Verbascum phlomoides and Solidago virgaureae herbs as natural source for preventing neurodegenerative diseases

In the current work, ethanol and water extracts of Verbascum phlomoides and Solidago virgaureae were examined for their inhibitory effects against acetylcholinesterase and tyrosinase, as well as for their antioxidant activity. The antioxidant activity was determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and a reducing power assay. The total content of phenolics, flavonoids and proanthocyanidins, and the high-performance liquid chromatography profile of the main phenolic compounds were also determined. Generally, ethanol extracts showed the strongest antioxidant and enzyme inhibitory activities, both of which were related to the total phenolic content. The V. phlomoides ethanol extract showed the highest inhibitory activity against both acetylcholinesterase (IC50 = 0.086 ± 0.005 mg/mL) and tyrosinase (IC50 = 0.109 ± 0.092 mg/mL). These results reveal that V. phlomoides and S. virgaureae are potential sources of active metabolites with acetylcholinesterase and tyrosinase inhibitory effects. As a result they could be considered for dietary food supplements for preventing neurodegenerative diseases.