engleski

Antioxidant and antiacetylcholinesterase activities of selected Croatian Thymus (Lamiaceae)species

Among the aromatic plants belonging to the Lamiaceae family, the genus Thymus is noteworthy for the numerous species and varieties of wild-growing plants, some known to have medicinal properties. The present study aimed to evaluate antioxidant and acetylcholinesterase (AChE) inhibitory activities of the ethanolic extracts of six selected Thymus species growing in Croatia (T. longicaulis C. Presl, T. praecox Opiz subsp. polytrichus (A. Kern. ex Borbás)Jalas, T. pulegioides L., T. serpyllum L. subsp. serpyllum, T. striatus Vahl and T. vulgaris L.). Contents of the total polyphenols (10.9-14.9%), tannins (2.7-5.2%) and flavonoids (0.6-1.5%) in the studied extracts were determined spectrophotometrically. Their antioxidant effectiveness was assessed using five different assays, in comparison with reference antioxidants. All tested Thymus extracts possessed DPPH (IC50 3-6 μg/mL) and hydroxyl (IC50 462-721 μg/mL) free radical scavenging activities, strong reducing properties (IC50 11-15 μg/mL), ferrous ion-chelating ability (IC50 124-394 μg/mL) and high total antioxidant capacities (238-294 mg AAE/g). In vitro screening for AChE inhibition showed that the Thymus extracts at concentration of 1000 μg/mL inhibited more then 50% of the enzyme activity. Overall, T. longicaulis was found to be the richest source of natural antioxidants and AChE inhibitors. Considering a very large body of evidence supporting the involvement of oxidative stress in neurodegenerative pathologies as well as the fact that AChE inhibition is up to now the most effective therapeutic approach to dementia, our findings indicated a great potential for novel use of Thymus species in preventing and treating of Alzheimer’s and other aging related diseases.

Thymus sp.; antioxidant activity; antiacetylcholinesterase activity; Lamiaceae; polyphenols

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