Antioxidant activity of chitooligosaccharides upon two biological systems: erythrocytes and bacteriophages

Most of the reports to date on the antioxidant capacity of chitosans and chitooligosaccharides (COS) are based on strictly chemical methods. When studying antioxidants with potential in vivo applications, the method used to evaluate the antioxidant activity should be representative of the conditions in which the antioxidant might have a protective effect. In this work we evaluate the antioxidant activity of two COS mixtures and a low MW chitosan (LMWC) upon two biological oxidizable substrates – erythrocytes and phages, subjected to accelerated oxidation conditions. Our results suggest that COS/LMWC can be used as antioxidants in biological systems. All the tested compounds reduced either the hemolytic and DNA damage, by inhibiting H2O2- and AAPH-radicals. However, the results obtained for these biological assays did not reveal a dose dependence, contrary to the chemical assay, suggesting that the protective concentrations should be established, in order to prevent enhancement of the oxidative damage – i.e. a prooxidant effect.info:eu-repo/semantics/acceptedVersio

Synthesis, Solubility, Permeability, and In Vitro Activity against Mycobacterium tuberculosis

Funding Information: This work was supported by FCT-MCTES (PTDC/QUI-QOR/32406/2017, PEst-C/LA0006/2013, RECI/BBBBQB/0230/2012) and by the Associate Laboratory for Green Chemistry-LAQV (FCT-MCTES UIDB/50006/2020 and UIDP/50006/2020). The NMR spectrometers are part of the National NMR Network (PTNMR) and are partially supported by Infrastructure Project N° 022161 (co-financed by FEDER through COMPETE 2020, POCI, PORL, and FCT through PIDDAC). Publisher Copyright: © 2022 by the authors.The development of novel pharmaceutical tools to efficiently tackle tuberculosis is the order of the day due to the rapid development of resistant strains of Mycobacterium tuberculosis. Herein, we report novel potential formulations of a repurposed drug, the antimalarial mefloquine (MFL), which was combined with organic anions as chemical adjuvants. Eight mefloquine organic salts were obtained by ion metathesis reaction between mefloquine hydrochloride ([MFLH][Cl]) and several organic acid sodium salts in high yields. One of the salts, mefloquine mesylate ([MFLH][MsO]), presented increased water solubility in comparison with [MFLH][Cl]. Moreover, all salts with the exception of mefloquine docusate ([MFLH][AOT]) showed improved permeability and diffusion through synthetic membranes. Finally, in vitro activity studies against Mycobacterium tuberculosis revealed that these ionic formulations exhibited up to 1.5-times lower MIC values when compared with [MFLH][Cl], particularly mefloquine camphorsulfonates ([MFLH][(1R)-CSA], [MFLH][(1S)-CSA]) and mefloquine HEPES ([MFLH][HEPES]).publishersversionpublishe

Histological evidence of wound healing improvement in rats treated with oral administration of hydroalcoholic extract of Vitis labrusca

Plant extracts rich in phenolic compounds have been demonstrated to accelerate wound healing, but their use by oral route has been poorly studied. The leaves of Vitis labrusca are rich in phenolic acids and flavonoids. The goal of this study was to assess the healing properties of the oral administration of hydroalcoholic extract of V. labrusca leaves (HEVL) in a murine model. HEVL was obtained by Soxhlet and dynamic maceration, and their yield and phenolic acids and flavonoid contents were determined. For the wound healing assay, 8 mm wounds were performed on the back of 48 Wistar rats, assigned into four groups (n=12): CTR (distilled water), HEVL100, HEVL200, and HEVL300 (HEVL at 100, 200, and 300 mg/kg, respectively). On days 7 and 14, wound closure rates were assessed, and the healing wounds were subjected to histological analysis. Soxhlet-obtained extract was selected for the wound healing assay because it provided a higher yield and phenolic acid and flavonoid contents. HEVL significantly reduced leukocytosis in the peripheral blood (p < 0.05), accelerated wound closure (p < 0.05), and improved collagenization (p < 0.05) on day 7, as well as enhanced the epidermal tissue thickness (p < 0.001) and elastic fiber deposition on day 14 (p < 0.01). Furthermore, HEVL promoted an increase in the histological grading of wound healing on both days 7 and 14 (p < 0.01). The doses of 200 and 300 mg/kg provided better results than 100 mg/Kg. Our data provide histological evidence that the oral administration of HEVL improves wound healing in rodents. Therefore, the extract can be a potential oral medicine for healing purposes.Brazilian Council for Research Support (CNPq) and the Foundation of research and technological innovation of Sergipe/Brazil (FAPITEC), and by the Portuguese Science and Technology Foundation (FCT/MCT), European Funds (PRODER/COMPETE)– project UIDB/04469/2020 (strategic fund), co-financed by FEDER, under the Partnership Agreement PT2020info:eu-repo/semantics/publishedVersio

Ageing in the critical contact process: a Monte Carlo study

The long-time dynamics of the critical contact process which is brought suddenly out of an uncorrelated initial state undergoes ageing in close analogy with quenched magnetic systems. In particular, we show through Monte Carlo simulations in one and two dimensions and through mean-field theory that time-translation invariance is broken and that dynamical scaling holds. We find that the autocorrelation and autoresponse exponents lambda_{Gamma} and lambda_R are equal but, in contrast to systems relaxing to equilibrium, the ageing exponents a and b are distinct. A recent proposal to define a non-equilibrium temperature through the short-time limit of the fluctuation-dissipation ratio is therefore not applicable.Comment: 18 pages, 7 figures, Latex2e with IOP macros; final for

Estudio de la estructura interna de los cúmulos del Survey VISCACHA

El analisis de la estructura interna de los cúmulos estelares nos puede brindar informacion importante acerca de la formación y evolución dinámica de los mismos. Utilizando los datos del Survey VISCACHA se realizo el estudio de la distribución espacial de estrellas en 83 cúmulos pertenecientes a las periferias de La Nube Menor y de la Nube Mayor de Magallanes. A través de la construcción del minimum spanning tree, se pudo caracterizar la estructura interna de cada cumulo, obteniéndose los parámetros m, s y Q, los cuales son útiles para distinguir entre distribuciones de puntos radiales, homogéneas o con subestructuras. También se investigo la dependencia de estos parámetros con las distintas características de los cúmulos, como son sus edades y distribución espacial.The analysis of the internal structure of star clusters can provide us important information abouttheir formation and dynamic evolution. Using data from the VISCACHA Survey, we studied the stars spatialdistribution in 83 clusters belonging to the peripheries of the Large Magellanic Cloud and the Small MagellanicCloud. Through the construction of the minimum spanning tree, it was possible to characterize the internalstructure of each cluster, obtaining the parameters m, s and Q, which are useful for distinguishing betweenradial, homogeneous or substructured distributions. The dependence of these parameters with the differentcharacteristics of the clusters, such as their ages and spatial distribution, was also investigated.Fil: Rodriguez, Maria Jimena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Dias, Bruno. Universidad de Tarapacá; ChileFil: Maia, F. S. M.. Universidade Federal do Rio de Janeiro; BrasilFil: Feinstein Baigorri, Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Baume, Gustavo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Kerber, L.. No especifíca;Fil: dos Santos, J. F. C.. No especifíca;63° Reunión Anual de la Asociación Argentina de AstronomíaCordobaArgentinaAsociación Argentina de Astronomí

Reversal of diabetic-induced myopathy by swimming exercise in pregnant rats:a translational intervention study

Gestational diabetes mellitus (GDM) plus rectus abdominis muscle (RAM) myopathy predicts long-term urinary incontinence (UI). Atrophic and stiff RAM are characteristics of diabetes-induced myopathy (DiM) in pregnant rats. This study aimed to determine whether swimming exercise (SE) has a therapeutic effect in mild hyperglycemic pregnant rats model. We hypothesized that SE training might help to reverse RAM DiM. Mild hyperglycemic pregnant rats model was obtained by a unique subcutaneous injection of 100 mg/kg streptozotocin (diabetic group) or citrate buffer (non-diabetic group) on the first day of life in Wistar female newborns. At 90 days of life, the rats are mated and randomly allocated to remain sedentary or subjected to a SE protocol. The SE protocol started at gestational day 0 and consisted of 60 min/day for 6 days/week in a period of 20 days in a swim tunnel. On day 21, rats were sacrificed, and RAM was collected and studied by picrosirius red, immunohistochemistry, and transmission electron microscopy. The SE protocol increased the fiber area and diameter, and the slow-twitch and fast-twitch fiber area and diameter in the diabetic exercised group, a finding was also seen in control sedentary animals. There was a decreased type I collagen but not type III collagen area and showed a similar type I/type III ratio compared with the control sedentary group. In conclusion, SE during pregnancy reversed the RAM DiM in pregnant rats. These findings may be a potential protocol to consider in patients with RAM damage caused by GDM