Introduction. Horehound (Marrubium vulgare, Lamiaceae) is a widely used plant
in traditional medicine used for prevention and treatment of various
diseases. High content of phenolic compounds makes it a significant source
of natural antioxidants. The aim of this research was to examine in vitro
antioxidant properties and anticholinesterase activity of horehound
water-alcoholic extract, followed by preliminary chemical characterization
of horehound. Material and Methods. The in vitro antioxidant potentials of
horehound water-alcoholic extract were assessed using several antioxidant
testsystems (neutralization of 2,2-diphenyl-1-picrylhydrazyl, hydroxyl, and
nitroso radical, determination of ferric reducing potential, as well as
inhibition of lipid peroxidation). Preliminary chemical profiling of the
extract included estimation of total phenolic and flavonoid contents, while
anticholinesterase potential of the examined extract was evaluated by
spectrophotometry. Results. The amounts of total phenolics and total
flavonoids in the obtained extract were 59.87 ? 7.31 mg gallic acid
equivalents/g of dry extract and 14.47 ? 0.54 mg quercetin equivalents/g of
dry extract respectively. Furthermore, significant antioxidant potential was
noticed in the ferric reducing potential assay (64.07 ? 2.68 mg ascorbic
acid equivalents/g of dry extract), while concentrations needed for
neutralization of 50% (IC50) of generated 2,2-diphenyl-1-picrylhydrazyl,
nitroso and hydroxyl were 13.41 ?g/mL, 64.86 ?g/mL and 63.99 ?g/mL,
respectively. The potential of the extract to inhibit lipid peroxidation
process was modest (IC50 = 823.82 ?g/mL), while in the case of
anticholinesterase potential, the recorded IC50 value was 2821.15 ?g/mL.
Conclusion. Horehound represents a significant natural antioxidant, mostly
as a result of high levels of phenolic compounds. In addition, the examined
ethanol extract has a certain anticholinesterase activity.