Níveis elevados de catalase em mutantes SOD de S. cerevisiae em condições de alta aeração

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Antifungal activity of yacon (Smallanthus sonchifolius) extract against candida spp.

Introduction: Yacon (Smallanthus sonchifolius) is a functional food, rich in fructooligosaccharides, and has been widely used in scientific research, showing effects in reducing lipid and glycemic levels, in addition to having antibacterial, antioxidant and neuroprotective properties. The objective was to evaluate the hydroalcoholic extract of yacon leaf in Candida species. Methods: Thirty-three samples of different species of the genus Candida treated with yacon leaf extract at concentrations of 25 to 400ug/ml were analyzed using the Minimum Inhibitory Concentration method described by the M27-A3 protocol of the Clinical and Laboratory Standards Institute. Results: Among the species of C. albicans, 16 samples showed sensitivity to the extract at the concentrations used. Conclusion: Yeasts of the Candida genus are able to adapt to different environments due to their high degree of resistance to antifungal agents, making it increasingly necessary to use natural substances as alternatives for the treatment of diseases caused by fungi. The antifungal activity of yacon leaf extract against fungi of the genus Candida is being reported for the first time in this study, making yacon a new therapeutic alternative

Antioxidative properties of 14-day supplementation with Yacon leaf extract in a hypercholesterolemic rat model

Yacon leaves are rich in phenolic compounds, which have antioxidant activity. The objective of this study was to evaluate the antioxidant effects of a Yacon leaf hydroalcoholic extract in hypercholesterolemic rats. Male Wistar rats were divided into seven groups: G1: normal diet (healthy) (0.9% NaCl); G2: hypercaloric diet (control) (0.9% NaCl); G3: oral suspension of 10 mg/Kg simvastatin (SIM); G4: 20 mg/Kg Yacon extract (YE20); G5: 40 mg/Kg Yacon extract (YE40); G6: YE20 + SIM; and G7: YE40 + SIM. Lyophilized extracts were administered once daily by gavage for 14 consecutive days. The hematological, biochemical, and oxidative parameters were determined by classical methodologies. The groups that received the Yacon extract showed decreases in glucose and lipid levels. Administering the extract significantly decreased serum levels of cardiac markers and reduced inflammation. Moreover, the extract reduced oxidative damage parameters and significantly increased antioxidant defenses. These results suggest that the lyophilized Yacon extract has significant antioxidant activity, possibly due to its high content of phenolic compounds

Increased oxidative damage in carriers of the germline TP53 p.R337H mutation

Germline mutations in TP53 are the underlying defect of Li-Fraumeni Syndrome (LFS) and Li-Fraumeni-like (LFL) Syndrome, autosomal dominant disorders characterized by predisposition to multiple early onset cancers. In Brazil, a variant form of LFS/LFL is commonly detected because of the high prevalence of a founder mutation at codon 337 in TP53 (p.R337H). The p53 protein exerts multiple roles in the regulation of oxidative metabolism and cellular anti-oxidant defense systems. Herein, we analyzed the redox parameters in blood samples from p.R337H mutation carriers (C, n = 17) and non-carriers (NC, n = 17). We identified a significant increase in erythrocyte GPx activity and in plasma carbonyl content,an indicator of protein oxidative damage, in mutation carriers compared to non-carriers (P = 0.048 and P = 0.035, respectively). Mutation carriers also showed a four-fold increase in plasma malondialdehyde levels, indicating increased lipid peroxidation (NC = 40.2060.71, C = 160.560.88, P,0.0001). Finally, carriers showed increased total antioxidant status but a decrease in plasma ascorbic acid content. The observed imbalance could be associated with deregulated cell bioenergetics and/or with increased inflammatory stress, two effects that may result from loss of wild-type p53 function. These findings provide the first evidence that oxidative damage occurs in carriers of a germline TP53 mutation, and these may have important implications regarding our understanding of the mechanisms responsible for germline TP53 p.R337H mutation-associated carcinogenesis

Globotriaosylceramide is correlated with oxidative stress and inflammation in Fabry patients treated with enzyme replacement therapy

AbstractFabry disease is an X-linked inborn error of glycosphingolipid catabolism due to deficient activity of α-galactosidase A that leads to accumulation of the enzyme substrates, mainly globotriaosylceramide (Gb3), in body fluids and lysosomes of many cell types. Some pathophysiology hypotheses are intimately linked to reactive species production and inflammation, but until this moment there is no in vivo study about it. Hence, the aim of this study was to investigate oxidative stress parameters, pro-inflammatory cytokines and Gb3 levels in Fabry patients under treatment with enzyme replacement therapy (ERT) and finally to establish a possible relation between them. We analyzed urine and blood samples of patients under ERT (n=14) and healthy age-matched controls (n=14). Patients presented decreased levels of antioxidant defenses, assessed by reduced glutathione (GSH), glutathione peroxidase (GPx) activity and increased superoxide dismutase/catalase (SOD/CAT) ratio in erythrocytes. Concerning to the damage to biomolecules (lipids and proteins), we found that plasma levels of malondialdehyde (MDA) and protein carbonyl groups and di-tyrosine (di-Tyr) in urine were increased in patients. The pro-inflammatory cytokines IL-6 and TNF-α were also increased in patients. Urinary Gb3 levels were positively correlated with the plasma levels of IL-6, carbonyl groups and MDA. IL-6 levels were directly correlated with di-Tyr and inversely correlated with GPx activity. This data suggest that pro-inflammatory and pro-oxidant states occur, are correlated and seem to be induced by Gb3 in Fabry patients

Preliminary in vitro assessment of the potential toxicity and antioxidant activity of Ceiba speciosa (A. St.-Hill) Ravenna (Paineira)

The bark tea of Ceiba speciosa, a tropical tree of the Malvaceae family, is used in the Northwestern Region of Rio Grande do Sul state, Brazil, to reduce blood cholesterol levels. However, there are no scientific data on the efficacy and safety of this plant. The aim of the present study was to evaluate the in vitro antioxidant and toxic potential of bark extracts of C. speciosa. We performed a preliminary phytochemical analysis by high-performance liquid chromatography-diode array detection (HPLC-DAD) and evaluated the oxidative damage to proteins and lipids, the radical scavenging effect, and genotoxicity of the lyophilized aqueous extract (LAECs) and the precipitate obtained from the raw ethanol extract (Cs1). The phytochemical profile demonstrated the presence of phenolic and flavonoid compounds. The LAECs and Cs1 prevented damage to lipids and proteins at concentrations of 50 and 10 µg/mL. They also showed a scavenging effect on 2,2-diphenyl-1-pricril-hydrazyl (DPPH) radicals in a concentration-dependent manner. Furthermore, no genotoxic effect was observed at concentrations of 10, 5 and 2 µg/mL in the Comet assay. The present study is the first evaluation regarding the characterization of C. speciosa and its safety, and the results demonstrate its antioxidant potential and suggest that its therapeutic use may be relatively safe