title: Antioxidant activity of ethanolic and aqueous extracts of Uncaria tomentosa (Willd.) DC.
abstract: The antioxidant properties of aqueous and ethanolic extracts of the Uncaria tomentosa bark were evaluated. The analysis included trolox equivalent antioxidant capacity (TEAC), peroxyl radical-trapping capacity (PRTC), superoxide radical scavenging activity (SOD) and quantitation of total tannins (TT) and total phenolic compounds (TPC). The obtained results indicate high antioxidant capacity of the studied materials in comparison to the other extracts of fruits, vegetables, cereals and medicinal plants. Higher antioxidant activity and total phenolic compounds of the alcoholic preparations -- TEAC=0.57 mmol of Trolox/g, PRTC=0.52 mmol of Trolox/g and SOD=0.39 U/mg than of the aqueous preparation -- TEAC=0.34 mmol of Trolox/g, PRTC=0.19 mmol of Trolox/g and SOD=0.10 U/mg were observed. These results might suggest higher medical suitability of alcoholic extracts. However, the highly elevated level of tannins in alcoholic extracts may cause undesirable gastric effects.
authors.affiliation: Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego str. 12/14, 61-704 Poznań, Poland.
authors.forename: Radosław
authors.initials: R
authors.lastname: Pilarski
authors.forename: Henryk
authors.initials: H
authors.lastname: Zieliński
authors.forename: Danuta
authors.initials: D
authors.lastname: Ciesiołka
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Gulewicz
mesh_terms: D000975:Antioxidants / Q000302:isolation & purification / Q000494:pharmacology*; D020948:Cat's Claw; D000431:Ethanol / Q000494:pharmacology*; D016166:Free Radical Scavengers / Q000302:isolation & purification / Q000494:pharmacology; D024301:Plant Bark; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology; D014867:Water / Q000494:pharmacology*
chemical_list: D000975:Antioxidants; D016166:Free Radical Scavengers; D010936:Plant Extracts; D014867:Water; D000431:Ethanol