Antibacterial action against food-borne microorganisms and antioxidant activity of carvacrol-rich oil from Lippia origanoides Kunth

• Published in: Lipids in health and disease 2015-11, Vol.14 (1), p.145-145, Article 145
• Main Authors: Sarrazin, Sandra Layse F, da Silva, Leomara A, Oliveira, Ricardo B, Raposo, Juliana Divina A, da Silva, Joyce Kelly R, Salimena, Fátima Regina G, Maia, José Guilherme S, Mourão, Rosa Helena V
• Format: Article
• Language: English
• Subjects: Animals; Anti-Bacterial Agents - chemistry; Anti-Bacterial Agents - pharmacology; Bacillus cereus - drug effects; Bacillus subtilis - drug effects; Biphenyl Compounds - chemistry; Disk Diffusion Antimicrobial Tests; Free Radical Scavengers - chemistry; Free Radical Scavengers - pharmacology; Lethal Dose 50; Lippia - chemistry; Male; Mice; Picrates - chemistry; Plant Extracts - chemistry; Plant Extracts - pharmacology; Plant Oils - chemistry; Plant Oils - pharmacology; Pseudomonas aeruginosa - drug effects; Salmonella typhimurium - drug effects
• ISSN: 1476-511X; 1476-511X
• DOI: 10.1186/s12944-015-0146-7

Lippia origanoides Kunth from Northeast Brazil is a plant of pleasant odor used by local people as a food seasoning in substitution the oregano where its carvacrol-rich oil has showed significant antimicrobial activity against human pathogens. GC and GC-MS analyzed the plant oil composition and its antibacterial activity was evaluated by disk diffusion and microdilution broth methods. The determination of oil antioxidant activity was made by DPPH radical scavenging assay. Oil toxicity was performed on mice. The main constituents of the oil were carvacrol (47.2%), thymol (12.8%), p-cymene (9.7%), and p-methoxythymol (7.4%). The oil was active against the bacteria of Bacillus cereus, B. subtilis, and Salmonella typhimurium, except for Pseudomonas aeruginosa. The antioxidant activity has displayed a high dose-response (r(2) = 0.92), with the inhibition of DPPH radical from 15 to 82%, at concentrations from 5 to 50 μg/mL, and also by the β-carotene bleaching assay, which showed a high inhibition of 85.2 ± 6.8 %, corresponding to about 80% of the inhibition of Trolox (93.4 ± 0.7%), used as a standard. The lethal dose (LD50) of the oil was determined in 1673.84 mg mL(-1). The results confirmed that the oil of L. origanoides could be utilized for the prevention of food bacterial growth, and as an antioxidative agent for retardation of food oxidation process. The oil has low toxicity, allowing its application in the food industry. Graphical Abstract Aerial parts of Lippia origanoides Kunth.