title: Turnera ulmifolia L. (Turneraceae): preliminary study of its antioxidant activity.
abstract: Turnera ulmifolia L. is used in Brazilian folk medicine as an anti-inflammatory. Since this activity may be correlated with the presence of antioxidant compounds, a leaf extract was evaluated for its radical scavenging capacity (RSC). The in vitro RSC of a 50% hydroethanolic (HE) extract was evaluated by beta-carotene/linoleic acid coupled oxidation system for the inhibition of oxidation and the lipid peroxidation inhibition in rat brain homogenates, using thiobarbituric acid reactive substances (TBARS) and chemiluminescence (CL). Results indicated, through peroxidation suppression, that this extract exhibited greater antioxidative activity (77.4% +/- 10%) than alpha-tocopherol (58.4% +/- 3.7%). TBARS and CL inhibition was concentration-dependent and Q(1/2) values were 8.2 and 6.0 microg/mL for TBARS and CL, respectively. For alpha-tocopherol these values were 7.1 microg/mL (TBARS) and 9.8 microg/mL (CL). Phenolic compounds may be responsible for this antioxidant capacity.
authors.affiliation: Departamento de Análises Clínicas e Toxicológicas, CCS, UFRN, 59.010-180 Natal, RN, Brazil.
authors.forename: M A
authors.initials: MA
authors.lastname: Nascimento
authors.forename: A K
authors.initials: AK
authors.lastname: Silva
authors.forename: L C B
authors.initials: LC
authors.lastname: França
authors.forename: E L J
authors.initials: EL
authors.lastname: Quignard
authors.forename: J A
authors.initials: JA
authors.lastname: López
authors.forename: M G
authors.initials: MG
authors.lastname: Almeida
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism / Q000494:pharmacology*; D001709:Biotechnology / Q000379:methods; D001921:Brain / Q000378:metabolism; D015195:Drug Design; D005609:Free Radicals; D015227:Lipid Peroxidation; D010936:Plant Extracts / Q000494:pharmacology*; D018515:Plant Leaves; D051381:Rats; D017208:Rats, Wistar; D017392:Thiobarbituric Acid Reactive Substances; D029647:Turnera / Q000378:metabolism*; D019207:beta Carotene / Q000378:metabolism
chemical_list: D000975:Antioxidants; D005609:Free Radicals; D010936:Plant Extracts; D017392:Thiobarbituric Acid Reactive Substances; D019207:beta Carotene