Valorisation of wild mushrooms as functional foods: chemoinformatic studies

As interacções intermoleculares desempenham um papel essencial nos diversos processos biológicos, sendo fundamental a compreensão destas interacções nos Sectores das Indústrias Farmacêuticas e de Alimentos Funcionais. Os cogumelos representam uma fonte ilimitada de compostos com propriedades antitumorais e imunoestimulantes, e o seu consumo foi já relacionado com a redução do risco de cancro da mama. No presente trabalho, foram desenvolvidos dois estudos in silico com o intuito de melhor compreender quais os mecanismos moleculares responsáveis por diferentes propriedades bioactivas dos cogumelos. Primeiro utilizou-se uma metodologia de modelação QCAR (Relações Quantitativas Composição – Actividade) para estudar e prever a actividade antioxidante de cogumelos. Num segundo estudo utilizaram-se ferramentas de “docking” molecular e “virtual ligand screening” (VLS) para tentar elucidar possíveis mecanismos de actividade dos cogumelos contra o cancro da mama. No estudo QCAR inicial foi utilizada a técnica estatística dos Mínimos Quadrados Parciais (PLS) para avaliar a relação entre o potencial antioxidante (efeitos bloqueadores de radicais livres e poder redutor) e a composição química de vinte e três amostras de dezassete espécies de cogumelos silvestres Portugueses. Estudaram-se vários parâmetros analíticos tais como cinzas, hidratos de carbono, proteínas, gorduras, ácidos gordos monoinsaturados, ácidos gordos polinsaturados, ácidos gordos saturados, fenóis, flavonóides, ácido ascórbico e β-caroteno, e os seus resultados foram analisados por PLS de forma a estabelecer correlações entre todos os parâmetros. A actividade antioxidante mostrou estar correlacionada com o teor em fenóis e flavonóides. Foi construído um modelo QCAR, cuja robustez e capacidade de previsão foram verificadas por métodos de validação cruzada internos e externos. Finalmente, este modelo provou ser uma ferramenta útil na previsão do poder redutor de cogumelos. Nos estudos de VLS foi utilizado o software de “docking” molecular Autodock 4 com o objectivo de identificar compostos de baixo peso molecular (LMW), incluindo antioxidantes, presentes em cogumelos e potencialmente envolvidos na actividade contra o cancro da mama. Foi seleccionado um grupo representativo de 43 compostos de LMW (ácidos fenólicos, flavonóides, tocoferóis, carotenóides, açúcares e ácidos gordos) e efectuou-se “docking” molecular usando como alvo três proteínas envolvidas no cancro da mama (Aromatase, Esterona Sulfatase e 17-β-hidroxi-esteróide desidrogenase 1). Os compostos LMW foram classificados quanto à sua capacidade de inibição do cancro da mama. A informação obtida estabelece um bom ponto de partida para o desenvolvimento de inibidores das proteínas mencionadas. O ácido 4-o-cafeoilquínico, a naringina e o licopeno revelaram-se, respectivamente, os melhores inibidores para Aromatase, Esterona Sulfatase e 17β-HSD1. Os estudos de Química Computacional realizados permitiram a valorização dos cogumelos como alimentos funcionais, podendo ser muito úteis para Indústrias que visem o desenvolvimento de novos nutracêuticos ou alimentos funcionais.Intermolecular interactions play essential roles in several life processes and understanding these interactions is critical for pharmaceutical and functional foods industries. Mushrooms represent an unlimited source of compounds with antitumor and immunostimulating properties and mushroom intake has been shown to reduce the risk of breast cancer. In this work, two in silico studies were performed in an attempt to elucidate potential mechanisms of mushroom bioactivity. First, a QCAR (Quantitative Composition-Activity Relationships) modelling approach was used to study and predict mushroom antioxidant activity. Next, molecular docking and virtual ligand screening (VLS) studies were performed in an attempt to elucidate possible mechanisms of mushroom anti-breast cancer activity. For the initial QCAR study a PLS (Partial Least Square) statistical technique was applied to evaluate the relationship between antioxidant potential (scavenging effect on free radicals and reducing power) and chemical composition of twenty three samples from seventeen Portuguese wild mushroom species. A wide range of analytical parameters including ash, carbohydrates, proteins, fat, monounsaturated fatty acids, polyunsaturated fatty acids, saturated fatty acids, phenolics, flavonoids, ascorbic acid and β-carotene was studied and the data was analyzed by the PLS regression analysis to find correlations between all the parameters. Antioxidant activity correlated well with phenolic and flavonoid contents. A QCAR model was constructed, and its robustness and predictability was verified by internal and external cross-validation methods. This model proved to be a useful tool in the prediction of mushrooms reducing power. For the VLS study, molecular docking software AutoDock 4 was used in order to evaluate which wild mushroom low molecular weight (LMW) compounds, including antioxidants, could be involved in anti-breast cancer activity. A representative dataset of 43 LMW compounds (individual phenolic acids, flavonoids, tocopherols, carotenoids, sugars and fatty acids) was selected and molecular docking was carried out against three known protein targets involved in breast cancer (Aromatase, Estrone Sulfatase and 17-β-hydroxysteroid dehydrogenase 1). The top ranked LMW compounds with breast cancer inhibition activity was predicted and the information provided showed several interesting starting points for further development of inhibitors of the mentioned proteins. 4-O-caffeoylquinic acid, naringin and lycopene stand out as the top ranked potential inhibitors for Aromatase, Estrone Sulfatase and 17β-HSD-1, respectively. The performed chemoinformatic studies allowed valorisation of mushrooms as functional foods and could be used in Industries focused on developing new nutraceuticals or functional foods

Virtual ligand screening studies between mushroom compounds and proteins involved in breast cancer

Mushrooms are a vast and yet largely untapped source of powerful new pharmaceutical products. In particular, and most importantly for modern medicine, they represent an unlimited source of compounds with antitumor and immunostimulating properties [1]. Particularly, the intake of some wild mushrooms has shown to reduce the risk of breast cancer in Chinese women [2]. A large number of LMW (low molecular weight) compounds have been "identified in wild mushrooms including phenolic acids, flavonoids, tocopherols, carotenoids, sugars and fatty acids [3]. In this study we used AutoDock 4 [4] to perform virtual ligand screening in order to evaluate which LMW compounds may be involved in the inhibition of the activity of proteins related to human breast cancer: aromatase (EC: 1.14.14.1), estrone sulfatase (EC: 3.1.6.2) and 17- hydroxysteroid dehydrogenase type 1 activity (17~-HSD-1; EC:. 1.1.1.62) [5]. A representative dataset of 43 LMW compounds was selected and molecular docking was performed against the three protein targets. 4-0-caffeoylquinic, naringin and lycopene stand out as the top ranked potential inhibitors for aromatase, estrone sulfatase and 1 7~HSD1, respectively. The information provided shows several interesting starting points for further development of inhibitors of the studied proteins, as also for the development of nutraceuticals or functional foods

QCAR models to predict wild mushrooms radical scavenging activity, reducing power and lipid peroxidation inhibition

Wild mushrooms have become attractive as a source of physiologically beneficial compounds including antioxidants such as phenolic compounds and tocopherols. The concentrations of antioxidant compounds (phenolics and α-tocopherol) and EC50 values of antioxidant activity (concentration required to achieve 50% of radical scavenging activity and lipid peroxidation inhibition, or 0.5 of absorbance in reducing power) were analyzed by partial least square (PLS) regression analysis. Three QCAR (Quantitative Composition-Activity Relationship) models were constructed and their robustness and predictability were verified by internal and external cross-validation methods. Antioxidant activity correlated well with phenolics and -tocopherol contents, the major antioxidants in wild mushrooms. The models proved to be useful tools in the prediction of mushrooms radical scavenging activity, reducing power and lipid peroxidation inhibition

Using molecular docking to investigate the anti-breast cancer activity of low molecular weight compounds present on wild mushrooms.

Mushrooms represent an unlimited source of compounds with antitumor and immunostimulating properties and mushroom intake as been shown to reduce the risk of breast cancer. A large number of LMW (low molecular weight) compounds present in mushrooms have been identified including: phenolic acids, flavonoids, tocopherols, carotenoids, sugars and fatty acids. In order to evaluate which wild mushroom LMW compounds may be involved in anti-breast cancer activity we selected a representative dataset of 43 LMW compounds and performed molecular docking against 3 known protein targets involved in breast cancer (Aromatase, Estrone Sulfatase and 17β-HSD-1) using AutoDock4 as docking software. The estimated inhibition constants for all LMW compounds were determined and the potential structure-activity relationships for the compounds with the best estimated inhibition constants are discussed for each compound family. 4-O-caffeoylquinic, naringin and lycopene stand out as the top ranked potential inhibitors for Aromatase, Estrone Sulfatase and 17β-HSD1, respectively, and the 3-D docked conformation for these compounds are discussed in detail. This information provides several interesting starting points for further development of Aromatase, Estrone Sulfatase and 17β-HSD1 inhibitors

Valorização de cogumelos silvestres como alimentos funcionais: estudos de química computacional

As interacções intermoleculares desempenham um papel essencial nos diversos processos biológicos, sendo fundamental a compreensão destas interacções nos Sectores das Indústrias Farmacêuticas e de Alimentos Funcionais. Os cogumelos representam uma fonte ilimitada de compostos com propriedades antitumorais e imunoestimulantes, e o seu consumo foi já relacionado com a redução do risco de cancro da mama. No presente trabalho, foram desenvolvidos dois estudos in silico com o intuito de compreender algumas das interacções moleculares presentes em cogumelos e responsáveis pela sua bioactividade. A técnica dos Mínimos Quadrados Parciais foi utilizada para avaliar a relação entre o potencial antioxidante (efeitos bloqueadores de radicais livres e poder redutor) e a composição química de vinte e três amostras de dezassete espécies de cogumelos silvestres Portugueses. Estudaram-se vários parâmetros analíticos tais como cinzas, hidratos de carbono, proteínas, gorduras, ácidos gordos monoinsaturados, ácidos gordos polinsaturados, ácidos gordos saturados, fenóis, flavonóides, ácido ascórbico e β-caroteno, e os seus resultados foram analisados pela técnica anteriormente mencionada de forma a estabelecer correlações entre todos os parâmetros. A actividade antioxidante mostrou estar correlacionada com o teor em fenóis e flavonóides. Foi construído um modelo QCAR (Relações Quantitativas Composição – Actividade), cuja robustez e previsibilidade foram verificadas por métodos de validação cruzada internos e externos. Finalmente, este modelo provou ser uma ferramenta útil na previsão do poder redutor de cogumelos

Docking studies to evaluate mushrooms low molecular weight compounds as inhibitors of the anti-apoptotic protein BCL-2

Several reports indicate that mushrooms have the ability to promote apoptosis in tumour cell lines, but the mechanism of action is not quite well understood. Inhibition of the interaction between Bcl-2 (anti-apoptotic protein) and pro-apoptotic proteins could be an important step that leads to apoptosis. Therefore, the discovery of compounds with the capacity to inhibit Bcl-2 is an ongoing research topic on cancer therapy. Herein, Autodock4 virtual screening was applied to a dataset of 40 low molecular weight compounds present in mushrooms, using 3D Bcl-2 protein structure (PDB:2XA0) as target. Results suggested that steroids mainly ergosta-4,6,8(14),22-tetraen-3-one, lucidenic lactone, cerevisterol, ganoderic acid w and ganoderic acid x, with a binding energy lower than -10 kcal/mol, had the ability to interact with Bcl-2

MOLA: a tool for automation of parallel virtual docking using AutoDock Vina in a heterogeneous set of computer clusters

The use of molecular docking lo search large databases of compounds for possible ligands of a protein receptor is usually termed virtual screening and has been successfully applied in several therapeutic programs at the lead discovery stage. However, large scale virtual screening is lime demanding and usually requires dedicated High Performance Computing (H PC) systems

Mdm2 as a potential target for mushrooms LMW compounds.

In some human cancer cases, the activity of p53 is inhibited by the overexpressed Mdm2 (E3 ubiquitin-protein ligase Mdm2) oncoprotein.1 Mdm2 acts as an ubiquitin ligase, resulting in p53 ubiquitination and subsequent p53 proteasomal degradation. The disruption of the Mdm2-p53 interaction using small-molecule inhibitors is recognized as a promising strategy for anticancer drug design.2 Mushrooms are a vast and yet largely untapped source of powerful new pharmaceutical products. In particular, and most importantly for modern medicine, they represent an unlimited source of compounds with antitumor and immunostimulating properties.3 In this study, a total of 85 LMW (low molecular weight) compounds present in mushrooms were used in a protein-ligand docking experiment using a Mdm2 protein structure (PDB:1T4E) as receptor protein target

Docking studies using proteins involved in breast cancer and low molecular weight compounds found in wild mushrooms

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