Browsing by Author "Sallam, I.E"

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    Metabolite profiling of three Opuntia ficus-indica fruit cultivars using UPLC-QTOF-MS in relation to their antioxidant potential
    (Elsevier Ltd, 2020-08) Farag, M.A; Sallam, I.E; Fekry, M.I; Zaghloul, S.S; El-Dine, R.S
    Opuntia ficus-indica is the economically important cactus species belonging to the Cactaceae family. Its importance arises from its nutritional value and various biological activities such as antioxidant, anticancer and antimicrobial activities. This study attempts to characterize the metabolic profile of three O. ficus cultivars having different colors, i.e., red ‘Rose’, greenish white ‘Bianca’ and yellow-orange represented by peels and pulp tissues using ultra-performance liquid chromatography coupled to high resolution time of flight mass spectrometry (UPLC-QTOF-MS). A total of 45 metabolites were identified mainly flavonoids: isorhamnetin conjugates and phenolic acids, whereas betaxanthins and coumarins were present at lower levels. Principle component analysis and orthogonal projection discriminant analysis showed that dihydroxy psoralen-O-hexoside and glycosidic conjugates of ferulic acid were the most discriminatory metabolites among the peels and pulps within the different cultivars. On the other hand, the level of flavonoids was comparable among the cultivars. The antioxidant activity of peels and pulps extracts were further measured using 2,2-diphenyl-1-picrylhydrazyl and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) assays. ‘‘Rose’’ cultivar peel rich in dihydroxy psoralen-O-hexoside showed the highest antioxidant activity in both assays. This suggested that coumarins and flavonoids mediated high antioxidant activity of O. ficus-indica fruits although present at low levels
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    Metabolomics reveals impact of seven functional foods on metabolic pathways in a gut microbiota model
    (ELSEVIER SCIENCE BV, 2020-05) von Bergen, M; Wessjohann, L.A; Ehrlich, A; Rolle-Kampczyk, U; Serena Schäpe, S; Fritz-Wallace, K; Jehmlich, N; el Shorbagi, M; Sallam, I.E; Abdelwareth, A; Farag, M.A
    Functional food defined as dietary supplements that in addition to their nutritional values, can beneficially modulate body functions becomes more and more popular but the reaction of the intestinal microbiota to it is largely unknown. In order to analyse the impact of functional food on the microbiota itself it is necessary to focus on the physiology of the microbiota, which can be assessed in a whole by untargeted metabolomics. Obtaining a detailed description of the gut microbiota reaction to food ingredients can be a key to understand how these organisms regulate and bioprocess many of these food components. Extracts prepared from seven chief functional foods, namely green tea, black tea, Opuntia ficus-indica (prickly pear, cactus pear), black coffee, green coffee, pomegranate, and sumac were administered to a gut consortium culture encompassing 8 microbes which are resembling, to a large extent, the metabolic activities found in the human gut. Samples were harvested at 0.5 and 24 h post addition of functional food extract and from blank culture in parallel and analysed for its metabolites composition using gas chromatography coupled to mass spectrometry detection (GC-MS). A total of 131 metabolites were identified belonging to organic acids, alcohols, amino acids, fatty acids, inorganic compounds, nitrogenous compounds, nucleic acids, phenolics, steroids and sugars, with amino acids as the most abundant class in cultures. Considering the complexity of such datasets, multivariate data analyses were employed to classify samples and investigate how functional foods influence gut microbiota metabolisms. Results from this study provided a first insights regarding how functional foods alter gut metabolism through either induction or inhibition of certain metabolic pathways, i.e. GABA production in the presence of higher acidity induced by functional food metabolites such as polyphenols. Likewise, functional food metabolites i.e., purine alkaloids acted themselves as direct substrate in microbiota metabolism. © 2020