title: Antioxidant activity and chemical composition of essential oils of three aromatic plants from La Rioja province.
abstract: BACKGROUND
  The use of many traditional medicinal plants is often hampered by the absence of a proper biochemical characterization, which is essential to identify the bioactive compounds present in it. The essential oils (EOs) of three native species from the La Rioja province were analyzed: Lippia turbinata Griseb and Lippia integrifolia (Griseb.) Hieron (Verbenaceae), and Clinopodium gilliesii (Benth.) Kuntze (Lamiaceae).
  
  
  OBJECTIVE
  The aim of this study was to evaluate their EOs antioxidant activity (AA) and their chemical composition.
  
  
  METHODS
  EOs were analyzed by gas chromatography-mass spectrometry (GC-MS). To enhance the aqueous solubilization of the EOs, EO-water emulsions were prepared (concentration range of 0.1-6 mg mL(-1)). AA was determined using ABTS, DPPH, and peroxyl radical scavenging assays, as well as by the β-carotene bleaching test.
  
  
  RESULTS
  Piperitenone oxide was a major constituent in L. turbinata, pulegone and piperitenone oxide in C. gilliesii, and β-caryophyllene in L. integrifolia. Lippia turbinata EO was the most active ABTS and DPPH radical scavenger (SC50 values of 0.40 ± 0.14 and 0.74 ± 0.08 mg mL(-1), respectively). Clinopodium gilliesii EO exhibited the highest hydrogen peroxide scavenging activity (SC25 value = 1.52 ± 0.27 mg mL(-1)). In the β-carotene assay, L. turbinata EO was more effective at inhibiting lipid peroxidation than the other two oils (IC25 value = 0.15 ± 0.04 mg mL(-1)).
  
  
  CONCLUSIONS
  Our results suggest that the AA observed can be justified by the presence of oxygenated monoterpenes, mainly piperitenone oxide. Finally, L. turbinata EO might be used as a safe natural antioxidant and food preservative in the food and cosmetic industries.
authors: a Departamento de Ciencias Básicas y Tecnológicas , Universidad Nacional de Chilecito , Chilecito , La Rioja , Argentina .
authors: Natalia
authors: N
authors: Barbieri
authors: b INQUINOA-CONICET, Universidad Nacional de Tucumán , Tucumán , Argentina , and.
authors: Milena
authors: M
authors: Costamagna
authors: c Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán , Tucumán , Argentina.
authors: Miguel
authors: M
authors: Gilabert
authors: c Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán , Tucumán , Argentina.
authors: Marina
authors: M
authors: Perotti
authors: c Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán , Tucumán , Argentina.
authors: Carola
authors: C
authors: Schuff
authors: b INQUINOA-CONICET, Universidad Nacional de Tucumán , Tucumán , Argentina , and.
authors: María Inés
authors: MI
authors: Isla
authors: a Departamento de Ciencias Básicas y Tecnológicas , Universidad Nacional de Chilecito , Chilecito , La Rioja , Argentina .
authors: Alba
authors: A
authors: Benavente
mesh_terms: D001118:Argentina; D052160:Benzothiazoles / Q000737:chemistry; D001713:Biphenyl Compounds / Q000737:chemistry; D004305:Dose-Response Relationship, Drug; D004655:Emulsions; D016166:Free Radical Scavengers / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D008401:Gas Chromatography-Mass Spectrometry; D019686:Lamiaceae / Q000737:chemistry*; D015227:Lipid Peroxidation / Q000187:drug effects; D032411:Lippia / Q000737:chemistry*; D009822:Oils, Volatile / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D010084:Oxidation-Reduction; D008517:Phytotherapy; D010851:Picrates / Q000737:chemistry; D035261:Plant Components, Aerial; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D010938:Plant Oils / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D010946:Plants, Medicinal; D013451:Sulfonic Acids / Q000737:chemistry; D013997:Time Factors; D029648:Verbenaceae / Q000737:chemistry*; D019207:beta Carotene / Q000737:chemistry
chemical_list: D052160:Benzothiazoles; D001713:Biphenyl Compounds; D004655:Emulsions; D016166:Free Radical Scavengers; D009822:Oils, Volatile; D010851:Picrates; D010936:Plant Extracts; D010938:Plant Oils; D013451:Sulfonic Acids; D019207:beta Carotene; C002502:2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid; C004931:1,1-diphenyl-2-picrylhydrazyl
keywords: Biological activity; Clinopodium gilliesii; Lippia integrifolia; Lippia turbinata; piperitenone oxide