title: Reevaluation of antimicrobial and antioxidant activity of Thymus spp. extracts before and after encapsulation in liposomes.
abstract: The antioxidant and antimicrobial activity of four Thymus species (boissieri, longicaulis, leucospermus, and ocheus) extracts were determined. Two methods (Rancimat and malondialdehyde by high-performance liquid chromatography) were used to measure the antioxidant action in comparison with common commercial antioxidants, including butylated hydroxytoluene and alpha-tocopherol. The extracts that presented high antioxidant activity were encapsulated in liposomes and their antioxidant action was again estimated. Thermal-oxidative decomposition of the samples (pure liposomes and encapsulating extracts) was studied using the differential scanning calorimetry method. The modification of the main transition temperature for the lipid mixture and the splitting of the calorimetric peak in the presence of the antioxidants were also demonstrated by differential scanning calorimetry. All extracts showed antioxidant and antimicrobial activities. Some extracts showed superior or equal antioxidant activity to alpha-tocopherol. When the extracts were encapsulated in liposomes, their antioxidant as well as antimicrobial activities proved to be superior from the same extracts in pure form.
authors.affiliation: Department of Food Technology, Technological Educational Institution (T.E.I.) of Larissa, Terma N. Temponera str., Karditsa, Greece.
authors.forename: Olga
authors.initials: O
authors.lastname: Gortzi
authors.forename: Stavros
authors.initials: S
authors.lastname: Lalas
authors.forename: Ioanna
authors.initials: I
authors.lastname: Chinou
authors.forename: John
authors.initials: J
authors.lastname: Tsaknis
mesh_terms: D000900:Anti-Bacterial Agents / Q000032:analysis / Q000494:pharmacology*; D000975:Antioxidants / Q000032:analysis / Q000494:pharmacology*; D002152:Calorimetry, Differential Scanning; D002851:Chromatography, High Pressure Liquid; D004339:Drug Compounding; D005519:Food Preservation / Q000379:methods*; D005524:Food Technology; D006801:Humans; D008081:Liposomes; D010084:Oxidation-Reduction; D010936:Plant Extracts / Q000032:analysis / Q000494:pharmacology*; D013696:Temperature; D046930:Thymus Plant / Q000737:chemistry; D024502:alpha-Tocopherol / Q000032:analysis / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D000975:Antioxidants; D008081:Liposomes; D010936:Plant Extracts; D024502:alpha-Tocopherol