Moreno Paolini

Reduction of oxidative stress by a new low-molecular-weight antioxidant improves metabolic alterations in a nonobese mouse diabetes model.

Objectives: We have previously established a nonobese diabetes mouse model characterized by moderate hyperglycemic levels, like those usually occurring in human type 2 diabetes. As oxidative stress is considered a major mechanism of progressive β-cell damage in diabetes, we tested in this model the protective effects of a new low-molecular-weight antioxidant, namely, bis(1-hydroxy-2,2,6,6-tetramethyl-4-piperidinyl)decandioate dihydrochloride (IAC). Methods: Diabetes was induced in C57Bl/6J mice by streptozotocin (STZ) and nicotinamide (NA) administration. Two weeks later, STZ-NA mice were treated for 5 weeks with different doses of IAC (15 or 30 mg/kg per day intraperitoneally) and monitored for glycemia, insulinemia, glucose tolerance, and pancreatic insulin content. Results: Streptozotocin-NA mice showed moderate hyperglycemia, hypoinsulinemia, glucose intolerance, growth impairment, and markedly reduced pancreatic insulin content (22% of controls). IAC-treated STZ-NA mice showed clear-cut reduction of hyperglycemia and attenuation of glucose intolerance, associated to higher residual pancreatic insulin content with respect to untreated diabetic animals. Plasma nitrotyrosine levels (an index of oxidative stress), enhanced 3-fold in diabetic mice, were significantly reduced by IAC treatment. Significant correlations were found between plasma nitrotyrosine values and either blood glucose levels or pancreatic insulin content. Conclusions: In the STZ-NA diabetic mouse model, the new antioxidant, IAC, improves diabetic metabolic alterations, likely by counteracting β-cell dysfunction and loss associated with oxidative stress.

E-cigarettes induce toxicological effects that can raise the cancer risk

Electronic cigarettes (e-cigs) are devices designed to deliver nicotine in a vaping solution rather than smoke and without tobacco combustion. Perceived as a safer alternative to conventional cigarettes, e-cigs are aggressively marketed as lifestyle-choice consumables, thanks to few restrictions and a lack of regulatory guidelines. E-cigs have also gained popularity among never-smokers and teenagers, becoming an emergent public health issue. Despite the burgeoning worldwide consumption of e-cigs, their safety remains largely unproven and it is unknown whether these devices cause in vivo toxicological effects that could contribute to cancer. Here we demonstrate the co-mutagenic and cancer-initiating effects of e-cig vapour in a rat lung model. We found that e-cigs have a powerful booster effect on phase-I carcinogen-bioactivating enzymes, including activators of polycyclic aromatic hydrocarbons (PAHs), and increase oxygen free radical production and DNA oxidation to 8-hydroxy-2′-deoxyguanosine. Furthermore, we found that e-cigs damage DNA not only at chromosomal level in peripheral blood, such as strand breaks in leucocytes and micronuclei formation in reticulocytes, but also at gene level such as point mutations in urine. Our results demonstrate that exposure to e-cigs could endanger human health, particularly among younger more vulnerable consumers.

Raphanus sativus cv. Sango Sprout Juice Decreases Diet-Induced Obesity in Sprague Dawley Rats and Ameliorates Related Disorders.

Background Obesity is recognized as a leading global health problem, correlated with an increased risk for several chronic diseases. One strategy for weight control management includes the use of vegetables rich in bioactive compounds to counteract weight gain, improve the antioxidant status and stimulate lipid catabolism. Aim of the Study The aim of this study was to investigate the role of Raphanus sativus Sango sprout juice (SSJ), a Brassica extraordinarily rich in anthocyanins (AC) and isothiocyanates (ITCs), in a non-genetic model of obesity (high fat diet-HFD induced). Methods Control groups were fed with HFD or regular diet (RD). After a 10-week period, animals were assigned to experimental units and treated by gavage for 28 days as follows: HFD and RD control groups (rats fed HFD or RD and treated with vehicle only) and HFD-treated groups (rats fed HFD and treated with 15, 75 or 150 mg/kg b.w. of SSJ). Body weight and food consumption were recorded and serum lipid profile was measured (total cholesterol, triglycerides, and non-esterified fatty acids). Hepatic phase-I, phase-II as well as antioxidant enzymatic activities were assessed. Results SSJ lowered total cholesterol level, food intake and liver weight compared with HFD rodents. SSJ at medium dose proved effective in reducing body-weight (~19 g reduction). SSJ was effective in up-regulating the antioxidant enzymes catalase, NAD(P)H:quinone reductase, oxidised glutathione reductase and superoxide dismutase, which reached or exceeded RD levels, as well as the phase II metabolic enzyme UDP-glucuronosyl transferase (up to about 43%). HFD up-regulated almost every cytochrome P450 isoform tested, and a mild down-regulation to baseline was observed after SSJ intervention. Conclusion This work reveals, for the first time, the antioxidant, hypolipidemic and antiobesity potential of SSJ, suggesting its use as an efficient new functional food/nutraceutical product.

Perturbation of xenobiotic metabolism in Dreissena polymorpha model exposed in situ to surface water (Lake Trasimene) purified with various disinfectants.

Sanitation is of crucial importance for the microbiological safety of drinking water. However, chlorination of water rich in organic material produces disinfection by-products (DBPs), many of which have been reported to be mutagenic and/or carcinogenic compounds such as haloacetic acids and trihalomethanes. Epidemiological studies have suggested a link between drinking water consumption and cancer. We previously observed that Cyprinus carpio fish exposed to DBPs, may be subject to epigenetic effects such as those referable to the up-regulation of cytochrome P450 (CYP) superfamily (ex. co-mutagenesis/co-carcinogenesis and oxidative stress) that has been associated to non-genotoxic carcinogenesis. Our goal was to study the xenobiotic metabolism in mollusks exposed in situ to surface water of Lake Trasimene (Central Italy) treated with several disinfectants such as the traditional chlorine dioxide (ClO2), sodium hypochlorite (NaClO) or the relatively new one peracetic acid (PAA). The freshwater bivalves (Dreissena polymorpha) being selected as biomarker, have the unique ability to accumulate pollutants. Freshwater bivalves were maintained in surface water containing each disinfectant individually (1-2 mg/L). Following an exposure period up to 20 days during the fall period, microsomes were collected from the mussels, then tested for various monooxygenases. Strong CYP inductions were observed. These data indicate that drinking water disinfection generates harmful DBP mixtures capable of determining a marked perturbation of CYP-supported reactions. This phenomenon, being associated to an increased pro-carcinogen bioactivation and persistent oxidative stress, could provide an explanation for the observational studies connecting the regular consumption of drinking water to increased risk of various cancers in humans.

Redox-Based Flagging of the Global Network of Oxidative Stress Greatly Promotes Longevity

Despite more than 50 years of investigations into the free radical theory, the direct role of oxidative stress (OS) in aging and age-related diseases remains unproven. Little progress in identifying antioxidant drugs promoting longevity has been made, likely due to selectivity toward one or few radical species, variable efficacy in vivo, inherent pro-oxidant behavior of such drugs, or lack of synergism with metabolic redox homeostasis. Silencing the wide range of reactive free radicals has a great impact on OS-linked outcomes and age-related disorders. Here we show that an innovative, redox-active, multi-radical-scavenger catalytic drug delays the age-associated decline in physiological processes and markedly prolongs the mean lifespan of the adult freshwater annelids Aeolosoma viride by 170%. This unprecedented extension is associated with a decreased OS status. Consistently, treatment of annelids increases their natural resistance to oxygen-derived damage without affecting mitochondrial respiration or reproductive activity. Conversely, the superoxide dismutase (SOD)-mimetic EUK 134 that we selected as a positive control led to an increase in lifespan of ~50%, the same increase previously observed in nematodes. Our results show that reduction of the global network of OS has a profound impact on aging, prompting the development of a possible redox-based therapeutic intervention to counteract the progression of aging.

The Chemopreventive Phytochemical Moringin Isolated from Moringa oleifera Seeds Inhibits JAK/STAT Signaling

Sulforaphane (SFN) and moringin (GMG-ITC) are edible isothiocyanates present as glucosinolate precursors in cruciferous vegetables and in the plant Moringa oleifera respectively, and recognized for their chemopreventive and medicinal properties. In contrast to the well-studied SFN, little is known about the molecular pathways targeted by GMG-ITC. We investigated the ability of GMG-ITC to inhibit essential signaling pathways that are frequently upregulated in cancer and immune disorders, such as JAK/STAT and NF-κB. We report for the first time that, similarly to SFN, GMG-ITC in the nanomolar range suppresses IL-3-induced expression of STAT5 target genes. GMG-ITC, like SFN, does not inhibit STAT5 phosphorylation, suggesting a downstream inhibitory event. Interestingly, treatment with GMG-ITC or SFN had a limited inhibitory effect on IFNα-induced STAT1 and STAT2 activity, indicating that both isothiocyanates differentially target JAK/STAT signaling pathways. Furthermore, we showed that GMG-ITC in the micromolar range is a more potent inhibitor of TNF-induced NF-κB activity than SFN. Finally, using a cellular system mimicking constitutive active STAT5-induced cell transformation, we demonstrated that SFN can reverse the survival and growth advantage mediated by oncogenic STAT5 and triggers cell death, therefore providing experimental evidence of a cancer chemopreventive activity of SFN. This work thus identified STAT5, and to a lesser extent STAT1/STAT2, as novel targets of moringin. It also contributes to a better understanding of the biological activities of the dietary isothiocyanates GMG-ITC and SFN and further supports their apparent beneficial role in the prevention of chronic illnesses such as cancer, inflammatory diseases and immune disorders.

Development of microparticles for oral administration of the non-conventional radical scavenger IAC and testing in an inflammatory rat model.

The bis (1-hydroxy-2,2,6,6-tetramethyl-4-piperidinyl)-decandioate (IAC), is an innovative non- radical scavenger used with success in numerous disease models such as inflammation, neurological disorders, hepatitis and diabetes. The pharmacological treatments have been performed by the intraperitoneal route of administration, representing to date, the main limit for the drug use. The aim of this study was to develop a delivery system that allows the oral administration of IAC while maintaining its therapeutic efficacy. Solid Lipid Microparticles (SLMs) containing a theoretical 18% (w/w) of IAC have been produced by the spray congealing technology; three formulations have been tested (A, B and C) using different low melting point carriers (stearic acid, Compritol(®) HD5ATO and carnauba wax) alone or in combination. All IAC loaded SLMs exhibited a spherical shape, encapsulation efficiency higher than 94% and particle size suitable for the oral route. Administered per os at different dosages in an inflammation rat model, all SLMs demonstrated their efficacy in reducing oedema and alleviating pain, compared to the gold standards Indomethacin and Paracetamol. These results suggested that the SLMs are an efficacious delivery system for the oral administration of IAC, potentially useful for the treatment of others diseases related to an over production of free radicals.

Disruption of redox homeostasis and carcinogen metabolizing enzymes changes by administration of vitamin E to rats.

AIMSnA large meta-analysis of randomized clinical trials has seriously questioned chemoprevention based on vitamins including vitamin E (VE), and an increased risk for cancer among long-term users was actually seen. However, the mechanism underlying these findings still remain unknown. To clarify the mechanism, in an in vivo model we studied the putative disruption of redox homeostasis and the perturbation of carcinogen metabolizing enzymes determined by VE.nnnMAIN METHODSnMale Sprague-Dawley rats were treated ip with either 100 or 200mg/kg b.w. daily for 7 or 14 consecutive days. Controls received vehicle only. Cytochrome P450 (CYP) content, CYP-reductase, CYP-linked monooxygenases, as well as phase-II and the antioxidant enzymes catalase andnnnNAD(P)Hnquinone reductase were investigated in both liver and kidney. Free radical species in tissue subcellular preparations were measured by electronic paramagnetic resonance (EPR) spectroscopy coupled to a radical probe technique.nnnKEY FINDINGSnNo substantial changes of hepatic xenobiotic metabolism enzymes were determined by VE. Conversely, a powerful booster effect of various renal phase-I carcinogen bioactivating enzymes at both dosages and observational times was recorded. While no relevant changes of post-oxidative phase-II reactions were found in the liver, a significant inactivating effect was caused by VE in renal tissues. Antioxidant enzymes were found mainly downregulated by the treatment. In the kidney, a marked free radical over-generation linked to CYP induction was observed.nnnSIGNIFICANCEnThis study proved that VE acts as a co-carcinogen and pro-oxidant agent. Such epigenetic mechanisms may contribute to explain the harmful outcomes observed in humans.

Comparison between in toto peach (Prunus persica L. Batsch) supplementation and its polyphenolic extract on rat liver xenobiotic metabolizing enzymes.

Over the past years, there has been a growing interest in the natural constituents of foods as a potential means of cancer control. To date, epidemiology studies seem to indicate an inverse association between regular consumption of fruit and vegetables and cancer risk. Here, the potential chemopreventive activity of the polyphenolic extract (PPE) of peach (Prunus persica L. Batsch) and of the freeze-dried fruit in toto (LFT), focusing on the modulation of xenobiotic metabolizing enzymes (XMEs) inxa0vivo, was investigated. Rats were daily supplemented with LFT at 250 and 500xa0mg/kg b.w. or with the corresponding amount of PPE (2.5 and 5xa0mL/kg b.w., respectively) for either 7 or 14 days. While PPE treatment resulted in a widespread phase-I inactivation, a complex modulation pattern with drastic decreases (7α-testosterone hydroxylase, pentoxyresorufin O-dealkylase (PROD)), coupled with marked up-regulations of ethoxyresorufin O-deethylase (EROD) and methoxyresorufin O-demethylase (MROD) after LFT administration, was seen. A notable down-regulation (over 50%) following LFT or PPE treatment for the phase-II enzymes was also recorded. The observed remarkable changes in XMEs, if reproduced in humans, might have public health implications. These data suggest caution in promoting peach fruit (mono-diet) consumption or its polyphenolic extract in the field of chemoprevention.

Effects of N-acetylcysteine on human ovarian tissue preservation undergoing cryopreservation procedure.

The aim of the study was to evaluate the effects of the antioxidant N-acetylcysteine (NAC), added in freezing/thawing solutions, on reactive oxygen species (RRS) levels and on ovarian tissue preservation after cryopreservation. Ovarian samples from 10 subjects suffering from cancer diseases were cryopreserved using the slow freezing/rapid thawing standard protocol without or with NAC supplementation. RRS levels produced during cryopreservation were monitored by electron paramagnetic resonance (EPR) spectroscopy. The preservation of fresh ovarian tissue (t0), thawed tissue (t1 and t1 NAC) and thawed tissue maintained at 4°C for 2 hrs (t2 and t2 NAC) was analysed by light microscopy, transmission electron microscopy, Ki67 immunohistochemical and TUNEL analysis. It was possible to design a maximum peak for RRS production at t1, which slightly decreased at t2. NAC reduced the extent of RRS levels in cryopreserved ovarian tissues if compared with non-supplemented ones, although not restoring RRS production to baseline values. Comparative analysis between the two cryopreservation protocols showed that a better preservation of morphological characteristics, proliferation index and DNA integrity of ovarian tissue was obtained using NAC and no differences between t1NAC and t2NAC were observed. The employment of NAC during cryopreservation procedure could be an useful strategy for preserving the function of endogenous cellular systems. Nevertheless, further studies on the viability of thawed ovarian tissue are needed to support the feasibility of this approach in clinical settings.