g body weight) and olive oil [1:1(v/v)] twice a week for 4 weeks to rats. ILF-RE was administered orally at 40, 80, and 120 mg/kg to rats for 4 weeks. Alanine transaminase (ALT), aspartate transaminase (AST), gamma-glutamyl transpeptidase (GGT), and lipid peroxidation assays were performed, and total triglyceride, cholesterol, and LDL-cholesterol levels were quantified. Furthermore, ER stress and lipogenesis-related gene expression including sterol regulatory element-binding transcription factor 1 (SREBP-1), fatty acid synthase (FAS), and P-AMPK were assessed. ILF-RE markedly protected against liver damage by inhibiting oxidative stress and increasing antioxidant enzyme activity including glutathione (GSH), glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase. Furthermore, hepatic dyslipidemia was regulated after ILF-RE administration. Moreover, hepatic lipid accumulation and its associated lipogenic genes, including those encoding SREBP-1 and FAS, were regulated after ILF-RE administration. This was accompanied by regulation of ER stress response signaling, suggesting a mechanism underlying ILF-RE-mediated hepatoprotection against lipid accumulation. The present results indicate that ILF-RE exerts hepatoprotective effects against chronic CCl4-induced dysfunction by suppressing hepatic oxidative stress and lipogenesis, suggesting that ILF-RE is a potential preventive/therapeutic natural product in treating hepatoxicity and associated dysfunction.

Diallyl sulfide ameliorates carbon tetrachloride-induced hepatotoxicity in rats via suppressing stress-activated MAPK signaling pathways.

The underlined effects of diallyl sulfide (DAS) against CCL4 -induced oxidative, inflammatory, and apoptotic acute hepatic damage were assessed. Administration of DAS (50, 100, and 200 mg/kg) along with CCL 4 effectively mitigated serum aspartate aminotransferase, alanine aminotransferase activities, MDA, TNF-α, IL-1ß, and MCP-1 levels, as well as significantly restored HO-1, GSH levels and SOD activity in liver tissues compared with those in rats treated with CCL 4 . Moreover, DAS inhibited CCL 4 -induced increase of liver NF-κB (p65), Bax, p38 MAPK, and JNK protein expression. In addition, DAS accelerated protein expression of Nrf2 and Bcl-2. The hepatoprotective properties of DAS were further confirmed by the reduced severity of hepatic damage as demonstrated by histopathological findings. In conclusion, DAS achieved its protective potential against CCL4-induced hepatotoxicity through antiapoptotic activity, as well as the synchronized modulation of NF-κB and Nrf2 for the favor of antioxidant/anti-inflammatory effects via suppression of the upstream stress-activated MAPKs pathways.

Anthocyanins isolated from blueberry ameliorates CCl4 induced liver fibrosis by modulation of oxidative stress, inflammation and stellate cell activation in mice.

To study the mechanism of anthocyanins from blueberry on mice model of hepatic fibrosis. We observed that the levels of serum ALT and AST of 100 mg*kg-1*d-1, 200 mg*kg-1*d-1 anthocyanins group were reduced compared to the CCl4 treated group. Mitochondrial electron chain complex 1 and 2 activities, determined by microplate assays, were reduced in CCl4 treated group and restored by anthocyanin treatment. MDA and protein carbonyl content of liver homogenate were induced by CCl4 and anthocyanin treated group reduced both significantly.Monocyte chemoattractant protein 1 (MCP1), Interleukin 1 beta (IL1ß), macrophage inflammatory protein 2 (MIP-2) were induced by CCl4 were attenuated by anthocyanin. Colagen Ⅲ and α-SMA was significantly increased as determined by histology and anthocyanins decreased their level. The protein levels of MMP-9, TIMP1 and PCNA of liver homogenate was also modulated by anthocyanins. In isolated hepatic stellate cells, activation as determined by fibrotic gene expression was attenuated by anthocyanin. Anthocyanins from blueberry may have protective effects on CCl4 induced hepatic fibrosis. The mechanism may be related to reduce ROS generating sources and associated oxidative damage, decrease the influence of pro-inflammatory cytokines, and suppress the activity of hepatic stellate cells and downregulation TIMP1, PCNA, Col-Ⅲ, α-SMA and up-regulation MMP-9.

Preliminary Characterization, Antioxidant and Hepatoprotective Activities of Polysaccharides from Taishan Pinus massoniana Pollen.

The objectives of the present study were to characterize the chemical composition, antioxidant activity and hepatoprotective effect of the polysaccharides from Taishan Pinus massoniana pollen (TPPPS). HPLC analysis showed that TPPPS was an acidic heteropolysaccharide with glucose and arabinose as the main component monosaccharides (79.6%, molar percentage). Fourier transform-infrared spectroscopy (FT-IR) analysis indicated that the spectra of TPPPS displayed infrared absorption peaks characteristic of polysaccharides. In in vitro assays TPPPS exhibited different degrees of dose-dependent antioxidant activities , and this was further verified by suppression of CCl4-induced oxidative stress in the liver with three tested doses of TPPPS (100, 200, and 400 mg/kg bw) in rats. Pretreatment with TPPPS significantly decreased the levels of alanine aminotransferase (AST), aspartate aminotransferase (ALT), alkaline phosphatase (ALP), lactic dehydrogenase (LDH) and malondialdehyde (MDA) against CCl4 injuries, and elevated the activities of superoxide dismutase (SOD) as well as glutathione peroxidase (GSH-Px). Histopathological observation further confirmed that TPPPS could protect the liver tissues from CCl4-induced histological alternation. These results suggest that TPPPS has strong antioxidant activities and significant protective effect against acute hepatotoxicity induced by CCl4. The hepatoprotective effect may partly be related to its free radical scavenging effect, increasing antioxidant activity and inhibiting lipid peroxidation.

Protective effect of flavonoids from Cyclocarya paliurus leaves against carbon tetrachloride-induced acute liver injury in mice.

Cyclocarya paliurus (Batal.) Iljinskaja (C. paliurus), known locally as 'sweet tea tree', is commonly cultivated in China. Flavonoids from Cyclocarya paliurus (Batal.) Iljinskaja (FC) is reported to exhibit multiple biological effects, including anti-inflammatory, anti-oxidant and anti-diabetic activities. However, their influence on carbon tetrachloride (CCl4)-induced acute liver injury remains unclear. This study was designed to investigate the hepatoprotective effect of total flavonoids from C. paliurus leaves. Results revealed that flavonoids from C. paliurus significantly decreased CCl4-induced elevation of activities of aspartate transaminase (AST), alanine transaminase (ALT) and superoxide dismutase (SOD) as well as the level of malondialdehyde (MDA), and markedly increased the levels of SOD, total antioxidant capacity (T-AOC) and glutathione peroxidase (GSH-Px) compared with the model group. Structures of mainly compounds were elucidated by nuclear magnetic resonance (NMR), mass spectrometry (MS) spectroscopic and chemical analyses. This study clearly shows that flavonoids from C. paliurus exert a potent protective effect against CCl4-induced acute liver injury in mice. Its hepatoprotective effect appears to be closely associated with its antioxidant activity. The results indicated that flavonoids from C. paliurus leaves could be considered as a potent food supplement in the prevention of acute liver injury.

Metabonomic profiling in study hepatoprotective effect of polysaccharides from Flammulina velutipes on carbon tetrachloride-induced acute liver injury rats using GC-MS.

This study was performed to evaluate the hepatoprotective effect of FVP on carbon tetrachloride induced acute liver injury rats. Transaminase levels, antioxidant effect and histopathology were used to assess the recovery of FVP treated acute liver injury rats. Metabolomic analysis of liver homogenate based on GC-MS was used to obtain a global understanding of metabolic change between acute liver injury model rats and FVP-treated rats in order to assess the underlying mechanisms. Multivariate statistical approaches such as principal component analysis and orthogonal projection to latent structure square-discriminant analysis revealed distinctions among the normal, liver injury model, and FVP groups. The results demonstrated that FVP had a hepatoprotective effect on acute liver injury by decreasing AST and ALT levels, enhancing antioxidant effect and attenuating pathological injury. Sixteen metabolites were identified as biomarkers. These biomarkers belonged to glyoxylate and dicarboxylate metabolism, galactose metabolism, glycine, serine and threonine metabolism, glycerolipid metabolism, alanine, aspartate and glutamate metabolism, TCA cycle, pyruvate metabolism, arginine and proline metabolism.

The involvement of sirtuin 1 and heme oxygenase 1 in the hepatoprotective effects of quercetin against carbon tetrachloride-induced sub-chronic liver toxicity in rats.

The present study was designed to evaluate the therapeutic potential of quercetin in a sub-chronic model of hepatotoxicity. The roles of putative antioxidant enzymes, sirtuin 1 (SIRT1) and heme oxygenase 1 (HO-1), in hepatoprotection were also addressed. Sub-chronic liver injury was induced in rats by intraperitoneal administration of 0.5 ml/kg carbon tetrachloride (CTC), once every 3 days, for 2 weeks. Some CTC rats were concurrently treated with 100 mg/kg quercetin, intragastrically, once every day, for 2 weeks. The effects of these drugs in the liver were evaluated by biochemical, histological, immunohistochemical and molecular biological studies. CTC triggered oxidative damage to the liver as unanimously shown by altered biochemical parameters and liver morphology. Furthermore, CTC highly upregulated HO-1 and SIRT1 expression levels. Concomitant treatment of rats with quercetin downregulated SIRT1 expression and ameliorated the hepatotoxic effects of CTC. However, quercetin did not have any significant effect on HO-1 expression and bilirubin levels. Collectively, these results suggest that the antioxidant and cytoprotective effects of quercetin in CTC treated rats were SIRT1 mediated and less dependent on HO-1. Thus, pharmacologic modulation of SIRT1 could provide a logic therapeutic approach in sub-chronic hepatotoxicity.

Combination of Sitagliptin and Silymarin ameliorates liver fibrosis induced by carbon tetrachloride in rats.

Liver fibrosis is a common pathological condition that occurs in most conditions associated with chronic liver injury. Silymarin is a herbal product widely used for its hepatoprotective effect. Sitagliptin, a dipeptidyl peptidase-4 inhibitor (DPP4-I), is clinically used as an oral antidiabetic agent. This study was designed to investigate the effects of Sitagliptin, Silymarin, and their combination on established liver fibrosis in carbon tetrachloride (CCl4) rat model. Male albino rats received intraperitoneal injections of CCl4 three times a week for 7 weeks, as well as daily oral treatments of Sitagliptin (100mg/kg) or Silymarin (100mg/kg) or their combination during the 7 weeks of intoxication. Hepatic fibrotic changes were evaluated by measuring hepatic enzymes (ALT, AST, ALP, and GGT) and markers of fibrosis (transforming growth factor ß1 (TGF-ß1), tissue 4-hydroxyproline level, histopathological score), oxidative stress (MDA, GSH, and NOx levels), inflammation (interleukin-6) as well as markers of HSCs activation (α-smooth muscle actin (α-SMA) expression). The injected rats with CCl4 for 7 weeks resulted in a marked elevation of hepatic fibrotic changes and reduction of GSH level, while the combination therapy showed a significant decrease in the former one and a significant increase in the later. In conclusion, this study shows that the combination therapy is more beneficial than monotherapy in ameliorating liver fibrosis in rats. Our findings suggest that Sitagliptin alone or in combination with Silymarin may introduce a new strategy for treating liver fibrosis in humans.