Carmela Loguercio

Chronic inflammation and oxidative stress in human carcinogenesis

A wide array of chronic inflammatory conditions predispose susceptible cells to neoplastic transformation. In general, the longer the inflammation persists, the higher the risk of cancer. A mutated cell is a sine qua non for carcinogenesis. Inflammatory processes may induce DNA mutations in cells via oxidative/nitrosative stress. This condition occurs when the generation of free radicals and active intermediates in a system exceeds the systems ability to neutralize and eliminate them. Inflammatory cells and cancer cells themselves produce free radicals and soluble mediators such as metabolites of arachidonic acid, cytokines and chemokines, which act by further producing reactive species. These, in turn, strongly recruit inflammatory cells in a vicious circle. Reactive intermediates of oxygen and nitrogen may directly oxidize DNA, or may interfere with mechanisms of DNA repair. These reactive substances may also rapidly react with proteins, carbohydrates and lipids, and the derivative products may induce a high perturbation in the intracellular and intercellular homeostasis, until DNA mutation. The main substances that link inflammation to cancer via oxidative/nitrosative stress are prostaglandins and cytokines. The effectors are represented by an imbalance between pro‐oxidant and antioxidant enzyme activities (lipoxygenase, cyclooxygenase and phospholipid hydroperoxide glutathione‐peroxidase), hydroperoxides and lipoperoxides, aldehydes and peroxinitrite. This review focalizes some of these intricate events by discussing the relationships occurring among oxidative/nitrosative/metabolic stress, inflammation and cancer.

Nutritional Supplementation With Branched-Chain Amino Acids in Advanced Cirrhosis: A Double-Blind, Randomized Trial

BACKGROUND & AIMS The role of oral supplementation with branched-chain amino acids (BCAA) in advanced cirrhosis is far from settled. A nutritional approach might prevent progressive liver failure and improve nutritional parameters and quality of life. METHODS A multicenter, randomized study comparing 1-year nutritional supplementation with BCAA against lactoalbumin or maltodextrins was performed in 174 patients with advanced cirrhosis. Primary outcomes were the prevention of a combined end point (death and deterioration to exclusion criteria), the need for hospital admission, and the duration of hospital stay. Secondary outcomes were nutritional parameters, laboratory data and Child-Pugh score, anorexia, health-related quality of life, and need for therapy. RESULTS Treatment with BCAA significantly reduced the combined event rates compared with lactoalbumin (odds ratio, 0.43; 95% confidence interval, 0.19-0.96; P = 0.039) and nonsignificantly compared with maltodextrins (odds ratio, 0.51; 95% confidence interval, 0.23-1.17; P = 0.108). The average hospital admission rate was lower in the BCAA arm compared with control treatments (P = 0.006 and P = 0.003, respectively). In patients who remained in the study, nutritional parameters and liver function tests were, on average, stable or improved during treatment with BCAA and the Child-Pugh score decreased (P = 0.013). Also, anorexia and health-related quality of life (SF-36 questionnaire) improved. Long-term compliance with BCAA was poor. CONCLUSIONS In advanced cirrhosis, long-term nutritional supplementation with oral BCAA is useful to prevent progressive hepatic failure and to improve surrogate markers and perceived health status. New formulas are needed to increase compliance.

Non-alcoholic fatty liver disease in an area of southern Italy: main clinical, histological, and pathophysiological aspects

BACKGROUND/AIMS Studies on non-alcoholic fatty liver disease (NAFLD) have included chronic liver damage attributed to various causes. Our investigation was held to observe the main clinical, histological, and pathophysiological aspects of NAFLD in patients not exposed to any known cause of chronic liver disease. METHODS We evaluated, in 84 in-patients (male/female, 66/18; median age, 36 years), the clinical and biochemical characteristics of NAFLD, and particularly its association with diabetes, dyslipidemia, hyperinsulinemia and/or with the increase of parameters of oxidative stress (blood levels of malonyldialdehyde, 4-hydroxynonenal and total plasma antioxidant capacity). RESULTS Ninety percent of patients had an increased body mass index (BMI), 35% had dyslipidemia, 40% had sub-clinical diabetes (only 3% had overt diabetes), 60% had hyperinsulinemia, and more than 90% had enhanced levels of lipid peroxidation markers. In 48 patients who had consented to liver biopsy, we found: 14 with simple steatosis, 32 with steatohepatitis, and two with cirrhosis. CONCLUSIONS Our data indicate that in our country, NAFLD may occur in young males with an increased BMI, with or without hyperinsulinemia, dyslipidemia and diabetes, generally associated with disorders of redox status, and that it may be differentiated from steatosis to steatohepatitis or cirrhosis only with a liver biopsy.

Non Alcoholic Fatty Liver: Epidemiology and Natural History

Non Alcoholic Fatty Liver Disease (NAFLD), defined as the presence of a significant amount of lipid accumulation in the liver (at least in 5% of hepatocytes), represents a challenging issue for the Hepatologists. NAFLD is not represented by a single entity, but rather by two different entities that have different natural history and evolution that range from simple fat accumulation in the liver (without any consequence), to necroinflammation, fibrosis, cirrhosis and hepatocellular carcinoma (HCC). The reason of these differences has to be found in the host characteristics and associated risk factors. Globally, its prevalence among liver diseases, and in the general population, is rising in the recent years along with its associated conditions: obesity, insulin resistance, metabolic syndrome and diabetes. This increment, together with the reported clinical conditions, may be accounted for changes in dietary habits and the increase of sedentary lifestyle. Its diffusion seems to be pandemic, given that it is beginning to affect the populations in the developing world due to the spread of Western lifestyle. This is particularly worrying in young adults and children in what seems to have become the main cause of liver disease. Even if the real rate of global incidence of NAFLD are not known, its worldwide prevalence in general population is estimated to be 20-30% in Western Countries and 5-18% in Asia and it is increasing over time. In this review we will report on the global and regional prevalence of NAFLD, the principal risk factors and the natural history of its different presentations.

Silybin, a component of sylimarin, exerts anti-inflammatory and anti-fibrogenic effects on human hepatic stellate cells

BACKGROUND/AIMS Hepatic fibrogenesis, a consequence of chronic liver tissue damage, is characterized by activation of the hepatic stellate cells (HSC). Silybin has been shown to exert anti-fibrogenic effects in animal models. However, scant information is available on the fine cellular and molecular events responsible for this effect. The aim of this study was to assess the mechanisms regulating the anti-fibrogenic and anti-inflammatory activity of Silybin. METHODS Experiments were performed on HSC isolated from human liver and activated by culture on plastic. RESULTS Silybin was able to inhibit dose-dependently (25-50 microM) growth factor-induced pro-fibrogenic actions of activated human HSC, including cell proliferation (P < 0.001), cell motility (P < 0.001), and de novo synthesis of extracellular matrix components (P < 0.05). Silybin (25-50 microM), inhibited the IL-1-induced synthesis of MCP-1 (P < 0.01) and IL-8 (P < 0.01) showing a potent anti-inflammatory activity. Silybin exerts its effects by directly inhibiting the ERK, MEK and Raf phosphorylation, reducing the activation of NHE1 (Na+/H+ exchanger, P < 0.05) and the IkBalpha phosphorylation. In addition, Silybin was confirmed to act as a potent anti-oxidant agent. CONCLUSION The results of the study provide molecular insights into the potential therapeutic action of Silybin in chronic liver disease. This action seems to be mostly related to a marked inhibition of the production of pro-inflammatory cytokines, a clear anti-oxidant effect and a reduction of the direct and indirect pro-fibrogenic potential of HSC.

Silybin combined with phosphatidylcholine and vitamin E in patients with nonalcoholic fatty liver disease: A randomized controlled trial

The only currently recommended treatment for nonalcoholic fatty liver disease (NAFLD) is lifestyle modification. Preliminary studies of silybin showed beneficial effects on liver function. Realsil (RA) comprises the silybin phytosome complex (silybin plus phosphatidylcholine) coformulated with vitamin E. We report on a multicenter, phase III, double-blind clinical trial to assess RA in patients with histologically documented NAFLD. Patients were randomized 1:1 to RA or placebo (P) orally twice daily for 12 months. Prespecified primary outcomes were improvement over time in clinical condition, normalization of liver enzyme plasma levels, and improvement of ultrasonographic liver steatosis, homeostatic model assessment (HOMA), and quality of life. Secondary outcomes were improvement in liver histologic score and/or decrease in NAFLD score without worsening of fibrosis and plasma changes in cytokines, ferritin, and liver fibrosis markers. We treated 179 patients with NAFLD; 36 were also HCV positive. Forty-one patients were prematurely withdrawn and 138 patients analyzed per protocol (69 per group). Baseline patient characteristics were generally well balanced between groups, except for steatosis, portal infiltration, and fibrosis. Adverse events (AEs) were generally transient and included diarrhea, dysgeusia, and pruritus; no serious AEs were recorded. Patients receiving RA but not P showed significant improvements in liver enzyme plasma levels, HOMA, and liver histology. Body mass index normalized in 15% of RA patients (2.1% with P). HCV-positive patients in the RA but not the P group showed improvements in fibrogenesis markers. This is the first study to systematically assess silybin in NAFLD patients. Treatment with RA but not P for 12 months was associated with improvement in liver enzymes, insulin resistance, and liver histology, without increases in body weight. These findings warrant further investigation.

Gut-liver axis: a new point of attack to treat chronic liver damage?

excision without further waiting for repeat endoscopy and “blind” tissue biopsy. Figure 1 shows a midtransverse lesion (Japanese Research Society Classification Isp) that was treated with EMR (8) after exclusion of a submucosally invasive type V pit pattern within an area of central depression. HRMC postresection demonstrated residual tissue with a type IIIs pit pattern. The resection margin was subsequently extended using a second lateralized submucosal saline “lift.” Resection margins at this point were then reassessed after a second dye spray with 0.5% indigo carmine. After this, a mucosal toilet with normal saline was applied with subsequent mucolysis using 5 mL of acetylcystine (2 mg/mL) and localized application of crystal violet (0.05%) using a steel tipped catheter (Olympus 111019, Tokyo, Japan) around the remaining circumferential border. Type I pit was evident, indicative of complete resection margins. Histological examination confirmed the complete excision of colonic adenocarcinoma, with clear vertical and horizontal margins. Further studies assessing the efficacy of this technique in a large prospective cohort are required.

Long-term effects of Enterococcus faecium SF68 versus lactulose in the treatment of patients with cirrhosis and grade 1–2 hepatic encephalopathy

In 40 patients with cirrhosis on a dietary protein regimen of 1 g/kg b.w., we determined the effect on chronic hepatic encephalopathy of long-term administration of Enterococcus faecium (SF68) versus lactulose. The patients received one of the two treatments for three periods of 4 weeks, each separated by drug-free 2-week intervals. The efficacy of treatment was assessed by arterial blood ammonia concentration, mental status, number connection (Reitans part A) test and flash-evoked visual potentials. At the end of the third period the reduction in both blood ammonia concentrations and Reitans test times was more enhanced in patients on SF68 than in patients on lactulose. Furthermore, while patients on lactulose tended to return to basal values during drug-free intervals, responders in the SF68 group maintained improvement throughout the study. In conclusion, SF68 is at least as useful as lactulose for the chronic treatment of chronic hepatic encephalopathy; it has no adverse effects, and treatment can be interrupted for 2 weeks without losing the beneficial effects.

The effect of a silybin-vitamin e-phospholipid complex on nonalcoholic fatty liver disease: a pilot study.

Oxidative stress leads to chronic liver damage. Silybin has been conjugated with vitamin E and phospholipids to improve its antioxidant activity. Eighty-five patients were divided into 2 groups: those affected by nonalcoholic fatty liver disease (group A) and those with HCV-related chronic hepatitis associated with nonalcoholic fatty liver disease (group B), nonresponders to treatment. The treatment consisted of silybin/vitamin E/phospholipids. After treatment, group A showed a significant reduction in ultrasonographic scores for liver steatosis. Liver enzyme levels, hyperinsulinemia, and indexes of liver fibrosis showed an improvement in treated individuals. A significant correlation among indexes of fibrosis, body mass index, insulinemia, plasma levels of transforming growth factor-β, tumor necrosis factor-α, degree of steatosis, and γ-glutamyl transpeptidase was observed. Our data suggest that silybin conjugated with vitamin E and phospholipids could be used as a complementary approach to the treatment of patients with chronic liver damage.

Direct evidence of oxidative damage in acute and chronic phases of experimental colitis in rats

During inflammatory colitis in man and experimental animals, the production of free radicals increases. This study evaluated the histological pattern and biochemical parameters of oxidative damage during acute and chronic colitis induced by 2,4,-trinitrobenzenesulfonic acid + ethanol in rats. On the samples of scraped mucosa of six groups of rats, one not treated, one killed after 1 hr, and those killed one, two, four, and eight weeks after the induced-damage, we determined the histological and superoxide dismutase activity and the concentration of lipoperoxides, malonyldialdheyde, and reduced glutathione. After 1 hr, the mucosal damage and superoxide dismutase activity were slight; glutathione, lipoperoxides, and malonyldialdheyde were significantly increased. At one week, the histological damage was severe, decreasing progressively, and significantly correlated to superoxide dismutase activity. Lipoperoxides and malonyldialdheyde were high throughout the study. Glutathione was significantly increased at one and two weeks and dramatically decreased thereafter. Therefore, in experimental colitis the cascade of free-radical production induces a constant self-maintaining lipoperoxidation and consumes the cellular antioxidant capability.