In vitro antioxidant activity and phenolic content of Cedrus brevifolia bark

Abstract

A raw extract and four extractive fractions were obtained from Cedrus brevifolia (Cyprus cedar) bark. They were all studied regarding the phenolic content and profile using spectrophotometry and HPLC-DAD-ESI-MS. The antioxidant activity was investigated using in vitro assays: DPPH and ABTS radicals scavenging and reducing power assays. The ethyl acetate fraction had the highest total phenolic and proanthocyanidin contents; a taxifolin-O-hexoside, catechin, epicatechin and procyanidin oligomers (three dimers, two trimers) were identified in this fraction. The ethyl acetate fraction was found to possess the highest DPPH and ABTS radicals scavenging effects (EC50=13.9 ± 0.3 and 2.3 ± 0.0 μg/mL, respectively) and reducing capacity (EC50=9.1 ± 0.1 μg/mL). Antioxidant effects were highly correlated with total phenolic and proanthocyanidin contents (r=0.89-0.99). These results suggest that Cedrus brevifolia bark is a new source of antioxidants.