201 research outputs found

    Enhanced mtDNA repair and cellular survival following oxidative stress by targeting the hOGG repair enzyme to mitochondria.

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    Oxidative damage to mtDNA has been implicated as a causative factor in many disease processes and in aging. We have recently discovered that different cell types vary in their capacity to repair this damage, and this variability correlates with their ability to withstand oxidative stress. To explore strategies to enhance repair of oxidative lesions in mtDNA, we have constructed a vector containing a mitochondrial transport sequence upstream of the sequence for human 8-oxoguanine glycosylase. This enzyme is the glycosylase/AP lyase that participates in repair of purine lesions, such as 8-oxoguanine. Western blot analysis confirmed this recombinant protein was targeted to mitochondria. Enzyme activity assays showed that mitochondrial extracts from cells transfected with the construct had increased enzyme activity compared to cells transfected with vector only, while nuclear enzyme activity was not changed. Repair assays showed that there was enhanced repair of oxidative lesions in mtDNA. Additional studies revealed that this augmented repair led to enhanced cellular viability as determined by reduction of tetrazolium compound to formazan, Trypan blue dye exclusion, and clonogenic assays. Therefore, targeting of DNA repair enzymes to mitochondria may be a viable approach for the protection of cells against some of the deleterious effects of oxidative stress

    Isolation and Identification of Steroid and Flavonoid Glycosides from the Flowers of Allium gramineum

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    peer reviewedThe isolation and identification of β-sitosterol 3-O-β-glucopyranoside, quercetin 3-O-β-glucopyranoside, isorhamnetin 3,4'-di-O-β-glucopyranosideand isorhamnetin 3,7-di-O-β-glucopyranosidefrom the flowers of Allium gramineumthat growsin Georgia.The structures of isolated compounds havebeen determined by 1H and 13C nuclear magnetic resonance (NMR) Isolation and Identification of Steroid and Flavonoid Glycosides from the Flowers of Allium gramineum. Available from: https://www.researchgate.net/publication/305851744_Isolation_and_Identification_of_Steroid_and_Flavonoid_Glycosides_from_the_Flowers_of_Allium_gramineum [accessed Aug 5, 2016]

    TRADITIONAL CHINESE MEDICINE: A PATH WORTH EXPLORING IN THE FIGHT AGAINST COVID-19?

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    By the end of December 2019, a new coronavirus SARS-CoV-2 capable of causing pneumonia and respiratory failure emerged in Wuhan, China. The disease resulting from the virus was named COVID-19. [1,2] Despite the efforts to contain the spread of the virus, by March 2020, the WHO declared the world is facing a full-scale pandemic. TCM has been practiced for more than 5000 years and has gathered knowledge throughout the millennia in the fight against epidemic and pandemic threats. [3,4] In this study, 69 TCM entities, as well as eight formulas, were tested in vitro to observe any possible antiviral activity against SARS-CoV-2 using Vero E6 cells as host cells for the virus. In conclusion, four entities and a formula showed remarkable antiviral activities against SARS-CoV-2: Moutan cortex, Glycyrrhizae radix et rhizoma, Armeniacae semen amarum,Cinnamomum ramulus, and Qingfei Paidu Decoction. The Qingfei Paidu Decoction contains twenty-one herbs and not only such as: Ephedrae herba, Glycyrrhizae radix, Armeniacae semen, Gypsum fibrosum, Cinnamomi ramulus, Alismatis rhizoma, Polyporus, Atractylodis macrocephalae rhizoma, Poria, Bupleuri radix, Scutellariae radix, Pinellinae rhizoma, Zingiberis rhizoma, Asteris radix, Farfarae flos, Belamcandae rhizoma, Asari radix et rhizoma, Dioscoreae rhizoma, Aurantii rructus immaturus, Citri reticulatae pericarpium and Pogostemonis herba. These results support the idea of using TCM as an adjuvant treatment to the western ones in the fight against COVID-19 disease.3. Good health and well-bein

    Natural Phenolic Compounds and Derivatives as Potential Antimalarial Agents.

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    peer reviewedMalaria is a parasitic disease endemic to tropical and subtropical regions responsible for hundreds of millions of clinical cases and hundreds of thousands of deaths yearly. Its agent, the Plasmodium sp., has a highly variable antigenicity, which accounts for the emergence and spread of resistance to all available treatments. In light of this rising problem, scientists have turned to naturally occurring compounds obtained from plants recurrently used in traditional medicine in endemic areas. Ethnopharmacological approaches seem to be helpful in selecting the most interesting plants for the search of new antiplasmodial and antimalarial molecules. However, this search for new antimalarials is complex and time-consuming and ultimately leads to a great number of interesting compounds with a lack of discussion of their characteristics. This review aims to examine the most promising antiplasmodial phenolic compounds (phenolic acids, flavonoids, xanthones, coumarins, lignans, among others) and derivatives isolated over the course of the last 28 y (1990 - 2018) and discuss their structure-activity relationships, mechanisms of action, toxicity, new perspectives they could add to the fight against malaria, and finally, the difficulties of transforming these potential compounds into new antimalarials

    Recent metabolomic developments for antimalarial drug discovery.

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    peer reviewedMalaria is a parasitic disease that remains a global health issue, responsible for a significant death and morbidity toll. Various factors have impacted the use and delayed the development of antimalarial therapies, such as the associated financial cost and parasitic resistance. In order to discover new drugs and validate parasitic targets, a powerful omics tool, metabolomics, emerged as a reliable approach. However, as a fairly recent method in malaria, new findings are timely and original practices emerge frequently. This review aims to discuss recent research towards the development of new metabolomic methods in the context of uncovering antiplasmodial mechanisms of action in vitro and to point out innovative metabolic pathways that can revitalize the antimalarial pipeline

    The eye contact effect: mechanisms and development

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    The ‘eye contact effect’ is the phenomenon that perceived eye contact with another human face modulates certain aspects of the concurrent and/or immediately following cognitive processing. In addition, functional imaging studies in adults have revealed that eye contact can modulate activity in structures in the social brain network, and developmental studies show evidence for preferential orienting towards, and processing of, faces with direct gaze from early in life. We review different theories of the eye contact effect and advance a ‘fast-track modulator’ model. Specifically, we hypothesize that perceived eye contact is initially detected by a subcortical route, which then modulates the activation of the social brain as it processes the accompanying detailed sensory information

    Phytochemical investigation and biological activities of Lantana rhodesiensis

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    peer reviewedLantana rhodesiensis Moldenke is a plant widely used to treat diseases, such as rheumatism, diabetes, and malaria in traditional medicine. To better understand the traditional uses of this plant, a phytochemical study was undertaken, revealing a higher proportion of polyphenols, including flavonoids in L. rhodesiensis leaf extract and moderate proportion in stem and root extracts. The antioxidant activity of the extracts was also determined using three different assays: the radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity, the FRAP method (Ferric-reducing antioxidant power) and the β-carotene bleaching test. The anti-malarial activity of each extract was also evaluated using asexual erythrocyte stages of Plasmodium falciparum, chloroquine-sensitive strain 3D7. The results showed that the leaf extract exhibited higher antioxidant and anti-malarial activities in comparison with the stem and root extracts, probably due to the presence of higher quantities of polyphenols including flavonoids in the leaves. A positive linear correlation was established between the phenolic compound content (total polyphenols including flavonoids and tannins; and total flavonoids) and the antioxidant activity of all extracts. Furthermore, four flavones were isolated from leaf dichloromethane and ethyl acetate fractions: a new flavone named rhodescine (5,6,3’,5’-tetrahydroxy-7,4’-dimethoxyflavone) (1), 5-hydroxy-6,7,3’,4’,5’-pentamethoxyflavone (2), 5-hydroxy-6,7,3′,4′-tetramethoxyflavone (3), and 5,6,3’-trihydroxy-7,4’-dimethoxyflavone (4). Their structures were elucidated by 1H, 13C NMR, COSY, HSQC, HMBC, and MS-EI spectral methods. Aside from compound 2, all other molecules were described for the first time in this plant species.EOHUB project 600873EPP-1-2018-1ES-EPPKA2-K
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