Inhibitory effect of olive oil on fibrosis induced by carbon tetrachloride in rat liver

Effects of altering the ratio of C16:0 and cis-9 C18:1 in rumen bypass fat on growth performance, lipid metabolism, intestinal barrier, cecal microbiota, and inflammation in fattening bulls

BACKGROUND

C16:0 and cis-9 C18:1 may have different effects on animal growth and health due to unique metabolism in vivo. This study was investigated to explore the different effects of altering the ratio of C16:0 and cis-9 C18:1 in fat supplements on growth performance, lipid metabolism, intestinal barrier, cecal microbiota, and inflammation in fattening bulls. Thirty finishing Angus bulls (626 ± 69 kg, 21 ± 0.5 months) were divided into 3 treatments according to the randomized block design: (1) control diet without additional fat (CON), (2) CON + 2.5% palmitic acid calcium salt (PA, 90% C16:0), and (3) CON + 2.5% mixed fatty acid calcium salt (MA, 60% C16:0 + 30% cis-9 C18:1). The experiment lasted for 104 d, after which all the bulls were slaughtered and sampled for analysis.

RESULTS

MA tended to reduce 0-52 d dry matter intake compared to PA (DMI, P = 0.052). Compared with CON and MA, PA significantly increased 0-52 d average daily gain (ADG, P = 0.027). PA tended to improve the 0-52 d feed conversion rate compared with CON (FCR, P = 0.088). Both PA and MA had no significant effect on 52-104 days of DMI, ADG and FCR (P > 0.05). PA tended to improve plasma triglycerides compared with MA (P = 0.077), significantly increased plasma cholesterol (P = 0.002) and tended to improve subcutaneous adipose weight (P = 0.066) when compared with CON and MA. Both PA and MA increased visceral adipose weight compared with CON (P = 0.021). Only PA increased the colonization of Rikenellaceae, Ruminococcus and Proteobacteria in the cecum, and MA increased Akkermansia abundance (P < 0.05). Compared with CON, both PA and MA down-regulated the mRNA expression of Claudin-1 in the jejunum (P < 0.001), increased plasma diamine oxidase (DAO, P < 0.001) and lipopolysaccharide (LPS, P = 0.045). Compared with CON and MA, PA down-regulated the ZO-1 in the jejunum (P < 0.001) and increased plasma LPS-binding protein (LBP, P < 0.001). Compared with CON, only PA down-regulated the Occludin in the jejunum (P = 0.013). Compared with CON, PA and MA significantly up-regulated the expression of TLR-4 and NF-κB in the visceral adipose (P < 0.001) and increased plasma IL-6 (P < 0.001). Compared with CON, only PA up-regulated the TNF-α in the visceral adipose (P = 0.01). Compared with CON and MA, PA up-regulated IL-6 in the visceral adipose (P < 0.001), increased plasma TNF-α (P < 0.001), and reduced the IgG content in plasma (P = 0.035). Compared with CON, PA and MA increased C16:0 in subcutaneous fat and longissimus dorsi muscle (P < 0.05), while more C16:0 was also deposited by extension and desaturation into C18:0 and cis-9 C18:1. However, neither PA nor MA affected the content of cis-9 C18:1 in longissimus dorsi muscle compared with CON (P > 0.05).

CONCLUSIONS

MA containing 30% cis-9 C18:1 reduced the risk of high C16:0 dietary fat induced subcutaneous fat obesity, adipose tissue and systemic low-grade inflammation by accelerating fatty acid oxidative utilization, improving colonization of Akkermansia, reducing intestinal barrier damage, and down-regulating NF-κB activation.

EVOO Polyphenols Exert Anti-Inflammatory Effects on the Microglia Cell through TREM2 Signaling Pathway

In Alzheimer's disease (AD), microglia, brain resident immune cells, become chronically inflammatory and neurotoxic. In recent years, neuroinflammation has attracted particular interest in the scientific community. The genetic variants of molecules associated with ''microgliopathies'', including the triggering receptor expressed in myeloid cells-2 (TREM2), result in increased risk of developing AD and cognitive decline. We performed a set of in vitro assays using human neuronal (SH-SY5Y) and microglial (BV2 and C13NJ) cell models. Cells were differentially treated with extra virgin olive oil (EVOO) polyphenols, oleuropein aglycone (OleA) and hydroxytyrosol (HT) before adding LPS. We evaluated the protective effects of these EVOO products by a set of biochemical and cell biology assays, including ELISA, MTT, ROS detection, Western blotting and immunofluorescence. Our results provide an integrated understanding of the neuroprotection exerted by polyphenols in terms of: (i) reduction of pro-inflammatory cytokines release (IL-6, IL-8, IP-10 and RANTES); (ii) activation of the TREM2-dependent anti-inflammatory pathway; (iii) enhancement of protective microglial activity favoring the M2 polarization phenotype. Such findings provide new and important insights into the mechanisms by which the dietary olive polyphenols exert beneficial properties against neuroinflammation and neuronal impairment.

Effect of olive oil phenols on oxidative stress biomarkers: A systematic review and dose–response meta‐analysis of randomized clinical trials

The phenolic content of olive oil has a role in cardiovascular protection. Some clinical trial studies demonstrated that phenolic compounds of olive oil have antioxidant activity which can protect macronutrients from oxidative damages. The aim of this study was to summarize the results of clinical trials which assessed the effects of high- versus low-phenol olive oil on oxidative stress biomarkers levels. We searched Scopus, PubMed, Web of Science, Google Scholar, ProQuest, and Embase up to July 2021. Eight clinical trials which evaluated the effect of the phenolic content of olive oil on oxidized-LDL (ox-LDL), malondialdehyde (MDA), or ferric-reducing ability of plasma (FRAP) were included the meta analysis. A significant decrease was observed in ox-LDL level (WMD: -0.29 U/L; 95% CI: -0.51, -0.07) and MDA (WMD: -1.82 μmoL/L; 95% CI: -3.13, -0.50). However, after subgroup analysis for MDA, the result was not significant for not serious limitation (SMD: -0.05, 95% CI: -0.35 to 0.24), but significant for serious limitation (SMD: -3.64, 95% CI: -4.29 to -2.99). Also, no significant change was found in FRAP (WMD: 0.0 mmoL/L; 95% CI: -0.03, 0.04) level. Dose-response analysis indicated a significant linear relationship between the phenolic content of olive oil and ox-LDL. The present study showed some beneficial effects of high-phenol compared with low-phenol olive oil on ox-LDL and MDA levels. According to the meta-regression analysis along with the increasing phenolic content of olive oil, a reduction in oxidative stress biomarkers was observed.

Olive Oil: Nutritional Applications, Beneficial Health Aspects and its Prospective Application in Poultry Production

Plant polyphenols have promoting health features, including anti-mutagenic, anti-inflammatory, anti-thrombotic, anti-atherogenic, and anti-allergic effects. These polyphenols improve the immune system by affecting the white blood cell proliferation, as well as by the synthesis of cytokines and other factors, which contribute to immunological resistance. Olive trees are one of the most famous trees in the world. Whereas, olive olive oil and derivatives represent a large group of feeding resource for farm animals. In recent years, remarkable studies have been carried out to show the possible use of olive oil and derivatives for improvement of both animal performance and product quality. In vivo application of olive oil and its derived products has shown to maintain oxidative balance owing to its polyphenolic content. Consumption of extra virgin olive oil reduces the inflammation, limits the risk of liver damage, and prevents the progression of steatohepatitis through its potent antioxidant activities. Also, the monounsaturated fatty acids content of olive oil (particularly oleic acid), might have positive impacts on lipid peroxidation and hepatic protection. Therefore, this review article aims to highlight the nutritional applications and beneficial health aspects of olive oil and its effect on poultry production.

A Review on Hepatoprotective Effects of Some Medicinal Plant Oils

Background:

The liver is the second largest organ inside the human body. It can be damaged by several toxic molecules and medicinal agents taken in overdoses. Indeed, there are some oils obtained from different herbs that can be used to protect the liver injury.

Objective:

This review aims to give details on some oils that have been tested for their hepatoprotective effect.

Methods:

We reviewed 79 articles published between 1980 and 2019 in English language using three databases Sciencedirect, Web of Science and PubMed. So, we have used the keywords related to hepatoprotective activity: Hepatoprotective, liver disease, plant and oil and we have classified the plants in alphabetical order as a list containing their scientific and family names, as well as the experimental assay and the results obtained from these studies.

Results:

As a result, we have described 18 species belonging to 18 families: Altingiaceae, Apiaceae, Arecaceae, Asteraceae, Cactaceae, Caryocaraceae, Cucurbitaceae, Lauraceae, Leguminoseae, Malvaceae, Moringaceae, Myrtaceae, Oleaceae, Pinaceae, Ranunculaceae, Rosaceae, Theaceae and Vitaceae. Among the most common fatty acids present in hepatoprotective oils are palmitic acid, linoleic acid, oleic acid and stearic acid.

Conclusion:

These oils have shown beneficial properties regarding the hepatoprotective activity.

Dendrobium officinale Polysaccharide Protected CCl4-Induced Liver Fibrosis Through Intestinal Homeostasis and the LPS-TLR4-NF-κB Signaling Pathway

We explored the therapeutic effects of Dendrobium officinale polysaccharide (DOP) on CCl₄-induced liver fibrosis with respect to the intestinal hepatic axis using a rat model. Histopathological staining results showed that DOP alleviated extensive fibrous tissue proliferation in interstitium and lessened intestinal mucosal damage. Western blot and PCR results showed that DOP maintained intestinal balance by upregulating the expression of tight junction proteins such as occludin, claudin-1, ZO-1, and Bcl-2 proteins while downregulating the expression of Bax and caspase-3 proteins in the intestine. The transepithelial electrical resistance (TEER) value of the LPS-induced Caco-2 monolayer cell model was increased after DOP administration. These illustrated that DOP can protect the intestinal mucosal barrier function. DOP also inhibited activation of the LPS-TLR4-NF-κB signaling pathway to reduce the contents of inflammatory factors TGF-β and TNF-α, increased the expression of anti-inflammatory factor IL-10, and significantly decreased α-SMA and collagen I expression. These results indicated that DOP maintained intestinal homeostasis by enhancing tight junctions between intestinal cells and reducing apoptosis, thereby inhibiting activation of the LPS-TLR4-NF-κB signaling pathway to protect against liver fibrosis.

Hepatoprotective Effect of Eriobotrya japonica Leaf Extract and Its Various Fractions against Carbon Tetra Chloride Induced Hepatotoxicity in Rats

Eriobotrya japonica is traditionally used as an antipyretic, digestive, and diuretic agent. Its flowers possess free radical-scavenging, antioxidative, and hepatoprotective effects. We investigated the hepatoprotective potential of E. japonica leaf extract and its various fractions against hepatotoxicity in rats. Liver injury was stimulated by the oral administration of carbon tetrachloride (CCl₄; 2.5 mL/kg b.wt.). Male albino rats (n = 55) were distributed arbitrarily into 11 groups: Group I, normal control group; Group II, CCl₄ (positive control group); Group III, CCl₄ + silymarin; Groups IV and V, CCl₄ + two doses of 250 and 500 mg/kg of the 80% methanolic extract of E. japonica leaves, respectively; Groups VI and VII, CCl₄ + 250 mg/kg and 500 mg/kg of the ethyl acetate fraction, respectively; Groups VIII and IX, CCl₄ + 250 and 500 mg/kg of the butanol fraction, respectively; and Groups X and XI, CCl₄ + 250 and 500 mg/kg of the aqueous fraction of E. Japonica leaves, respectively. CCl₄-treated rats that were given 250 or 500 mg/kg of the methanol extract of E. Japonica leaves, or its ethyl acetate, butanol, or aqueous fractions, had significantly lower levels of biochemical parameters such as alanine aminotransferase, aspartate transaminase, alkaline phosphate, total protein, gamma-glutamyl transferase, and bilirubin levels than those of the CCl₄ positive group. However, the extract and fractions did not significantly affect lipid profiles. Thus, we conclude that Eriobotrya leaf extract and its fractions have a hepatoprotective effect against CCl₄-induced hepatotoxicity in rats.

Metabolomic mechanisms of gypenoside against liver fibrosis in rats: An integrative analysis of proteomics and metabolomics data

Aims

To investigate mechanisms and altered pathways of gypenoside against carbon tetrachloride (CCl₄)-induced liver fibrosis based on integrative analysis of proteomics and metabolomics data.

Methods

CCl₄-induced liver fibrosis rats were administrated gypenoside. The anti-fibrosis effects were evaluated by histomorphology and liver hydroxyproline (Hyp) content. Protein profiling and metabolite profiling of rats liver tissues were examined by isobaric tags for relative and absolute quantitation (iTRAQ) approach and gas chromatography-mass spectrometer (GC-MS) technology. Altered pathways and pivotal proteins and metabolites were searched by integrative analysis of proteomics and metabolomics data. The levels of some key proteins in altered pathways were determined by western blot.

Results

Histopathological changes and Hyp content in gypenoside group had significant improvements (P<0.05). Compared to liver fibrosis model group, we found 301 up-regulated and 296 down-regulated proteins, and 9 up-regulated and 8 down-regulated metabolites in gypenoside group. According to integrative analysis, some important pathways were found, including glycolysis or gluconeogenesis, fructose and mannose metabolism, glycine, serine and threonine metabolism, lysine degradation, arginine and proline metabolism, glutathione metabolism, and sulfur metabolism. Furthermore, the levels of ALDH1B1, ALDH2 and ALDH7A1 were found increased and restored to normal levels after gypenoside treated (P<0.05).

Conclusions

Gypenoside inhibited CCl₄-induced liver fibrosis, which may be involved in the alteration of glycolysis metabolism and the protection against the damage of aldehydes and lipid peroxidation by up-regulating ALDH.

The hepatoprotective activity of olive oil and Nigella sativa oil against CCl4 induced hepatotoxicity in male rats

BACKGROUND

Liver disease is the major cause of serious health problem leading to morbidity and mortality worldwide and the problem has increased in search for hepatotherapeutic agents from plants. The present study was designed to compare the probable hepatoprotective activity of olive oil and N. sativa oil on CCl4 induced liver damage in male rats.

METHODS

Forty males of a new model of albino rats (Wistar strain) (175-205 g) were divided into four groups. The 1st Group (G1) was the negative control group, the remaining rats were injected with CCl4 (1 ml/kg body weight) with equal amount of olive oil on the 1st and 4th day of every week for 4 weeks. The 2nd group (G2) was the positive control, the 3rd group (G3) and the fourth group (G4) were treated orally with N. sativa oil and olive oils using stomach tube.

RESULTS

The positive control group showed an increase in hepatic enzymes, total bilirubin, creatinine, uric acid, lipid peroxide total cholesterol, triglyceride, low density lipoprotein, very low density lipoproteins, interleukin-6, and a decrease in antioxidant enzymes, high density lipoprotein cholesterol, a decrease in total protein and albumin an when compared with negative control group. Histology of the CCl4 treated group revealed inflammation and damage of liver cells. Treating the hepatotoxic rats with olive oil and N. sativa oil showed a significant improvement in all biochemical tests compared with the positive CCl4 control group. In addition, the liver tissues of olive oil treated group showed mild improvement in inflammatory infiltration and in N. sativa oil treated group showed normal hepatocytes with no evidence of inflammation.

CONCLUSION

This study revealed that olive oil and N. sativa oil have a protective effect against CCl4-induced hepatotoxicity in male rats. Nigella sativa oil was more effective than olive oil.

Olive oil and its phenolic compounds (hydroxytyrosol and tyrosol) ameliorated TCDD-induced heptotoxicity in rats via inhibition of oxidative stress and apoptosis

CONTEXT

Naturally occurring polyphenols including olive oil (OO) and its constituents hydroxytyrosol (HT) and tyrosol (TY), consumed in the Mediterranean diet, have shown to treat various ailments due to their remarkable antioxidant properties.

OBJECTIVE

The present study investigates the hepatoprotective effects of OO and its phenolic compounds HT and TY against TCDD-induced hepatotoxicity in male Wistar rats.

MATERIALS AND METHODS

TCDD was administered at a dose of 100 ng/kg p.o. for 20 d. Administration of OO (10 ml/kg; oral), HT (0.5 mg/kg; oral), and TY (30 mg/kg; i.p) was started 5 d prior to TCDD administration, and continued for 25 d with or without TCDD administration. At the end of the experiment (25 d), blood was taken for biochemical analyses and liver for the measurement of macromolecular damages, antioxidant status, expressions of CYP1A1, and apoptotic factors.

RESULTS

TCDD administration resulted in significant (p < 0.05) increase in the level of hepatic stress markers ALT (101.6 ± 3.07 IU/l), AST (295.0 ± 3.0 IU/l), and ALP (266.66 ± 3.7 IU/l). Also, biochemical analyses of liver reported elevation in nitrite and protein carbonyl content and depletion of NQO1 and HO. However, OO, HT, and TY restored the antioxidant status. Protein expressions by Western Blot technique showed an increase in the level of CYP1A1 and Bax and a decreased level of Bcl-2 on TCDD treatment, and vice versa on OO, HT, and TY treatment.

DISCUSSION AND CONCLUSION

Our work concludes that dietary supplementation of OO, HT, and TY could serve as a potential preventive drug for TCDD-induced hepatotoxicity.

Differential protective effects of extra virgin olive oil and corn oil in liver injury: a proteomic study

Extra virgin olive oil (EVOO) presents benefits against chronic liver injury induced by hepatotoxins such as carbon tetrachloride (CCl4); however, the protective mechanisms remain unclear. In the present study, a two-dimensional gel based proteomic approach was constructed to explore the mechanisms. Rats are injected with CCl4 twice a week for 4 weeks to induce liver fibrosis, and were fed laboratory chow plus 20% (w/w) of either corn oil or EVOO over the entire experimental period. Histological staining, MDA assay and fibrogenesis marker gene analysis illustrate that the CCl4-treated animals fed EVOO have a lower fibrosis and lipid peroxidation level in the liver than the corn oil fed group. The proteomic study indicates that the protein expression of thioredoxin domain-containing protein 12, peroxiredoxin-1, thiosulphate sulphurtransferase, calcium-binding protein 1, Annexin A2 and heat shock cognate 71 kDa protein are higher in livers from EVOO-fed rats with the CCl4 treatment compared with those from rats fed with corn oil, whereas the expression of COQ9, cAMP-dependent protein kinase type I-alpha regulatory subunit, phenylalanine hydroxylase and glycerate kinase are lower. Our findings confirmed the benefits of EVOO against chronic liver injury, which may be attributable to the antioxidant effects, hepatocellular function regulation and hepatic metabolism modification effects of EVOO.

Toll-like receptor 4 (TLR4) modulation by synthetic and natural compounds: an update

Toll-like receptor 4 (TLR4), together with MD-2, binds bacterial endotoxins (E) with high affinity, triggering formation of the activated homodimer (E.MD-2.TLR4)2. Activated TLR4 induces intracellular signaling leading to activation of transcription factors that result in cytokine and chemokine production and initiation of inflammatory and immune responses. TLR4 also responds to endogenous ligands called danger associated molecular patterns (DAMPs). Increased sensitivity to infection and a variety of immune pathologies have been associated with either too little or too much TLR4 activation. We review here the molecular mechanisms of TLR4 activation (agonism) or inhibition (antagonism) by small organic molecules of both natural and synthetic origin. The role of co-receptors MD-2 and CD14 in the TLR4 modulation process is also discussed. Recent achievements in the field of chemical TLR4 modulation are reviewed, with special focus on nonclassical TLR4 ligands with a chemical structure different from that of lipid A.

The antihepatic fibrotic effects of fluorofenidone via MAPK signalling pathways

BACKGROUND

Fluorofenidone (AKF-PD) is a novel pyridone agent. The purpose of this study is to investigate the inhibitory effects of AKF-PD on dimethylnitrosamine (DMN)-induced liver fibrosis in rats and the involved molecular mechanism related to hepatic stellate cells (HSCs).

MATERIALS AND METHODS

Wistar rats were randomly divided into normal control, DMN, DMN/AKF-PD treatment and DMN/pirfenidone (PFD) treatment groups. AKF-PD and PFD treatments were, respectively, performed for two activated HSCs lines, rat CFSC-2G and human LX2. The cell proliferation was analysed by MTT. The expression of collagen I was determined by immunohistochemical staining and real-time RT-PCR. The expression of α-smooth muscle actin (α-SMA), tissue inhibitor of metalloproteinases-1 (TIMP-1), extracellular signal regulated kinase (ERK1/2), p38 MAPK (p38), and c-Jun N-terminal kinase/stress-activated protein kinase (JNK) were also detected by real-time RT-PCR and/or Western blot.

RESULTS

AKF-PD significantly reduced PDGF-BB-induced proliferation and activation of HSCs, as determined by reducing protein expression of α-SMA and TIMP-1. AKF-PD treatment attenuated PDGF-BB-induced upregulation of phosphorylation of ERK1/2, p38 and JNK. In fibrotic rat liver, AKF-PD reduced the degree of liver injury and hepatic fibrosis, which was associated with reduced the expression of collagen I, α-SMA, TIMP-1 at both mRNA and protein levels.

CONCLUSION

AKF-PD treatment inhibits the progression of hepatic fibrosis by suppressing HSCs proliferation and activation via MAPK signalling pathway.

Extraction optimization of Angelica sinensis polysaccharides and its antioxidant activity in vivo

Extraction of Angelica sinensis polysaccharides (ASP) was optimized by the utilization of response surface methodology, RSM. Through the analysis, extraction time and water/solid were found to be the most significant factors. Based on contour plots and variance analysis, optimum operational conditions for maximizing polysaccharides yield (5.6%) were found to be extraction time 130 min, water/solid 5, and extraction number 5. A. sinensis polysaccharides (150 and 300 mg/kg) were administered for 15 days. The hepatoprotective activity was assessed using various biochemical parameters. Serum aspartate aminotransferase (AST), alanine aminotransfere (ALT) and alkaline phosphatase (ALP) levels were significantly restored toward normalization by the extracts (150 and 300 mg/kg body weight). ASP (150 and 300 mg/kg body weight) significantly increased the levels of antioxidant enzymes. It can be concluded that ASP possesses significant protective effect against hepatotoxicity induced by carbon tetrachloride (CCl4). This protective effect appears due to ASP antioxidant properties.

Hepatoprotective effect of the ethanol extract of Vitis thunbergii on carbon tetrachloride-induced acute hepatotoxicity in rats through anti-oxidative activities

ETHNOPHARMACOLOGICAL RELEVANCE

Vitis thunbergii var. taiwaniana are traditionally used for the treatment of diarrhea, fracture and injury, jaundice, and hepatitis in Taiwan.

AIM OF THE STUDY

The hepatoprotective activity of its plant extracts seems to be been associated with its antioxidant activity. This paper aims to investigate the in vitro and in vivo antioxidant effects of the ethanol extract of Vitis thunbergii (EVT).

MATERIALS AND METHODS

In HPLC analysis, the fingerprint chromatogram of EVT was established. Antioxidant ability of EVT was investigated by employing several established in vitro methods. In vivo antioxidant activity was tested against CCl(4)-induced toxicity in mice. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were detected in the blood to indicate hepatic injury. Product of lipid peroxidation (MDA), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and reduced glutathione (GSH) contents were evaluated for oxidative stress in hepatic injury. Moreover, histopathological observation was assayed for the degree of hepatic injury.

RESULTS

EVT exhibited strong antioxidant ability in vitro. After oral administration of EVT significantly decreased ALT and AST, and ameliorated the oxidative stress in hepatic tissue and increased the activity of CAT, SOD, GPx, and GSH. Serum tumor necrosis factor-alpha (TNF-α), interleukin-1β (IL-1β), and nitric oxide (NO) were decreased in the group treated with CCl(4) plus EVT. Western blotting revealed that EVT blocked protein expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) in CCl(4)-treated rats, significantly. Histopathological examination of livers showed that EVT reduced fatty degeneration, cytoplasmic vacuolization and necrosis in CCl(4)-treated rats.

CONCLUSION

This study suggests that EVT possesses antioxidant effects in vitro and hepatoprotective effect on acute liver injuries induced by CCl(4)in vivo, and the results suggested that the effect of EVT against CCl(4)-induced liver damage is related to its antioxidant properties.

Cancer cells metabolically "fertilize" the tumor microenvironment with hydrogen peroxide, driving the Warburg effect: implications for PET imaging of human tumors

Previously, we proposed that cancer cells behave as metabolic parasites, as they use targeted oxidative stress as a "weapon" to extract recycled nutrients from adjacent stromal cells. Oxidative stress in cancer-associated fibroblasts triggers autophagy and  mitophagy, resulting in compartmentalized cellular catabolism, loss of mitochondrial function, and the onset of aerobic glycolysis, in the tumor stroma. As such, cancer-associated fibroblasts produce high-energy nutrients (such as lactate and ketones) that fuel mitochondrial biogenesis, and oxidative metabolism in cancer cells. We have termed this new energy-transfer mechanism the "reverse Warburg effect." To further test the validity of this hypothesis, here we used an in vitro MCF7-fibroblast co-culture system, and quantitatively measured a variety of metabolic parameters by FACS analysis (analogous to laser-capture micro-dissection).  Mitochondrial activity, glucose uptake, and ROS production were measured with highly-sensitive fluorescent probes (MitoTracker, NBD-2-deoxy-glucose, and DCF-DA). Interestingly, using this approach, we directly show that cancer cells initially secrete hydrogen peroxide that then triggers oxidative stress in neighboring fibroblasts. Thus, oxidative stress is contagious (spreads like a virus) and is propagated laterally and vectorially from cancer cells to adjacent fibroblasts. Experimentally, we show that oxidative stress in cancer-associated fibroblasts quantitatively reduces mitochondrial activity, and increases glucose uptake, as the fibroblasts become more dependent on aerobic glycolysis.  Conversely, co-cultured cancer cells show significant increases in mitochondrial activity, and corresponding reductions in both glucose uptake and GLUT1 expression. Pre-treatment of co-cultures with extracellular catalase (an anti-oxidant enzyme that detoxifies hydrogen peroxide) blocks the onset of oxidative stress, and potently induces the death of cancer cells, likely via starvation.  Given that cancer-associated fibroblasts show the largest increases in glucose uptake, we suggest that PET imaging of human tumors, with Fluoro-2-deoxy-D-glucose (F-2-DG), may be specifically detecting the tumor stroma, rather than epithelial cancer cells.

Induction of lipocalin-2 expression in acute and chronic experimental liver injury moderated by pro-inflammatory cytokines interleukin-1β through nuclear factor-κB activation

BACKGROUND

Lipocalin-2 (LCN2) belongs to the lipocalin superfamily, sharing a barrel-shaped tertiary structure with a hydrophobic pocket and an ability to bind lipophilic molecules. LCN2 has recently emerged as an important modulator of cellular homeostasis in several organs, i.e. heart, lung and kidney, but little is known about the expression of LCN2 in acute and chronic liver injury.

AIMS

In this study, we wanted to analyse the expression and regulation of LCN2 in models of acute and chronic experimental liver injury.

MATERIALS AND METHODS

We analysed LCN2 expression in livers of rats subjected to bile duct ligation or repeated doses of carbon tetrachloride and tested the impact of various pro-inflammatory cytokines in cultured primary liver cells.

RESULTS

By using primary cultures of hepatic stellate cells and hepatocytes isolated from normal and injured rat livers, we found a significant LCN2 expression in early hepatic stellate cell cultures, a lower expression in fully transdifferentiated myofibroblasts and no expression in freshly isolated hepatocytes. However, LCN2 expression and secretion in hepatocytes increased dramatically during culturing. In addition, chronic in vivo liver injury resulting from both bile duct ligation and repeated application of carbon tetrachloride resulted in rapid and well-sustained induction of LCN2 expression. Immunohistochemistry and primary liver cell isolation identified injured hepatocytes as the main source of LCN2 production. LCN2 is strongly induced in both primary hepatocytes and immortalized hepatocellular carcinoma cell line HepG2 by the pro-inflammatory cytokine interleukin-1β via nuclear factor-κB activation, but not by the profibrotic cytokines platelet-derived growth factor and transforming growth factor-β.

CONCLUSION

LCN2 expression shows clear correlation to liver damage and resulting inflammatory responses, rather than to the degree of liver fibrosis, which in fact may imply a distinct diagnostic value as an early biomarker of liver inflammation.

Anti-inflammatory properties of Ajuga bracteosa in vivo and in vitro study and their effects on mouse model of liver fibrosis

ETHNOPHARMACOLOGICAL RELEVANCE

The entire plant of Ajuga bracteosa Wall has been used to treat various inflammatory disorders, including hepatitis, in Taiwan.

AIM

This study evaluated the hepatoprotective ability of Ajuga bracteosa extract (ABE).

MATERIALS AND METHODS

We investigated the inhibitory action of a chloroform fraction of ABE (ABCE) on lipopolysaccharide (LPS)-stimulated RAW264.7 cells and Kupffer cells. Hepatic fibrosis was induced in mice through the administration of CCl(4) twice a week for 8 weeks. Mice in three CCl(4) groups were treated daily with water and ABE throughout the duration of the experiment.

RESULTS

In LPS-stimulated RAW264.7 cells and Kupffer cells, ABCE inhibited the production of NO and/or TNF-α and also blocked the LPS-induced expression of NO synthase. ABCE inhibited the activation of NF-κB induced by LPS, associated with the abrogation of IκBα degradation, with a subsequent decrease in nuclear p65 and p50 protein levels. The phosphorylation of MAPKs in LPS-stimulated RAW264.7 cells was also suppressed using ABCE. In the in vivo study, ABE protected the liver from injury by reducing the activity of plasma aminotransferase, and by improving the histological architecture of the liver. RT-PCR analysis showed that ABE inhibited the hepatic mRNA expression of LPS binding protein, CD14, TNF-α, collagen(α1)(I), and α-smooth actin.

CONCLUSION

These results indicate that ABE alleviated CCl(4)-induced liver fibrosis, and that this protection is probably due to the suppression of macrophage activation.

Hepatoprotection of Graptopetalum paraguayense E. Walther on CCl₄-induced liver damage and inflammation

AIM OF THIS STUDY

Graptopetalum paraguayense E. Walther, a vegetable consumed in Taiwan, has been used in folk medicine for protection against liver injury, although its actual efficacy remains uncertain. Therefore, we investigated the protective effects of Graptopetalum paraguayense E. Walther against carbon tetrachloride (CCl(4))-induced liver damage in rats.

MATERIALS AND METHODS

Water extracts of Graptopetalum paraguayense E. Walther (WGP) were administered for 8 consecutive weeks to male Sprague-Dawley rats. And a dose-dependent manner in preventing liver damage was confirmed. Moreover, the major ingredient of WGP, gallic acid, was also orally administrated in the CCl(4)-induced rats. The hepatoprotective activity was assessed using various biochemical parameters such as antioxidant enzymes and histopathological studies.

RESULTS

WGP ranging from 50 to 300 mg/kg bw administrations significantly lowered serum aspartate transaminase (AST) and alanine transaminase (ALT) levels, and inhibited malondialdehyde (MDA) generation in CCl(4)-treated rats. WGP increased cellular GSH level and antioxidant enzymes, including superoxide dismutase, glutathione reductase, and catalase. Serum tumor necrosis factor-alpha (TNF-α) was decreased in the group treated with CCl(4) plus WGP (150 and 300 mg/kg bw). Histopathological examination of livers showed that WGP reduced fatty degeneration, cytoplasmic vacuolization and necrosis in CCl(4)-treated rats. In contrary, 10mg/kg bw of gallic acid was administrated, this dose was related with WGP (300 mg/kg bw), and had significantly decreased the AST and ALT compared to the CCl(4)-treated group. Aforesaid results suggested that gallic acid from WGP offered antioxidative activity against CCl(4)-induced oxidative liver damage.

CONCLUSIONS

Taken together, this study is the first time to suggest that Graptopetalum paraguayense E. Walther exerts hepatoprotection via promoting antioxidative and anti-inflammatory properties against CCl(4)-induced oxidative liver damage.

Effects of dahuangzhechong pills on cytokines and mitogen activated protein kinase activation in rats with hepatic fibrosis

RELEVANCE TO ETHNOPHARMACOLOGY: Dahuangzhechong pill (DHZCP), a well-known and canonical Chinese medicine formula from "The Synopsis of Prescriptions of the Golden Chamber", is officially approved and recommended by Chinese association of integrative medicine for the prevention and treatment of hepatic fibrosis in China.

AIM OF THE STUDY

To test the hypothesis that therapeutic effects of DHZCP on hepatic fibrosis are conferred by regulating cytokine profile through a mitogen activated protein kinase (MAPK) pathway.

MATERIALS AND METHODS

Hepatic fibrosis is inducted by carbon tetrachloride (CCl(4)) in rats which then were randomly divided into six groups: hepatic fibrosis model group, high dose DHZCP group, low dose DHZCP group, Fufang Biejia Ruangan Pian (FBRP) group, Colchicine group and control group. Pathological, immunohistochemical, multiplex immunoassay and protein expression studies (Western blotting) are performed.

RESULTS

DHZCP significantly decreases the levels of alanine aminotransferase, aspartate aminotransferase, hyaluronic acid, laminin, type IV collagen and procollagen III, and reverses hepatic fibrosis in rat model. DHZCP also could reduce the expression of α-smooth muscle actin, and lower the serum level of tumor necrosis factor alpha (TNF-α) and interleukin 13 (IL-13). The expressions of phosphorylated p38 MAPK and extracellular signal-regulated kinase (ERK) are down-regulated, while no significant changes are found in phosphorylation of c-Jun N-terminal kinase (JNK).

CONCLUSIONS

DHZCP can alleviate hepatic fibrosis induced by CCl(4). The anti-fibrotic effects of DHZCP are conferred by decreasing the secretion of TNF-α and IL-13 through down-regulating p38 and ERK phosphorylation.

Protease-activated receptor-2 induces myofibroblast differentiation and tissue factor up-regulation during bleomycin-induced lung injury: potential role in pulmonary fibrosis

Idiopathic pulmonary fibrosis constitutes the most devastating form of fibrotic lung disorders and remains refractory to current therapies. The coagulation cascade is frequently activated during pulmonary fibrosis, but this observation has so far resisted a mechanistic explanation. Recent data suggest that protease-activated receptor (PAR)-2, a receptor activated by (among others) coagulation factor (F)Xa, plays a key role in fibrotic disease; consequently, we assessed the role of PAR-2 in the development of pulmonary fibrosis in this study. We show that PAR-2 is up-regulated in the lungs of patients with idiopathic pulmonary fibrosis and that bronchoalveolar lavage fluid from these patients displays increased procoagulant activity that triggers fibroblast survival. Using a bleomycin model of pulmonary fibrosis, we show that bleomycin induces PAR-2 expression, as well as both myofibroblast differentiation and collagen synthesis. In PAR-2-/- mice, both the extent and severity of fibrotic lesions are reduced, whereas myofibroblast differentiation is diminished and collagen expression is decreased. Moreover, fibrin deposition in the lungs of fibrotic PAR-2-/- mice is reduced compared with wild-type mice due to differential tissue factor expression in response to bleomycin. Taken together, these results suggest an important role for PAR-2 in the development of pulmonary fibrosis, and the inhibition of the PAR-2-coagulation axis may provide a novel therapeutic approach to treat this devastating disease.

Therapeutic effects of Lanyuzan granules on hepatic fibrosis in rats

AIM: To explore the curative effects of Lanyuzan granules on hepatic fibrosis in dimethylnitrosamine (DMN)-induced SD rat model and its mechanism.

METHODS: Forty-five female SD rats were randomly divided into six groups: a control group (n = 5), a model group (n = 8), three treatment groups with different dosage of Lanyuzan granules (n = 8), and a positive control group (n = 8). In the following 30 days, an intraperitoneal injection of dimethylnitrosamine (DMN) 10 mg/kg was performed in five groups every three days, except in the control group. On the thirty-first day, the five indexes of hepatic function, serum concentrations of ALT, AST and ALB, the expressions of a-smooth muscle actin (a-SMA) and matrix metalloproteinase-2 (MMP-2) were measured. Moreover, pathological changes were observed on liver tissue with HE staining.

RESULTS: In liver fibrosis model group, serum concentrations of ALT and AST were significantly higher and concentration of ALB was significantly lower (P < 0.05), while significant increase in a-SMA expression and significant decrease in MMP-2 expression were observed compared with the normal group (182.042 ± 0.658 vs 60.879 ± 0.987; 145.612 ± 4.66 vs 74.824 ± 9.004; 16.078 ± 0.633 vs 28.971 ± 0.443; 161.667 ± 26.766 vs 80.167 ± 10.135; 5.994 ± 1.360 vs 8.270 ± 0.289, all P < 0.05). Decreased ALT and AST serum concentrations, significantly increased ALB concentration, lowered a-SMA expression and elevated MMP-2 expression in liver tissue, were observed in Lanyuzan granules treatment group compared with model control group (87.856 ± 8.526, 106.69 ± 0.987, 136.11 ± 0.329 vs 182.042 ± 0.658; 94.208 ± 2.017, 107.602 ± 20.014, 118.847 ± 5.486 vs 145.612 ± 4.66; 23.412 ± 0.775, 19.653 ± 0.775, 18.635 ± 0.221 vs 16.078 ± 0.633; 109.958 ± 3.607, 117.833 ± 6.600, 119.833 ± 6.167 vs 161.667 ± 26.766; 11.610 ± 0.523, 10.367 ± 0.714 vs 5.994 ± 1.360, all P < 0.05). No notable difference was observed between low dosage group and model control group. The pathological observation showed hepatic fibrosis was alleviated markedly.

CONCLUSION: Lanyuzan granules may play a part in the alleviation of inflammation and the protection of liver by markedly relieving and inhibiting the formation of hepatic fibrosis induced by dimethylnitrosamine.

Restrictive model of compensated carbon tetrachloride-induced cirrhosis in rats

AIM: To develop a simplified and quick protocol to induce cirrhosis and standardize models of partial liver resection in rats.

METHODS: In Fischer F344 rats two modified protocols of phenobarbital-carbon tetrachloride (CCl₄) (dilution 50%) gavage to induce cirrhosis (frequency adjusted according to weight, but each subsequent dose was systematically administered) were tested, i.e. the rapid and slow protocols. Prothrombin time (PT) and total bilirubin (TB) were also evaluated. Animals from the rapid group underwent 15% hepatectomy and animals from the slow group underwent 70% hepatectomy.

RESULTS: Rapid protocol: This corresponded to 1 gavage/4 d over 6 wk (mortality 30%). Mean PT was 35.2 ± 2.8 s (normal: 14.5 s), and mean TB was 1.8 ± 0.2 mg/dL (normal: 0.1 mg/dL). Slow protocol: This corresponded to 1 gavage/6 d over 9 wk (mortality 10%). Mean PT was 11.8 ± 0.2 s (normal: 14.5 s), and mean TB was 0.4 ± 0.04 mg/dL (normal: 0.1 mg/dL). Pathological analyses were performed in both protocols which showed persistent cirrhosis at 3 mo. Rat mortality in the rapid gavage group who underwent 15% hepatectomy and in the slow gavage group who underwent 70% hepatectomy was 50% and 70%, respectively.

CONCLUSION: Our modified model is a simplified method to induce cirrhosis which is rapid (6 to 9 wk), efficient and stable up to 3 mo. Using this method, “Child Pugh A” or “Child Pugh BC” cirrhotic rats were obtained. Our models of cirrhosis and hepatectomy can be used in various situations focusing on postoperative survival.