Untargeted Metabolomics Analysis of the Orchid Species Oncidium sotoanum Reveals the Presence of Rare Bioactive C-Diglycosylated Chrysin Derivatives

Plants are valuable sources of secondary metabolites with pharmaceutical properties, but only a small proportion of plant life has been actively exploited for medicinal purposes to date. Underexplored plant species are therefore likely to contain novel bioactive compounds. In this study, we investigated the content of secondary metabolites in the flowers, leaves and pseudobulbs of the orchid Oncidium sotoanum using an untargeted metabolomics approach. We observed the strong accumulation of C-diglycosylated chrysin derivatives, which are rarely found in nature. Further characterization revealed evidence of antioxidant activity (FRAP and DPPH assays) and potential activity against neurodegenerative disorders (MAO-B inhibition assay) depending on the specific molecular structure of the metabolites. Natural product bioprospecting in underexplored plant species based on untargeted metabolomics can therefore help to identify novel chemical structures with diverse pharmaceutical properties

Intracellular Polyphenol Wine Metabolites Oppose Oxidative Stress and Upregulate Nrf2/ARE Pathway

Moderate wine consumption has been associated with several benefits to human health due to its high polyphenol content. In this study, we investigated whether polyphenols contained in a particular red wine, rich in polyphenols, can pass the cell membrane and switch the oxidant/antioxidant balance toward an antioxidant pattern of THP-1 cells and human cardiomyocytes through a gene regulatory system. First, we identified which metabolite polyphenols present in red wine extract cross cell membranes and may be responsible for antioxidant effects. The results showed that the wine metabolites in treated cells belonged mainly to stilbenes, flavan-3-ols derivatives, and flavonoids. Other metabolites present in cells were not typical wine metabolites. Then, we found that red wine extract dose-dependently lowered reactive oxygen species (ROS) induced by tert-butyl hydroperoxide (TBHP) up to 50 +/- 7% in both cell lines (p < 0.01). Furthermore, wine extract increased nuclear Nrf2 of about 35 +/- 5% in both cell lines (p < 0.01) and counteracted its reduction induced by TBHP (p < 0.01). The rise in Nrf2 was paralleled by the increase in hemeoxygenase-1 and glutamate-cysteine ligase catalytic subunit gene expression (both mRNA and protein) (p < 0.01). These results could help explain the healthful activity of wine polyphenols within cells

COVID-19 atypical Parsonage-Turner syndrome: a case report

Background Neurological manifestations of Sars-CoV-2 infection have been described since March 2020 and include both central and peripheral nervous system manifestations. Neurological symptoms, such as headache or persistent loss of smell and taste, have also been documented in COVID-19 long-haulers. Moreover, long lasting fatigue, mild cognitive impairment and sleep disorders appear to be frequent long term neurological manifestations after hospitalization due to COVID-19. Less is known in relation to peripheral nerve injury related to Sars-CoV-2 infection. Case presentation We report the case of a 47-year-old female presenting with a unilateral chest pain radiating to the left arm lasting for more than two months after recovery from Sars-CoV-2 infection. After referral to our post-acute outpatient service for COVID-19 long haulers, she was diagnosed with a unilateral, atypical, pure sensory brachial plexus neuritis potentially related to COVID-19, which occurred during the acute phase of a mild Sars-CoV-2 infection and persisted for months after resolution of the infection. Conclusions We presented a case of atypical Parsonage-Turner syndrome potentially triggered by Sars-CoV-2 infection, with symptoms and repercussion lasting after viral clearance. A direct involvement of the virus remains uncertain, and the physiopathology is unclear. The treatment of COVID-19 and its long-term consequences represents a relatively new challenge for clinicians and health care providers. A multidisciplinary approach to following-up COVID-19 survivors is strongly advised

Secondary metabolites of edule fruits and vegetables display MAO-B inhibitory activity

Monoamine oxidase (MAO) are mitochondrial membrane-bound enzymes that catalyze the oxidative deamination of many neurotransmitters and biogenic amines. There are two MAO isoenzymes: MAO-A and MAO-B, which differ in their substrate specificities, tissue localizations and inhibitor sensitivities. The inhibition of MAO-B is an important target in the prevention and the treatment of neurodegenerative diseases such as Parkinson, due to its role in the regulation of dopaminergic neurotransmission. Increased activity of MAO-B has also been linked to oxidative damage in the brain because of the production of reactive oxygen species. Plants produce secondary metabolites with many known biological activities, including the inhibition of MAO. This activity has been studied mostly in medicinal and hallucinogenic plants, while the most commonly consumed fruits and vegetables are often overlooked. We investigated the MAO-B inhibitory activity of 19 different fruits and vegetables, analyzing their biological activity on MAO-B through an in vitro assay based on luminescence. Preliminary analysis suggested that this activity is produced by secondary metabolites. The most active fruits and vegetables found were cucumber, red chicory, sweet cherry, shallot, lettuce and sweet pepper. We then carried out further analysis to identify the metabolites responsible for this activity in two selected species: lettuce and sweet cherry. The metabolome of lettuce was investigated through UPLC-MS analysis. Data revealed that the main secondary metabolites belong to the classes of hydroxycinnamic acids and to the class of sesquiterpene lactones, such as derivatives of lactucopicrin and lactucin, compounds known for having many biological activities on humans. Furthermore, previous HPLC-DAD analysis elucidated the metabolome of sweet cherries and allowed us to investigate in more detail the MAO-B inhibitory activity of this fruit, in particular we focused on the cultivar Roana. An artificial simplified phytocomplex was made to mimic the composition of sweet cherry on the basis of its pholyphenols content. We found that hydroxycinnamic acids are metabolites active on MAO at the concentrations found in fruits, while quercetins are not. We also hypothesized that ascorbic acid might instead suppress the inhibition of MAO-B. These results suggest that fruits and vegetables provide molecules potentially active on human MAO-B, thus stressing the role of fruits and vegetables in the protection from oxidative stress

Inhibition of Human Monoamine Oxidases A and B by Specialized Metabolites Present in Fresh Common Fruits and Vegetables

Diets rich in fruits and vegetables are associated with better psychological wellbeing and cognitive functions, although it is unclear which molecules and mechanisms are involved. One potential explanation is the inhibition of monoamine oxidases (MAOs), which have been linked to several neurological disorders. The present study investigated the ability of kiwifruit to inhibit MAO-A and MAO-B, refining an in vitro assay to avoid confounding effects. Ultra-performance liquid chromatography/mass spectrometry (UPLC-QTOF) and nuclear magnetic resonance spectroscopy (NMR) were used to select individual kiwifruit metabolites for further analysis. Moreover, extracts of other common fruits and vegetables were screened to identify promising candidate inhibitors. Multiple extracts and compounds inhibited both enzymes, and the selective inhibition of MAO-B by the major kiwifruit specialized metabolite D-(-)-quinic acid was observed. These results suggest that fruits and vegetables contain metabolites that inhibit the activity of MAO-A and -B, offering a potential natural option for the treatment of neurological disorders, in which MAOs are involved

Untargeted and Targeted Metabolomics and Tryptophan Decarboxylase In Vivo Characterization Provide Novel Insight on the Development of Kiwifruits (<i>Actinidia deliciosa</i>)

Kiwifruit (Actinidia deliciosa cv. Hayward) is a commercially important crop with highly nutritional green fleshy fruits. The post-harvest maturation of the fruits is well characterized, but little is known about the metabolic changes that occur during fruit development. Here we used untargeted metabolomics to characterize the non-volatile metabolite profile of kiwifruits collected at different time points after anthesis, revealing profound metabolic changes before the onset of ripening including the depletion of many classes of phenolic compounds. In contrast, the phytohormone abscisic acid accumulated during development and ripening, along with two indolamines (serotonin and its precursor tryptamine), and these were monitored in greater detail by targeted metabolomics. The role of indolamines in kiwifruit development is completely unknown, so we also characterized the identity of genes encoding tryptophan decarboxylase in A. deliciosa and its close relative A. chinensis to provide insight into the corresponding biological processes. Our results indicate that abscisic acid and indolamines fulfill unrecognized functions in the development and ripening of kiwifruits

Methodology Report Identification of Multiple Hypoxia Signatures in Neuroblastoma Cell Lines by l 1 -l 2 Regularization and Data Reduction

Hypoxia is a condition of low oxygen tension occurring in the tumor and negatively correlated with the progression of the disease. We studied the gene expression profiles of nine neuroblastoma cell lines grown under hypoxic conditions to define gene signatures that characterize hypoxic neuroblastoma. The l 1 -l 2 regularization applied to the entire transcriptome identified a single signature of 11 probesets discriminating the hypoxic state. We demonstrate that new hypoxia signatures, with similar discriminatory power, can be generated by a prior knowledge-based filtering in which a much smaller number of probesets, characterizing hypoxia-related biochemical pathways, are analyzed. l 1 -l 2 regularization identified novel and robust hypoxia signatures within apoptosis, glycolysis, and oxidative phosphorylation Gene Ontology classes. We conclude that the filtering approach overcomes the noisy nature of the microarray data and allows generating robust signatures suitable for biomarker discovery and patients risk assessment in a fraction of computer time

Identification of Multiple Hypoxia Signatures in Neuroblastoma Cell Lines by l [subscript 1]-l subscript 2] Regularization and Data Reduction

Hypoxia is a condition of low oxygen tension occurring in the tumor and negatively correlated with the progression of the disease. We studied the gene expression profiles of nine neuroblastoma cell lines grown under hypoxic conditions to define gene signatures that characterize hypoxic neuroblastoma. The l[subscript 1]-l[subscript 2] regularization applied to the entire transcriptome identified a single signature of 11 probesets discriminating the hypoxic state. We demonstrate that new hypoxia signatures, with similar discriminatory power, can be generated by a prior knowledge-based filtering in which a much smaller number of probesets, characterizing hypoxia-related biochemical pathways, are analyzed. l[subscript 1]-l[subscript 2] regularization identified novel and robust hypoxia signatures within apoptosis, glycolysis, and oxidative phosphorylation Gene Ontology classes. We conclude that the filtering approach overcomes the noisy nature of the microarray data and allows generating robust signatures suitable for biomarker discovery and patients risk assessment in a fraction of computer time.Fondazione Italiana per la Lotta al NeuroblastomaItalian Association for Cancer Research (AIRC)Italian Ministry of HealthEU Integrated Project Health-e-Child (IST-2004-027749)Compagnia di San Paolo (Foundation) (Project 4998- ID/CV 2007.0887

Secondary metabolites and bioactivity of sweet cherry...and others

Consumption of fruits and vegetables has been associated with several benefits for human health, their regular consumption has been associated with a reduced risk of a number of chronic diseases. In fact, food provides bioactive compounds with a known activity in health promotion and disease prevention. We found, through NMR spectroscopy and HPLC-DAD analysis, that the metabolomic composition of sweet cherry fruits vary substantially among 18 different cultivars analyzed (Marostica PGI zone). Data revealed that the main polyphenolic compounds in the fruits were anthocyanins, hydroxycinnamic acid and flavonoids with strong differences between cultivar. For example, the Sandra tardiva cultivar accumulated higher levels of cyanidins whereas Grace star cultivar show low abundance of this pholyphenols. Furthermore, many sweet cherry metabolites possess antioxidant activity, so we investigate the in vitro antioxidant properties of fruit extracts using ABTS and FRAP assays. The two assays gave similar results and in general we found that in vitro antioxidant activity correlates mainly with the anthocyanin and quercetin content. To investigate in more details antioxidant properties, artificial simplified phytocomplexs were made to mimic the composition of Sandra Tardiva, Sandra and Grace Star cultivars on the basis of their pholyphenols content. We found that anthocyanins, quercetins and ascorbic acid, when mixed together at the same concentrations found in the Sandra Tardiva extracts, displayed strong synergistic antioxidant activity in the FRAP assay. However when the same components were mixed in the proportions found in the Sandra and Grace Star cultivars, the effects were additive rather than synergistic In order to gain the in vivo antioxidant activity of the cherry fruits we tested their antioxidant activity in a cellular model. THP-1 cell line were incubated with Sandra Tardiva, Sandra and Grace Star extracts and the antioxidant activity was evaluated by flow cytometry. The intracellular reactive oxygen species (ROS) were detected using the ROS-sensitive fluorescent dye, H2DCFDA that upon cleavage of acetate groups by intracellular esterases and oxidation is converted to the highly fluorescence DCF. Our results shows a reduced emission of fluorescence in cell-treated with cherry extracts suggesting an antioxidant effect due to accumulation of antioxidant metabolites of cherry fruits. To investigate the absorption of cherry metabolites and their potential role in the oxidative stress protection, cell incubated with Sandra Tardiva, Sandra and Grace were analysed in mass spectromery. Following the treatment with cherry extract many of principal metabolites of cherry, such as cyanidin 3-O-glucoside, feruilc acid and coumaroyl quinic acid were found able to penetrate cell membranes. Nowadays we are interested in studying the effects of several fruits and raw vegetables on monoamine oxidase, that are responsible for the degradation of neurotransmitters in the central nervous system, in order to evalutate antidepressant like-activity of their metabolites