Comprehensive metabolite profiling of Phoenix rupicola pulp and seeds using UPLC-ESI-MS/MS and evaluation of their...

Dates have been consumed since ancient times as functional foods which beside their high nutritional value possess various biological activities. Phoenix rupicola T. Anderson (Cliff date palm) produces non-conventional edible dates, however, due to low natural abundance, these dates aren't commercially important as the dates of Phoenix dactylifera L. The present study was designed to evaluate the phytochemical constituents as well as the estrogenic activity of P. rupicola dates. UPLC-ESI-MS/MS approach was used to study the metabolite profile of the 70% aqueous methanol extracts of P. rupicola dates (pulps and seeds) for the first time. A total of fifty-five metabolites were tentatively identified in both extracts, belonging to different classes, chiefly phenolic compounds viz. procyanidins, flavonoid glycosides, hydroxycinnamic acid derivatives, as well as, fatty acids, organic acids and sphingolipids. Acute toxicity studies revealed that the studied extracts were safe at oral doses up to 2 g/kg. Besides, they possessed significant (P < 0.05) estrogenic activity in ovariectomized rat model, as compared to ovariectomized (OVX) and reference standard (17β-estradiol; OVX-E) groups. Moreover, the extracts showed significant improvement on bone metabolism, lipid profile, liver and kidney functions. In silico docking study revealed that various metabolites possessed high binding affinities to both ERs, where 2-palmitoyl glycerol (-10.28 Kcal/mol) and aminotetradecanetriol (-9.61 Kcal/mol) showed the strongest affinities to Erα and Erβ, respectively. Thus, it can be concluded that P. rupicola pulp and seeds possess bioactive phytoconstituents comparable to those in P. dactylifera and can be used as a safe and efficient natural estrogen substitute in postmenopausal women.