Sonia Terezinha dos Anjos Lopes

Bio: Sonia Terezinha dos Anjos Lopes is an academic researcher from Universidade Federal de Santa Maria. The author has contributed to research in topics: Trypanosoma evansi & Parasitemia. The author has an hindex of 26, co-authored 219 publications receiving 2467 citations.

Oxidative stress parameters in blood, liver, and kidney of diabetic rats treated with curcumin and/or insulin

Abstract: This study evaluated the effects of curcumin and/or insulin on antioxidant enzyme activity in blood, liver, and kidney, as well as on lipid peroxidation and delta aminolevulinic dehydratase (δ-ALA-D) activity, and a histopathological analysis of streptozotocin-induced diabetic rats. The animals were divided into six groups (n = 6): control/saline (C); control/curcumin (CCur); diabetic/saline (D); diabetic/insulin (DIns); diabetic/curcumin (DCur); and diabetic/insulin/curcumin (DInsCur). After 30 days of treatment with curcumin and/or insulin, the animals were sacrificed and the liver, kidney, and serum were used for experimental determinations. Results of histopathological analysis showed that the treatment with insulin ameliorate renal and hepatic lesions from both DIns and DInsCur groups. TBARS levels were significantly increased in serum, liver, and kidney in D group and the administration of curcumin and insulin prevented this increase in DIns and DCur groups. The activities of catalase (CAT), superoxide dismutase, and δ-ALA-D presented a significant decrease in the liver and kidney D group when compared to C group (P < 0.05). The animals treated with curcumin and insulin presented an increase of CAT activity, revealing a positive interaction between both substances. The treatments with curcumin or insulin prevented oxidative stress in blood, through modulation of enzymatic antioxidant defenses. These findings contributed to the comprehension that antioxidants from medicinal plants could be used as adjuvant in the treatment of this endocrinopathy and not as single therapy.

Anthocyanins suppress the secretion of proinflammatory mediators and oxidative stress, and restore ion pump activities in demyelination.

Abstract: The aim of this study was to investigate the protective effect of anthocyanins (ANT) on oxidative and inflammatory parameters, as well as ion pump activities, in the pons of rats experimentally demyelinated with ethidium bromide (EB). Rats were divided in six groups: control, ANT 30 mg/kg, ANT 100 mg/kg, EB (0.1%), EB plus ANT 30 mg/kg and EB plus ANT 100 mg/kg. The EB cistern pons injection occurred on the first day. On day 7, there was a peak in the demyelination. During the 7 days, the animals were treated once per day with vehicle or ANT. It was observed that demyelination reduced Na+,K+-ATPase and Ca2+-ATPase activities and increased 4-hydroxynonenal, malondialdehyde, protein carbonyl and NO2plus NO3 levels. In addition, a depletion of glutathione reduced level/nonprotein thiol content and a decrease in superoxide dismutase activity were also seen. The dose of 100 mg/kg showed a better dose–response to the protective effects. The demyelination did not affect the neuronal viability but did increase the inflammatory infiltrate (myeloperoxidase activity) followed by an elevation in interleukin (IL)-1β, IL-6, tumor necrosis factor-α and interferon-γ levels. ANT promoted a reduction in cellular infiltration and proinflammatory mediators. Furthermore, ANT restored the levels of IL-10. Luxol fast blue staining confirmed the loss of myelin in the EB group and the protective effect of ANT 100 mg/kg. In conclusion, this study was the first to show that ANT are able to restore ion pump activities and protect cellular components against the inflammatory and oxidative damages induced by demyelination.

The Role of Oxidative Stress and Antioxidants in Liver Diseases

Abstract: A complex antioxidant system has been developed in mammals to relieve oxidative stress. However, excessive reactive species derived from oxygen and nitrogen may still lead to oxidative damage to tissue and organs. Oxidative stress has been considered as a conjoint pathological mechanism, and it contributes to initiation and progression of liver injury. A lot of risk factors, including alcohol, drugs, environmental pollutants and irradiation, may induce oxidative stress in liver, which in turn results in severe liver diseases, such as alcoholic liver disease and non-alcoholic steatohepatitis. Application of antioxidants signifies a rational curative strategy to prevent and cure liver diseases involving oxidative stress. Although conclusions drawn from clinical studies remain uncertain, animal studies have revealed the promising in vivo therapeutic effect of antioxidants on liver diseases. Natural antioxidants contained in edible or medicinal plants often possess strong antioxidant and free radical scavenging abilities as well as anti-inflammatory action, which are also supposed to be the basis of other bioactivities and health benefits. In this review, PubMed was extensively searched for literature research. The keywords for searching oxidative stress were free radicals, reactive oxygen, nitrogen species, anti-oxidative therapy, Chinese medicines, natural products, antioxidants and liver diseases. The literature, including ours, with studies on oxidative stress and anti-oxidative therapy in liver diseases were the focus. Various factors that cause oxidative stress in liver and effects of antioxidants in the prevention and treatment of liver diseases were summarized, questioned, and discussed.

In the absence of endogenous IL-10, mice acutely infected with Toxoplasma gondii succumb to a lethal

Abstract: To examine the function of IL-10 synthesis during early infection with the intracellular protozoan Toxoplasma gondii, IL-10 knockout (KO) mice were inoculated with an avirulent parasite strain (ME-49). In contrast to control littermates that displayed 100% survival, the IL-10-deficient animals succumbed within the first 2 wk of the infection, with no evidence of enhanced parasite proliferation. The mortality in the IL-10 KO mice was associated with enhanced liver pathology characterized by increased cellular infiltration and intense necrosis. Levels of IL-12 and IFN-gamma in sera of infected IL-10-deficient animals were four- to sixfold higher than those in sera from control mice, as were mRNA levels for IFN-gamma, IL-1 beta, TNF-alpha, and IL-12 in lung tissue. Similarly, macrophages from IL-10 KO mice activated in vitro or in vivo with T. gondii produced higher levels of TNF-alpha and IL-12 than macrophages from control animals. Moreover, spleen cells from IL-10 KO mice infected with T. gondii secreted more IFN-gamma than splenocytes from nondeficient animals. In vitro depletion experiments indicated that CD4+ lymphocytes are the major source of the latter cytokine in the spleen cell populations, and in vivo depletion with anti-CD4 Abs protected the IL-10 KO mice from parasite-induced mortality. Together the data suggest that endogenous IL-10 synthesis plays an important role in vivo in down-regulating monokine and IFN-gamma responses to acute intracellular infection, thereby preventing host immunopathology.