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    Ana Marçal-Pessoa

    A cicatrização deficiente é uma complicação do Diabetes Mellitus (DM), associada ao estresse oxidativo promovido pela hiperglicemia crônica. O objetivo deste estudo foi avaliar os efeitos da administração sistêmica (por via oral,... more
    A cicatrização deficiente é uma complicação do Diabetes Mellitus (DM), associada ao estresse oxidativo promovido pela hiperglicemia crônica. O objetivo deste estudo foi avaliar os efeitos da administração sistêmica (por via oral, vitaminas E+C) e tópica (utilizando nanopartículas lipídicas sólidas NLSs, vitamina E) de vitaminas antioxidantes na cicatrização de feridas cutâneas em camundongos diabéticos. Uma ferida dorsal foi realizada e os animais tratados com antioxidantes por via oral ou topicamente, diariamente. Os resultados mostraram um atraso na cicatrização das feridas nos diabéticos, menor intensidade da reação inflamatória no 3º dia. No 14º dia, observou-se persistência da reação inflamatória, atraso na reepitelização e menor conteúdo de colágenos fibrilares. O tratamento com vitaminas antioxidante, tanto sistêmico quanto tópico, foi efetivo na aceleração da cicatrização das feridas, por meio da modulação do estresse oxidativo e da reação inflamatória. Concluímos que o trat...
    PurposeIt is known that obesity has a multifactorial etiology that involves genetic and environmental factors. The WHO estimates the worldwide prevalence of 1.9 billion overweight adults and more than 650 million people with obesity.... more
    PurposeIt is known that obesity has a multifactorial etiology that involves genetic and environmental factors. The WHO estimates the worldwide prevalence of 1.9 billion overweight adults and more than 650 million people with obesity. These alarming data highlight the high and growing prevalence of obesity and represent a risk factor for the development and aggravation of other chronic diseases, such as nonalcoholic fatty liver disease (NAFLD) that is frequently considered the hepatic outcome of type 2 diabetes. The use of non-pharmacological therapies such as food supplements, nutraceuticals, and natural integrative therapies has grown as an alternative tool for obesity-related diseases compared to conventional medications. However, it is a still little explored research field and lacks scientific evidence of therapeutic effectiveness. Considering this, the aim is to evaluate whether a new nutraceutical supplement composition can improve and supply essential mineral nutrients, provi...
    Impaired wound healing has been widely reported in diabetes. Linoleic acid (LA) accelerates the skin wound healing process in non-diabetic rats. However, LA has not been tested in diabetic animals. We investigated whether oral... more
    Impaired wound healing has been widely reported in diabetes. Linoleic acid (LA) accelerates the skin wound healing process in non-diabetic rats. However, LA has not been tested in diabetic animals. We investigated whether oral administration of pure LA improves wound healing in streptozotocin-induced diabetic rats. Dorsal wounds were induced in streptozotocin-induced type-1 diabetic rats treated or not with LA (0.22 g/kg b.w.) for 10 days. Wound closure was daily assessed for two weeks. Wound tissues were collected at specific time-points and used to measure fatty acid composition, and contents of cytokines, growth factors and eicosanoids. Histological and qPCR analyses were employed to examine the dynamics of cell migration during the healing process. LA reduced the wound area 14 days after wound induction. LA also increased the concentrations of cytokine-induced neutrophil chemotaxis (CINC-2αβ), tumor necrosis factor-α (TNF-α) and leukotriene B4 (LTB4), and reduced the expression ...
    The use of natural products and derivatives for the prevention and control of non-communicable chronic diseases, such as type-2 diabetes (T2D), obesity, and hepatic steatosis is a way to achieve homeostasis through different metabolic... more
    The use of natural products and derivatives for the prevention and control of non-communicable chronic diseases, such as type-2 diabetes (T2D), obesity, and hepatic steatosis is a way to achieve homeostasis through different metabolic pathways. Thus, male C57BL/6 mice were divided into the following groups: high-fat diet (HFD) vehicle, HFD+Supplemented, HFD+Supplemented_S, and isolated compounds. The vehicle and experimental formulations were administered orally by gavage once a day over the four weeks of the diet (28 consecutive days). We evaluated the energy homeostasis, cytokines, and mitochondrial gene expression in these groups of mice. After four weeks of supplementation, only the new nutraceutical group (HFD+Supplemented) experienced reduced fasting glycemia, insulin, HOMA index, HOMA-β, dyslipidemia, ectopic fat deposition, and hepatic fibrosis levels. Additionally, the PPARγ coactivator 1 α (Pgc-1α), interleukin-6 (Il-6), and interleukin-10 (Il-10) gene expression were augm...
    Background Cachexia is a paraneoplastic syndrome that accompanies and compromises cancer treatment, especially in advanced stages, affecting the metabolism and function of several organs. The adipose tissue is the first to respond to the... more
    Background Cachexia is a paraneoplastic syndrome that accompanies and compromises cancer treatment, especially in advanced stages, affecting the metabolism and function of several organs. The adipose tissue is the first to respond to the presence of the tumor, contributing to the secretion of factors which drive the systemic inflammation, a hallmark of the syndrome. While inflammation is a defensive innate response, the control mechanisms have been reported to be disrupted in cachexia. On the other hand, little is known about the role of NLRP3 inflammasome in this scenario, a multiprotein complex involved in caspase-1 activation and the processing of the cytokines IL-1β and IL-18. Aim based on the evidence from our previous study with a rodent model of cachexia, we examined the activation of the NLRP3 inflammasome pathway in two adipose tissue depots obtained from patients with colorectal cancer and compared with that another inflammatory pathway, NF-κB. Results For CC we found oppo...
    AIM The influence of thyroid hormones on exocrine pancreas function is poorly understood, and limited to the postnatal development period. Here, we evaluated the effects of hypo- and hyperthyroidism on the morphology and enzyme content of... more
    AIM The influence of thyroid hormones on exocrine pancreas function is poorly understood, and limited to the postnatal development period. Here, we evaluated the effects of hypo- and hyperthyroidism on the morphology and enzyme content of this tissue. MAIN METHODS To induce hypothyroidism male Wistar rats were subjected to a thyroidectomy (Tx) or sham operated (SO). After 40 days, some of the Tx and SO rats were treated with T3 for 7 days. Following euthanization, the pancreas was removed and evaluated for morphology, as well as amylase, lipase and trypsin content, using histological and immunoreactive techniques analyses, respectively. Serum amylase levels were also evaluated. KEY FINDINGS The pancreatic acinar cells of Tx rats were smaller, exhibited reduced Haematoxyllin stained areas, and contained lower amylase and lipase levels, indicative of low cell activity. Tx rats also presented higher collagen levels, and high trypsin content in pancreatic extracts. Interestingly, T3 adm...
    Type 1 diabetes is associated with systemic low grade inflammation (LGI). We have previously shown that LGI in diabetic mice depends on systemic circulation of leukotriene (LTB4) which potentiates the toll-like/IL1β receptors response in... more
    Type 1 diabetes is associated with systemic low grade inflammation (LGI). We have previously shown that LGI in diabetic mice depends on systemic circulation of leukotriene (LTB4) which potentiates the toll-like/IL1β receptors response in macrophages. Impaired wound healing is an important co-morbidity in diabetes, and macrophages play a key role in this process. Here, we investigated the role of leukotrienes on monocytes and macrophages phenotype and in the impaired wound healing in diabetic mice. Type 1 diabetes was induced with streptozotocin in 129SvE wild-type (WT) and leukotrienes-deficient 5LO−/− (5-lipoxygenase knockout) mice. In diabetics, the systemic levels of LTB4, TNF-α, IL-6, IL-10, IL-12 and IFNγ were increased as well as the frequency of pro-inflammatory monocytes (CD11b+Ly6ChighLy6G−) compared to healthy mice. In diabetic 5LO−/− mice, these parameters were similar to those in healthy mice. Resident peritoneal macrophages from diabetic WT mice showed a classically act...
    The need of pharmacological strategies to preclude breast cancer development motivated us to develop a non-aqueous microemulsion (ME) capable of forming a depot after administration in the mammary tissue and uptake of interstitial fluids... more
    The need of pharmacological strategies to preclude breast cancer development motivated us to develop a non-aqueous microemulsion (ME) capable of forming a depot after administration in the mammary tissue and uptake of interstitial fluids for prolonged release of the retinoid fenretinide. The selected ME was composed of phosphatidylcholine/tricaprylin/propylene glycol (45:5:50, w/w/w) and presented a droplet diameter of 175.3 ± 8.9 nm. Upon water uptake, the ME transformed successively into a lamellar phase, gel, and a lamellar phase-containing emulsion in vitro as the water content increased and released 30% of fenretinide in vitro after 9 days. Consistent with the slow release, the ME formed a depot in cell cultures and increased fenretinide IC50 values by 68.3- and 13.2-fold in MCF-7 and T-47D cells compared to a solution, respectively. At non-cytotoxic concentrations, the ME reduced T-47D cell migration by 75.9% and spheroid growth, resulting in ∼30% smaller structures. The depot...
    Diabetic foot affects 4 to 10% of diabetic patients per year and has a high rate of amputation and mortality (39-80%). Diabetes Mellitus (DM) is among the chronic diseases that increase reactive oxygen molecular species (ROS) generation... more
    Diabetic foot affects 4 to 10% of diabetic patients per year and has a high rate of amputation and mortality (39-80%). Diabetes Mellitus (DM) is among the chronic diseases that increase reactive oxygen molecular species (ROS) generation by glucose oxidation. Antioxidants-associated lipid nanocarriers is a promising tool in the diabetic healing treatment. The mini-review aim is to introduce the pathophysiological and how vitamin E-mechanism could be to prevent and treat this diabetic wound, as well as the solid lipid nanocarriers (SLN), which can help accelerate the impaired diabetic wound healing process when associated with vitamin E.
    The healing time of burn wounds depends on surface area and depth of the burn and associated comorbidities. Diabetes mellitus (DM) causes delays in the healing process by extending the inflammatory phase. Treatment with topical insulin... more
    The healing time of burn wounds depends on surface area and depth of the burn and associated comorbidities. Diabetes mellitus (DM) causes delays in the healing process by extending the inflammatory phase. Treatment with topical insulin can improve the inflammatory phase, restore metabolic dysregulation, and modulate impaired cellular signaling in burn wounds. The objective of this study was to evaluate markers of the inflammatory and proliferative phases of second-degree burns after topical insulin treatment in diabetic rats. Type I DM was induced with streptozotocin in male Wistar rats. The animals’ backs were shaved and subjected to thermal burning. Rats were randomized into two groups: control diabetic (DC) and insulin diabetic (DI). At Days 7 and 14 postburn, rats were euthanized, and wound-tissue sections were evaluated by hematoxylin and eosin, Weigert, and Verhöeff staining, immunohistochemistry-paraffin, and enzyme-linked immunosorbent assay. A significant increase in reepit...
    Oxidative stress aggravates several long-term complications in diabetes mellitus. We evaluated the effectiveness of the oral administration of antioxidants (vitamins E and C, 40 and 100 mg/kg b.w., respectively) on skin wound healing... more
    Oxidative stress aggravates several long-term complications in diabetes mellitus. We evaluated the effectiveness of the oral administration of antioxidants (vitamins E and C, 40 and 100 mg/kg b.w., respectively) on skin wound healing acceleration in alloxan-induced diabetic mice. Mice were wounded 30 days after the induction of diabetes. Antioxidants were effective in preventing oxidative stress, as assessed by TBARS. The enzymes catalase, glutathione reductase, glutathione peroxidase, and superoxide dismutase were increased in diabetics on the 3rd day post-wounding; catalase and glutathione peroxidase remained still augmented in diabetics after 14th day postwounding, and the treatment with vitamins restored their activities to control. After 3 days, diabetic mice showed lower infiltration of inflammatory cells (including CD11b(+) and Ly6G(+) cells) and reduced levels of KC, TNF-α, IL-1β, and IL-12 p40 when compared with control mice. The treatment restored cytokine levels. After 14...
    The healing process is complex in diabetic wounds, and the healing mechanism of burn wounds is different from that of incisional or excisional wounds. Data from our previous study indicated that topical insulin cream reduced wound closure... more
    The healing process is complex in diabetic wounds, and the healing mechanism of burn wounds is different from that of incisional or excisional wounds. Data from our previous study indicated that topical insulin cream reduced wound closure time in diabetic rats. Our aim was to investigate the effect of topical insulin cream on wound healing following second-degree burns in control and diabetic rats. Rats were divided into four groups: control (nondiabetic) rats treated with placebo (CP), control (nondiabetic) rats treated with topical insulin cream (CI), diabetic rats treated with placebo (DP), and diabetic rats treated with topical insulin cream (DI). The wounds were assessed at 4 time points (1, 7, 14, and 26 days) post-wounding for morphometric analysis of wound sections stained with hematoxylin/eosin, α-smooth muscle actin, and Picrosirius red to evaluate general aspects of the wound, inflammatory infiltrate, blood vessels, and Types I and III collagen fibers. Histological analys...
    Gap junctions between β-cells participate in the precise regulation of insulin secretion. Adherens junctions and their associated proteins are required for the formation, function and structural maintenance of gap junctions. Increases in... more
    Gap junctions between β-cells participate in the precise regulation of insulin secretion. Adherens junctions and their associated proteins are required for the formation, function and structural maintenance of gap junctions. Increases in the number of the gap junctions between β-cells and enhanced glucose-stimulated insulin secretion are observed during pregnancy. In contrast, protein restriction produces structural and functional alterations that result in poor insulin secretion in response to glucose. We investigated whether protein restriction during pregnancy affects the expression of mRNA and proteins involved in gap and adherens junctions in pancreatic islets. An isoenergetic low-protein diet (6% protein) was fed to non-pregnant or pregnant rats from day 1-15 of pregnancy, and rats fed an isocaloric normal-protein diet (17% protein) were used as controls. The low-protein diet reduced the levels of connexin 36 and β-catenin protein in pancreatic islets. In rats fed the control ...
    The effects of oral ingestion of oleic (OLA) and linoleic (LNA) acids on wound healing in rats were investigated. LNA increased the influx of inflammatory cells, the concentration of hydrogen peroxide (H(2)O(2)) and cytokine-induced... more
    The effects of oral ingestion of oleic (OLA) and linoleic (LNA) acids on wound healing in rats were investigated. LNA increased the influx of inflammatory cells, the concentration of hydrogen peroxide (H(2)O(2)) and cytokine-induced neutrophil chemoattractant-2αβ (CINC-2αβ), and the activation of the transcription factor activator protein-1 (AP-1) in the wound at 1 hour post wounding. LNA decreased the number of inflammatory cells and IL-1, IL-6, and macrophage inflammatory protein-3 (MIP-3) concentrations, as well as NF-κB activation in the wound at 24 hours post wounding. LNA accelerated wound closure over a period of 7 days. OLA increased TNF-α concentration and NF-κB activation at 1 hour post wounding. A reduction of IL-1, IL-6, and MIP-3α concentrations, as well as NF-κB activation, was observed 24 hours post wounding in the OLA group. These data suggest that OLA and LNA accelerate the inflammatory phase of wound healing, but that they achieve this through different mechanisms.