Antioxidant and Anticholinesterase Potential of SixThymusSpecies

Abstract

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, T. praecox subsp. polytrichus, T. pulegioides, T. serpyllum subsp. serpyllum, T. striatus, and T. vulgaris). Antioxidant effectiveness was assessed using six different assays, in comparison with rosmarinic acid, luteolin, and reference antioxidants. All tested Thymus extracts possessed DPPH (IC50 = 3–6 μg/mL) and nitric oxide (IC50 = 70–177 μg/mL) free radical scavenging activities, strong reducing properties (IC50 = 11–15 μg/mL), ferrous ion chelating activity (IC50 = 126–389 μg/mL), ability to inhibit lipid peroxidation (IC50 = 34–80 μg/mL), and high total antioxidant capacities (238–294 mg AAE/g). AChE inhibitory activity was examined using Ellman's colorimetric method and all tested extracts showed anti-AChE activity in a dose dependent manner. The values of 10–28%, 23–39%, and 64–86% were obtained for tested concentrations of 0.25, 0.5, and 1 mg/mL, respectively. Additionally, the contents of total hydroxycinnamic derivatives, flavonoids, and tannins in dried plant samples were determined spectrophotometrically. Our results highlighted Thymus species as a rich source of natural antioxidants and AChE inhibitors that could be useful in preventing and treating Alzheimer's disease and other neurodegenerative disorders.

Evaluation of enzyme inhibitory and antioxidant activity of some Lamiaceae plants

“…polytrichus, T. pulegioides, T. serpyllum subsp. serpyllum, T. striatus, and T. vulgaris were demonstrated inhibitory activity against AChE [18]. This activity may be caused from carvacrol, which is one of most important compounds of Thymus species [40].…”

“…On the other hand, many researchers have conducted studies on the antidiabetic activities of Salvia and Lamium species to date [15,16]. Also, literature survey clearly demonstrated that there are many studies on anticholinesterase activity of different Origanum, Salvia, and Thymus species [17][18][19].…”

Phytochemical Constituents, Safety and Efficacy Study of Thymus schimperi and Thymus serrulatus

“…The oils of T. schimperi possess antifungal and antibacterial activity against different species of fungus and bacteria [3,11,40,43] which was similar with pharmacologic activity of oils of T. hirtus, T. kotschyanus boiss, T. vulgaris, T. mastichina, T. serpyllum and T. algeriensis species [28,41,46,47]. T. schimperi oil had antioxidant and preservative effects [4] and consistent with other species of thymus [2,41,44,46,48,49] and seem to be applicable in both medicine and food industry. The oils of T. serrulatus and T. schimperi from different Ethiopian localities had promising protective activity against paracetamol induced hepatic damage in rats [30].…”

“…serpyllum had potent effect on inhibition of human tumor cells lines growth [44]. T. longicaulis, T. pulegioides, T. vulgaris, T. serpyllum, T. striatus and T. praecox also showed anti-acetylcholinesterase activities [2]. All this entire species of thymus had comparable pharmacologic property with T. schimperi and T. serrulatus.…”

“…The genus Thymus is one of the most taxonomically complex genera in the Lamiaceae family. It includes 250-350 species and varieties of wild growing evergreen species of herbaceous perennials, subshrubs and aromatic [1,2]. The Thymus species in Eritrea and Ethiopia are restricted to Afromontane and afro alpine regions the species are well known medicinal plants because of their biological and pharmacological properties [3].…”