Acetylcholinesterase inhibitory and antioxidant properties of roots extracts from the Tunisian Scabiosa arenaria Forssk

The total phenolic, flavonoid and tannin contents of Scabiosa arenaria Forssk roots were determined by colorimetry. The in vitro antioxidant activity was characterized by varied assays like 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2-azinobis 3-ethylbenzothiazoline-6-sulfonic acid (ABTS), reducing power and beta-carotene bleaching inhibition activity. The anti-acetylcholinesterase activity was also evaluated. Total phenolics and flavonoids contents were highest in the butanol fraction with 82.36 mg gallic acid equivalents/g and 5.86 mg quercetin/g of dry weight, respectively. This fraction exhibited an interesting antioxidant activity, mainly with the beta-carotene bleaching inhibition test (IC50=0.018 +/- 0.009 mg/mL). The same fraction showed the best anti-acetylcholinesterase activity (IC50=0.02 +/- 0.003 mg/mL). The major phenolic compounds of the butanol extract were identified by RP-HPLC (reverse phase-high-performance liquid chromatography). A total of nine compounds were characterized, including p-coumaric acid, N-propyl gallate, myricetin and methyl-4-hydroxybenzoate. The active compounds identified and quantified in this fraction were mainly responsible for these in vitro biological activities. Published by Elsevier B.V.