Browsing by Author "Fekry, M.I"

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    Ficus deltoidea extract down-regulates protein tyrosine phosphatase 1B expression in a rat model of type 2 diabetes mellitus: A new insight into its antidiabetic mechanism
    (Cambridge University Press, 2020) Mohamed, S.O; Mansour, D.F; Fekry, M.I; Hessin, A.F; Abd-Elsalam, R.M; Ogaly, H.A; Ezzat, Shahira M; Abdel-Rahman, R.F
    Ficus deltoidea var. deltoidea Jack (FD) is a well-known plant used in Malay folklore medicine to lower blood glucose in diabetic patients. For further research of the antihyperglycemic mechanisms, the protein tyrosine phosphatase 1B (PTP1B)-inhibitory effect of FD was analysed both in vitro and in vivo. To optimise a method for FD extraction, water, 50, 70, 80, 90 and 95 % ethanol extracts were prepared and determined for their total phenolic and triterpene contents, and PTP1B-inhibition capacity. Among the tested extracts, 70 % ethanol FD extract showed a significant PTP1B inhibition (92·0 % inhibition at 200 μg/ml) and high phenolic and triterpene contents. A bioassay-guided fractionation of the 70 % ethanol extract led to the isolation of a new triterpene (3β,11β-dihydroxyolean-12-en-23-oic acid; F3) along with six known compounds. In vivo, 4 weeks' administration of 70 % ethanol FD extract (125, 250 and 500 mg/kg/d) to streptozotocin-nicotinamide-induced type 2 diabetic rats reversed the abnormal changes of blood glucose, insulin, total Hb, GLUT2, lipid profile, and oxidative stress in liver and pancreas. Moreover, FD reduced the mRNA expression of the key gluconeogenic enzymes (phosphoenolpyruvate carboxykinase and glucose 6-phosphatase) and restored insulin receptor and GLUT2 encoding gene (Slc2a2) expression. In addition, FD significantly down-regulated the hepatic PTP1B gene expression. These results revealed that FD could potentially improve insulin sensitivity, suppress hepatic glucose output and enhance glucose uptake in type 2 diabetes mellitus through down-regulation of PTP1B. Together, our findings give scientific evidence for the traditional use of FD as an antidiabetic agent. © The Author(s) 2020.
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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