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1.
Int J Mol Sci ; 25(12)2024 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-38928331

RESUMO

Parkinson's disease (PD) is the second most prevalent neurodegenerative disorder currently affecting the ageing population. Although the aetiology of PD has yet to be fully elucidated, environmental factors such as exposure to the naturally occurring neurotoxin rotenone has been associated with an increased risk of developing PD. Rotenone inhibits mitochondrial respiratory chain (MRC) complex I activity as well as induces dopaminergic neuronal death. The aim of the present study was to investigate the underlying mechanisms of rotenone-induced mitochondrial dysfunction and oxidative stress in an in vitro SH-SY5Y neuronal cell model of PD and to assess the ability of pre-treatment with Coenzyme Q10 (CoQ10) to ameliorate oxidative stress in this model. Spectrophotometric determination of the mitochondrial enzyme activities and fluorescence probe studies of reactive oxygen species (ROS) production was assessed. Significant inhibition of MRC complex I and II-III activities was observed, together with a significant loss of neuronal viability, CoQ10 status, and ATP synthesis. Additionally, significant increases were observed in intracellular and mitochondrial ROS production. Remarkably, CoQ10 supplementation was found to reduce ROS formation. These results have indicated mitochondrial dysfunction and increased oxidative stress in a rotenone-induced neuronal cell model of PD that was ameliorated by CoQ10 supplementation.


Assuntos
Mitocôndrias , Neurônios , Estresse Oxidativo , Espécies Reativas de Oxigênio , Rotenona , Ubiquinona , Ubiquinona/análogos & derivados , Ubiquinona/farmacologia , Ubiquinona/deficiência , Rotenona/toxicidade , Rotenona/efeitos adversos , Mitocôndrias/metabolismo , Mitocôndrias/efeitos dos fármacos , Humanos , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Neurônios/metabolismo , Neurônios/efeitos dos fármacos , Neurônios/patologia , Doença de Parkinson/metabolismo , Doença de Parkinson/patologia , Doença de Parkinson/etiologia , Linhagem Celular Tumoral , Debilidade Muscular/metabolismo , Debilidade Muscular/induzido quimicamente , Debilidade Muscular/patologia , Sobrevivência Celular/efeitos dos fármacos , Complexo I de Transporte de Elétrons/metabolismo , Ataxia , Doenças Mitocondriais
2.
Mar Drugs ; 22(1)2023 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-38276640

RESUMO

One of the major threats to skin aging and the risk of developing skin cancer is excessive exposure to the sun's ultraviolet radiation (UVR). The use of sunscreens containing different synthetic, organic, and inorganic UVR filters is one of the most widespread defensive measures. However, increasing evidence suggests that some of these compounds are potentially eco-toxic, causing subtle damage to the environment and to marine ecosystems. Resorting to natural products produced in a wide range of marine species to counteract UVR-mediated damage could be an alternative strategy. The present work investigates marine-inspired thiol compounds, derivatives of ovothiol A, isolated from marine invertebrates and known to exhibit unique antioxidant properties. However, their potential use as photoprotective molecules for biocompatible sunscreens and anti-photo aging formulations has not yet been investigated. Here, we report on the UVR absorption properties, photostability, and in vitro UVA shielding activities of two synthetic ovothiol derivatives, 5-thiohistidine and iso-ovothiol A, by spectrophotometric and fluorimetric analysis. We found that the UVA properties of these compounds increase upon exposure to UVA and that their absorption activity is able to screen UVA rays, thus reducing the oxidative damage induced to proteins and lipids. The results of this work demonstrate that these novel marine-inspired compounds could represent an alternative eco-friendly approach for UVR skin protection.


Assuntos
Protetores Solares , Raios Ultravioleta , Raios Ultravioleta/efeitos adversos , Protetores Solares/farmacologia , Ecossistema , Pele , Compostos de Sulfidrila
3.
Int J Mol Sci ; 24(7)2023 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-37047738

RESUMO

The demand for organic UV filters as active components in sunscreen products has rapidly risen over the last century, as people have gradually realized the hazards of overexposure to UV radiation. Their extensive usage has resulted in their ubiquitous presence in different aquatic matrices, representing a potential threat to living organisms. In this context, the need to replace classic UV filters such as octyl methoxycinnamate (OMC), one of the most popular UV filters reported to be a potential pollutant of aquatic ecosystems, with more environmentally friendly ones has emerged. In this study, using zebrafish, the first in vivo results regarding the effect of exposure to tempol-methoxycinnamate (TMC), a derivative of OMC, are reported. A comparative study between TMC and OMC was performed, analyzing embryos exposed to similar TMC and OMC concentrations, focusing on morphological and molecular changes. While both compounds seemed not to affect hatching and embryogenesis, OMC exposure caused an increase in endoplasmic reticulum (ER) stress response genes, according to increased eif2ak3, ddit3, nrf2, and nkap mRNA levels and in oxidative stress genes, as observed from modulation of the sod1, sod2, gpr, and trx mRNA levels. On the contrary, exposure to TMC led to reduced toxicity, probably due to the presence of the nitroxide group in the compound's molecular structure responsible for antioxidant activity. In addition, both UV filters were docked with estrogen and androgen receptors where they acted differently, in agreement with the molecular analysis that showed a hormone-like activity for OMC but not for TMC. Overall, the results indicate the suitability of TMC as an alternative, environmentally safer UV filter.


Assuntos
Raios Ultravioleta , Peixe-Zebra , Animais , Raios Ultravioleta/efeitos adversos , Ecossistema , Protetores Solares/farmacologia , Protetores Solares/química , RNA Mensageiro , Cinamatos/farmacologia , Cinamatos/química
4.
Int J Mol Sci ; 24(11)2023 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-37298165

RESUMO

Post-prandial hyperglycemia typical of diabetes mellitus could be alleviated using plant-derived compounds such as polyphenols, which could influence the activities of enzymes involved in carbohydrate digestion and of intestinal glucose transporters. Here, we report on the potential anti-hyperglycemic effect of Crocus sativus tepals compared to stigmas, within the framework of valorizing these by-products of the saffron industry, since the anti-diabetic properties of saffron are well-known, but not those of its tepals. In vitro assays showed that tepal extracts (TE) had a greater inhibitory action than stigma extracts (SE) on α-amylase activity (IC50: TE = 0.60 ± 0.09 mg/mL; SE = 1.10 ± 0.08 mg/mL; acarbose = 0.051 ± 0.07) and on glucose absorption in Caco-2 differentiated cells (TE = 1.20 ± 0.02 mg/mL; SE = 2.30 ± 0.02 mg/mL; phlorizin = 0.23 ± 0.01). Virtual screening performed with principal compounds from stigma and tepals of C. sativus and human pancreatic α-amylase, glucose transporter 2 (GLUT2) and sodium glucose co-transporter-1 (SGLT1) were validated via molecular docking, e.g., for human pancreatic α-amylase, epicatechin 3-o-gallate and catechin-3-o-gallate were the best scored ligands from tepals (-9.5 kcal/mol and -9.4 kcal/mol, respectively), while sesamin and episesamin were the best scored ones from stigmas (-10.1 kcal/mol). Overall, the results point to the potential of C. sativus tepal extracts in the prevention/management of diabetes, likely due to the rich pool of phytocompounds characterized using high-resolution mass spectrometry, some of which are capable of binding and interacting with proteins involved in starch digestion and intestinal glucose transport.


Assuntos
Crocus , Diabetes Mellitus , Humanos , Polifenóis/farmacologia , Polifenóis/metabolismo , Crocus/química , Hipoglicemiantes/farmacologia , Hipoglicemiantes/metabolismo , alfa-Amilases Pancreáticas/metabolismo , Células CACO-2 , Simulação de Acoplamento Molecular , Glucose/metabolismo , Extratos Vegetais/química
5.
Molecules ; 28(9)2023 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-37175212

RESUMO

Tea (Camellia sinensis) is the second most consumed beverage worldwide, playing a key role in the human diet. Tea is considered a healthy drink, as its consumption has been linked to a lower risk of cardiovascular disease-related events and death, stroke, metabolic syndrome and obesity. However, several studies have shown that C. sinensis is a hyperaccumulator of Al and other elements that are considered potentially toxic. In the present study, the contents of 15 elements (both essential and toxic) were determined for the first time in tea leaves collected in tea gardens located in six different European countries and processed to provide black and green tea. The results showed that Al was the major toxic element detected, followed by Ni, Cr, Pb, As, Cd, Ag, and Hg. Essential elements were detected in the order of Mn, Fe, Zn, Cu, Co, and Se. Statistically significant correlations (p < 0.05) were found in the distribution of some elements, highlighting mechanisms of synergic or antagonist interaction. Multivariate analysis revealed that geographical origin was the main driver in clustering the samples, while the different treatment processes (black or green) did not significantly affect the contents of elements in the leaves. The estimation of potential non-carcinogenic risk revealed no risk for the consumption of European teas for consumers in terms of potentially toxic elements.


Assuntos
Camellia sinensis , Mercúrio , Humanos , Chá , Bebidas , Medição de Risco
6.
Molecules ; 28(11)2023 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-37298828

RESUMO

Olea europaea L. leaf extracts (OLEs) represent highly value-added agro-industrial byproducts, being promising sources of significant antioxidant compounds, such as their main component, oleuropein. In this work, hydrogel films based on low-acyl gellan gum (GG) blended with sodium alginate (NaALG) were loaded with OLE and crosslinked with tartaric acid (TA). The films' ability to act as an antioxidant and photoprotectant against UVA-induced photoaging, thanks to their capability to convey oleuropein to the skin, were examined with the aim of a potential application as facial masks. Biological in vitro performances of the proposed materials were tested on normal human dermal fibroblasts (NhDFs), both under normal conditions and after aging-induced UVA treatment. Overall, our results clearly show the intriguing properties of the proposed hydrogels as effective and fully naturally formulated anti-photoaging smart materials for potential use as facial masks.


Assuntos
Envelhecimento da Pele , Dermatopatias , Humanos , Alginatos/farmacologia , Antioxidantes/farmacologia , Polissacarídeos Bacterianos/farmacologia
7.
Mar Drugs ; 19(7)2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-34209059

RESUMO

In the last few decades, the thinning of the ozone layer due to increased atmospheric pollution has exacerbated the negative effects of excessive exposure to solar ultraviolet radiation (UVR), and skin cancer has become a major public health concern. In order to prevent skin damage, public health advice mainly focuses on the use of sunscreens, along with wearing protective clothing and avoiding sun exposure during peak hours. Sunscreens present on the market are topical formulations that contain a number of different synthetic, organic, and inorganic UVR filters with different absorbance profiles, which, when combined, provide broad UVR spectrum protection. However, increased evidence suggests that some of these compounds cause subtle damage to marine ecosystems. One alternative may be the use of natural products that are produced in a wide range of marine species and are mainly thought to act as a defense against UVR-mediated damage. However, their potential for human photoprotection is largely under-investigated. In this review, attention has been placed on the molecular strategies adopted by marine organisms to counteract UVR-induced negative effects and we provide a broad portrayal of the recent literature concerning marine-derived natural products having potential as natural sunscreens/photoprotectants for human skin. Their chemical structure, UVR absorption properties, and their pleiotropic role as bioactive molecules are discussed. Most studies strongly suggest that these natural products could be promising for use in biocompatible sunscreens and may represent an alternative eco-friendly approach to protect humans against UV-induced skin damage.


Assuntos
Organismos Aquáticos , Neoplasias Cutâneas/prevenção & controle , Protetores Solares/uso terapêutico , Animais , Produtos Biológicos , Humanos , Protetores Solares/química
8.
Int J Mol Sci ; 22(21)2021 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-34768878

RESUMO

Many neurodegenerative and inherited metabolic diseases frequently compromise nervous system function, and mitochondrial dysfunction and oxidative stress have been implicated as key events leading to neurodegeneration. Mitochondria are essential for neuronal function; however, these organelles are major sources of endogenous reactive oxygen species and are vulnerable targets for oxidative stress-induced damage. The brain is very susceptible to oxidative damage due to its high metabolic demand and low antioxidant defence systems, therefore minimal imbalances in the redox state can result in an oxidative environment that favours tissue damage and activates neuroinflammatory processes. Mitochondrial-associated molecular pathways are often compromised in the pathophysiology of neurodegeneration, including the parkin/PINK1, Nrf2, PGC1α, and PPARγ pathways. Impairments to these signalling pathways consequently effect the removal of dysfunctional mitochondria, which has been suggested as contributing to the development of neurodegeneration. Mitochondrial dysfunction prevention has become an attractive therapeutic target, and there are several molecular pathways that can be pharmacologically targeted to remove damaged mitochondria by inducing mitochondrial biogenesis or mitophagy, as well as increasing the antioxidant capacity of the brain, in order to alleviate mitochondrial dysfunction and prevent the development and progression of neurodegeneration in these disorders. Compounds such as natural polyphenolic compounds, bioactive quinones, and Nrf2 activators have been reported in the literature as novel therapeutic candidates capable of targeting defective mitochondrial pathways in order to improve mitochondrial function and reduce the severity of neurodegeneration in these disorders.


Assuntos
Doenças Metabólicas/metabolismo , Mitocôndrias/metabolismo , Doenças Neurodegenerativas/metabolismo , Animais , Antioxidantes/farmacologia , Humanos , Doenças Metabólicas/tratamento farmacológico , Doenças Metabólicas/fisiopatologia , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/patologia , Mitocôndrias/fisiologia , Mitofagia/efeitos dos fármacos , Doenças Neurodegenerativas/tratamento farmacológico , Doenças Neurodegenerativas/fisiopatologia , Neurônios/metabolismo , Oxirredução , Estresse Oxidativo/fisiologia , Espécies Reativas de Oxigênio/metabolismo
9.
Biochem J ; 476(2): 245-259, 2019 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-30602587

RESUMO

Glioblastoma (GB) represents the most common and aggressive form of malignant primary brain tumour associated with high rates of morbidity and mortality. In the present study, we considered the potential use of idebenone (IDE), a Coenzyme Q10 analogue, as a novel chemotherapeutic agent for GB. On two GB cell lines, U373MG and U87MG, IDE decreased the viable cell number and enhanced the cytotoxic effects of two known anti-proliferative agents: temozolomide and oxaliplatin. IDE also affected the clonogenic and migratory capacity of both GB cell lines, at 25 and 50 µM, a concentration equivalent to that transiently reached in plasma after oral intake that is deemed safe for humans. p21 protein expression was decreased in both cell lines, indicating that IDE likely exerts its effects through cell cycle dysregulation, and this was confirmed in U373MG cells only by flow cytometric cell cycle analysis which showed S-phase arrest. Caspase-3 protein expression was also significantly decreased in U373MG cells indicating IDE-induced apoptosis that was confirmed by flow cytometric Annexin V/propidium iodide staining. No major decrease in caspase-3 expression was observed in U87MG cells nor apoptosis as observed by flow cytometry analysis. Overall, the present study demonstrates that IDE has potential as an anti-proliferative agent for GB by interfering with several features of glioma pathogenesis such as proliferation and migration, and hence might be a drug that could be repurposed for aiding cancer treatments. Furthermore, the synergistic combinations of IDE with other agents aimed at different pathways involved in this type of cancer are promising.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Glioblastoma , Ubiquinona/análogos & derivados , Caspase 3/metabolismo , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Glioblastoma/tratamento farmacológico , Glioblastoma/metabolismo , Glioblastoma/patologia , Humanos , Proteínas de Neoplasias/metabolismo , Ubiquinona/farmacologia
10.
Int J Food Sci Nutr ; 66(5): 491-7, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26017324

RESUMO

The influence of commonly used steeping times and temperatures, as well as leaf size on the antioxidant activity and sensory attributes of tea were studied. Five unblended white and green tea samples from China and Malawi, infused in hot (70 °C and 90 °C; 7 min) or cold water (room temperature: 15, 30, 60, or 120 min) either as whole leaves or as milled, were analyzed. Total phenolic and flavonoid contents as well as antioxidant power (ABTS assay) were measured. The results show that the maximum extraction efficiency occurs with cold water for 120 min and with hot water at 90 °C and that only in the case of teas from whole, large leaves, the extraction was greater in cold than in hot infusions. Moreover, tea infusions prepared from milled leaves have the greatest antioxidant activity. In the sensory evaluation of some of the tea infusions, white teas were perceived more fragrant than green ones and were judged as the most favorite by the majority of the judges, especially for the brew prepared in cold water from whole leaves; all infusions obtained from the milled leaves in fact have a more bitter and astringent taste.


Assuntos
Antioxidantes/farmacologia , Camellia sinensis/química , Odorantes , Extratos Vegetais/farmacologia , Polifenóis/farmacologia , Paladar , Chá/química , Adulto , Antioxidantes/análise , Benzotiazóis/metabolismo , Flavonoides/farmacologia , Humanos , Pessoa de Meia-Idade , Tamanho da Partícula , Fenóis/farmacologia , Extratos Vegetais/química , Ácidos Sulfônicos/metabolismo , Temperatura , Adulto Jovem
11.
Food Chem ; 453: 139641, 2024 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-38761733

RESUMO

This study presents a comprehensive analysis of the elemental profiles of tea leaves coming from plants grown in several European gardens, with a focus on the bioaccumulation of essential and potentially toxic trace elements in relation to processing and location of tea garden. Samples were collected from various gardens across Europe, including Portugal, the Azores, Germany, the Netherlands, and Switzerland. Elemental analysis was conducted on fresh tea leaves, dried leaves, and leaves processed for the production of green and black tea, along with soil samples from the root zones of tea plants. The results reveal no significant differences in elemental content based on the processing of tea leaves. However, distinct elemental profiles were observed among tea leaves of plants grown in gardens from different European regions. Utilizing chemometric and machine learning tools, the study highlights the potential of these elemental profiles for enhancing the traceability of tea products.


Assuntos
Camellia sinensis , Folhas de Planta , Chá , Oligoelementos , Camellia sinensis/química , Camellia sinensis/crescimento & desenvolvimento , Camellia sinensis/metabolismo , Folhas de Planta/química , Folhas de Planta/metabolismo , Oligoelementos/análise , Chá/química , Europa (Continente) , Jardins , Solo/química
12.
Biofactors ; 2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-38318672

RESUMO

Obesity is a pressing problem worldwide for which standard therapeutic strategies have limited effectiveness. The use of natural products seems to be a promising approach to alleviate obesity and its associated complications. The tepals of Crocus sativus (Cr) plant, usually wasted in saffron production, are an unexplored source of bioactive compounds. Our aim was to elucidate the mechanisms of Cr tepals extract in obesity by investigating its effects on adipocyte differentiation, visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) hypertrophy, and lipid metabolism in an animal model of diet-induced obesity. To this end, mouse 3T3-F442A preadipocytes were treated with Cr tepals extract and the expression of adipocyte differentiation genes was determined. Caloric intake, body mass, triglycerides, systemic insulin sensitivity, histology, insulin signaling, and lipid metabolism in VAT and SAT were analyzed in mice fed a 60% fat diet for 14 weeks and treated orally with Cr tepals extract during the last 5 weeks of the diet. We demonstrated for the first time that Cr tepals extract inhibits adipocyte differentiation in vitro. The animal model confirmed that oral treatment with Cr tepals extract results in weight loss, improved systemic insulin sensitivity, lower triglycerides, and improved lipid peroxidation. The suppressive effect of Cr tepals extract on adipocyte hypertrophy and inflammation was observed only in SAT, which, together with preserved SAT insulin signaling, most likely contributed to improved systemic insulin sensitivity. Our results suggest the functionality of SAT as a possible target for the treatment of obesity and its complications.

13.
Chem Biol Interact ; 384: 110702, 2023 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-37717644

RESUMO

Paraoxonase-2 (PON2) is an intracellular protein, that exerts a protective role against cell oxidative stress and apoptosis. Genetic and environmental factors (i.e. dietary factors, cigarette smoke, drugs) are able to modulate cellular PON2 levels. The effect of ultraviolet A radiation (UVA), the oxidizing component of sunlight, on PON2 in human dermal fibroblasts (HuDe) has not been previously explored. Excessive UVA radiation is known to cause direct and indirect skin damage by influencing intracellular signalling pathways through oxidative stress mediated by reactive oxygen species (ROS) that modulate the expression of downstream genes involved in different processes, e.g. skin photoaging and cancer. The aim of this study was, therefore, to investigate the modulation of PON2 in terms of protein expression and enzyme activity in HuDe exposed to UVA (270 kJ/m2). Our results show that PON2 is up-regulated immediately after UVA exposure and that its levels and activity decrease in the post-exposure phase, in a time-dependent manner (2-24 h). The trend in PON2 levels mirror the time-course study of UVA-induced ROS. To confirm this, experiments were also performed in the presence of a SPF30 sunscreen used as shielding agent to revert modulation of PON2 at 0 and 2 h post-UVA exposure where other markers of photo-oxidative stress were also examined (NF-KB, γH2AX, advanced glycation end products). Overall, our results show that the upregulation of PON2 might be related to the increase in intracellular ROS and may play an important role in mitigation of UVA-mediated damage and in the prevention of the consequences of UV exposure, thus representing a new marker of early-response to UVA-induced damage in skin fibroblasts.

14.
Foods ; 13(1)2023 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-38201143

RESUMO

ATR-FTIR (Attenuated Total Reflectance Fourier Transform InfraRed) spectroscopy, combined with chemometric, represents a rapid and reliable approach to obtain information about the macromolecular composition of food and plant materials. With a single measurement, the chemical fingerprint of the analyzed sample is rapidly obtained. Hence, this technique was used for investigating 13 differently processed tea leaves (green, black and white) all grown and processed in European tea gardens, and their vacuum-dried tea brews, prepared using both hot and cold water, to observe how the components differ from tea leaf to the in-cup infusion. Spectra were collected in the 1800-600 cm-1 region and were submitted to Principal Component Analysis (PCA). The comparison of the spectral profiles of leaves and hot and cold infusions of tea from the same country, emphasizes how they differ in relation to the different spectral regions. Differences were also noted among the different countries. Furthermore, the changes observed (e.g., at ~1340 cm-1) due to catechin content, confirm the antioxidant properties of these teas. Overall, this experimental approach could be relevant for rapid analysis of various tea types and could pave the way for the industrial discrimination of teas and of their health properties without the need of time-consuming, lab chemical assays.

15.
Antioxidants (Basel) ; 12(6)2023 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-37372036

RESUMO

Tea is grown around the world under extremely diverse geographic and climatic conditions, namely, in China, India, the Far East and Africa. However, recently, growing tea also appears to be feasible in many regions of Europe, from where high-quality, chemical-free, organic, single-estate teas have been obtained. Hence, the aim of this study was to characterize the health-promoting properties in terms of the antioxidant capacity of traditional hot brews as well as cold brews of black, green and white teas produced across the European territory using a panel of antioxidant assays. Total polyphenol/flavonoid contents and metal chelating activity were also determined. For differentiating the characteristics of the different tea brews, ultraviolet-visible (UV-Vis) spectroscopy and ultra-high performance liquid chromatography coupled with high-resolution mass spectrometry were employed. Overall, our findings demonstrate for the first time that teas grown in Europe are good quality teas that are endowed with levels of health-promoting polyphenols and flavonoids and that have an antioxidant capacity similar to those grown in other parts of the world. This research is a vital contribution to the characterization of European teas, providing essential and important information for both European tea growers and consumers, and could be of guidance and support for the selection of teas grown in the old continent, along with having the best brewing conditions for maximizing the health benefits of tea.

16.
Antioxidants (Basel) ; 12(11)2023 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-38001796

RESUMO

European countries have recently started experimenting with growing and producing their own teas in small quantities, mainly for the specialty tea sector. To characterize European teas, this study investigated a set of five tea types obtained from different Camellia sinensis varieties/cultivars, representing various oxidation grades (green, white, yellow, oolong, black), all grown and processed in the only tea garden in Europe (in Germany) that focuses on all five types. Hot and cold brews were studied by measuring the total phenolic (TPC) and flavonoid contents (TFC), the antioxidant capacity and UV-Vis spectra, also with the objective of discriminating between the different tea types and the different plant varieties. The dried leaves were analyzed to measure the content of essential and toxic elements and by ATR-FTIR spectroscopy to determine a chemical fingerprint for identifying the tea varieties and types. The average levels of TPC (hot brew = 5.82 ± 2.06; cold brew = 5.4 ± 2.46 mM GAEq), TFC (hot brew = 0.87 ± 0.309; cold brew = 0.87 ± 0.413 mM CAEq), and antioxidant capacity (ORAC assay-hot brew = 20.9 ± 605; cold brew = 21.8 ± 8.0 mM TXEq, ABTS assay-hot brew = 15.2 ± 5.09; cold brew = 15.1 ± 5.8 mM TXEq, FRAP assay-hot brew = 9.2 ± 3.84; cold brew = 10.4 ± 5.23 mM AAEq) observed compared well with those from other parts of the world such as China, Africa, and Taiwan. The hazard quotient <1 and the hazard index of 0.14 indicate that there is no non-carcinogenic risk from consumption of these teas. The obtained information is essential for elucidating the characteristics and the impact of tea processing and tea variety on the health benefits of these tea products coming from a single European tea garden. This multifaceted approach would help tea growers in Europe increase their knowledge on the health attributes of the teas they grow, ultimately leading to optimization of the nutraceutical properties of these teas.

17.
Pharmaceuticals (Basel) ; 17(1)2023 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-38256900

RESUMO

Pimpinella anisum L., or anise, is a plant that, besides its nutritional value, has been used in traditional medical practices and described in many cultures in the Mediterranean region. A possible reason for anise's therapeutic value is that it contains coumarins, which are known to have many biomedical and antioxidant properties. HPLC analysis in our laboratory of the anise extract shows the presence of the coumarin esculetin. We used a hydrodynamic voltammetry rotating ring-disk electrode (RRDE) method to measure the superoxide scavenging abilities of anise seeds and esculetin, which has marked scavenging activity. A related coumarin, 4-methyl-esculetin, also showed strong antioxidant activity as measured by RRDE. Moreover, this study includes the X-ray crystal structure of esculetin and 4-methyl-esculetin, which reveal the H-bond and the stacking intermolecular interactions of the two coumarins. Coordinates of esculetin crystal structure were used to perform a DFT study to arrive at the mechanism of superoxide scavenging. Besides performing a H(hydroxyl) abstraction in esculetin position 6 by superoxide, the scavenging also includes the presence of a second superoxide radical in a π-π approach. Both rings of esculetin were explored for this attack, but only the pyrone ring was effective. As a result, one product of esculetin scavenging is H2O2 formation, while the second superoxide remains π-π trapped within the pyrone ring to form an esculetin-η-O2 complex. Comparison with other coumarins shows that subtle structural differences in the coumarin framework can imply marked differences in scavenging. For instance, when the catechol moiety of esculetin (position 6,7) is shifted to position 7,8 in 4-methyl-7,8-dihydroxy coumarin, that coumarin shows a superoxide dismutase action, which, beside H2O2 formation, includes the formation and elimination of a molecule of O2. This is in contrast with the products formed through esculetin superoxide scavenging, where a second added superoxide remains trapped, and forms an esculetin-η-O2 complex.

19.
Plant Foods Hum Nutr ; 67(1): 31-8, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22212954

RESUMO

Several monofloral Cuban honeys were analyzed to determine their free radical-scavenging activity and from this the total antioxidant content was estimated. The protective effect against lipid peroxidation in an in vitro model of rat liver homogenates was evaluated and, lastly, the mineral content of the honeys, which can be related to the maintenance of intracellular oxidative balance, was determined. The scavenging capacities against hydroxyl and superoxide radicals were determined using the spin-trapping technique and the hypoxanthine/xanthine oxidase assay, respectively. Lipid peroxidation was evaluated through the production of TBARS and hydroperoxides. All honeys tested showed potential antioxidant activity with Linen vine displaying the highest scavenging capacity towards the DPPH, hydroxyl and superoxide radicals, while the least efficient was Christmas vine honey. Honeys also inhibited, in a concentration-dependent mode, lipid peroxidation in rat liver homogenates, with Linen vine resulting the best while the least effective was Christmas vine honey. The ability to scavenge free radicals and protect against lipid peroxidation may contribute to the ability of certain Cuban honeys to help in preventing/reducing some inflammatory diseases in which oxidative stress is involved. A total of eight minerals were identified and quantified as follows: cadmium, chromium, copper, nickel, iron, manganese, lead, and zinc. Minerals found in higher concentrations were iron, zinc and manganese.


Assuntos
Antioxidantes/farmacologia , Sequestradores de Radicais Livres/farmacologia , Mel/análise , Peroxidação de Lipídeos/efeitos dos fármacos , Magnoliopsida/química , Minerais/análise , Animais , Antioxidantes/análise , Cuba , Flores/química , Sequestradores de Radicais Livres/análise , Radical Hidroxila/metabolismo , Concentração Inibidora 50 , Fígado/metabolismo , Masculino , Estresse Oxidativo/efeitos dos fármacos , Pólen/química , Ratos , Ratos Wistar , Detecção de Spin , Superóxidos/metabolismo
20.
Nutrients ; 14(20)2022 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-36297001

RESUMO

Epigenetic mechanisms play an important role in the etiology of colorectal cancer (CRC) and other malignancies due, in part, to deregulated bromodomain (BRD) functions. Inhibitors of the bromodomain and extraterminal (BET) family have entered into clinical trials as anticancer agents, and interest has grown in other acetyl 'reader' proteins as therapeutic targets, including non-BET member bromodomain-containing protein 9 (BRD9). We report here that overexpression of BRD9 is associated with poor prognosis in CRC patients, and that siRNA-mediated knockdown of BRD9 decreased cell viability and activated apoptosis in human colon cancer cells, coincident with increased DNA damage. Seeking natural compounds as BRD9 antagonists, molecular docking in silico identified several polyphenols such as Epigallocatechin-3-gallate (EGCG), Equol, Quercetin, and Aspalathin, with favorable binding energies, supported by BROMOscan® (DiscoverX) and isothermal titration calorimetry experiments. Polyphenols mimicked BRD9 knockdown and iBRD9 treatment in reducing colon cancer cell viability, inhibiting colony formation, and enhancing DNA damage and apoptosis. Normal colonic epithelial cells were unaffected, signifying cancer-specific effects. These findings suggest that natural polyphenols recognize and target BRD9 for inhibition, and might serve as useful lead compounds for bromodomain therapeutics in the clinical setting.


Assuntos
Antineoplásicos , Neoplasias do Colo , Humanos , Polifenóis/farmacologia , Simulação de Acoplamento Molecular , RNA Interferente Pequeno , Equol , Quercetina , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Apoptose , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/genética , Dano ao DNA
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