Antioxidant activity of propolis extracts from Serbia: A polarographic approach

• Published in: Food and chemical toxicology Vol. 50; no. 10; pp. 3614 - 3618
• Main Authors: Potkonjak, Nebojša I., Veselinović, Dragan S., Novaković, Miroslav M., Gorjanović, Stanislava Ž., Pezo, Lato L., Sužnjević, Desanka Ž.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-10-2012; Elsevier
• Subjects: analysis of variance; Antioxidant activity; Antioxidants - chemistry; Biological and medical sciences; Biphenyl Compounds - chemistry; Food Analysis; free radical scavengers; Hydrogen peroxide; markets; Medical sciences; mercury; Oxidation-Reduction; Picrates - chemistry; Polarography; Polarography - methods; propolis; Propolis - chemistry; Propolis extract; Serbia; Toxicology; Serbia; Southern Europe; Balkan Peninsula; Europe; Mediterranean Basin; Hydrogen peroxide; TPC; ΔH2O2; BHT; SD; Propolis extract; Polarography; ANOVA; HSD; EC50; DME; PEs; DPPH; Antioxidant activity; ip0; CL; AO; EEP; GEP; SCE; HPEq; Δip; FC; i–E; DC; Geographical division; Natural resin; Propolis; Extract; Antioxidant; Temperate zone; Biological activity
• ISSN: 0278-6915; 1873-6351
• DOI: 10.1016/j.fct.2012.07.029

► We report applicability of polarographic antioxidant method on propolis extracts. ► Antioxidant activity was correlated with hydrogen peroxide electrode reaction. ► DPPH-radical scavenging activity and phenolic content of propolis extracts was done. ► Antioxidant activity quantification of commercial propolis extracts was introduced.
Antioxidant activity (AO) of commercial propolis extracts (PEs), available on Serbian market, was determined by direct current (DC) polarography. Polarographic anodic current of 5.0mmolL−1 alkaline solution of H2O2 was recorded at potentials of mercury dissolution. Decrease of the current was plotted against the volume of gradually added PEs. The volume of PE causing 20% current decrease was determined from the linear part of the plot. Antioxidant activity was expressed in H2O2 equivalent (HPEq), representing the volume of PE that corresponds to 1.0mmolL−1 H2O2 decrease. Resulting HPEq ranged between 1.71±0.11 and 8.00±0.18μL. Range of 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging activity was from 0.093±0.004% to 0.346±0.006%. Total phenolic content (TCP) of PE with superior AO activity was 5.31±0.05%g GAE, while the extract with the lowest activity contained 1.45±0.02%g GAE. Antioxidant activity, determined by polarographic method, was correlated with DPPH scavenging activity (R2=0.991) and TCP (R2=0.985). Validity of obtained results was further confirmed using ANOVA and post hoc Tukey HSD test.