Use of Saccharomyces cerevisiae and Caenorhabditis elegans as model organisms to study the effect of cocoa polyphenols in the resistance to oxidative stress

Optimization of bacterioruberin production from Halorubrum ruber and assessment of its antioxidant potential

Haloarchaea produce bacterioruberin, a major C50 carotenoid with antioxidant properties that allow for its potential application in the food, cosmetic, and pharmaceutical industries. This study aimed to optimize culture conditions for total carotenoid, predominantly comprising bacterioruberin, production using Halorubrum ruber MBLA0099. A one-factor-at-a-time and statistically-based experimental design were applied to optimize the culture conditions. Culture in the optimized medium caused an increase in total carotenoid production from 0.496 to 1.966 mg L- 1 Maximal carotenoid productivity was achieved in a 7-L laboratory-scale fermentation and represented a 6.05-fold increase (0.492 mg L-1 d-1). The carotenoid extracts from strain MBLA0099 exhibited a 1.8-10.3-fold higher antioxidant activity in vitro, and allowed for a higher survival rate of Caenorhabditis elegans under oxidative stress conditions. These results demonstrated that Hrr. ruber MBLA0099 has significant potential as a haloarchaon for the commercial production of bacterioruberin.

Bifidobacterium animalis subsp. lactis BPL1™ and Its Lipoteichoic Acid Modulate Longevity and Improve Age/Stress-Related Behaviors in Caenorhabditis elegans

Life expectancy has increased globally in recent decades, driving interest in maintaining a healthy life that includes preservation of physical and mental abilities, particularly in elderly people. The gut microbiome becomes increasingly perturbed with aging so the use of probiotics can be a strategy for maintaining a balanced gut microbiome. A previous report showed that Bifidobacterium animalis subsp. lactis BPL1™ induces through its lipoteichoic acid (LTA) fat reduction activities via the insulin/IGF-1 signaling pathway. Here, we have delved into the mechanism of action, eliminating alternative pathways as putative mechanisms. Furthermore, we have identified that BPL1™, its heat treated form (BPL1™ HT) and its LTA prolong longevity in Caenorhabditis elegans (C. elegans) in an insulin/IGF-1-dependent mechanism, and its consumption improves the oxidative stress response, gut permeability and protection against pathogenic infections. Furthermore, positive effects on C. elegans stress-related behaviors and in the Alzheimer's Disease model were found, highlighting the potential of the strain in improving the cognitive functions and proteotoxicity in the nematode. These results indicate the pivotal role of the IGF-1 pathway in the activity of the strain and pave the way for potential applications of BPL1™, BPL1™ HT and its LTA in the field of longevity and age-related markers.

Effects of a lotion containing probiotic ferment lysate as the main functional ingredient on enhancing skin barrier: a randomized, self-control study

There is an emergent need to develop functional cosmetic ingredients for the topical management of skin barrier function. This study aimed to investigate the efficacy of a lotion containing fermented lysates VHProbi® Mix R for enhancing the skin barrier. In vitro studies demonstrated that fermented cultures of both Lacticaseibacillus rhamnosus VHProbi® E06 (E06) and L. paracasei VHProbi® E12 (E12) had antioxidant capacity, showing promising scavenging capability for 2,2-diphenyl-1-picryl-hydrazyl. The antioxidant capacity of these strains was also demonstrated in the model of Caenorhabditis elegans. In addition, the fermented lysates of both E06 and E12 enhanced the proliferation of HaCaT cells and ameliorated the toxicity induced by Staphylococcus aureus ATCC 25923, hydrogen peroxide, and ultraviolet B radiation in the HaCaT cell models, which simulated the irritants that facial sensitive skin is exposed to. Subsequently, the ingredient VHProbi® Mix R was formulated using four kinds of fermented lysates: E06, E12, Lactiplantibacillus plantarum VHProbi® E15, and Lactobacillus helveticus VHProbi® Y21. A clinical study was conducted to investigate whether a lotion containing VHProbi® Mix R would be beneficial for people to enhance skin barrier. The participants were asked to use the investigational product for 30 days. Several indicators, including transepidermal water loss (TEWL), skin moisturization, and redness were measured at day 0 and day 30 using VISIA®-CR and CK®-MPA systems. Meanwhile, the burden of sensitive skin (BoSS) and self-assessment questionnaires were performed at baseline and endpoint of this study. The study data showed that at day 30, there was a significant decrease in TEWL (P < 0.01), redness measured by CK®-MPA (P < 0.01), and redness profile measured by VISIA®-CR compared with the baseline measurements. Skin moisturization had significantly increased after treatment with the lotion for 30 days. BoSS and self-assessment questionnaires also substantiated that the participants felt a markedly positive change in their sensitive skin. Hence, we hypothesize that applying the topical functional VHProbi® Mix R could confer effective benefits for people with sensitive skin and this represents a promising intervention for enhancing skin barrier.

Characterization of Cetobacterium somerae CPU-CS01 isolated from the intestine of healthy crucian carp (Carassius auratus) as potential probiotics against Aeromonas hydrophila infection

Cetobacterium somerae is a commensal bacterium for many fish species. However, research on C. somerae has been limited so far, and its function and beneficial potential require to be further investigated. The objective of this study was to evaluate the probiotic properties of C. somerae CPU-CS01 isolated from the intestinal contents of crucian carp (Carassius auratus). Hemolytic activity, antibiotic susceptibility, acid tolerance, bile salt tolerance, free radical scavenging, and enzyme production properties were tested for in vitro. Caenorhabditis elegans and zebrafish (Danio rerio) model were used to evaluate the antioxidant and anti-infective effects of C. somerae CPU-CS01 in vivo. Our results showed that C. somerae CPU-CS01 had no hemolytic activity, it produced cellulase, amylase, and survived at low pH (2.0-3.0) and in the presence of bile salts. The cell-free culture supernatant (CFCS) of C. somerae CPU-CS01 possessed DPPH radical, hydroxyl radical, and superoxide anion scavenging activity. C. elegans fed with C. somerae CPU-CS01 were more resistant to hydrogen peroxide-induced oxidative stress and Aeromonas hydrophila infection. In addition, zebrafish-fed diets containing C. somerae CPU-CS01 showed improved survival after A.hydrophila infection. Based on these results, the positive probiotic properties of C. somerae CPU-CS01 isolated from the intestinal contents of crucian carp make it a potential candidate for probiotic.

Effect-Directed, Chemical and Taxonomic Profiling of Peppermint Proprietary Varieties and Corresponding Leaf Extracts

During the development of novel, standardized peppermint extracts targeting functional applications, it is critical to adequately characterize raw material plant sources to assure quality and consistency of the end-product. This study aimed to characterize existing and proprietary, newly bred varieties of peppermint and their corresponding aqueous extract products. Taxonomy was confirmed through genetic authenticity assessment. Non-target effect-directed profiling was developed using high-performance thin-layer chromatography-multi-imaging-effect-directed assays (HPTLC-UV/Vis/FLD-EDA). Results demonstrated substantial differences in compounds associated with functional attributes, notably antioxidant potential, between the peppermint samples. Further chemical analysis by high-performance liquid chromatography-photodiode array/mass spectrometry detection (HPLC-PDA/MS) and headspace solid-phase microextraction-gas chromatography-flame ionization/MS detection (headspace SPME-GC-FID/MS) confirmed compositional differences. A broad variability in the contents of flavonoids and volatiles was observed. The peppermint samples were further screened for their antioxidant potential using the Caenorhabditis elegans model, and the results indicated concordance with observed content differences of the identified functional compounds. These results documented variability among raw materials of peppermint leaves, which can yield highly variable extract products that may result in differing effects on functional targets in vivo. Hence, product standardization via effect-directed profiles is proposed as an appropriate tool.

Immunomodulatory and Antioxidant Properties of a Novel Potential Probiotic Bacillus clausii CSI08

Spore-forming bacteria of the Bacillus genus have demonstrated potential as probiotics for human use. Bacillus clausii have been recognized as efficacious and safe agents for preventing and treating diarrhea in children and adults, with pronounced immunomodulatory properties during several in vitro and clinical studies. Herein, we characterize the novel strain of B. clausii CSI08 (Munispore^®) for probiotic attributes including resistance to gastric acid and bile salts, the ability to suppress the growth of human pathogens, the capacity to assimilate wide range of carbohydrates and to produce potentially beneficial enzymes. Both spores and vegetative cells of this strain were able to adhere to a mucous-producing intestinal cell line and to attenuate the LPS- and Poly I:C-triggered pro-inflammatory cytokine gene expression in HT-29 intestinal cell line. Vegetative cells of B. clausii CSI08 were also able to elicit a robust immune response in U937-derived macrophages. Furthermore, B. clausii CSI08 demonstrated cytoprotective effects in in vitro cell culture and in vivo C. elegans models of oxidative stress. Taken together, these beneficial properties provide strong evidence for B. clausii CSI08 as a promising potential probiotic.

Composition of Nonextractable Polyphenols from Sweet Cherry Pomace Determined by DART-Orbitrap-HRMS and Their In Vitro and In Vivo Potential Antioxidant, Antiaging, and Neuroprotective Activities

Sweet cherry pomace is an important source of phenolic compounds with beneficial health properties. As after the extraction of phenolic compounds, a phenolic fraction called nonextractable polyphenols (NEPs) remains usually retained in the extraction residue, alkaline and acid hydrolyses and enzymatic-assisted extraction (EAE) were carried out in this work to recover NEPs from the residue of conventional extraction from sweet cherry pomace. In vitro and in vivo evaluation of the antioxidant, antihypertensive, antiaging, and neuroprotective capacities employing Caenorhabditis elegans was achieved for the first time. Extractable phenolic compounds and NEPs were separated and identified by families by high-performance thin-layer chromatography (HPTLC) with UV/Vis detection. A total of 39 phenolic compounds were tentatively identified in all extracts by direct analysis in real-time high-resolution mass spectrometry (DART-Orbitrap-HRMS). EAE extracts presented the highest in vitro and in vivo antioxidant capacity as well as the highest in vivo antiaging and neuroprotective capacities. These results showed that NEPs with interesting biological properties are retained in the extraction residue, being usually underestimated and discarded.

Antioxidant properties and phenolic composition of "Composed Yerba Mate"

Yerba mate contains bioactive compounds, and is widely consumed as a decoction beverage in several Southern American countries. At present, the consumption of mate with added herbal blends and flavors, called "composed yerba mate", has increased; however, no studies on the antioxidant characteristics of these products have been published. In this sense, the main objective was to assess the antioxidant characteristics of "composed yerba mate" compared to "traditional yerba mate", in the form it is traditionally consumed. Total polyphenols content ranged from 15 to 45 mg/g GAE in all decoctions analyzed. Seventeen phenolic compounds were identified and quantified by HPLC-DAD-MS/MS, mainly belonging to the caffeoylquinic acids group. The antioxidant capacity was measured using in vitro assays, Ferric reducing ability of plasma (FRAP) and Trolox equivalent antioxidant capacity (TEAC), and with Saccharomyces cerevisiae as the in vivo model organism. All decoctions displayed antioxidant activity and were capable of rescuing yeast cells between 10.68 and 18.38% from oxidative stress. Multiple regression analysis showed a high correlation between phenolic composition and activity of samples, where different compounds indicate a significant contribution to the observed activity. Significant differences were found in the content, profile and antioxidant activity of polyphenols when "traditional yerba mate" and "composed yerba mate" were compared. In some cases, the antioxidant capacity was similar or higher in composed yerba mate; while the rest displayed lower biological activity. Based on these findings, it would be possible to assume that the addition of herb mixtures modifies the antioxidant and biological properties of mate.

Supplementary Information

The online version contains supplementary material available at (10.1007/s13197-020-04961-x).

Weissella confusa CGMCC 19,308 Strain Protects Against Oxidative Stress, Increases Lifespan, and Bacterial Disease Resistance in Caenorhabditis elegans

The aim of this study was to investigate the antioxidant activity of Weissella confusa CGMCC 19,308 and its influence on longevity and host defense against Salmonella Typhimurium of Caenorhabditis elegans. The CFCS (cell-free culture supernatant) of W. confusa CGMCC 19,308 possessed DPPH radicals, hydroxyl radicals, and superoxide anion scavenging activity. The lifespan of the C. elegans fed W. confusa CGMCC 19,308 was significantly (p < 0.001) longer than that of worms fed Escherichia coli OP50. Moreover, worms fed W. confusa CGMCC 19,308 were more resistant to oxidative stress induced by hydrogen peroxide and S. Typhimurium infection. RNA-seq analysis showed that the most significantly differentially expressed genes (DEGs) in C. elegans fed with W. confusa CGMCC 19,308 were mainly col genes (col-43, col-2, col-40, col-155, col-37), glutathione-S-transferase (GST)-related genes (gst-44, gst-9, gst-17, gst-18, gstk-2), cnc-9 (immune-related gene), and sod-5 (superoxide dismutase). These results indicated that cuticle collagen synthesis, immunity, and antioxidant defense (AOD) system of C. elegans were affected after being fed with W. confusa CGMCC 19,308 instead of E. coli OP50. Our study suggested W. confusa CGMCC 19,308 had the antioxidant activity and could prolong lifespan and enhance the host defense against S. Typhimurium of C. elegans. This study provided new evidences for the W. confusa CGMCC 19,308 as a potential probiotic candidate for anti-aging and anti-bacterial infection.

Heat-Treated Bifidobacterium longum CECT-7347: A Whole-Cell Postbiotic with Antioxidant, Anti-Inflammatory, and Gut-Barrier Protection Properties

Non-viable preparations of probiotics, as whole-cell postbiotics, attract increasing interest because of their intrinsic technological stability, and their functional properties, such as immune system modulation, gut barrier maintenance, and protection against pathogens. However, reports on Bifidobacteria-derived postbiotics remain scarce. This study aims to demonstrate the functional properties of a heat-treated (HT), non-viable, Bifidobacterium longum strain, CECT-7347, a strain previously selected for its anti-inflammatory phenotype and ability to improve biomarkers of intestinal integrity in clinical trials. The study used the nematode Caenorhabditis elegans and HT-29 cell cultures as eukaryotic model systems. Our results show that HT-CECT-7347 preserves the capacity to protect against oxidative stress damage, while it also reduces acute inflammatory response and gut-barrier disruption, and inhibits bacterial colonization, by activating pathways related to innate immune function. These findings highlight the interest of the ingredient as a novel postbiotic and pave the way to broaden the range of HT-CECT-7347 applications in gut health.

Caffeic and Dihydrocaffeic Acids Promote Longevity and Increase Stress Resistance in Caenorhabditis elegans by Modulating Expression of Stress-Related Genes

Caffeic and dihydrocaffeic acid are relevant microbial catabolites, being described as products from the degradation of different phenolic compounds i.e., hydroxycinnamoyl derivatives, anthocyanins or flavonols. Furthermore, caffeic acid is found both in free and esterified forms in many fruits and in high concentrations in coffee. These phenolic acids may be responsible for a part of the bioactivity associated with the intake of phenolic compounds. With the aim of progressing in the knowledge of the health effects and mechanisms of action of dietary phenolics, the model nematode Caenorhabditis elegans has been used to evaluate the influence of caffeic and dihydrocaffeic acids on lifespan and the oxidative stress resistance. The involvement of different genes and transcription factors related to longevity and stress resistance in the response to these phenolic acids has also been explored. Caffeic acid (CA, 200 μM) and dihydrocaffeic acid (DHCA, 300 μM) induced an increase in the survival rate of C. elegans under thermal stress. Both compounds also increased the mean and maximum lifespan of the nematode, compared to untreated worms. In general, treatment with these acids led to a reduction in intracellular ROS concentrations, although not always significant. Results of gene expression studies conducted by RT-qPCR showed that the favorable effects of CA and DHCA on oxidative stress and longevity involve the activation of several genes related to insulin/IGF-1 pathway, such as daf-16, daf-18, hsf-1 and sod-3, as well as a sirtuin gene (sir-2.1).

Potential of Caenorhabditis elegans as an antiaging evaluation model for dietary phytochemicals: A review

Aging is an inevitable process characterized by the accumulation of degenerative damage, leading to serious diseases that affect human health. Studies on aging aim to develop pre-protection or therapies to delay aging and age-related diseases. A preventive approach is preferable to clinical treatment not only to reduce investment but also to alleviate pain in patients. Adjusting daily diet habits to improve the aging condition is a potentially attractive strategy. Fruits and vegetables containing active compounds that can effectively delay the aging process and reduce or inhibit age-related degenerative diseases have been identified. The signaling pathways related to aging in Caenorhabditis elegans are evolutionarily conserved; thus, studying antiaging components by intervening senescence process may contribute to the prevention and treatment of age-related diseases in humans. This review focuses on the effects of food-derived extracts or purified substance on antiaging in nematodes, as well as the underlying mechanisms, on the basis of several major signaling pathways and key regulatory factors in aging. The aim is to provide references for a healthy diet guidance and the development of antiaging nutritional supplements. Finally, challenges in the use of C. elegans as the antiaging evaluation model are discussed, together with the development that potentially inspire novel strategies and research tools.

Chitosan and procyanidin composite films with high antioxidant activity and pH responsivity for cheese packaging

Chitosan-procyanidin composite films (CS-PC films) with different mass ratios were prepared by solution casting method. Their structural, thermal, physical, and antioxidant properties, antibacterial activity and pH responsivity were determined. Compared with CS-control film, CS-PC films exhibited lower solubility and higher tensile strength. The antimicrobial properties against Escherichia coli and Aspergillus niger were improved by 20.0% and 30.4%, respectively. CS-PC films indicated good antioxidant activity through their DPPH and ABTS⁺ scavenging rates, which were 2.45 times higher than CS-control film. pH responsivity was represented by the outstanding changes in color, which were visible to the naked eye. Food packaging film with high antioxidant activity, bacteriostatic properties and pH responsivity was prepared by CS and PC. Compared with the initial properties of cheese, the characteristics of cheese packaged with CS-PC films were obviously better than those of the control groups.

Characterization of Novel Synthetic Polyphenols: Validation of Antioxidant and Vasculoprotective Activities

Antioxidant compounds, including polyphenols, have therapeutic effects because of their anti-inflammatory, antihypertensive, antithrombotic and antiproliferative properties. They play important roles in protecting the cardiovascular and neurological systems, by having preventive or protective effects against free radicals produced by either normal or pathological metabolism in such systems. For instance, resveratrol, a well-known potent antioxidant, has a counteracting effect on the excess of reactive oxygen species (ROS) and has a number of therapeutic benefits, like anti-inflammatory, anti-cancer and cardioprotective activities. Based on previous work from our group, and on the most frequent OH substitutions of natural polyphenols, we designed two series of synthetically accessible bis-polyhydroxyphenyl derivatives, separated by amide or urea linkers. These compounds exhibit high antioxidant ability (oxygen radical absorbance capacity (ORAC) assay) and interesting radical scavenging activity (RSA) values (2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and α,α-diphenyl-β-picrylhydrazyl (DPPH) tests). Some of the best polyphenols were evaluated in two biological systems, endothelial cells (in vitro) and whole aorta (ex vivo), highly susceptible for the deleterious effects of prooxidants under different inflammatory conditions, showing protection against oxidative stress induced by inflammatory stimuli relevant in cardiovascular diseases, i.e., Angiotensin II and IL-1β. Selected compounds also showed strong in vivo antioxidant properties when evaluated in the model organism Saccharomyces cerevisiae.

Current and future experimental approaches in the study of grape and wine polyphenols interacting gut microbiota

Interactions between polyphenols and gut microbiota are indeed a major issue of current interest in food science research. Knowledge in this subject is progressing as the experimental procedures and analysis techniques do. The aim of this article is to critically review the more leading-edge approaches that have been applied so far in the study of the interactions between grape/wine polyphenols and gut microbiota. This is the case of in vitro dynamic gastrointestinal simulation models that try to mitigate the limitations of simple static models (batch culture fermentations). More complex approaches include the experimentation with animals (mice, rats, pigs, lambs and chicks) and nutritional intervention studies in humans. Main advantages and limitations as well as the most relevant findings achieved by each approach in the study of how grape/wine polyphenols can modulate the composition and/or functionality of gut microbiota, are detailed. Also, common findings obtained by the three approaches (in vitro, animal models and human nutritional interventions) such as the fact that the Firmicutes/Bacteroidetes ratio tends to decrease after the feed/intake/consumption of grape/wine polyphenols are highlighted. Additionally, a nematode (Caenorhabditis elegans) model, previously used for investigating the mechanisms of processes such as aging, neurodegeneration, oxidative stress and inflammation, is presented as an emerging approach for the study of polyphenols interacting gut microbiota. © 2020 Society of Chemical Industry.

Caernohabditis elegans as a Model Organism to Evaluate the Antioxidant Effects of Phytochemicals

The nematode Caenorhabditis elegans was introduced as a model organism in biological research by Sydney Brenner in the 1970s. Since then, it has been increasingly used for investigating processes such as ageing, oxidative stress, neurodegeneration, or inflammation, for which there is a high degree of homology between C. elegans and human pathways, so that the worm offers promising possibilities to study mechanisms of action and effects of phytochemicals of foods and plants. In this paper, the genes and pathways regulating oxidative stress in C. elegans are discussed, as well as the methodological approaches used for their evaluation in the worm. In particular, the following aspects are reviewed: the use of stress assays, determination of chemical and biochemical markers (e.g., ROS, carbonylated proteins, lipid peroxides or altered DNA), influence on gene expression and the employment of mutant worm strains, either carrying loss-of-function mutations or fluorescent reporters, such as the GFP.

Plant and fungal products that extend lifespan in Caenorhabditis elegans

The nematode Caenorhabditis elegans is a useful model to study aging due to its short lifespan, ease of manipulation, and available genetic tools. Several molecules and extracts derived from plants and fungi extend the lifespan of C. elegans by modulating aging-related pathways that are conserved in more complex organisms. Modulation of aging pathways leads to activation of autophagy, mitochondrial biogenesis and expression of antioxidant and detoxifying enzymes in a manner similar to caloric restriction. Low and moderate concentrations of plant and fungal molecules usually extend lifespan, while high concentrations are detrimental, consistent with a lifespan-modulating mechanism involving hormesis. We review here molecules and extracts derived from plants and fungi that extend the lifespan of C. elegans, and explore the possibility that these natural substances may produce health benefits in humans.

The Mechanisms Behind the Biological Activity of Flavonoids

Flavonoids are phenolic compounds widely distributed in the human diet. Their intake has been associated with a decreased risk of different diseases such as cancer, immune dysfunction or coronary heart disease. However, the knowledge about the mechanisms behind their in vivo activity is limited and still under discussion. For years, their bioactivity was associated with the direct antioxidant and radical scavenging properties of phenolic compounds, but nowadays this assumption is unlikely to explain their putative health effects, or at least to be the only explanation for them. New hypotheses about possible mechanisms have been postulated, including the influence of the interaction of polyphenols and gut microbiota and also the possibility that flavonoids or their metabolites could modify gene expression or act as potential modulators of intracellular signaling cascades. This paper reviews all these topics, from the classical view as antioxidants in the context of the Oxidative Stress theory to the most recent tendencies related with the modulation of redox signaling pathways, modification of gene expression or interactions with the intestinal microbiota. The use of C. elegans as a model organism for the study of the molecular mechanisms involved in biological activity of flavonoids is also discussed.

Trehalose Protects the Probiotic Yeast Saccharomyces boulardii against Oxidative Stress-Induced Cell Death

Saccharomyces boulardii is the only probiotic yeast with US Food and Drug Administration approval. It is routinely used to prevent or treat acute diarrhea and other gastrointestinal disorders, including the antibiotic-associated diarrhea caused by Clostridium difficile infections. The formation of reactive oxygen species (ROS), specifically H₂O₂ during normal aerobic metabolism, contributes to programmed cell death and represents a risk to the viability of the probiotic microbe. Moreover, a loss of viability reduces the efficacy of the probiotic treatment. Therefore, inhibiting the accumulation of ROS in the oxidant environment could improve the viability of the probiotic yeast and lead to more efficacious treatment. Here, we provide evidence that supplementation with a non-reducing disaccharide, namely trehalose, enhanced the viability of S. boulardii exposed to an oxidative environment by preventing metacaspase YCA1-mediated programmed cell death through inhibition of intracellular ROS production. Our results suggest that supplementation with S. boulardii together with trehalose could increase the viability of the organism, and thus improve its effectiveness as a probiotic and as a treatment for acute diarrhea and other gastrointestinal disorders.

Proteomic Analysis of Saccharomyces cerevisiae Response to Oxidative Stress Mediated by Cocoa Polyphenols Extract

The present study addressed the protective effects against oxidative stress (OS) of a cocoa powder extract (CPEX) on the protein expression profile of S. cerevisiae. A proteomic analysis was performed after culture preincubation with CPEX either without stress (−OS) or under stress conditions (+OS) (5 mM of H₂O₂). LC-MS/MS identified 33 differentially expressed proteins (–OS: 14, +OS: 19) that were included By Gene Ontology analysis in biological processes: biosynthesis of amino acids, carbohydrate metabolism and reactive oxygen species metabolic process. In a gene-knockout strains study, eight proteins were identified as putative candidates for being involved in the protective mechanism of cocoa polyphenols against OS induced by H₂O₂. CPEX was able to exert its antioxidant activity in yeast mainly through the regulation of: (a) amino acids metabolism proteins by modulating the production of molecules with known antioxidant roles; (b) stress-responsive protein Yhb1, but we were unable to fully understand its down-regulation; (c) protein Prb1, which can act by clipping Histone H3 N-terminal tails that are related to cellular resistance to DNA damaging agents.

Chemical Composition and Antioxidant Properties of Essential Oils from Peppermint, Native Spearmint and Scotch Spearmint

Natural antioxidants have drawn growing interest for use in animal feed and the food industry. In the current study, essential oils (EOs) obtained from hydrodistillation of three mentha species, including Mentha piperita (peppermint), Mentha spicata (native spearmint) and Mentha gracilis (Scotch spearmint), harvested in the Midwest region in the United States, were analyzed for their chemical composition using gas chromatography-mass spectrometry, and their antioxidant properties were assessed through chemical assays, in vitro cell culture modeling and in Caenorhabditis elegans (C. elegans). The activity of ferric iron reduction and free-radical scavenging capacity were assessed through chemical-based assays, including the reducing power assay, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, and Trolox equivalent antioxidant capacity assay (TEAC). Subsequently, the capacity of EOs to mitigate lipid peroxidation was analyzed at various doses using fresh liver homogenates from pigs. A porcine jejunum epithelial cell line (IPEC-J2) was employed as in vitro model to study the cellular antioxidant activity of the mint EOs. Finally, the effectiveness of mint EOs to alleviate acute systemic oxidative damage were evaluated in vivo using C. elegans. Data were analyzed by the MIXED procedure of SAS. Contrast statement was performed to assess linear or quadratic effects of mint EOs given at various doses. All three EOs are mostly composed of monoterpenes and their derivatives (76-90%), but differed in the major compounds, which are menthol and menthone (50%) in peppermint EO and carvone (70%) in spearmint EOs. Three mint EOs demonstrated prominent radical scavenging and Fe³⁺ reducing activity in chemical-based assays. In comparison with native and Scotch spearmint EOs, peppermint EO had the lowest (p < 0.05) half maximal effective concentration (EC50) in DPPH and TEAC assays and higher efficacy in the reducing power assay. All three EOs exhibited equivalent activity in mitigation of chemical-induced lipid peroxidation in liver tissues in a dose-dependent manner (linear, p < 0.001). The maximal cellular antioxidant activity (CAA) was observed at 5 µg/mL for peppermint, and 100 µg/mL for native and Scotch spearmint EOs. The addition of 25 µg/mL of both spearmint EOs increased (p < 0.05) cellular concentrations of glutathione in H₂O₂-treated IPEC-J2 cells, suggesting enhanced endogenous antioxidant defense. Supplementation of 100 µg/mL of peppermint or Scotch spearmint EO significantly increased (p < 0.05) the survival rate of C. elegans in response to H₂O₂-induced oxidative stress. The protective effect is comparable to that of supplementation of 10 µg/mL of ascorbic acid. However native spearmint EO failed to reduce the death rate within the same supplementation dose (10-200 μg/mL).

Antioxidant Characterization and Biological Effects of Grape Pomace Extracts Supplementation in Caenorhabditis elegans

The aim of this work was to evaluate the biological activity of four grape pomace (GP) extracts that are rich in polyphenols using C. elegans as an in vivo model. Different concentrations of the GP extracts were assessed for their effects on the resistance of C. elegans against thermally induced oxidative stress, accumulation of reactive oxygen species (ROS), and lifespan. The cultivation of C. elegans with relatively low concentrations of GP extracts increased their resistance against thermal stress and prolonged their lifespan, while high levels displayed detrimental effects. In the studied extracts, maximum protection was observed for levels of polyphenols around 7 to 9 µg gallic acid equivalents per cultivation plate. The obtained results suggested that small changes in the ROS levels could have beneficial effects, although further studies are required to fully understand the impact of the extracts and assayed doses on ROS levels to explain the mechanism that is involved in the observed effects.

Epicatechin modulates stress-resistance in C. elegans via insulin/IGF-1 signaling pathway

The nematode Caenorhabditis elegans has been used to examine the influence of epicatechin (EC), an abundant flavonoid in the human diet, in some stress biomarkers (ROS production, lipid peroxidation and protein carbonylation). Furthermore, the ability of EC to modulate the expression of some key genes in the insulin/IGF-1 signaling pathway (IIS), involved in longevity and oxidative or heat shock stress response, has also been explored. The final aim was to contribute to the elucidation of the mechanisms involved in the biological effects of flavonoids. The results showed that EC-treated wild-type C. elegans exhibited increased survival and reduced oxidative damage of biomolecules when submitted to thermal stress. EC treatment led to a moderate elevation in ROS levels, which might activate endogenous mechanisms of defense protecting against oxidative insult. The enhanced stress resistance induced by EC was found to be mediated through the IIS pathway, since assays in daf-2, age-1, akt-1, akt-2, sgk-1, daf-16, skn-1 and hsf-1 loss of function mutant strains failed to show any heat-resistant phenotype against thermal stress when treated with EC. Consistently, EC treatment upregulated the expression of some stress resistance associated genes, such as gst-4, hsp-16.2 and hsp-70, which are downstream regulated by the IIS pathway.

β-Cryptoxanthin Reduces Body Fat and Increases Oxidative Stress Response in Caenorhabditis elegans Model

β-Cryptoxanthin (BCX) is a major dietary pro-vitamin A carotenoid, found mainly in fruits and vegetables. Several studies showed the beneficial effects of BCX on different aspects of human health. In spite of the evidence, the molecular mechanisms of action of BCX need to be further investigated. The Caenorhabditis elegans model was used to analyze in vivo the activity of BCX on fat reduction and protection to oxidative stress. Dose-response assays provided evidence of the efficacy of BCX at very low dose (0.025 µg/mL) (p < 0.001) on these processes. Moreover, a comparative analysis with other carotenoids, such as lycopene and β-carotene, showed a stronger effect of BCX. Furthermore, a transcriptomic analysis of wild-type nematodes supplemented with BCX revealed upregulation of the energy metabolism, response to stress, and protein homeostasis as the main metabolic targets of this xanthophyll. Collectively, this study provides new in vivo evidence of the potential therapeutic use of BCX in the prevention of diseases related to metabolic syndrome and aging.

Small Library of Triazolyl Polyphenols Correlating Antioxidant Activity and Stability with Number and Position of Hydroxyl Groups

Polyphenolic compounds have attracted much interest because of their antioxidant properties and multiple applications, from food or cosmetic preservatives to free radical scavengers as therapeutic agents. Inspired by common OH substitutions in natural products, here we describe a small library of 1,2,3-triazoles disubstituted with polyphenol groups at 1,4-positions, in an attempt to correlate the number and position of hydroxyl groups in the aromatic rings with the antioxidant activity. Some compounds from this library exhibit strong radical scavenging activities in the oxygen radical absorbance capacity assay, similar to or even higher than resveratrol and other well-kwon flavonoids. The antioxidant activity for selected compounds was confirmed in vitro through the 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate) test and in vivo by a Saccharomyces cerevisiae model organism assay. The activity depends on the number and position of the hydroxyl groups, with compounds bearing a 2″5″-hydroxyl substituents on the phenyl ring at position 4 showing the best antioxidant values. The presence of two quinone-forming phenolic groups at the same molecule is behind the instability of some of these compounds in aqueous media.

Antioxidant Activity of Selected Polyphenolics in Yeast Cells: The Case Study of Montenegrin Merlot Wine

Screens of antioxidant activity (AA) of various natural products have been a focus of the research community worldwide. This work aimed to differentiate selected samples of Merlot wines originated from Montenegro, with regard to phenolic profile and antioxidant capacity studied by survival rate, total sulfhydryl groups and activities of glutathione peroxidase (GPx), glutathione reductase and catalase in H₂O₂⁻stressed Saccharomyces cerevisiae cells. In this study, DPPH assay was also performed. Higher total phenolic content leads to an enhanced AA under both conditions. The same trend was observed for catechin and gallic acid, the most abundant phenolics in the examined wine samples. Finally, the findings of an Artificial Neural Network (ANN) model were in a good agreement (r² = 0.978) with the experimental data. All tested samples exhibited a protective effect in H₂O₂⁻stressed yeast cells. Pre-treatment with examined wines increased survival in H₂O₂⁻stressed cells and shifted antioxidative defense towards GPx⁻mediated defense. Finally, sensitivity analysis of obtained ANN model highlights the complexity of the impact that variations in the concentrations of specific phenolic components have on the antioxidant defense system.

Tryptophan-Containing Dual Neuroprotective Peptides: Prolyl Endopeptidase Inhibition and Caenorhabditis elegans Protection from β-Amyloid Peptide Toxicity

Neuroprotective peptides represent an attractive pharmacological strategy for the prevention or treatment of age-related diseases, for which there are currently few effective therapies. Lactoferrin (LF)-derived peptides (PKHs) and a set of six rationally-designed tryptophan (W)-containing heptapeptides (PACEIs) were characterized as prolyl endopeptidase (PEP) inhibitors, and their effect on β-amyloid peptide (Aβ) toxicity in a Caenorhabditis elegans model of Alzheimer's disease (AD) was evaluated. Two LF-derived sequences, PKH8 and PKH11, sharing a W at the C-terminal end, and the six PACEI heptapeptides (PACEI48L to PACEI53L) exhibited significant in vitro PEP inhibition. The inhibitory peptides PKH11 and PACEI50L also alleviated Aβ-induced paralysis in the in vivo C. elegans model of AD. Partial or total loss of the inhibitory effect on PEP was achieved by the substitution of W residues in PKH11 and PACEI50L and correlated with the loss of protection against Aβ toxicity, pointing out the relevance of W on the neuroprotective activity. Further experiments suggest that C. elegans protection might not be mediated by an antioxidant mechanism but rather by inhibition of Aβ oligomerization and thus, amyloid deposition. In conclusion, novel natural and rationally-designed W-containing peptides are suitable starting leads to design effective neuroprotective agents.

Edible coatings incorporating pomegranate peel extract and biocontrol yeast to reduce Penicillium digitatum postharvest decay of oranges

This study investigated the potential use of two edible coatings, chitosan (CH) and locust bean gum (LBG), which incorporated chemically characterized water pomegranate peel extract (WPPE) or methanol pomegranate peel extract (MPPE) and the biocontrol agent (BCA) Wickerhamomyces anomalus, to control the growth of Penicillium digitatum and to reduce the postharvest decay of oranges. CH and LBG including pomegranate peel extracts (PPEs) at different concentrations were tested in vitro against P. digitatum to determine their antifungal efficacy; at the same time, the tolerance of viable cells of W. anomalus to increasing concentrations of WPPE and MPPE extracts was assessed. The potential application of selected bioactive coatings was evaluated in vivo on oranges, which had been artificially inoculated with P. digitatum, causal agent of green mold decay. CH incorporating MPPE or WPPE at all concentrations was able to inhibit in vitro P. digitatum, while LBG was active only at the highest MPPE or WPPE concentrations. W. anomalus BS91 was slightly inhibited only by MPPE-modified coatings, while no inhibition was observed by WPPE, which was therefore selected for the in vivo trials on oranges artificially inoculated with P. digitatum. The experimental results proved that the addition of 0.361 g dry WPPE/mL, both to CH and LBG coatings, significantly reduced disease incidence (DI) by 49 and 28% respectively, with respect to the relative controls. Besides the combination CH or LBG + WPPE, the addition of W. anomalus cells to coatings strengthened the antifungal effect with respect to the relative controls, as demonstrated by the significant reduction of DI (up to 95 and 75% respectively). The findings of the study contribute to the valorization of a value-added industrial byproduct and provide a significant advancement in the development of new food protectant formulations, which benefit from the synergistic effect between biocontrol agents and natural bioactive compounds.

Longevity promoting efficacies of different plant extracts in lower model organisms

Past investigations have shown that various plant extracts are capable of promoting longevity in lower model organisms like Caenorhabditis elegans, Drosophila melanogaster, Saccharomyces cerevisiae, Bombyx mori etc. Longevity studies on such organisms provide a foundation to explore anti-aging efficacies of such plant extracts in higher organisms. Plant extracts of acai palm, apple, asparagus, blueberry, cinnamon, cocoa, Damnacanthus, maize, milk thistle, mistletoe, peach, pomegranate, Rhodiola, rose, Sasa, turmeric, and Withania have extended lifespan in lower model organisms via diverse mechanisms like insulin like growth factor (IGF) signaling pathway, and antioxidant defense mechanisms. Knowledge of pathways altered by the extracts can be investigated as potential drug-targets for natural anti-aging interventions. Thus, the aim of the review is to scrutinize longevity promoting efficacies of various plant extracts in lower model organisms.

Use of Medaka Fish as Vertebrate Model to Study the Effect of Cocoa Polyphenols in the Resistance to Oxidative Stress and Life Span Extension

Oxidative stress (OS) can induce cell apoptosis and thus plays an important role in aging. Antioxidant foods protect tissues from OS and contribute to a healthier lifestyle. In this study, we described the used of medaka embryos (Oryzias latipes) to study the putative antioxidant capacity of dietary cocoa extract in vertebrates. A polyphenol-enriched cocoa extract regulated the expression of several genes implicated in OS, thereby protecting fish embryos from induced OS. The cocoa extract activated superoxide dismutase enzyme activity in embryos and adult fish tissues, suggesting a common mechanism for protection during embryonic development and adulthood. Furthermore, long-term feeding of the cocoa extract increased fish life span. Our study demonstrates that the polyphenol-enriched cocoa extract decreases OS and extends life span in medaka fish, validating the use of medaka embryos as an economical platform to screen the antioxidant capacity of food compounds.

Inhibitory effects of phenolic compounds of rice straw formed by saccharification during ethanol fermentation by Pichia stipitis

In this study, it was found that the type of phenolic acids derived from rice straw was the major factor affecting ethanol fermentation by Pichia stipitis. The aim of this study was to investigate the inhibitory effect of phenolic acids on ethanol fermentation with rice straw. Different cellulases produced different ratios of free phenolic acids to soluble conjugated phenolic acids, resulting in different fermentation efficiencies. Free phenolic acids exhibited much higher inhibitory effect than conjugated phenolic acids. The flow cytometry results indicated that the damage to cell membranes was the primary mechanism of inhibition of ethanol fermentation by phenolic acids. The removal of free phenolic acids from the hydrolysates increased ethanol productivity by 2.0-fold, indicating that the free phenolic acids would be the major inhibitors formed during saccharification. The integrated process for ethanol and phenolic acids may constitute a new strategy for the production of low-cost ethanol.

Probiotic administration improves sperm quality in asthenozoospermic human donors

The objective of this study is to analyse the effect of the ingestion of two selected antioxidant probiotics strains (Lactobacillus rhamnosus CECT8361 and Bifidobacterium longum CECT7347) on sperm quality parameters in asthenozoospermic males after three and six weeks of administration. Nine asthenozoospermic men without any medical treatment under similar diet conditions participated in the study. The quality of individual sperm samples was evaluated before (previous to ingestion), during (after 3 and 6 weeks of ingestion) and after probiotic administration (3 and 6 weeks after finishing the treatment). Sperm motility was evaluated by computer-assisted sperm analysis system, DNA fragmentation by sperm chromatin structure assay, cell viability by flow cytometry and measurement of intracellular H₂O₂ (reactive oxygen species; ROS) by flow cytometry using dichloro-dihydrofluorescein diacetate. Sperm motility was drastically improved after the treatment (approximately 6 fold change), DNA fragmentation was statistically reduced after probiotic administration from (approximately 1.2 fold change) and intracellular H₂O₂ level was decreased (approximately 3.5 fold change). Cell viability was not affected by the treatment. The significant improvement in sperm motility and the decrease in DNA fragmentation reported in this study provide preliminary evidence that probiotics could be administrated to improve motility and decrease DNA fragmentation and ROS levels in asthenozoospermic human males.

Evaluation of the Ability of Polyphenol Extracts of Cocoa and Red Grape to Promote the Antioxidant Response in Yeast Using a Rapid Multiwell Assay

Saccharomyces cerevisiae has been used as a model organism to study the capacity of cocoa and red grape extracts to trigger an antioxidant response. A methodology adapted to microtiter plates has been developed to monitor yeast growth after culture preincubation with food ingredients and exposure to oxidative stress by hydrogen peroxide and menadione. This methodology proved effective in measuring the ability of cocoa and red grape extracts to promote an antioxidant response in yeast, and also the prospect of conducting dose-response studies. Additionally, the method has proven useful to perform studies with mutant strains lacking genes that may be related to the mechanism of action underlying the antioxidant properties. Thus, in a single assay, it is possible to elucidate the sensitivity of strains to oxidative stress, the ability of an ingredient to promote an antioxidant response, and the possible implication of certain genes. Results of assays using strain hst3Δ showed that the antioxidant protection provided by exposure to cocoa and red grape extracts was not present in the strain lacking gene HST3 when H₂ O₂ and menadione were used as oxidizing agents. This effect was previously reported for cocoa extract only, with H₂ O₂ as stressor. Moreover, the results showed that the mutant strain hst3Δ is more resistant to menadione and H₂ O₂ in the absence of preincubation with cocoa and red grape extract, hinting at the possible implication of sirtuin Hst3 in the antioxidant cellular response.

A literature review of flavonoids and lifespan in model organisms

Epidemiological data on consumption of flavonoid-containing food points to the notion that some of these secondary plant metabolites may favour healthy ageing. The aim of the present paper was to review the literature on lifespan extension by flavonoids in worms, flies and mice. In most studies, worms and flies experienced lifespan extension when supplemented with flavonoids either as extracts or single compounds. Studies with mutant worms and flies give hints as to which gene products may be regulated by flavonoids and consequently enhance longevity. We discuss the data considering putative mechanisms that may underlie flavonoid action such as energy-restriction-like effects, inhibition of insulin-like-growth-factor signalling, induction of antioxidant defence mechanisms, hormesis as well as antimicrobial properties. However, it remains uncertain whether human lifespan could be prolonged by increased flavonoid intake.

A nutritional supplement containing lactoferrin stimulates the immune system, extends lifespan, and reduces amyloid β peptide toxicity in Caenorhabditis elegans

Lactoferrin is a highly multifunctional glycoprotein involved in many physiological functions, including regulation of iron absorption and immune responses. Moreover, there is increasing evidence for neuroprotective effects of lactoferrin. We used Caenorhabditis elegans as a model to test the protective effects, both on phenotype and transcriptome, of a nutraceutical product based on lactoferrin liposomes. In a dose‐dependent manner, the lactoferrin‐based product protected against acute oxidative stress and extended lifespan of C. elegans N2. Furthermore, Paralysis of the transgenic C. elegans strain CL4176, caused by Aβ1‐42 aggregates, was clearly ameliorated by treatment. Transcriptome analysis in treated nematodes indicated immune system stimulation, together with enhancement of processes involved in the oxidative stress response. The lactoferrin‐based product also improved the protein homeostasis processes, cellular adhesion processes, and neurogenesis in the nematode. In summary, the tested product exerts protection against aging and neurodegeneration, modulating processes involved in oxidative stress response, protein homeostasis, synaptic function, and xenobiotic metabolism. This lactoferrin‐based product is also able to stimulate the immune system, as well as improving reproductive status and energy metabolism. These findings suggest that oral supplementation with this lactoferrin‐based product could improve the immune system and antioxidant capacity. Further studies to understand the molecular mechanisms related with neuronal function would be of interest.

Probiotic Strain Bifidobacterium animalis subsp. lactis CECT 8145 Reduces Fat Content and Modulates Lipid Metabolism and Antioxidant Response in Caenorhabditis elegans

Recently, microbial changes in the human gut have been proposed as a possible cause of obesity. Therefore, modulation of microbiota through probiotic supplements is of great interest to support obesity therapeutics. The present study examines the functional effect and metabolic targets of a bacterial strain, Bifidobacterium animalis subsp. lactis CECT 8145, selected from a screening in Caenorhabditis elegans. This strain significantly reduced total lipids (40.5% ± 2.4) and triglycerides (27.6% ± 0.5), exerting antioxidant effects in the nematode (30% ± 2.8 increase in survival vs control); activities were also preserved in a final food matrix (milk). Furthermore, transcriptomic and metabolomic analyses in nematodes fed with strain CECT 8145 revealed modulation of the energy and lipid metabolism, as well as the tryptophan metabolism (satiety), as the main metabolic targets of the probiotic. In conclusion, our study describes for the first time a new B. animalis subsp. lactis strain, CECT 8145, as a promising probiotic for obesity disorders. Furthermore, the data support future studies in obesity murine models.

Yellow Pigment Aurovertins Mediate Interactions between the Pathogenic Fungus Pochonia chlamydosporia and Its Nematode Host

Nematophagous fungi are globally distributed soil fungi and well-known natural predators of soil-dwelling nematodes. Pochonia chlamydosporia can be found in diverse nematode-suppressive soils as a parasite of nematode eggs and is one of the most studied potential biological control agents of nematodes. However, little is known about the functions of small molecules in the process of infection of nematodes by this parasitic fungus or about small-molecule-mediated interactions between the pathogenic fungus and its host. Our recent study demonstrated that a P. chlamydosporia strain isolated from root knots of tobacco infected by the root-knot nematode Meloidogyne incognita produced a class of yellow pigment metabolite aurovertins, which induced the death of the free-living nematode Panagrellus redivevus. Here we report that nematicidal P. chlamydosporia strains obtained from the nematode worms tended to yield a total yellow pigment aurovertin production exceeding the inhibitory concentration shown in nematicidal bioassays. Aurovertin D was abundant in the pigment metabolites of P. chlamydosporia strains. Aurovertin D showed strong toxicity toward the root-knot nematode M. incognita and exerted profound and detrimental effects on the viability of Caenorhabditis elegans even at a subinhibitory concentration. Evaluation of the nematode mutation in the β subunit of F1-ATPase, together with the application of RNA interference in screening each subunit of F1FO-ATPase in the nematode worms, demonstrated that the β subunit of F1-ATPase might not be the specific target for aurovertins in nematodes. The resistance of C. elegans daf-2(e1370) and the hypersensitivity of C. elegans daf-16(mu86) to aurovertin D indicated that DAF-16/FOXO transcription factor in nematodes was triggered in response to the aurovertin attack. These findings advance our understanding of the roles of aurovertin production in the interactions between nematodes and the pathogen fungus P. chlamydosporia.

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.

Nutraceuticals for geriatrics

Geriatrics is a medical practice that addresses the complex needs of older patients and emphasizes maintaining functional independence even in the presence of chronic disease. Treatment of geriatric patients requires a different strategy and is very complex. Geriatric medicines aim to promote health by preventing and treating diseases and disabilities in older adults. Development of effective dietary interventions for promoting healthy aging is an active but challenging area of research because aging is associated with an increased risk of chronic disease, disability, and death. Aging populations are a global phenomenon. The most widespread conditions affecting older people are hypertension, congestive heart failure, dementia, osteoporosis, breathing problems, cataract, and diabetes to name a few. Decreased immunity is also partially responsible for the increased morbidity and mortality resulting from infectious agents in the elderly. Nutritional status is one of the chief variables that explains differences in both the incidence and pathology of infection. Elderly people are at increased risk for micronutrient deficiencies due to a variety of factors including social, physical, economic, and emotional obstacles to eating. Thus there is an urgent need to shift priorities to increase our attention on ways to prevent chronic illnesses associated with aging. Individually, people must put increased efforts into establishing healthy lifestyle practices, including consuming a more healthful diet. The present review thus focuses on the phytochemicals of nutraceutical importance for the geriatric population.

Caenorhabditis elegans as model system in pharmacology and toxicology: effects of flavonoids on redox-sensitive signalling pathways and ageing

Flavonoids are secondary plant compounds that mediate diverse biological activities, for example, by scavenging free radicals and modulating intracellular signalling pathways. It has been shown in various studies that distinct flavonoid compounds enhance stress resistance and even prolong the life span of organisms. In the last years the model organism C. elegans has gained increasing importance in pharmacological and toxicological sciences due to the availability of various genetically modified nematode strains, the simplicity of modulating genes by RNAi, and the relatively short life span. Several studies have been performed demonstrating that secondary plant compounds influence ageing, stress resistance, and distinct signalling pathways in the nematode. Here we present an overview of the modulating effects of different flavonoids on oxidative stress, redox-sensitive signalling pathways, and life span in C. elegans introducing the usability of this model system for pharmacological and toxicological research.

Chemical Composition and Antioxidant Properties of Juniper Berry (Juniperus communis L.) Essential Oil. Action of the Essential Oil on the Antioxidant Protection of Saccharomyces cerevisiae Model Organism

The essential oil of juniper berries (Juniperus communis L., Cupressaceae) is traditionally used for medicinal and flavoring purposes. As elucidated by gas chromatography/flame ionization detector (GC/FID) and gas chromatography/mass spectrometry (GC/MS methods), the juniper berry oil from Bulgaria is largely comprised of monoterpene hydrocarbons such as α-pinene (51.4%), myrcene (8.3%), sabinene (5.8%), limonene (5.1%) and β-pinene (5.0%). The antioxidant capacity of the essential oil was evaluated in vitro by 2,2-Diphenyl-1-picrylhydrazyl (DPPH) scavenging, 2,2-azino-bis-3-ethylbenzothiazoline-6 sulfonic acid (ABTS) radical cation scavenging, hydroxyl radical (ОН^•) scavenging and chelating capacity, superoxide radical (^•O₂⁻) scavenging and xanthine oxidase inhibitory effects, hydrogen peroxide scavenging. The antioxidant activity of the oil attributable to electron transfer made juniper berry essential oil a strong antioxidant, whereas the antioxidant activity attributable to hydrogen atom transfer was lower. Lipid peroxidation inhibition by the essential oil in both stages, i.e., hydroperoxide formation and malondialdehyde formation, was less efficient than the inhibition by butylated hydroxytoluene (BHT). In vivo studies confirmed these effects of the oil which created the possibility of blocking the oxidation processes in yeast cells by increasing activity of the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx).

Natural compounds with anti-ageing activity

Ageing is a complex molecular process driven by diverse molecular pathways and biochemical events that are promoted by both environmental and genetic factors. Specifically, ageing is defined as a time-dependent decline of functional capacity and stress resistance, associated with increased chance of morbidity and mortality. These effects relate to age-related gradual accumulation of stressors that result in increasingly damaged biomolecules which eventually compromise cellular homeostasis. Nevertheless, the findings that genetic or diet interventions can increase lifespan in evolutionarily diverse organisms indicate that mortality can be postponed. Natural compounds represent an extraordinary inventory of high diversity structural scaffolds that can offer promising candidate chemical entities in the major healthcare challenge of increasing health span and/or delaying ageing. Herein, those natural compounds (either pure forms or extracts) that have been found to delay cellular senescence or in vivo ageing will be critically reviewed and summarized according to affected cellular signalling pathways. Moreover, the chemical structures of the identified natural compounds along with the profile of extracts related to their bioactive components will be presented and discussed. Finally, novel potential molecular targets for screening natural compounds for anti-ageing activity, as well as the idea that anti-ageing interventions represent a systemic approach that is also effective against age-related diseases will be discussed.

Metabolic engineering of β-carotene in orange fruit increases its in vivo antioxidant properties

Orange is a major crop and an important source of health-promoting bioactive compounds. Increasing the levels of specific antioxidants in orange fruit through metabolic engineering could strengthen the fruit's health benefits. In this work, we have afforded enhancing the β-carotene content of orange fruit through blocking by RNA interference the expression of an endogenous β-carotene hydroxylase gene (Csβ-CHX) that is involved in the conversion of β-carotene into xanthophylls. Additionally, we have simultaneously overexpressed a key regulator gene of flowering transition, the FLOWERING LOCUS T from sweet orange (CsFT), in the transgenic juvenile plants, which allowed us to obtain fruit in an extremely short period of time. Silencing the Csβ-CHX gene resulted in oranges with a deep yellow ('golden') phenotype and significant increases (up to 36-fold) in β-carotene content in the pulp. The capacity of β-carotene-enriched oranges for protection against oxidative stress in vivo was assessed using Caenorhabditis elegans as experimental animal model. Golden oranges induced a 20% higher antioxidant effect than the isogenic control. This is the first example of the successful metabolic engineering of the β-carotene content (or the content of any other phytonutrient) in oranges and demonstrates the potential of genetic engineering for the nutritional enhancement of fruit tree crops.