Toxicological and pharmacological properties of essential oils of Calamintha nepeta, Origanum virens and Thymus mastichina of Alentejo (Portugal)

• Published in: Food and chemical toxicology Vol. 133; p. 110747
• Main Authors: Arantes, Sílvia Macedo, Piçarra, Andreia, Guerreiro, Marisa, Salvador, Cátia, Candeias, Fátima, Caldeira, A. Teresa, Martins, M. Rosário
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.11.2019
• Subjects: Animals; Anti-Bacterial Agents - pharmacology; Anti-Bacterial Agents - toxicity; Antineoplastic Agents - pharmacology; Antineoplastic Agents - toxicity; Antioxidants - pharmacology; Antioxidants - toxicity; Artemia - drug effects; Bacteria - drug effects; Calamintha nepeta (syn. Clinopodium nepeta); Cell Line, Tumor; Essential oils; Humans; Male; Mice; Microbial Sensitivity Tests; Nepeta - chemistry; Oils, Volatile - pharmacology; Oils, Volatile - toxicity; Origanum - chemistry; Origanum virens; Pharmacological properties; Plant Oils - pharmacology; Plant Oils - toxicity; Portugal; Thymus mastichina; Thymus Plant - chemistry; Portugal; Calamintha nepeta (syn. Clinopodium nepeta); Origanum virens; Thymus mastichina; Essential oils; Pharmacological properties
• ISSN: 0278-6915; 1873-6351
• DOI: 10.1016/j.fct.2019.110747

Three autochthonous flavouring herbs from Alentejo (Portugal), Calamintha nepeta (syn. Clinopodium nepeta), Origanun virens and Thymus mastichina, were selected to evaluate toxicological, antioxidant, antiproliferative and antimicrobial potential of their essential oils (EOs). C. nepeta and T. mastichina EOs showed a high content of oxygenated monoterpenes (86–91%) while O. virens had similar content of oxygenated and hydrocarbon monoterpenes (45%). Toxicological assessment suggests high activity against A. salina (31.8 < CL50 < 128.4 mg/L) and very low toxicity in Swiss mice (DL50 ≥ 1500 mg/kg). EOs showed high antioxidant ability by DPPH radical scavenging assay (0.1–0.6 mg QE/mL EO), total reducing power method (0.2–1.7 mg QE/mL EO) and β-carotene/linoleic acid system (11–501 mg QE/mL EO). An important antiproliferative effect against human breast tumour cell line was observed (88.9 < EC50 < 108.5 mg/L). Moreover, EOs presented a large antibacterial spectrum. Results point out the low toxicity and high antioxidant, antiproliferative and antimicrobial activities of EOs of these endemic aromatic plants, suggesting their potential use in biotechnological, food and/or pharmaceutical industries. [Display omitted] •Essential oils of autochthonous plants showed high nutraceutical potential.•Oils showed important antioxidant activity by all tested mechanisms.•Oils exhibited high antibacterial spectrum against multi-drug resistant strains.•A high antiproliferative effect was observed against human breast carcinoma cells.