Thymus Species from Romanian Spontaneous Flora as Promising Source of Phenolic Secondary Metabolites with Health-Related Benefits

Abstract

Wild thyme aerial parts (Serpylli herba) are recognized as a valuable herbal product with antioxidant, anti-inflammatory, and antibacterial effects. Although pharmacopoeial regulations allow its collection exclusively from Thymus serpyllum, substitution with other species is frequent in current practice. This study analyzed the phenolic composition, antioxidant, and enzyme-inhibitory and antimicrobial activity of the hydroethanolic extracts obtained from five Romanian wild thyme species (Thymus alpestris, T. glabrescens, T. panonicus, T. pulcherimus and T. pulegioides). The analysis of individual phenolic constituents was performed through LC-ESI-DAD/MS2, while for the in vitro evaluation of antioxidant potential, TEAC, FRAP, DPPH, TBARS and OxHLIA assays were employed. The anti-enzymatic potential was tested in vitro against tyrosinase, α-glucosidase and acetylcholinesterase. High rosmarinic acid contents were quantified in all species (20.06 ± 0.32–80.49 ± 0.001 mg/g dry extract); phenolic acids derivatives (including salvianolic acids) were confirmed as the principal metabolites of T. alpestris and T. glabrescens, while eriodictyol-O-di-hexoside was found exclusively in T. alpestris. All species showed strong antioxidant potential and moderate anti-enzymatic effect against α-glucosidase and acetylcholinesterase, showing no anti-tyrosinase activity. This is the first detailed report on the chemical and biological profile of T. alpestris collected from Romanian spontaneous flora.

Implications of the Cultivation of Rosemary and Thyme (Lamiaceae) in Plant Communities for the Development of Antioxidant Therapies

“…Numerous studies from the accessed scientific literature underline the pharmacological potential and phytotherapeutic applications of Rosmarinus officinalis L. [15][16][17][18][19] and Thymus vulgaris L. [20][21][22][23][24] from the Lamiaceae family. Rosemary leaves contain 1-2.5% volatile oil with a variable composition, depending on the crop variety and pedoclimatic conditions.…”

Evaluation of the Essential Oil Composition of Five Thymus Species Native to Greece

“…Thymus vulgaris is the most studied species of the genus. Its phytochemistry (volatile and non-volatile metabolites) has been studied by numerous researchers [9][10][11][12][13][14], and its biological activity, attributed to its rich chemical profile, has been documented [4,5,15,16]. The chemical analysis of its volatile profile has revealed a chemotypic diversity.…”