The biological activity of the wine anthocyanins delphinidin and petunidin is mediated through Msn2 and Msn4 in Saccharomyces cerevisiae

The effect of DMSO on Saccharomyces cerevisiae yeast with different energy metabolism and antioxidant status

We studied the effect of dimethyl sulfoxide (DMSO) on the biochemical and physiological parameters of S. cerevisiae yeast cells with varied energy metabolism and antioxidant status. The wild-type cells of varied genetic backgrounds and their isogenic mutants with impaired antioxidant defences (Δsod mutants) or response to environmental stress (ESR) (Δmsn2, Δmsn4 and double Δmsn2msn4 mutants) were used. Short-term exposure to DMSO even at a wide range of concentrations (2-20%) had little effect on the metabolic activity of the yeast cells and the stability of their cell membranes, but induced free radicals production and clearly altered their proliferative activity. Cells of the Δsod1 mutant showed greater sensitivity to DMSO in these conditions. DMSO at concentrations from 4 to 10-14% (depending on the strain and genetic background) activated the ESR programme. The effects of long-term exposure to DMSO were mainly depended on the type of energy metabolism and antioxidant system efficiency. Yeast cells with reduced antioxidant system efficiency and/or aerobic respiration were more susceptible to the toxic effects of DMSO than cells with a wild-type phenotype and respiro-fermentative or fully fermentative metabolism. These studies suggest a key role of stress response programs in both the processes of cell adaptation to small doses of this xenobiotic and the processes related to its toxicity resulting from large doses or chronic exposure to DMSO.

In vitro assessment of multipotential therapeutic importance of Hericium erinaceus mushroom extracts using different solvents

Infectious disease is one of the major threats to humans and it is the second leading cause of death worldwide. Edible mushrooms have many nutritional and medicinal values to human health. The medicinal properties of edible mushroom extract in inhibiting pathogenic microorganisms had advantages over the use of chemically synthetic antimicrobial compounds due to less unwanted side effects and can combat microbial resistance. This study hypothesized that the polarity affects the extraction quality of Hericium erinaceus fruiting bodies which was prepared and subsequently affects its activity as an antimicrobial against six tested microorganisms, including MRSA, and Streptococcus mutans, Enterobacter cloaca, Salmonella typhimurium, and Candida lipolytica; antiviral against Hepatitis A virus (HAV) virus; antioxidant using 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay; and anti-inflammatory potential. So, the mushroom was quantitatively evaluated to assess its content of flavonoids, alkaloids, tannins, saponins, carbohydrates, protein, nitrogen, and oil. The current research clarified here that aquatic extract has a significant activity as an antioxidant (IC50 = 53.7 µg/mL) and antiviral (IC50 = 24.97 µg/mL), while ethyl acetate extract showed a reasonable antimicrobial activity rather than all tested extract against tested microorganisms. Unfortunately, all extracts under investigation possess low anti-inflammatory action according to the adopting protocol. The superior results of both water and ethyl acetate extracts were later investigated by HPTLC and GC-MS for preliminary prediction of the chemical constitution of those extracts. H. erinaceus mushroom succeeded to establish promising antimicrobial, antiviral, and antioxidant activities while it has low anti-inflammatory activity. Both HPTLC and GC-MS could identify the chemical constituents of the mushroom crude extract.

On the Role of the Carboxyl Group to the Protective Effect of o-dihydroxybenzoic Acids to Saccharomyces cerevisiae Cells upon Induced Oxidative Stress

In the present work, the role of the carboxyl group of o-dihydroxybenzoic acids (pyrocatechuic, 2,3-diOH-BA and protocatechuic, 3,4-diOH-BA) on the protection against induced oxidative stress in Saccharomyces cerevisiae was examined. Catechol (3,4-diOH-B) was included for comparison. Cell survival, antioxidant enzyme activities, and TBARS level were used to evaluate the efficiency upon the stress induced by H₂O₂ or cumene hydroperoxide. Theoretical calculation of atomic charge values, dipole moment, and a set of indices relevant to the redox properties of the compounds was also carried out in the liquid phase (water). Irrespective of the oxidant used, 2,3-diOH-BA required by far the lowest concentration (3–5 μM) to facilitate cell survival. The two acids did not activate catalase but reduced superoxide dismutase activity (3,4-diOH-BA>2,3-diOH-BA). TBARS assay showed an antioxidant effect only when H₂O₂ was used; equal activity for the two acids and inferior to that of 3,4-diOH B. Overall, theoretical and experimental findings suggest that the 2,3-diOH-BA high activity should be governed by metal chelation. In the case of 3,4-diOH BA, radical scavenging increases, and chelation capacity decreases. The lack of carboxyl moiety (3,4-diOH B) improves to radical scavenging, interaction with lipophilic free radicals, and antioxidant enzymes. The present study adds to our knowledge of the antioxidant mechanism of dietary phenols in biological systems.

Extracts of Digested Berries Increase the Survival of Saccharomyces cerevisiae during H2O2 Induced Oxidative Stress

Many studies suggest anthocyanins may prevent the development of several diseases. However, anthocyanin bioactivity against cellular stress is not fully understood. This study aimed to evaluate the protective effect of berry anthocyanins on stressed cells using Saccharomyces cerevisiae. The impact of in vitro gastrointestinal digestion on anthocyanin profiles was also assessed. Bilberry and blackcurrant had higher anthocyanin levels than raspberry and strawberry, but digestion reduced the detected anthocyanins by approximately 90%. Yeast cells with and without digested or nondigested anthocyanin extracts were exposed to H₂O₂ and examined for survival. In the presence of anthocyanins, particularly from digested strawberry, a significant increase in cell survival was observed, suggesting that the type and levels of anthocyanins are important factors, but they also need to undergo gastrointestinal (GI) structural modifications to induce cell defence. Results also showed that cells need to be exposed to anthocyanins before the stress was applied, suggesting induction of a cellular defence system by anthocyanins or their derivatives rather than by a direct antioxidative effect on H₂O₂. Overall, data showed that exposure of severely stressed yeast cells to digested berry extracts improved cell survival. The findings also showed the importance of considering gastrointestinal digestion when evaluating anthocyanins’ biological activity.

The Multifunctional Benefits of Naturally Occurring Delphinidin and Its Glycosides

Delphinidin (Del) and its glycosides are water-soluble pigments, belonging to a subgroup of flavonoids. They are health-promoting candidates for pharmaceutical and nutraceutical uses, as indicated by exhibiting antioxidation, anti-inflammation, antimicroorganism, antidiabetes, antiobesity, cardiovascular protection, neuroprotection, and anticancer properties. Glycosylation modification of Del is associated with increased stability and reduced biological activity. Del and its glycosides can be the alternative inhibitors of CBRs, ERα/β, EGFR, BCRP, and SGLT-1, and virtual docking indicates that the sugar moiety may not effectively interact with the active sites of the targets. Structure-based characteristics confer the multifunctional properties of Del and its glycosides. Because of their health-promoting effects, Del and its glycosides are promising and have been developed as potential pharmaceuticals. However, more investigation on the underlying mechanisms of Del and its glycosides in mediating cellular processes with high specificity are still needed. The research progression of Del and its glycosides over the last 10 years is comprehensively reviewed in this article.

Aminoacids and Flavonoids Profiling in Tempranillo Berries Can Be Modulated by the Arbuscular Mycorrhizal Fungi

(1) Background: Vitis vinifera L. cv. Tempranillo is cultivated over the world for its wine of high quality. The association of Tempranillo with arbuscular mycorrhizal fungi (AMF) induced the accumulation of phenolics and carotenoids in leaves, affected the metabolism of abscisic acid (ABA) during berry ripening, and modulated some characteristics and quality aspects of grapes. The objective of this study was to elucidate if AMF influenced the profiles and the content of primary and secondary metabolites determinants for berry quality in Tempranillo. (2) Methods: Fruit-bearing cuttings inoculated with AMF or uninoculated were cultivated under controlled conditions. (3) Results: Mycorrhizal symbiosis modified the profile of metabolites in Tempranillo berries, especially those of the primary compounds. The levels of glucose and amino acids clearly increased in berries of mycorrhized Tempranillo grapevines, including those of the aromatic precursor amino acids. However, mycorrhizal inoculation barely influenced the total amount and the profiles of anthocyanins and flavonols in berries. (4) Conclusions: Mycorrhizal inoculation of Tempranillo grapevines may be an alternative to the exogenous application of nitrogen compounds in order to enhance the contents of amino acids in grapes, which may affect the aromatic characteristics of wines.

Proteomic analysis of Saccharomyces cerevisiae to study the effects of red wine polyphenols on oxidative stress

Understanding the molecular mechanisms underlying the "French paradox" has contributed to a growing interest in the investigation of the biological activity of red wine polyphenols (RWP). The main goal of this research is to provide valuable information on how RWP could exert their biological action at the cellular level. So, we report a proteomic analysis of S. cerevisiae exposed to both pro-oxidant (H₂O₂) and antioxidant (wine) agents. Cellular proteome analysis shows that RWP modify the level of certain proteins. Under both normal conditions (Wine treatment) and oxidative stress situations (Wine + H₂O₂ treatment), the proteins involved in the metabolism and biosynthesis of biomolecules were down-regulated, while one ribosomal protein was up-regulated, probably performing its ribosome-independent functions, and so contributing to the stress defense system. Considering this action mechanism, we suggest that RWP may be acting as mild pro-oxidants and, therefore, exerting a hormetic effect that leads to the strengthening of cells' antioxidant capacity.

Chemical Characterization of an Encapsulated Red Wine Powder and Its Effects on Neuronal Cells

Red wine polyphenols are known for their implications for human health protection, although they suffer from high instability. For this reason, a red wine powder was prepared by freeze-drying encapsulation in maltodextrin/arabic gum matrix, and its composition was determined by means of high-performance liquid chromatography coupled quadrupole time-of-flight mass spectrometry (HPLC-MS-QTOF). More than thirty polyphenols, including anthocyanins, flavanols, flavonols, phenolic acids and stilbenoids, were identified. Some of the main quantified polyphenols were: malvidin-3-O-glucoside, malvidin 3-O-(6″-acetyl-glucose), petunidin-3-O-glucoside, quercetin-3-O-glucuronide, syringenin-3-O-glucoside, epicatechin, gallic acid and syringic acid. The biological activity of this de-alcoholized and encapsulated red wine on human neuroblastoma SH-SY5Y cells was studied. The results showed that the encapsulated red wine powder has active redox properties, as verified by performing reactive oxygen species (ROS) analysis utilizing a neuronal model. This could help explain its action against the neurotoxicity induced by 6-hydroxydopamine (6-OHDA).

Effect of myricetin, pyrogallol, and phloroglucinol on yeast resistance to oxidative stress

The health beneficial effects of dietary polyphenols have been attributed to their intrinsic antioxidant activity, which depends on the structure of the compound and number of hydroxyl groups. In this study, the protective effects of pyrogallol, phloroglucinol, and myricetin on the yeast Saccharomyces cerevisiae were investigated. Pyrogallol and myricetin, which have a pyrogallol structure in the B ring, increased H2O2 resistance associated with a reduction in intracellular oxidation and protein carbonylation, whereas phloroglucinol did not exert protective effects. The acquisition of oxidative stress resistance in cells pretreated with pyrogallol and myricetin was not associated with an induction of endogenous antioxidant defences as assessed by the analysis of superoxide dismutase and catalase activities. However, myricetin, which provided greater stress resistance, prevented H2O2-induced glutathione oxidation. Moreover, myricetin increased the chronological lifespan of yeast lacking the mitochondrial superoxide dismutase (Sod2p), which exhibited a premature aging phenotype and oxidative stress sensitivity. These findings show that the presence of hydroxyl groups in the ortho position of the B ring in pyrogallol and myricetin contributes to the antioxidant protection afforded by these compounds. In addition, myricetin may alleviate aging-induced oxidative stress, particularly when redox homeostasis is compromised due to downregulation of endogenous defences present in mitochondria.

Antioxidant, antimutagenic, and anticarcinogenic effects of Papaver rhoeas L. extract on Saccharomyces cerevisiae

The aim of this work was to analyze the antioxidant and antimutagenic/anticarcinogenic capacity of Papaver rhoeas L. water extract against standard mutagen/carcinogen methyl methanesulfonate (MMS) and radiomimetic zeocin (Zeo) on a test system Saccharomyces cerevisiae. The following assays were used: 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, quantitative determination of superoxide anion (antireactive oxygen species [antiROS test]), DNA topology assay, D7ts1 test--for antimutagenic--and Ty1 transposition test--for anticarcinogenic effects. Strong pro-oxidative capacity of Zeo was shown to correlate with its well-expressed mutagenic and carcinogenic properties. The mutagenic and carcinogenic effects of MMS were also confirmed. Our data concerning the antioxidant activity of P. rhoeas L. extract revealed that concentration corresponding to IC(50) in the DPPH assay possessed the highest antioxidant activity in the antiROS biological assay. It was also observed that a concentration with 50% scavenging activity expressed the most pronounced antimutagenic properties decreasing Zeo-induced gene conversion twofold, reverse mutation fivefold, and total aberrations fourfold. The same concentration possessed well-expressed anticarcinogenic properties measured as reduction of MMS-induced Ty1 transposition rate fivefold and fourfold when Zeo was used as an inductor. Based on the well-expressed antioxidant, antimutagenic, and anticarcinogenic properties obtained in this work, the P. rhoeas L. extract could be recommended for further investigations and possible use as a food additive.

Strain design of Ashbya gossypii for single-cell oil production

Single-cell oil (SCO) represents a sustainable alternative for the oil industry. Accordingly, the identification of microorganisms with either higher lipidogenic ability or novel capacities for the transformation of raw materials constitutes a major challenge for the field of oil biotechnology. With this in mind, here, we were prompted to address the lipidogenic profile of the filamentous hemiascomycete Ashbya gossypii, which is currently used for the microbial production of vitamins. We found that A. gossypii mostly accumulates unsaturated fatty acids (FAs), with more than 50% of the total FA content corresponding to oleic acid. In addition, we engineered A. gossypii strains both lacking the beta-oxidation pathway and also providing ATP-citrate lyase (ACL) activity to block the degradation of FA and to increase the cytosolic acetyl-coenzyme A (CoA) content, respectively. The lipidogenic profile of the newly developed strains demonstrates that the mere elimination of the beta-oxidation pathway in A. gossypii triggers a significant increase in lipid accumulation that can reach 70% of cell dry weight. The use of A. gossypii as a novel and robust tool for the production of added-value oils is further discussed.

Quercetin protects Saccharomyces cerevisiae against oxidative stress by inducing trehalose biosynthesis and the cell wall integrity pathway

BACKGROUND

Quercetin is a naturally occurring flavonol with antioxidant, anticancer and anti-ageing properties. In this study we aimed to identify genes differentially expressed in yeast cells treated with quercetin and its role in oxidative stress protection.

METHODS

A microarray analysis was performed to characterize changes in the transcriptome and the expression of selected genes was validated by RT-qPCR. Biological processes significantly affected were identified by using the FUNSPEC software and their relevance in H(2)O(2) resistance induced by quercetin was assessed.

RESULTS

Genes associated with RNA metabolism and ribosome biogenesis were down regulated in cells treated with quercetin, whereas genes associated with carbohydrate metabolism, endocytosis and vacuolar proteolysis were up regulated. The induction of genes related to the metabolism of energy reserves, leading to the accumulation of the stress protectant disaccharide trehalose, and the activation of the cell wall integrity pathway play a key role in oxidative stress resistance induced by quercetin.

CONCLUSIONS

These results suggest that quercetin may act as a modulator of cell signaling pathways related to carbohydrate metabolism and cell integrity to exert its protective effects against oxidative stress.