Browsing by Author "Cabalin, Carolina"

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    Analysis of Carotenoids in Haloarchaea Species from Atacama Saline Lakes by High Resolution UHPLC-Q-Orbitrap-Mass Spectrometry: Antioxidant Potential and Biological Effect on Cell Viability
    (2021) Cabalin, Carolina
    Haloarchaea are extreme halophilic microorganisms belonging to the domain Archaea, phylum Euryarchaeota, and are producers of interesting antioxidant carotenoid compounds. In this study, four new strains of Haloarcula sp., isolated from saline lakes of the Atacama Desert, are reported and studied by high-resolution mass spectrometry (UHPLC-Q-Orbitrap-MS/MS) for the first time. In addition, determination of the carotenoid pigment profile from the new strains of Haloarcula sp., plus two strains of Halorubrum tebenquichense, and their antioxidant activity by means of several methods is reported. The effect of biomass on cellular viability in skin cell lines was also evaluated by MTT assay. The cholinesterase inhibition capacity of six haloarchaea (Haloarcula sp. ALT-23; Haloarcula sp. TeSe-41; Haloarcula sp. TeSe-51; Haloarcula sp. Te Se-89 and Halorubrum tebenquichense strains TeSe-85 and Te Se-86) is also reported for the first time. AChE inhibition IC50 was 2.96 +/- 0.08 mu g/mL and BuChE inhibition IC50 was 2.39 +/- 0.09 mu g/mL for the most active strain, Halorubrum tebenquichense Te Se-85, respectively, which is more active in BuCHe than that of the standard galantamine. Docking calculation showed that carotenoids can exert their inhibitory activity fitting into the enzyme pocket by their halves, in the presence of cholinesterase dimers.
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    Involvement of A2B adenosine receptors as anti-inflammatory in gestational diabesity.
    (2019) Cabalin, Carolina
    Pregnant women that are obese may develop gestational diabetes mellitus (GDM) configuring a new metabolic condition referred to as gestational diabesity. The metabolic alterations seen in gestational diabesity include a combination of an exacerbated pro-inflammatory state and fetoplacental endothelial dysfunction. Also, gestational diabesity associates with supra-physiological extracellular concentration of adenosine in the foetoplacental blood. Since adenosine plays a central role in the inflammatory response in GDM and obesity, it is likely that this nucleoside will play a similar role in gestational diabesity. However, the effect of adenosine in the foetoplacental vasculature in this condition is not yet addressed. Adenosine exerts its biological actions via four adenosine receptors. Activation of A(2B) adenosine receptors (A(2B)AR) subtype associates with an anti-inflammatory response in several tissue and diseases. In tissues from pregnant women with GDM, there is an overexpression of A(2B)AR, and higher mRNA expression of ADORA2B (for A(2B)AR) was shown to correlate with hyperglycaemia and oxidative stress. A(2B)AR shows low affinity for adenosine (micromolar) and its activation results in triggering intracellular signalling cascades lowering the inflammatory response. This phenomenon requires a high level of extracellular adenosine in diseases of pregnancy such as GDM or gestational diabesity. In this review, we focused on the role of A(2B)AR involvement in the biological actions of adenosine on inflammation in the foetoplacental vasculature in gestational diabesity. Some factors including oxidative stress and hypoxia in this phenomenon are discussed.
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    Vitamin D status and supplementation in Antarctica: a systematic review and meta- analysis
    (2021) Cabalin, Carolina; Iturriaga, Carolina; Perez Mateluna, Guillermo; Echeverria, Denise; Camargo Jr, Carlos A.; Borzutzky Schachter, Arturo
    Living at high latitudes is associated with vitamin D (VD) deficiency. An ideal setting to study this is the Antarctic continent, which has temporary inhabitants, but the magnitude of the effect of living in Antarctica and the effects of VD supplementation on this population remain unclear. We performed a systematic review and meta-analysis to assess the effect of temporary residence in Antarctica and impact of VD supplementation on VD status of this population. Random-effects meta-analyses were performed to assess serum 25-hydroxyvitamin D (25(OH)D) concentration changes after Antarctic residence (13 studies, 294 subjects) and after VD supplementation (5 studies, 213 subjects). Serum 25(OH)D mean difference after temporary residence in Antarctica was -15.0 nmol/L (95%CI: -25.9, -4.2; I-2=92%). Subgroup meta-analyses of studies evaluating Antarctic summer and winter stays showed 25(OH)D only decreases when overwintering (winter 25(OH)D change -17.0 nmol/L [95%CI: -24.1, -9.8; I-2=83%] vs. summer 25(OH)D change 1.3 nmol/L [95%CI: -14.6, 17.1; I-2=86%]). The meta-analysis of VD supplementation studies in Antarctica showed a mean 25(OH)D increase after supplementation of 10.8 nmol/L (95%CI: 3.3, 18.3; I-2=88%). In conclusion, VD status significantly worsens after inhabiting Antarctica, particularly when over-wintering. VD supplementation can prevent worsening of VD status and should be considered in this population.