Vanja Vasiljev Marchesi

Differential hepatoprotective mechanisms of rutin and quercetin in CCl 4 -intoxicated BALB/cN mice

Aim:To investigate the mechanisms underlying the protective effects of quercetin-rutinoside (rutin) and its aglycone quercetin against CCl4-induced liver damage in mice.Methods:BALB/cN mice were intraperitoneally administered rutin (10, 50, and 150 mg/kg) or quercetin (50 mg/kg) once daily for 5 consecutive days, followed by the intraperitoneal injection of CCl4 in olive oil (2 mL/kg, 10% v/v). The animals were sacrificed 24 h later. Blood was collected for measuring the activities of ALT and AST, and the liver was excised for assessing Cu/Zn superoxide dismutase (SOD) activity, GSH and protein concentrations and also for immunoblotting. Portions of the livers were used for histology and immunohistochemistry.Results:Pretreatment with rutin and, to a lesser extent, with quercetin significantly reduced the activity of plasma transaminases and improved the histological signs of acute liver damage in CCl4-intoxicated mice. Quercetin prevented the decrease in Cu/Zn SOD activity in CCl4-intoxicated mice more potently than rutin. However, it was less effective in the suppression of nitrotyrosine formation. Quercetin and, to a lesser extent, rutin attenuated the inflammation in the liver by down-regulating the CCl4-induced activation of nuclear factor-kappa B (NF-κB), tumor necrosis factor-α (TNF-α) and cyclooxygenase (COX-2). The expression of inducible nitric oxide synthase (iNOS) was more potently suppressed by rutin than by quercetin. Treatment with both flavonoids significantly increased NF-E2-related factor 2 (Nrf2) and heme oxygenase (HO-1) expression in injured livers, although quercetin was less effective than rutin at an equivalent dose. Quercetin more potently suppressed the expression of transforming growth factor-β1 (TGF-β1) than rutin.Conclusion:Rutin exerts stronger protection against nitrosative stress and hepatocellular damage but has weaker antioxidant and anti-inflammatory activities and antifibrotic potential than quercetin, which may be attributed to the presence of a rutinoside moiety in position 3 of the C ring.

Rosmarinic acid ameliorates acute liver damage and fibrogenesis in carbon tetrachloride-intoxicated mice

The aim of this study was to investigate the therapeutic potential of rosmarinic acid (RA), a natural phenolic, in the treatment of acute liver toxicity. RA at 10, 25 and 50mg/kg was administered by gavage once daily for 2 consecutive days, 6h after CCl(4) intoxication. CCl(4) intoxication caused hepatic necrosis and increased serum ALT activity. In the livers, oxidative/nitrosative stress was evidenced by increased 3-nitrotyrosine (3-NT) and thiobarbituric acid reactive substances (TBARS) formation and a significant decrease in Cu/Zn superoxide dismutase (SOD) activity. CCl(4) administration triggered inflammatory response in mice livers by activating nuclear factor-kappaB (NF-κB), which coincided with the induction of tumor necrosis factor-alpha (TNF-α) and cyclooxygenase-2 (COX-2). RA improved histological and serum markers of liver damage and significantly ameliorated oxidative/nitrosative stress and inflammatory response in liver tissue. Additionally, RA prevented transforming growth factor-beta1 (TGF-β1) and alpha-smooth muscle actin (α-SMA) expression, suggesting suppression of profibrotic response. Furthermore, RA significantly inhibited the CCl(4)-induced apoptosis, which was evident from decreased cleavage of caspase-3. The hepatoprotective activity of RA coincided with enhanced NF-E2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) expression. The results of this study indicates that RA possesses antioxidant, anti-inflammatory, antiapoptotic and antifibrotic activity against acute liver toxicity.

Preventive and therapeutic effects of oleuropein against carbon tetrachloride-induced liver damage in mice

Olives and olive products, an inevitable part of the Mediterranean diet, possess various beneficial effects, such as a decreased risk of cardiovascular disease and cancer. Oleuropein is a non-toxic secoiridoid found in the leaves and fruits of olive (Olea europaea L.). In this study, we have investigated the hepatoprotective activity of oleuropein in carbon tetrachloride (CCl(4))-induced liver injury in male BALB/cN mice. Oleuropein in doses of 100 and 200mg/kg was administered intraperitoneally (ip) once daily for 3 consecutive days, prior to CCl(4) administration (the preventive treatment), or once daily for 2 consecutive days 6h after CCl(4) intoxication (the curative treatment). CCl(4) intoxication resulted in a massive hepatic necrosis and increased plasma transaminases. Liver injury was associated with oxidative/nitrosative stress evidenced by increased nitrotyrosine formation as well as a significant decrease in superoxide dismutase activity and glutathione levels. CCl(4) administration triggered inflammatory response in mice livers by inducing expression of nuclear factor-kappaB, which coincided with the induction of tumor necrosis factor-alpha, cyclooxygenase-2 and inducible nitric oxide synthase. In both treatment protocols, oleuropein significantly attenuated oxidative/nitrosative stress and inflammatory response and improved histological and plasma markers of liver damage. Additionally, in the curative regimen, oleuropein prevented tumor necrosis factor-beta1-mediated activation of hepatic stellate cells, as well as the activation of caspase-3. The hepatoprotective activity of oleuropein was, at least in part, achieved through the NF-E2-related factor 2-mediated induction of heme oxygenase-1. The present study demonstrates antioxidant, anti-inflammatory, antiapoptotic, and antifibrotic activity of oleuropein, with more pronounced therapeutic than prophylactic effects.

Resolution of Liver Fibrosis by Isoquinoline Alkaloid Berberine in CCl4-Intoxicated Mice Is Mediated by Suppression of Oxidative Stress and Upregulation of MMP-2 Expression

Liver fibrosis is the result of chronic liver injury, and it represents a widespread medical problem. The aim of this study is to investigate the antifibrotic activity of isoquinoline alkaloid berberine in carbon tetrachloride (CCl₄)-induced damage in mice. Hepatic fibrosis was induced by intraperitoneal (i.p.) administration of CCl₄ (2 mL/kg, 20% v/v in olive oil) twice a week for 8 weeks. Berberine at the doses of 3 and 9 mg/kg and silymarin at the dose of 50 mg/kg were given i.p. once daily for the next 2 weeks. CCl₄ intoxication increased the levels of serum transaminases and induced oxidative stress in the liver. Hepatic fibrosis was evidenced by a massive deposition of collagen, which coincided with increased expression of tumor necrosis factor (TNF)-α and transforming growth factor (TGF)-β1 and the activation of hepatic stellate cells. The high-dose berberine (9 mg/kg) ameliorated oxidative stress, decreased TNF-α and TGF-β1 expression, increased the levels of matrix metalloproteinase (MMP)-2, and stimulated the elimination of fibrous deposits. Berberine at the dose of 9 mg/kg exhibited stronger therapeutic activity against hepatic fibrosis than silymarin at the dose of 50 mg/kg. In vitro analyses show an important scavenging activity of berberine against oxygen and nitrogen reactive species. The results of this study suggest that berberine could ameliorate liver fibrosis through the suppression of hepatic oxidative stress and fibrogenic potential, concomitantly stimulating the degradation of collagen deposits by MMP-2.

Increased Risk-Taking Behaviour and Brain-Derived Neurotrophic Factor Val66Met Polymorphism Correlates to Decreased Serum Brain-Derived Neurotrophic Factor Level in Heroin Users

Background: This study has examined the relationships and interactions between serum brain-derived neurotrophic factor (BDNF) levels, BDNF Val66Met polymorphism and self-reported risk-taking behaviour in individuals with a history of heroin use undergoing outpatient treatment in comparison to healthy individuals. Methods: We enrolled 167 heroin users and 86 healthy subjects and examined serum BDNF levels, Val66Met polymorphism, and personal characteristics using Connor Davidson Resilience Scale, Risk-taking (RT) propensity questionnaire, and Personality Assessment Inventory. Results: Heroin users had significantly higher serum BDNF levels than controls. In addition, serum BDNF levels were significantly higher in Val/Val carriers than in Met/Val or Met/Met in all recruited subjects. Furthermore, a stepwise multiple regression analysis of serum BDNF levels as a dependent variable with related factors showed that in heroin users, Alcohol Use Disorder Identification Test score, anxiety and RT score were found as independent contributors to serum BDNF levels. When performing gene-environment interaction it was additionally found that heroin users with self-reported high risk-taking behaviour had significantly lower levels of serum BDNF among heroin users with the Met allele. Conclusions: These results indicate that genetic variant Met66 decreased the serum BDNF levels in combination with self-reported risk-taking propensity among heroin users. If results of future work confirm the influence of this combined effect between neurotrophic genotype and risk-taking behaviour, 66Met carriers might require higher levels of intervention to overcome their drug use pattern and risky behaviour.

Evaluation design of Urban Health Centres Europe (UHCE): preventive integrated health and social care for community dwelling older persons in five European cities

BackgroundOlder persons often have interacting physical and social problems and complex care needs. An integrated care approach in the local context with collaborations between community-, social-, and health-focused organisations can contribute to the promotion of independent living and quality of life. In the Urban Health Centres Europe (UHCE) project, five European cities (Greater Manchester, United Kingdom; Pallini (in Greater Athens Area), Greece; Rijeka, Croatia; Rotterdam, the Netherlands; and Valencia, Spain) develop and implement a care template that integrates health and social care and includes a preventive approach. The UHCE project includes an effect and process evaluation.MethodsIn a one-year pre-post controlled trial, in each city 250 participants aged 75+ years are recruited to receive the UHCE approach and are compared with 250 participants who receive ‘care as usual’. Benefits of UHCE approach in terms of healthy life styles, fall risk, appropriate medication use, loneliness level and frailty, and in terms of level of independence and health-related quality of life and health care use are assessed. A multilevel modeling approach is used for the analyses. The process evaluation is used to provide insight into the reach of the target population, the extent to which elements of the UHCE approach are executed as planned and the satisfaction of the participants.DiscussionThe UHCE project will provide new insight into the feasibility and effectiveness of an integrated care approach for older persons in different European settings.Trial registrationISRCTN registry number is ISRCTN52788952. Date of registration is 13/03/2017.

The kinetics of IL-17 production in the lungs and plasma of mice after intratracheal infection with Klebsiella pneumoniae

BACKGROUND: Interleukin-17 is a proinflammatory cytokine predominantly produced by the T cells, which is involved in the innate immune responses to various physiologic and pathophysiologic processes including bacterial host defence. The neutralisation experiments showed that the lack of IL-17 leads to decreased neutrophil emigration and systemic granulopoietic responses to bacterial pathogens and allergens. The aim of our study was to determine the kinetics of IL-17 in plasma and lungs of animals intratracheally infected with Klebsiella pneumoniae. MATERIALS AND METHODS: In our experiments we used eight to twelve weeks old BALB/c male mice. Mice were intratracheally inoculated with 150 CFU of K. pneumoniae strain Caroli. At different time points mice were sacrificed and the lung and blood were aseptically removed and prepared for the cytokine determination. Cytokine determination was preformed by commercial ELISA kit (BenderMed Systems, Vienna, Austria). RESULTS: The IL-17 concentration in lung homogenates slightly increases in the first two hours of infection. Then it slightly decreases and again started to increase 24 hours after the infection. The concentration in lungs reached the maximal value 48 hours post infection. These results are consistent with data previously published by others. On the other hand, we also found increased plasma values of IL-17. Its concentration in plasma started to increase 12 hours after the infection and reaches the peak value 24 hours post infection. These results are in contrast with the results of others that reported no changes in systemic IL-17 production after the intratracheal K. pneumoniae challenge. CONCLUSIONS: The IL-17 in local host defences against Gram- negative pathogens is undoubtedly important for the clearance of microorganisms, but its importance in the systemic host response is still not resolved. Its maximal concentration in plasma correlates with the appearance of the bacteria in the blood after 24 hours, so we speculate that its role is to stimulate systemic proinflammatory cytokines to combat with a release of bacteria and/or their toxic products in the blood system.