Study on chemical composition, antioxidant and anti-inflammatory activities of hot water extract from Picea mariana bark and its proanthocyanidin-rich fractions

Hot water extract (HWE) from Picea mariana (black spruce) bark was evaluated for its antioxidant and anti-inflammatory activities. HWE was fractionated into an oligomeric proanthocyanidin-rich fraction (OPF) and a polymeric proanthocyanidin-rich (PPF) fraction, and their bioactivities were also evaluated. OPF exhibited the highest antioxidant and anti-inflammatory activities. The compositions of HWE, OPF and PPF were also evaluated. OPF was richest in total polyphenol but the lowest in total proanthocyanidin (PA) content. Thiolysis coupled with HPLC-DAD has shown that the PAs of the black spruce bark were procyanidin type. The mean degrees of polymerisation (DPm) of HWE, OPF and PPF were, respectively, 6.0, 3.3 and 7.6.