Simulated Dynamical Weakening and Abelian Avalanches in Mean-Field Driven Threshold Models

Mean-field coupled lattice maps are used to approximate the physics of driven threshold systems with long range interactions. However, they are incapable of modeling specific features of the dynamic instability responsible for generating avalanches. Here we present a method of simulating specific frictional weakening effects in a mean field slider block model. This provides a means of exploring dynamical effects previously inaccessible to discrete time simulations. This formulation also results in Abelian avalanches, where rupture propagation is independent of the failure sequence. The resulting event size distribution is shown to be generated by the boundary crossings of a stochastic process. This is applied to typical models to explain some commonly observed features.Comment: 27 pages, 9 figure

Yerba mate aqueous extract improves the oxidative and inflammatory states of rats with adjuvant-induced arthritis

Healthy and adjuvant-induced arthritic rats were treated for 23 days with daily doses of 400 and 800 mg kg−1 Ilex paraguariensis extract. This treatment (a) diminished the ROS levels in the liver and brain, (b) decreased oxidative protein and lipid damage in liver and brain, (c) increased the plasma antioxidant capacity, (d) increased the GSH levels and the GSH/GSSH ratio in both the liver and the brain, (e) almost restored the enzymatic activities linked to the metabolism of GSH–GSSG, and (f ) reversed the modified activities of xanthine oxidase, superoxide dismutase and catalase. The anti-inflammatory actions (firstly) and the antioxidant actions (in the second place) of the yerba mate constituents (e.g., chlorogenic acid derivatives) are the causes of these beneficial effects. Daily ingestion of traditional yerba mate beverages may be effective in attenuating the symptoms of inflammatory diseases, especially in older adults.This work was financially supported by grants from the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq-307944/2015-8), Coordenação do Aperfeiçoamento de Pessoal do Ensino Superior (CAPES) and Fundação Araucária. The authors are also indebted to Jailson Araújo Dantas for his technical assistance and to Dr Ciomar A. B. Amado for facilitating access to equipment of the Pharmacology and Therapeutics Department of the State University of Maringá. The authors are also grateful to the Foundation for Science and Technology (FCT, Portugal) and FEDER under Programme PT2020 for financial support to CIMO (UID/AGR/00690/2013) and L. Barros contract.info:eu-repo/semantics/publishedVersio

Chestnut and lemon balm based ingredients as natural preserving agents of the nutritional profile in matured “Serra da Estrela” cheese

Chestnut flowers, lemon balm plants and their decoctions were incorporated into "Serra da Estrela" cheese, to assess their potential to preserve its nutritional properties and provide new foodstuffs. The analyses were carried out after the normal ripening period of 1month and after 6months of storage. The most abundant nutrients were proteins and fats. The most abundant minerals were Ca and Na, while C16:0 and C18:1 were the main fatty acids. Saturated fatty acids were the most abundant, followed by the monounsaturated. Moisture seemed to be lower in the samples with the plants incorporated. The dried plants, when incorporated, seemed to be more efficient as preservers then the decoctions, although these better preserved the proteins. These plants can be regarded as promising natural preservers in foodstuffs cheese, given the preservation of key parameters and the slight impact on the nutritional value.The authors are grateful to Queijos Casa Matias, Lda and Mais Ervas, Lda. For providing the cheese and M. officinalis samples, respectively. The authors also acknowledge PRODER project No. 46577-PlantLact, the Foundation for Science and Technology (FCT, Portugal) for financial support to the CIMO research centre (Pest-OE/AGR/UI0690/2014) and ALIMNOVA research group (UCM-951505/2012), J.C.M. Barreira acknowledges the FCT for his post-doctoral grant (BPD/72802/2010)

Effects of in vitro digestion and in vitro colonic fermentation on stability and functional properties of yerba mate (Ilex paraguariensis A. St. Hil.) beverages

Yerba mate (Ilex paraguariensis) is a plant that grows naturally in South America. From its leaves and thin stems different kinds of beverages are prepared (chimarrão, tererê and tea mate), all of them rich in bioactive substances. The aim of this study was to evaluate the influence of in vitro gastrointestinal digestion and colonic fermentation on the stability of the polyphenols and on the antioxidant, antimicrobial and antitumoral activities of the yerba mate beverages. The phenolic chromatographic profile revealed that both the in vitro digestion and the colonic fermentation caused a pronounced decrease in 3,5-O-dicaffeoylquinic acid and 5-O-caffeoylquinic acid in the preparations. However, 3-O-caffeoylquinic acid, 4-O-caffeoylquinic acid and salvianolic acid I were only barely affected in all preparations. Despite the decrease in the phytochemicals content, yerba mate beverages maintain their functional properties such as antioxidant, antibacterial and antitumoral activities.The authors thank the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq, Proc. 3079/2015-8) and Fundação Araucária (Proc.24/2012) for funding this study. Authors V.G. Correa and G.A. Gonçalves thanks Coordenação de Aperfeiçoamento do Pessoal do Ensino Superior (CAPES) for the financial support provided for their post-graduate studies in Universidade Estadual de Maringá. A. Bracht, and R.M. Peralta research grant recipients of CNPq. The authors are also thankful to the Foundation for Science and Technology (FCT, Portugal) and FEDER under Program PT2020 for financial support to CIMO (UID/AGR/00690/2013), L. Barros (SFRH/BPD/107855/2015) and M.I. Dias (SFRH/BD/84485/2012) grant. To POCI-01-0145-FEDER-006984 (LA LSRE-LCM), funded by ERDF, through POCI-COMPETE2020 and FCT.info:eu-repo/semantics/publishedVersio

The inhibitory action of purple tea on in vivo starch digestion compared to other Camellia sinensis teas

In order to contribute to improve knowledge about the actions of Camellia sinensis extracts on starch digestion, several varieties were compared. The latter were green, oolong, white, black, and purple teas. The results are hoped to contribute to our understanding of the mode of action and potency of the various tea preparations as possible adjuvants in the control of post-prandial glycemia. The extracts were prepared in way similar to their form of consumption. All extracts decreased starch digestion, but the purple tea extract was the strongest inhibitor, their inhibitory tendency started at the dose of 50 mg/kg and was already maximal with 250 mg/kg. Maltose tolerance was not significantly affected by the extracts. Glucose tolerance was not affected by purple tea, but black tea clearly diminished it; green tea presented the same tendency. Purple tea was also the strongest inhibitor of pancreatic α-amylase, followed by black tea. The green tea, oolong tea, and white tea extracts tended to stimulate the pancreatic α-amylase at low concentrations, a phenomenon that could be counterbalancing its inhibitory effect on starch digestion. Based on chemical analyses and molecular docking simulations it was concluded that for both purple and black tea extracts the most abundant active component, epigallocatechin gallate, seems also to be the main responsible for the inhibition of the pancreatic α-amylase and starch digestion. In the case of purple tea, the inhibitory activity is likely to be complemented by its content in deoxyhexosidehexoside- containing polyphenolics, especially the kaempferol and myricetin derivatives. Polysaccharides are also contributing to some extent. Cyanidins, the compounds giving to purple tea its characteristic color, seem not to be the main responsible for its effects on starch digestion. It can be concluded that in terms of postprandial anti-hyperglycemic action purple tea presents the best perspectives among all the tea varieties tested in the present study.This work was financially supported by grants from the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq-304090/ 2016-6), Coordenação do Aperfeiçoamento de Pessoal do Ensino Superior (CAPES) and Fundação Araucária (53/2019). The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support through national funds FCT/MCTES to CIMO (UIDB/00690/2020) and through the institutional scientific employment program-contract for L. Barros and M.I. Dias contracts. This work was also funded by the European Regional Development Fund (ERDF) through the Regional Operational Program North 2020, within the scope of Project Mobilizador ValorNatural®: Norte-01-0247-FEDER-024479 and GreenHealth: Norte-01-0145-FEDER-000042.info:eu-repo/semantics/publishedVersio

Effects of a Myrciaria jaboticaba peel extract on starch and triglyceride absorption and the role of cyanidin-3- O -glucoside

The purpose of this study was to perform a parallel and comparative investigation of the effects of a Myrciaria jaboticaba (common name jabuticaba) peel extract and of its constituent cyanidin-3-O-glucoside on the overall process of starch and triglyceride intestinal absorption. The peel extract inhibited both the porcine pancreactic α-amylase and the pancreatic lipase but was 13.6 times more potent on the latter (IC50 values of 1963 and 143.9 μg mL-1, respectively). Cyanidin-3-O-glucoside did not contribute significantly to these inhibitions. The jabuticaba peel extract inhibited starch absorption in mice at doses that were compatible with its inhibitory action on the α-amylase. No inhibition of starch absorption was found with cyanidin-3-O-glucoside doses compatible with its content in the extract. The extract also inhibited triglyceride absorption, but at doses that were considerably smaller than those predicted by its strength in inhibiting the pancreatic lipase (ID50 = 3.65 mg kg-1). In this case, cyanidin-3-O-glucoside was also strongly inhibitory, with 72% inhibition at the dose of 2 mg kg-1. When oleate + glycerol were given to mice, both the peel extract and cyanidin-3-O-glucoside strongly inhibited the appearance of triglycerides in the plasma. The main mechanism seems, thus, not to be the lipase inhibition but rather the inhibition of one or more steps (e.g., transport) in the events that lead to the transformation of free fatty acids in the intestinal tract into triglycerides. Due to the low active doses, the jabuticaba peel extract presents many favourable perspectives as an inhibitor of fat absorption and cyanidin-3-O-glucoside seems to play a decisive role. This journal is.This work was financially supported by grants from the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq-304090/2016-6) and Coordenação do Aperfeiçoamento de Pessoal do Ensino Superior (CAPES). The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support through national funds FCT/MCTES to CIMO (UIDB/00690/2020) and through the institutional scientific employment program-contract for L. Barros contract. This work was also funded by the European Regional Development Fund (ERDF) through the Regional Operational Program North 2020, within the scope of Project Mobilizador Norte-01-0247-FEDER-024479: ValorNatural®.info:eu-repo/semantics/publishedVersio

Potential anti-diabetic properties of Merlot grape pomace extract: an in vitro, in silico and in vivo study of α-amylase and α-glucosidase inhibition

A practical approach to control glycemia in diabetes is to use plant natural products that delay hydrolysis of complex sugars and promote the diminution of the release of glucosyl units into the blood plasma. Polyphenolics have been described as being effective in inhibiting amylases and α-glucosidases. Grape pomace is an important sub product of the wine industry, still rich in many compounds such as polyphenolics. In this context, the purpose of this study was to search for possible effects of a grape pomace extract on salivary and pancreatic α-amylases and α-glucosidase, as well as on intestinal glucose absorption. The Merlot grape pomace extract (MGPE) was prepared using a hydroalcoholic mixture (40% ethanol + 60% water). In vitro inhibition was quantified using potato starch (for amylases) and maltose (for α-glucosidase) as substrates. In vivo inhibition was evaluated by running starch and maltose tolerance tests in rats with or without administration of MGPE. Ranking of the extract compounds for its affinity to the α-amylases was accomplished by computer simulations using three different programs. Both α-amylases, pancreatic and salivary, were inhibited by the MGPE. No inhibition on α-glucosidase, however, was detected. The IC50 values were 90 ± 10 μg/mL and 143 ± 15 μg/mL for salivary and pancreatic amylases, respectively. Kinetically this inhibition showed a complex pattern, with multiple binding of the extract constituents to the enzymes. Furthermore, the in silico docking simulations indicated that several phenolic substances, e.g., peonidin-3-O-acetylglucoside, quercetin-3-O-glucuronide and isorhamnetin-3-O-glucoside, besides catechin, were the most likely polyphenols responsible for the α-amylase inhibition caused by MGPE. The hyperglycemic burst, an usual phenomenon that follows starch administration, was substantially inhibited by the MGPE. Our results suggest that the MGPE can be adequate for maintaining normal blood levels after food ingestion.The authors wish to thank to the Fundação Araucária (Brazil), Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES, Brazil), Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq, Brazil), Cesumar Institute of Science Technology and Innovation (ICETI, Brazil), and FEDER-Interreg España-Portugal for their financial help.info:eu-repo/semantics/publishedVersio

Glutamine dipeptide supplementation improves clinical responses in patients with diabetic foot syndrome

The effect of glutamine dipeptide (GDP) supplementation in patients with diabetic foot syndrome was evaluated. A total of 22 patients took part in the study. GDP was supplied in 10 g sachets, and was dissolved in water immediately before use, with ingestion once a day, after lunch or after dinner (20 g/day) over a period of 30 days. Quantification of foot insensitive areas, oxidative stress, blood cytokines, and biochemical, hematological and toxicological parameters was performed before and after GDP supplementation. We observed an increase in blood levels of interferon-α (P=0.023), interferon-γ (P=0.038), interleukin-4 (P=0.003), interleukin-6 (P=0.0025), interleukin-7 (P=0.028), interleukin-12 p40 (P=0.017), interleukin-13 (P=0.001), leukocytes (P=0.037), eosinophils (P=0.049), and typical lymphocytes (