Giovanna Mazzone

Coffee reduces liver damage in a rat model of steatohepatitis: the underlying mechanisms and the role of polyphenols and melanoidins.

Epidemiological data associate coffee consumption with a lower prevalence of chronic liver disease and a reduced risk of elevated liver enzyme levels (γ glutamyl transpeptidase and alanine aminotransferase), advanced liver disease and its complications, and hepatocellular carcinoma. Knowledge of the mechanisms underlying these effects and the coffee components responsible for these properties is still lacking. In this study, 1.5 mL/day of decaffeinated coffee or its polyphenols or melanoidins (corresponding to approximately 2 cups of filtered coffee or 6 cups of espresso coffee for a 70‐kg person) were added for 8 weeks to the drinking water of rats who were being fed a high‐fat, high‐calorie solid diet (HFD) for the previous 4 weeks. At week 12, HFD + water rats showed a clinical picture typical of advanced nonalcoholic steatohepatitis compared with control rats (normal diet + water). In comparison, HFD + coffee rats showed: (1) reduced hepatic fat and collagen, as well as reduced serum alanine aminotransferase and triglycerides; (2) a two‐fold reduced/oxidized glutathione ratio in both serum and liver; (3) reduced serum malondialdehyde (lipid peroxidation) and increased ferric reducing antioxidant power (reducing activity); (4) reduced expression of tumor necrosis factor α (TNF‐α), tissue transglutaminase, and transforming growth factor β and increased expression of adiponectin receptor and peroxisome proliferator‐activated receptor α in liver tissue; and (5) reduced hepatic concentrations of proinflammatory TNF‐α and interferon‐γ and increased anti‐inflammatory interleukin‐4 and interleukin‐10. Conclusion: Our data demonstrate that coffee consumption protects the liver from damage caused by a high‐fat diet. This effect was mediated by a reduction in hepatic fat accumulation (through increased fatty acid β‐oxidation); systemic and liver oxidative stress (through the glutathione system); liver inflammation (through modulation of genes); and expression and concentrations of proteins and cytokines related to inflammation. (HEPATOLOGY 2010;52:1652‐1661)

Eicosapentaenoic acid free fatty acid prevents and suppresses colonic neoplasia in colitis-associated colorectal cancer acting on Notch signaling and gut microbiota

Inflammatory bowel diseases are associated with increased risk of developing colitis‐associated colorectal cancer (CAC). Epidemiological data show that the consumption of ω‐3 polyunsaturated fatty acids (ω‐3 PUFAs) decreases the risk of sporadic colorectal cancer (CRC). Importantly, recent data have shown that eicosapentaenoic acid‐free fatty acid (EPA‐FFA) reduces polyp formation and growth in models of familial adenomatous polyposis. However, the effects of dietary EPA‐FFA are unknown in CAC. We tested the effectiveness of substituting EPA‐FFA, for other dietary fats, in preventing inflammation and cancer in the AOM‐DSS model of CAC. The AOM‐DSS protocols were designed to evaluate the effect of EPA‐FFA on both initiation and promotion of carcinogenesis. We found that EPA‐FFA diet strongly decreased tumor multiplicity, incidence and maximum tumor size in the promotion and initiation arms. Moreover EPA–FFA, in particular in the initiation arm, led to reduced cell proliferation and nuclear β‐catenin expression, whilst it increased apoptosis. In both arms, EPA‐FFA treatment led to increased membrane switch from ω‐6 to ω‐3 PUFAs and a concomitant reduction in PGE2 production. We observed no significant changes in intestinal inflammation between EPA‐FFA treated arms and AOM‐DSS controls. Importantly, we found that EPA‐FFA treatment restored the loss of Notch signaling found in the AOM‐DSS control and resulted in the enrichment of Lactobacillus species in the gut microbiota. Taken together, our data suggest that EPA‐FFA is an excellent candidate for CRC chemoprevention in CAC.

Apple polyphenol extracts prevent aspirin-induced damage to the rat gastric mucosa

Aspirin causes gastroduodenal ulcers and complications. Food bioactive compounds could exert beneficial effects in the gastrointestinal tract. We evaluated whether apple polyphenol extract (APE) reduced aspirin-induced injury to the rat gastric mucosa. Rats were treated with APE (10(-4) m catechin equivalent) before oral aspirin (200 mg/kg). Cyclo-oxygenase-2 (COX-2), transforming growth factor-alpha (TGF alpha) and heparin-binding epidermal-growth-factor-like growth factor (HB-EGF) mRNA and protein expression were assessed by RT-PCR and Western blot analysis, respectively; malondialdehyde (MDA) was determined by HPLC; gastric secretion was evaluated in pylorus-ligated rats. APE decreased acute and chronic aspirin injury both macroscopically and microscopically (approximately 50 % decrease in lesion score; P < 0.05). Aspirin up-regulated mRNA and protein expression of COX-2 and HB-EGF, but not of TGF alpha; APE reduced aspirin-induced mRNA and protein over-expression of COX-2 and HB-EGF; aspirin significantly increased gastric MDA and this effect was counteracted by APE pre-treatment. APE did not significantly affect gastric acid secretion. In conclusion, APE reduces aspirin-induced gastric injury independently of acid inhibition. We speculate that APE might be of therapeutic use in the prophylaxis of aspirin-related gastropathy.

Rapid "breath-print" of liver cirrhosis by proton transfer reaction time-of-flight mass spectrometry. A pilot study.

The aim of the present work was to test the potential of Proton Transfer Reaction Time-of-Flight Mass Spectrometry (PTR-ToF-MS) in the diagnosis of liver cirrhosis and the assessment of disease severity by direct analysis of exhaled breath. Twenty-six volunteers have been enrolled in this study: 12 patients (M/F 8/4, mean age 70.5 years, min-max 42–80 years) with liver cirrhosis of different etiologies and at different severity of disease and 14 healthy subjects (M/F 5/9, mean age 52.3 years, min-max 35–77 years). Real time breath analysis was performed on fasting subjects using a buffered end-tidal on-line sampler directly coupled to a PTR-ToF-MS. Twelve volatile organic compounds (VOCs) resulted significantly differently in cirrhotic patients (CP) compared to healthy controls (CTRL): four ketones (2-butanone, 2- or 3- pentanone, C8-ketone, C9-ketone), two terpenes (monoterpene, monoterpene related), four sulphur or nitrogen compounds (sulfoxide-compound, S-compound, NS-compound, N-compound) and two alcohols (heptadienol, methanol). Seven VOCs (2-butanone, C8-ketone, a monoterpene, 2,4-heptadienol and three compounds containing N, S or NS) resulted significantly differently in compensate cirrhotic patients (Child-Pugh A; CP-A) and decompensated cirrhotic subjects (Child-Pugh B+C; CP-B+C). ROC (Receiver Operating Characteristic) analysis was performed considering three contrast groups: CP vs CTRL, CP-A vs CTRL and CP-A vs CP-B+C. In these comparisons monoterpene and N-compound showed the best diagnostic performance. Conclusions Breath analysis by PTR-ToF-MS was able to distinguish cirrhotic patients from healthy subjects and to discriminate those with well compensated liver disease from those at more advanced severity stage. A breath-print of liver cirrhosis was assessed for the first time.

Apple polyphenols extract (APE) improves colon damage in a rat model of colitis

BACKGROUND AND AIM Searching for alternative therapies that are effective, safe and less expensive of those currently used for ulcerative colitis, we investigated the efficacy of a polyphenol extract from apple in rat colitis. METHODS Rats with trinitrobenzensulphonic acid-induced colitis were treated daily with rectal administration of apple polyphenols 10(-4) M for 14 days. COX-2, TNF-α, tissue transglutaminase and calpain in colon mucosa samples were assessed by reverse transcription-polymerase chain reaction and western blot analyses. To ascertain the role of tissue transglutaminase in mucosal healing, wounded rat fibroblasts were incubated with cystamine (a tissue transglutaminase activity inhibitor). RESULTS Colitis was associated with increased COX-2, TNF-α, calpain, and tissue transglutaminase mRNA. The protein expression of COX-2, TNF-α and calpain was increased whilst tissue transglutaminase was decreased. Apple extract treatment reduced the severity of colitis (p<0.05) and restored all the considered biomarkers at the baseline level. Apple polyphenols reduced the degradation of tissue transglutaminase protein occurring through calpain action. Apple polyphenols-treated wounded fibroblast recovered within 24h showing intense immunoreactivity for tissue transglutaminase. CONCLUSION The efficacy of apple extract is mediated by its effects on COX-2 and TNF-α. The unbalance between calpain and tissue transglutaminase may play a role in colonic damage and future therapeutic interventions in ulcerative colitis can target this mechanisms.

Garlic extract prevents CCl4-induced liver fibrosis in rats: The role of tissue transglutaminase

BACKGROUND AND AIM Tissue transglutaminase contributes to liver damage in the development of hepatic fibrosis. In a model of neurodegeneration, the therapeutic benefit of cystamine has been partly attributed to its inhibition of transglutaminase activity. Garlic extract contains many compounds structurally related to cystamine. We investigated the anti-fibrotic effect of garlic extract and cystamine as specific tissue transglutaminase inhibitors. METHODS Rat liver fibrosis was induced by intraperitoneal injection of carbon tetrachloride (CCl(4)) for 7 weeks. Cystamine or garlic extract was administrated by daily intraperitoneal injection, starting from the day after the first administration of CCl(4). Hepatic function, histology, tissue transglutaminase immunostaining and image analysis to quantify Red Sirius stained collagen deposition were examined. Reverse transcription-polymerase chain reaction to detect alpha-SMA, IL-1beta and tissue transglutaminase expression and Western blot for tissue transglutaminase protein amount were performed. Transglutaminase activity was assayed on liver homogenates by a radio-enzymatic method. RESULTS Transglutaminase activity was increased in CCl(4) group and reduced by cystamine and garlic extract (p<0.05). Treatment with cystamine and garlic extract reduced the liver fibrosis and collagen deposition, particularly in the garlic extract group (p<0.01). Moreover, the liver damage improved and serum alanine aminotransferase was decreased (p<0.05). Tissue transglutaminase immunolocalised with collagen fibres and is mainly found in the ECM of damaged liver. Alpha-SMA, IL-1beta, tissue transglutaminase mRNA and tissue transglutaminase protein were down-regulated in the cystamine and garlic extract groups compared to controls. CONCLUSION These findings concurrently suggest that transglutaminase may play a pivotal role in the pathogenesis of liver fibrosis and may identify garlic cystamine-like molecules as a potential therapeutic strategy in the treatment of liver injury.

Symbiotic formulation in experimentally induced liver fibrosis in rats: intestinal microbiota as a key point to treat liver damage?

Evidence indicates that intestinal microbiota may participate in both the induction and the progression of liver damage. The aim of our research was the detection and evaluation of the effects of chronic treatment with a symbiotic formulation on CCl4‐induced rat liver fibrosis.

Garlic extract attenuating rat liver fibrosis by inhibiting TGF-β1

BACKGROUND & AIMS We previously demonstrated the efficacy of garlic extract (GE) in the prevention of rat liver fibrosis by inhibiting tissue transglutaminase (tTG) activity. In the present study we aimed to evaluate the potential of GE in the regression of liver fibrosis and the underlining mechanism. METHODS Male Wistar rats were i.p. injected, twice a week, for 7 weeks, with CCl(4) to develop liver fibrosis. Successively, a group was immediately sacrificed, while the remaining two groups received the GE or the vehicle, respectively, over the following 2 wks. A group of normal rats was also included in the study. Liver function, histology, and collagen deposition in parallel with gene and protein expression of α-SMA, tTG, TGF-β1, SEMA-7A, and metalloproteinase inhibitor 1 (TIMP1) as well as measure of active by total TGF-β1 were assessed. RESULTS CCl(4) administration increased alanine-aminotransferase (ALT) activity, hepatic collagen deposition and gene and protein expression of all monitored markers. GE, but not the sole vehicle, restored liver histology and function by decreasing fibrogenesis markers (α-SMA, tTG, TGF-β1, SEMA-7A and TIMP1). Active by total TGF-β1 was significantly reduced (p < 0.05) in GE treated rats compared to the CCl(4) at 7 weeks, and vehicle rats. CONCLUSIONS These findings concurrently suggested that GE elicited therapeutic effect against liver fibrosis. Regression of liver fibrosis occurred by reducing myofibroblasts (through modulation of HSCs activation mechanisms), remodelling extracellular matrix (through increase of its degradation) and regenerating liver tissue and functions: three processes regulated by fine mechanisms where active TGF-β1 and tTG play a central role.

Dietary supplementation of vitamin D prevents the development of western diet-induced metabolic, hepatic and cardiovascular abnormalities in rats

Background The western diet high in fat and fructose may cause metabolic disorders and cardiovascular diseases. Objective To evaluate whether long-term daily vitamin D3 supplementation prevents hepatic steatosis and cardiovascular abnormalities and restores insulin sensitivity caused by fat diet in rats without vitamin D deficiency. Methods Three groups of rats were fed for 6 months with standard diet (SD), western diet (WD) or WD containing 23 IU/day/rat vitamin D3, respectively. Tail-cuff systolic blood pressure (SBP)measurements in conscious rats and transthoracic echocardiography were performed in basal condition, and after 3 and 6 months of diet. Hepatic steatosis and myocardial fibrosis were assessed in liver and cardiac tissues using standard methods. Serum insulin and 25(OH)D3 concentrations were determined using rat-specific ELISA kits. Insulin resistance was determined according to the homeostasis model assessment of insulin resistance (HOMA-IR) method. Results Sixty-one per cent of hepatocytes in WD rats had steatotic vacuoles compared with just 27% in rats on a WD plus vitamin D3 (p < 0.05).HOMA-IR was reduced in rats with vitamin D supplementation compared with WD alone (19.4 ± 5.2 vs 41.9 ± 8.9, p < 0.05). Rat blood pressure and left ventricular mass were both reduced by vitamin D3 supplementation. Conclusion In animal models of liver and cardiovascular metabolic damage, the supplementation of vitamin D3 shows liver and cardio-protective effects.

Mo1045 Decaffeinated Coffee Reduces Intestinal Leakiness in Rats Fed With a Hfd by Modulating Occludin and Zonulin-1 Expression

2; p,.01), and LMMS restored liver triglyceride content to normal levels (db/db + LMMS vs. WT + SED, p=.13). LMMS training had no effect on fasting glucose, inguinal and interscapular fat pad weights, or plasma markers of lipid metabolism and hepatic injury (all p..05). Conclusion: LMMS was effective in improving insulin sensitivity and suppressing abdominal obesity and fatty liver. LMMS should be further explored in the prevention and treatment of type 2 diabetes and NASH.