Green tea as a promising extract of active food packaging

Introduction: Tea is one of the most popular and frequently consumed beverages in the world and its consumption dates back to more than 2000 years in China and then spread to other areas including Japan and later on to Europe (Zhao et al., 2014). Green tea is produced from Camellia sinensis (L.) Kuntze leaf infusion and is well known for its pleasant flavour and is associated with positive health effects. The biological activity of green tea is related with the considerable amount of catechins and other phenolic compounds, in particular flavonols and phenolic acids, present in its composition (Zhao et al., 2014). These phenolic compounds prevent the oxidative damage through their antioxidant activity and also reduce the risk of cancer, cardiovascular and neurodegenerative diseases (Lorenzo et al., 2014). The process of oxidation is one of the most common mechanisms of degradation of foodstuffs and it can alter food texture and colour, decrease nutritional quality, develop off-odours and also produce possible toxic compounds. As a consequence, the shelf-life and commercial acceptability of the food products decrease. Currently, one of the major concerns of the consumers is the impact of food on health. In line with this, food industry is trying to substitute synthetic additives by natural compounds. These can be directly added to food or incorporated in food packaging with the aim of being controlled released throughout the product shelf life. This concept is so-called Active packaging and allows the packaging to positively interact with foods to increase food shelf-life. This interaction can be due to the intended release of compounds from packaging to the foods or to their headspace, or due to the scavenging of compounds by the packaging from the packaged foods. Due to the antioxidant capacity of green tea, its extract can be proposed as an alternative to synthetic antioxidants (Giménez et al., 2013). In fact, it has already been applied in active food packaging. Material and Methods: The present review focuses on the application of green tea extract in active packaging. In this regard, an extensive bibliographic research was carried out in order to evaluate the polymers already used to incorporate green tea extract, as well as the mechanical and barrier properties and efficiency of these packaging systems in contact with foods. Results and Discussion: The chemical composition of tea leaves on active compounds with antioxidant activity is well documented. Bioactive constituents of the tea leaves include catechin gallates such as epigallocatechin gallate and gallocatechin gallate (López de Dicastillo et al., 2011). However the levels of these compounds depend on many factors, such as the edaphoclimatic conditions and drying conditions of the Camellia sinensis leaves. Moreover the extraction and analysis methods can also have a great influence in their content. Green tea extract has already been incorporated into different polymers. In fact, most of them are edible such as proteic films from distilled dry beans (Yang et al., 2016), agar (Lacey et al., 2014), chitosan (Siripatrawan et al., 2012; Siripatrawan et al., 2010) and gelatine (Hong et al (2009). Green tea extract (GTE) can offers protection against oxidation, significantly reducing rancidity and thereby extending the shelf-life of packaged foods. Moreover the sensory analysis also demonstrated that packaged food was unaffected by GTE (Carrizo et al., 2016). According to Yang et al. (2016), the incorporation of the GTE did not alter the physical properties of the films. According to Siripatrawan et al. (2010), the incorporation of GTE improved the mechanical and water vapour barrier properties. In general, GTE provides a very positive impact in the reduction of oxidation of all types of food, from aqueous to fatty (López de Dicastillo et al., 2011), although most of the studies selected meat (e.g. pork, pork sausages, pork loins), or fish products (e.g. fillets of hake, salted sardines) to test the efficiency of the active films. Conclusion: Green tea has great potential of application in active food packaging due to its antioxidant capacity. Therefore, in the near future, is it possible that new food packaging based on GTE will arise in the market. However, more studies are require to elucidate about the concentrations of GTE that do not affect or affect positively the mechanical or barrier properties of the packaging and that are effective as oxidation inhibitors of packaged foodsThis work was supported by the research project “Development of methodologies for the evaluation of polymeric food packaging components and determination of their structural and mechanical properties” (2016DAN 1289) funded by the National Institute of Health Dr Ricardo Jorge, I.P., Lisbon, Portugal.N/

Filme ativo com extrato de chá verde: eficácia contra a oxidação lipídica

As embalagens ativas têm como objetivo proteger e prolongar a vida útil dos alimentos, aumentando a sua qualidade, segurança e integridade. Na industria alimentar, este conceito de embalagem ativa foi aplicado como forma de controlar o fenomeno da oxidacao lipidica em alimentos com alto teor de gordura, sendo que esta e uma das principais causas de perda de qualidade destes alimentos. A composição química do chá verde tem revelado um grande interesse no que diz respeito a prevenção da oxidação lipídica. Na sua constituição, as folhas de chá verde possuem um teor elevado de compostos fenólicos, que tem sido associados a sua atividade antioxidante. Devido às suas propriedades, o chá verde e considerado um ótimo agente antioxidante natural. O poli (acido láctico) ou ácido poliláctico (PLA) e um polímero alifático cujo monómero e derivado de recursos renováveis, como amido de milho, raízes de tapioca e cana de açúcar. O polímero e formado através da fermentação de amido e condensação de ácido láctico. No presente estudo, fatias de salmão fumado foram embaladas com um filme de PLA, com extrato de chá verde incorporado em diferentes concentrações, 1% e 2%, e, posteriormente, armazenadas durante 7, 15, 30, 45 e 60 dias, em refrigeração. Um filme de PLA sem o extrato de chá verde foi usado como controlo. Para avaliar a eficácia do filme ativo contra a oxidação lipídica, utilizou-se o teste de Substancias Reativas ao Ácido Tiobarbiturico (TBARS). Este ensaio mede o conteudo de malonaldeido (MDA) que e formado durante a oxidação lipídica pela decomposição dos ácidos gordos polinsaturados em hidroperoxidos. Os resultados foram expressos em mg de MDA por kg de salmão fumado. Os resultados mostraram que as fatias de salmão fumado embaladas com o filme de PLA/chá verde apresentaram menor teor de MDA do que aquelas embaladas com o filme controlo. As fatias de salmão fumado embaladas com o PLA/chá verde2% apresentaram menor quantidade de MDA em todos os momentos de contacto, exceto apos 15 dias, onde se verificou menor teor de MDA nas fatias de salmão embaladas com o filme ativo com 1% de extrato de chá verde. Estes resultados mostraram que a incorporação do extrato de chá verde no PLA protege o salmão fumado da oxidação lipídica. Contudo, devem ser realizados estudos adicionais para confirmar a inibição da oxidação lipídica, como o índice de peróxido, o valor de p-anisidina e a determinação do hexanal.Este trabalho foi financiado pelo projeto de investigação “Development of methodologies for the evaluation of polymeric food packaging components and determination of their structural and mechanical properties (2016DAN 1289)” financiado pelo Instituto Nacional de Saúde Doutor Ricardo Jorge (INSA, I.P.). Mariana Andrade agradece a bolsa de investigação (2016/iFILM/BM) no âmbito do projeto iFILM.N/

Development of a new application of the comet assay to assess levels of O6-methylguanine in genomic DNA (CoMeth)

O6-methylguanine (O6meG) is one of the most premutagenic, precarcinogenic, and precytotoxic DNA lesions formed by alkylating agents. Repair of this DNA damage is achieved by the protein MGMT, which transfers the alkyl groups from the O6 position of guanine to a cysteine residue in its active center. Because O6meG repair by MGMT is a stoichiometric reaction that irreversibly inactivates MGMT, which is subsequently degraded, the repair capacity of O6meG lesions is dependent on existing active MGMT molecules. In the absence of active MGMT, O6meG is not repaired, and during replication, O6meG:T mispairs are formed. The MMR system recognizes these mispairs and introduces a gap into the strand. If O6meG remains in one of the template strands the futile MMR repair process will be repeated, generating more strand breaks (SBs). The toxicity of O6meG is, therefore, dependent on MMR and DNA SB induction of cell death. MGMT, on the other hand, protects against O6meG toxicity by removing the methyl residue from the guanine. Although removal of O6meG makes MGMT an important anticarcinogenic mechanism of DNA repair, its activity significantly decreases the efficacy of cancer chemotherapeutic drugs that aim at achieving cell death through the action of the MMR system on unrepaired O6meG lesions. Here, we report on a modification of the comet assay (CoMeth) that allows the qualitative assessment of O6meG lesions after their conversion to strand breaks in proliferating MMR-proficient cells after MGMT inhibition. This functional assay allows the testing of compounds with effects on O6meG levels, as well as on MGMT or MMR activity, in a proliferating cell system. The expression of MGMT and MMR genes is often altered by promoter methylation, and new epigenetically active compounds are being designed to increase chemotherapeutic efficacy. The CoMeth assay allows the testing of compounds with effects on O6meG, MGMT, or MMR activity. This proliferating cell system complements other methodologies that look at effects on these parameters individually through analytical chemistry or in vitro assays with recombinant proteins.We thank the COST Action TD0905 “Epigenetics: From Bench to Bedside” for financial support. A.A. Ramos and D. Pedro are supported by the Foundation for Science and Technology, Portugal, Grant SFRH/BD/35672/2007 and SFRH/BD/64817/2009, respectively. The work was supported by FCT research grant PEst-C/BIA/UI4050/2011, which is co-funded by the program COMPETE from QREN with co-participation from the European Community fund FEDER

Compostos fenólicos totais de extratos de Fucus vesiculosus e Gracilaria sp.: potencial aplicação a embalagens alimentares

Os compostos fenólicos encontram-se presentes na grande maioria do mundo vegetal, fazendo parte do metabolismo secundário das plantas e contribuindo para a defesa destas contra a radiação ou organismos patogénicos, parasitas e predadores. Encontrando-se distribuídos por todas as frações das plantas, estes compostos são ainda responsáveis pela coloração e propriedades organoléticas das mesmas. São os compostos fenólicos os grandes responsáveis pela bioactividade das plantas, como a capacidade antioxidante e antimicrobiana. Em particular, os florotaninos, são os compostos fenólicos mais presentes em espécies de algas marinhas, em especial nas algas castanhas. As embalagens alimentares representam um grave problema ambiental, uma vez que, são na sua maioria, produzidas através de produtos de fontes não renováveis e não biodegradáveis. Para tentar combater este problema, a indústria alimentar em conjunto com a comunidade cientifica tem procurado materiais mais sustentáveis e amigos do meio ambiente para este tipo de produtos. Aliada a esta procura está também a substituição de antioxidantes sintéticos por antioxidantes naturais, igualmente poderosos. Estes podem ser extraídos sob a forma de óleos essenciais e extratos naturais através de plantas aromáticas, especiarias, algas, frutos, entre outros. Estas substâncias bioativas podem ser incorporadas em embalagens alimentares ativas antioxidantes que, interagem intencionalmente com o alimento embalado, libertando para o mesmo compostos bioativos capazes de retardar ou inibir a oxidação dos mesmos, aumentando assim o seu tempo de vida útil. A Gracilaria sp é uma alga vermelha (Rhodophyta) muito utilizada na produção de agar, enquanto que a Fucus vesiculosus é uma alga castanha que cresce abundantemente nas zonas frias e temperadas do Oceano Atlântico. O objetivo deste estudo foi quantificar o total de florotaninos presentes em cinco extratos hidro-etanólicos das duas espécies e avaliar a sua potencial aplicação a embalagens alimentares.Financiado pelo projeto de investigação “i.FILM- Multifunctional Films for Intelligent and Active Applications” (nº 17921), cofinanciado pelo Fundo Europeu de Desenvolvimento Regional (FEDER) através do Programa Operacional Competitividade e Internacionalização no âmbito do Programa “Portugal 2020” (Sistema de Incentivos à Investigação e Desenvolvimento Tecnológico (SI I&DT), Aviso nº 33/SI/2015, Projetos em Co-Promoção).N/

Colon cancer chemoprevention by sage tea drinking: decreased DNA damage and cell proliferation

Salvia officinalis and some of its isolated compounds have been found to be preventive of DNA damage and increased proliferation in vitro in colon cells. In the present study, we used the azoxymethane model to test effects of S. officinalis on colon cancer prevention in vivo. The results showed that sage treatment reduced the number of ACF formed only if administered before azoxymethane injection, demonstrating that sage tea drinking has a chemopreventive effect on colorectal cancer. A decrease in the proliferation marker Ki67 and in H2O2-induced and azoxymethane-induced DNA damage to colonocytes and lymphocytes were found with sage treatment. This confirms in vivo the chemopreventive effects of S. officinalis. Taken together, our results show that sage treatment prevented initiation phases of colon carcinogenesis, an effect due, at least in part, to DNA protection, and reduced proliferation rates of colon epithelial cell that prevent mutations and their fixation through cell replication. These chemopreventive effects of S. officinalis on colon cancer add to the many health benefits attributed to sage and encourage its consumption.Fundação para a Ciência e a Tecnologia (FCT) - grant SFRH/BD/35672/2007, SFRH/BD/64817/200

Rarity of monodominance in hyperdiverse Amazonian forests.

Tropical forests are known for their high diversity. Yet, forest patches do occur in the tropics where a single tree species is dominant. Such "monodominant" forests are known from all of the main tropical regions. For Amazonia, we sampled the occurrence of monodominance in a massive, basin-wide database of forest-inventory plots from the Amazon Tree Diversity Network (ATDN). Utilizing a simple defining metric of at least half of the trees ≥ 10 cm diameter belonging to one species, we found only a few occurrences of monodominance in Amazonia, and the phenomenon was not significantly linked to previously hypothesized life history traits such wood density, seed mass, ectomycorrhizal associations, or Rhizobium nodulation. In our analysis, coppicing (the formation of sprouts at the base of the tree or on roots) was the only trait significantly linked to monodominance. While at specific locales coppicing or ectomycorrhizal associations may confer a considerable advantage to a tree species and lead to its monodominance, very few species have these traits. Mining of the ATDN dataset suggests that monodominance is quite rare in Amazonia, and may be linked primarily to edaphic factors

Landscape dynamics and diversification of the megadiverse South American freshwater fish fauna

Landscape dynamics are widely thought to govern the tempo and mode of continental radiations, yet the effects of river network rearrangements on dispersal and lineage diversification remain poorly understood. We integrated an unprecedented occurrence dataset of 4,967 species with a newly compiled, time-calibrated phylogeny of South American freshwater fishes—the most species-rich continental vertebrate fauna on Earth—to track the evolutionary processes associated with hydrogeographic events over 100 Ma. Net lineage diversification was heterogeneous through time, across space, and among clades. Five abrupt shifts in net diversification rates occurred during the Paleogene and Miocene (between 30 and 7 Ma) in association with major landscape evolution events. Net diversification accelerated from the Miocene to the Recent (c. 20 to 0 Ma), with Western Amazonia having the highest rates of in situ diversification, which led to it being an important source of species dispersing to other regions. All regional biotic interchanges were associated with documented hydrogeographic events and the formation of biogeographic corridors, including the Early Miocene (c. 23 to 16 Ma) uplift of the Serra do Mar and Serra da Mantiqueira and the Late Miocene (c. 10 Ma) uplift of the Northern Andes and associated formation of the modern transcontinental Amazon River. The combination of high diversification rates and extensive biotic interchange associated with Western Amazonia yielded its extraordinary contemporary richness and phylogenetic endemism. Our results support the hypothesis that landscape dynamics, which shaped the history of drainage basin connections, strongly affected the assembly and diversification of basin-wide fish fauna

Deregulation of desmosomal proteins and extracellular matrix proteases in odontogenic keratocyst

OBJECTIVE : Odontogenic keratocyst (OKC) is a benign lesion that tends to recur after surgical treatment. In an attempt to clarify the molecular basis underlining the OKC pathobiology, we aimed to analyze its proteomic profile. MATERIALS AND METHODS : We compared the proteomic profiles of five OKC and matched normal oral mucosa by using liquid chromatography–tandem mass spectrometry (LC-MS/MS). Then, we performed enrichment analysis and a literature search for the immunoexpression of the proteomics targets. RESULTS : We identified 1,150 proteins and 72 differently expressed proteins (log2 fold change ≥ 1.5; p < .05). Twenty-seven peptides were exclusively detected in the OKC samples. We found 35 enriched pathways related to cell differentiation and tissue architecture, including keratinocyte differentiation, keratinization, desmosome, and extracellular matrix (ECM) organization and degradation. The immunoexpression information of 11 out of 50 proteins identified in the enriched pathways was obtained. We found the downregulation of four desmosomal proteins (JUP, PKP1, PKP3, and PPL) and upregulation of ECM proteases (MMP-2, MMP-9, and cathepsins). CONCLUSIONS : Proteomic analysis strengthened the notion that OKC cells have a similar proteomic profile to oral keratinocytes. Contextual investigation of the differentially expressed proteins revealed the deregulation of desmosome proteins and ECM degradation as important alterations in OKC pathobiology.Conselho Nacional de Desenvolvimento Científico e Tecnológico and Coordenação de Aperfeiçoamento de Pessoal de Nível Superior.http://www.wileyonlinelibrary.com/journal/odihj2022Oral Pathology and Oral Biolog

Synthesis, in vitro and in vivo anti-Trypanosoma cruzi and toxicological activities of nitroaromatic Schiff bases.

Chagas disease is a major health problem not only in Latin America but also in Europe and North America due to the spread of this disease into nonendemic areas. In terms of global burden, this major tropical infection is considered to be one of the most neglected diseases, and there are currently only two available chemotherapies: benznidazole and nifurtimox. Unfortunately, although these chemotherapies are beneficial in the acute phase of the disease, benznidazole and nifurtimox lead to significant side effects, including hepatitis and neurotoxicity. Therefore, the search for and development of more effective, safe and inexpensive anti-Trypanosoma cruzi drugs are required. In this work, a series of 10 nitroaromatic Schiff bases bearing different (nitro) aromatic rings-was synthesized. Subsequently, the in vitro and in vivo anti-T. cruzi activities of the Schiff bases were investigated, as well as the in vivo toxicity and the biological effects. The basic structure of the most promising in vivo Schiff base, 10 would be useful in the synthesis of new compounds for Chagas disease treatment