Viviani Nardini

Anthocyanin-rich açaí (Euterpe oleracea Mart.) extract attenuates manganese-induced oxidative stress in rat primary astrocyte cultures.

Manganese (Mn) is an essential element for human health. However, at high concentrations Mn may be neurotoxic. Mn accumulates in astrocytes, affecting their redox status. In view of the high antioxidant and anti-inflammatory properties of the exotic Brazilian fruit açaí (Euterpe oleracea Mart.), its methanolic extract was obtained by solid-phase extraction (SPE). This açaí extract showed considerable anthocyanins content and direct antioxidant capacity. The açaí extract scavenged 2,2-diphenyl-1-picrylhydrazyl radicals (DPPH•) with an EC50 of 19.1 ppm, showing higher antioxidant activity compared to butylated hydroxytoluene (BHT), but lower than ascorbic acid and quercetin. This obtained açaí extract also attenuated Mn-induced oxidative stress in primary cultured astrocytes. Specifically, the açaí extract at an optimal and nutritionally relevant concentration of 0.1 μg/ml prevented Mn-induced oxidative stress by (1) restoring GSH/GSSG ratio and net glutamate uptake, (2) protecting astrocytic membranes from lipid peroxidation, and (3) decreasing Mn-induced expression of erythroid 2-related factor (Nrf2) protein. A larger quantity of açaí extract exacerbated the effects of Mn on these parameters except with respect to lipid peroxidation assessed by means of F2-isoprostanes. These studies indicate that at nutritionally relevant concentration, anthocyanins obtained from açaí protect astrocytes against Mn neurotoxicity, but at high concentrations, the “pro-oxidant” effects of its constituents likely prevail. Future studies may be profitably directed at potential protective effects of açaí anthocyanins in nutraceutical formulations.

Association among genetic predisposition, gut microbiota, and host immune response in the etiopathogenesis of inflammatory bowel disease

Inflammatory bowel disease (IBD), which includes Crohns disease (CD) and ulcerative colitis (UC), is a chronic disorder that affects thousands of people around the world. These diseases are characterized by exacerbated uncontrolled intestinal inflammation that leads to poor quality of life in affected patients. Although the exact cause of IBD still remains unknown, compelling evidence suggests that the interplay among immune deregulation, environmental factors, and genetic polymorphisms contributes to the multifactorial nature of the disease. Therefore, in this review we present classical and novel findings regarding IBD etiopathogenesis. Considering the genetic causes of the diseases, alterations in about 100 genes or allelic variants, most of them in components of the immune system, have been related to IBD susceptibility. Dysbiosis of the intestinal microbiota also plays a role in the initiation or perpetuation of gut inflammation, which develops under altered or impaired immune responses. In this context, unbalanced innate and especially adaptive immunity has been considered one of the major contributing factors to IBD development, with the involvement of the Th1, Th2, and Th17 effector population in addition to impaired regulatory responses in CD or UC. Finally, an understanding of the interplay among pathogenic triggers of IBD will improve knowledge about the immunological mechanisms of gut inflammation, thus providing novel tools for IBD control.

Classical and recent advances in the treatment of inflammatory bowel diseases.

Crohns disease (CD) and ulcerative colitis (UC) are intestinal disorders that comprise the inflammatory bowel diseases (IBD). These disorders have a significant effect on the quality of life of affected patients and the increasing number of IBD cases worldwide is a growing concern. Because of the overall burden of IBD and its multifactorial etiology, efforts have been made to improve the medical management of these inflammatory conditions. The classical therapeutic strategies aim to control the exacerbated host immune response with aminosalicylates, antibiotics, corticosteroids, thiopurines, methotrexate and anti-tumor necrosis factor (TNF) biological agents. Although successful in the treatment of several CD or UC conditions, these drugs have limited effectiveness, and variable responses may culminate in unpredictable outcomes. The ideal therapy should reduce inflammation without inducing immunosuppression, and remains a challenge to health care personnel. Recently, a number of additional approaches to IBD therapy, such as new target molecules for biological agents and cellular therapy, have shown promising results. A deeper understanding of IBD pathogenesis and the availability of novel therapies are needed to improve therapeutic success. This review describes the overall key features of therapies currently employed in clinical practice as well as novel and future alternative IBD treatment methods.

Identification of species of the Euterpe genus by rare earth elements using inductively coupled plasma mass spectrometry and linear discriminant analysis

The açaí (Euterpe oleracea Mart.) and juçara (Euterpe edulis Mart.) produce similar fruits which are rich in energy, minerals, vitamins and natural compounds with antioxidant and anti-inflammatory properties. Although the drink obtained from these species is similar, it is important to develop tools to establish the identity of the fruit species and growing regions. To assess claims of origin and for other purposes, we use multivariate analysis to investigate the differentiation of açaí and juçara fruits based on rare earth element (REE) content determined by Inductively Coupled Plasma Mass Spectrometry. REE content, in particular Sm, Th, La, Pr, Gd, and especially Ce and Nd varied between species. PCA analysis was not efficient in differentiating açaí from juçara fruit samples. In contrast, LDA analysis permitted a correct differentiation between species with a predictive ability of 83.3%. The methodology that we have applied confirms that REE can be used to differentiate between açaí and juçara fruit samples and to identify their origin.

Predicting soluble solid content in intact jaboticaba [Myrciaria jaboticaba (Vell.) O. Berg] fruit using near-infrared spectroscopy and chemometrics

The aim of this study was to evaluate the potential of near-infrared reflectance spectroscopy (NIR) as a rapid and non-destructive method to determine soluble solid content (SSC) in intact jaboticaba [Myrciaria jaboticaba (Vell.) O. Berg] fruit. Multivariate calibration techniques were compared with pre-processed data and variable selection algorithms, such as partial least squares (PLS), interval partial least squares (iPLS), a genetic algorithm (GA), a successive projections algorithm (SPA) and nonlinear techniques (BP-ANN, back propagation of artificial neural networks; LS-SVM, least squares support vector machine) were applied to building the calibration models. The PLS model produced prediction accuracy (R(2)=0.71, RMSEP=1.33 °Brix, and RPD=1.65) while the BP-ANN model (R(2)=0.68, RMSEM=1.20 °Brix, and RPD=1.83) and LS-SVM models achieved lower performance metrics (R(2)=0.44, RMSEP=1.89 °Brix, and RPD=1.16). This study was the first attempt to use NIR spectroscopy as a non-destructive method to determine SSC jaboticaba fruit.

Aedes aegypti salivary gland extract ameliorates experimental inflammatory bowel disease

Current therapies for inflammatory bowel disease (IBD) are not totally effective, resulting in persistent and recurrent disease for many patients. Mosquito saliva contains immunomodulatory molecules and therein could represent a novel therapy for IBD. Here, we demonstrated the therapeutic activity of salivary gland extract (SGE) of Aedes aegypti on dextran sulfate sodium (DSS)-induced colitis. For this purpose, C57BL/6 male mice were exposed to 3% DSS in drinking water and treated with SGE at early (days 3-5) or late (days 5-8) time points, followed by euthanasia on days 6 and 9, respectively, for sample collection. The results showed an improvement in clinical disease outcome and postmortem scores after SGE treatment, accompanied by the systemic reduction in peripheral blood lymphocytes, with no impact on bone marrow and mesenteric lymph nodes cellularity or macrophages toxicity. Moreover, a local diminishment of IFN-γ, TNF-α, IL-1β and IL-5 cytokines together with a reduction in the inflammatory area were observed in the colon of SGE-treated mice. Strikingly, early treatment with SGE led to mice protection from a late DSS re-challenging, as observed by decreased clinical and postmortem scores, besides reduced circulating lymphocytes, indicating that the mosquito saliva may present components able to prevent disease relapse. Indeed, high performance liquid chromatography (HPLC) experiments pointed to a major SGE pool fraction (F3) able to ameliorate disease signs. In conclusion, SGE and its components might represent a source of important immunomodulatory molecules with promising therapeutic activity for IBD.

NIRS and iSPA-PLS for predicting total anthocyanin content in jaboticaba fruit.

The aim of this study was to evaluate the potential of the successive projection algorithm for interval selection in partial least squares (iSPA-PLS) together with near-infrared reflectance spectroscopy (NIRS) as a feasible method to determine the total anthocyanin content (TAC) of intact jaboticaba fruit [Myrciaria jaboticaba (Vell.) O. Berg]. A total of 579 jaboticaba fruit were collected in three different harvests in three separate years (2011 and 2013). The correlation coefficients between the predicted and measured TAC were between 0.65 and 0.89, the RMSEPs were 7.55 g kg(-1) and 9.35 g kg(-1) (good accuracy) for prediction set, respectively. The RPD ratios for TAC were in the range of 2.57-3.19 with iSPA-PLS, which showed better predictive performance (acceptable precision). These results suggest that the NIR spectroscopy and wavelength selection (iSPA-PLS) algorithm can be used to determine the TAC of intact jaboticaba fruit.

Dehydroepiandrosterone (DHEA) restrains intestinal inflammation by rendering leukocytes hyporesponsive and balancing colitogenic inflammatory responses

Dehydroepiandrosterone (DHEA) is a hormone that plays an important role in the modulation of inflammatory responses. However, the precise mechanisms that link the actions of this androgen with protection or susceptibility to inflammatory bowel diseases (IBD) remain uknown. Here we showed that low dose DHEA inhibited proliferation of spleen cells and IFN-у production. The hormone was not toxic to myeloid lineage cells, although it caused necrosis of spleen cells at the intermediate and highest doses in vitro (50 and 100μM). The treatment of C57BL/6 mice with DHEA during colitis induction by dextran sodium sulfate (DSS) led to a reduction in weight loss and clinical signs of disease. There were decreased peripheral blood monocytes on day 6 of DSS exposure and treatment, besides increase in circulating neutrophils in the tissue repair phase. DHEA also led to reduced lamina propria cellularity and restoration of normal colon length. These results were accompanied by decreased expression of IL-6 and TGF-β mRNA, while IL-13 was augmented in the colon on day 6, which was probably related to attenuation of inflammation. There was retention of CD4(+) cells in the spleen after use of DHEA, along with augmented frequency of CD4(+)IL-4(+) cells, decreased CD4(+)IFN-ɣ(+) in spleen and constrained CD4(+)IL-17(+) population in the mesenteric lymph nodes. Moreover, splenocytes of mice treated with DHEA became hyporesponsive, as observed by reduced proliferation after re-stimulation ex-vivo. In conclusion, DHEA modifyies leukocyte activity and balances the exacerbated immune responses which drive local and systemic damages in IBD.

Side-chain modifications of highly functionalized 3(2H)-furanones.

A series of 3(2H)-furanones, based on side-chain modifications of a parent 3(2H)-furanone, was synthesized in good yield. The parent compound was prepared by hydrogenolysis, and subsequent acid hydrolysis, of isoxazole derivatives. The isoxazole was prepared by a [3+2] 1,3-dipolar cycloaddition reaction between 3-butyn-2-ol and nitrile oxide.

Amelioration of experimental colitis after short‐term therapy with glucocorticoid and its relationship to the induction of different regulatory markers

The clinical benefits of short‐term therapy with glucocorticoids (GC) in patients with inflammatory bowel disease (IBD) are widely known. However, the effects of this treatment towards the re‐establishment of the regulatory network in IBD are not fully explored. We have evaluated the immunological effects of the abbreviated GC therapy in experimental colitis induced by 3% dextran sulphate sodium in C57BL/6 mice. Treatment with GC improved disease outcome, constrained circulating leucocytes and ameliorated intestinal inflammation. The control of the local inflammatory responses involved a reduction in the expression of interferon‐γ and interleukin‐1β, associated with augmented mRNA levels of peroxisome proliferator‐activated receptors (α and γ) in intestine. Furthermore, there was a reduction of CD4+ T cells producing interferon‐γ, together with an increased frequency of the putative regulatory population of T cells producing interleukin‐10, in spleen. These systemic alterations were accompanied by a decrease in the proliferative potential of splenocytes of mice treated in vivo with GC. Notably, treatment with GC also led to an increase in the frequency of the regulatory markers GITR, CTLA‐4, PD‐1, CD73 and FoxP3, more prominently in spleen. Taken together, our results pointed to a role of GC in the control of leucocyte responsiveness and re‐establishment of a regulatory system, which probably contributed to disease control and the restoration of immune balance. Finally, this is the first time that GC treatment was associated with the modulation of a broad number of regulatory markers in an experimental model of colitis.