Abstract
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•Aqueous acetone (50%) is optimum for extraction of polyphenols from Ajwa fruits.•LC-MS metabolic profile of Ajwa was recorded and 33 compounds were identified.•Hepatoprotective activity of Ajwa fruit was correlated to its polyphenols content.•Polyphenols loading in microemulsion significantly enhanced their bioavailability.
Ajwa fruits are among the most nutritious and economically valuable fruits. In this study, the effect of different solvents on the extraction of polyphenols was investigated. Aqueous acetone (50%) extract contained the highest content of polyphenols and flavonoids. Filtration of the extract through a Diaion HP-20 column led to a polyphenols-enriched fraction (Fr 1) that had the highest antioxidant activity as measured with ORAC and DPPH assays. Metabolic profiling of the different extracts using HPLC-ESI-QTOF-MS-MS led to the tentative identification of 33 secondary metabolites: 3 phenolic acids, 19 flavonoid glycosides including 4 sulfated derivatives, 2 lignans, and 9 fatty acids. Fr 1 showed a promising hepatoprotective activity when tested in-vitro utilizing HepG2 cell lines and in-vivo against thioacetamide-induced liver fibrosis in mice. Ingestion of Fr 1 in the form of a microemulsion had significantly higher oral bioavailability than when ingested as a suspension in water.