Prospective neurobiological effects of the aerial and root extracts and some pure compounds of randomly selected Scorzonera species

Context: Scorzonera L. species (Asteraceae) are edible and as medicinal plants are used for various purposed in folk medicine. Objective: The methanol extracts of the aerial parts and roots from 27 Scorzonera taxa were investigated for their possible neurobiological effects. Materials and methods: Inhibitory potential of the Scorzonera species was tested against acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and tyrosinase (TYRO) at 100 mu gmL(-1) using ELISA microtiter assay. Antioxidant activity of the extracts was tested with radical scavenging activity, metal-chelation capacity, ferric-(FRAP), and phosphomolibdenum-reducing antioxidant power (PRAP) assays. Chlorogenic acid, hyperoside, rutin, and scorzotomentosin-4-O-beta-glucoside were also screened in the same manner. Total phenol and flavonoid quantification in the extracts were determined spectrophotometrically. Results: The aerial parts of Scorzonera pisidica (40.25 +/- 0.74%) and chlorogenic acid (46.97 +/- 0.82%) displayed the highest TYRO inhibition, while the remaining samples showed only trivial inhibition against cholinesterases (2.08 +/- 1.35% -25.32 +/- 1.37%). The same extract of S. pisidica was revealed to be the most potent in scavenging of all three radicals and FRAP assay. Discussion and conclusion: Out of 27 taxa, S. pisidica, in particular, may deserve further investigation for its neuroprotective potential.