Biomedical potential of horehound extract (Marrubium vulgare, Lamiaceae)

Abstract

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 test-systems (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 μg/mL, 64.86 μg/mL and 63.99 μg/mL, respectively. The potential of the extract to inhibit lipid peroxidation process was modest (IC50 = 823.82 μg/mL), while in the case of anticholinesterase potential, the recorded IC50 value was 2821.15 μg/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.