Health-promoting effects of Thymus herba-barona, Thymus pseudolanuginosus, and Thymus caespititius decoctions

• Autor(a) principal: Afonso, Andrea Luísa Fernandes
• Data de Publicação: 2017
• Outros Autores: Pereira, Olívia R., Neto, Rodrigo, Silva, Artur, Cardoso, Susana M.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10198/15505
• topic: Anti-inflammatory; Antimicrobial activity; Antioxidant; Antiradicalar; LC-MS; Mass spectrometry; Phenolic; Thyme; Thymus

Thymus herba-barona, Thymus pseudolanuginosus, and Thymus caespititius decoctions were screened for their phenolic constituents, along with their potential antioxidant, anti-inflammatory, and antibacterial activities. The total phenolic compounds in the extracts of the three plants ranged from 236.0 ± 26.6 mgGAE/g (T. caespititus) to 293.0 ± 30.5 mgGAE/g of extract (T. pseudolanuginosus), being particularly rich in caffeic acid derivatives, namely rosmarinic acid and its structural isomers, as well as flavones, such as luteolin-O-glucuronide. The T. pseudolanuginosus extract presented the best DPPH radical scavenging ability (EC 50 = 10.9 ± 0.7 µg/mL), a high reducing power (EC 50 = 32.2 ± 8.2 µg/mL), and effectively inhibited the oxidation of β-carotene (EC 50 = 2.4 ± 0.2 µg/mL). The extracts also showed NO· scavenging activity close to that of ascorbic acid, and thus might be useful as anti-inflammatory agents. In addition, they exhibited antibacterial activity against gram-negative and gram-positive bacteria. Staphylococcus aureus strains were the most sensitive bacteria to thyme extracts, with minimum inhibitory concentration and minimum bactericidal concentration values in the range of 0.6–3.5 mg/mL. Overall, this work is an important contribution for the phytochemical characterization and the potential antioxidant, anti-inflammatory, and antimicrobial activities of these three Thymus species, which have been poorly explored.