Total phenolic content, antioxidant and antimicrobial activity ofHaberlea rhodopensisextracts obtained by pressurized liquid extraction

Abstract

The present study was designed to investigate the antioxidant and antimicrobial activities of pressurized liquid extracts from Haberlea rhodopensis Friv. The total phenolic content was performed using the Folin-Ciocalteu phenol reagent. To determine the antioxidant activities of the extracts, several complementary tests were used: ABTS and DPPH radical scavenging activities, oxygen radical absorbance capacity, and ferric-reducing antioxidant power assay. The phenolic concentration was 15.98±0.09 and 9.42±0.06 mg GAE g−1 DW for 70 and 85% ethanol extracts, respectively. Of all the performed methods, the highest antioxidant activity values were measured by the ORAC assay — 224.6±6.6 and 154.0±9.9 μM TE g−1 DW for 70 and 85% ethanol extracts, respectively. Results also showed that both extracts exhibited very weak antimicrobial activity against the examined microorganisms. However, the 70% ethanol extract possessed higher inhibition ability, which correlated with higher total phenolic content and antioxidant...