In vitro studies to assess the antidiabetic, anti-cholinesterase and antioxidant potential of Spergularia rubra

Spergularia rubra is distributed all over the world, being its infusion used as diuretic. In spite of its large use, the antidiabetic, anti-cholinesterase and antioxidant activities of this species have not been assessed and its chemical composition is scarcely known. In the work herein a hydromethanolic extract was studied. Thirty-six phenolic compounds were determined by HPLC-DAD, comprising non-acylated C-glycosyl flavones (38%), C-glycosyl flavones acylated with aromatic acids (36%), C-glycosyl flavones acylated with aliphatic acids (13%) and 10% corresponded to C-glycosyl flavones with a mixed acylation. Organic acids (oxalic, citric, malic, quinic and fumaric acids) and fatty acids (azelaic, myristic, palmitic, linoleic, linolenic and stearic acids) are described for the first time. Their determination by HPLC-UV and GC-IT-MS allowed finding concentrations of 192.15 and 34.87 g/kg, respectively. The extract showed a dose-dependent response against DPPH, superoxide and nitric oxide radicals. The same effect was observed in the cc-glucosidase inhibitory assay and against acetylcholinesterase and butyrylcholinesterases. The bioactivities observed may be due, at least partially, to the presence of the different metabolites determined in the present study. The results suggest that the dried extract of S. rubra may be interesting for incorporation in pharmaceutical preparations for human health, since it can suppress hyperglycaemia and inhibit cholinesterases, and or as food additive due to its antiradical activity. (C) 2011 Elsevier Ltd. All rights reserved.