Evaluation of In Vitro Antioxidant Activity of the Water Extract Obtained from Dried Pine Needle ( Pinus densiflora ).

Antioxidant activities of water extracts obtained from dried pine needle ( Pinus densiflora ) were measured at 0, 4, 20, 100, 500, 1,000, and 1,200 ppm and compared with those of phenolic compounds of butylated hydroxyanisole, butylated hydroxytoluene, tert -butylhydroquinone, ferulic acid, and α-tocopherol. The activity was determined as the ability to scavenge 1,1-diphenyl-2-picrylhydrazyl radical and hydrogen peroxide, reductive power, and inhibition of lipid peroxidation in a linoleic acid system using the ferric thiocyanate method and thiobarbituric acid method, respectively. Pine needle water extract (PNWE) exhibited antioxidant activity in a concentration-dependent mode at the same parameters mentioned above, and a significant difference ( P <0.05) was observed at 1,000 ppm. The protective activity of PNWE as a potent antioxidant in a non-cellular system was compared with that of phenolics at 150.67 μg/mL in the two assays using biological cellular systems, namely 2,2'-azobis(2-amidinopropane) dihydrochloride-initiated hemolysis and Fe2+ -induced lipid peroxidation, using rat red blood cells and rat brain homogenate, respectively. The PNWE showed a strong power comparable to those of commercial phenolic compounds in biological systems. These results indicated that the protective activity of PNWE could be due to the presence of naturally-occurring phenolic compounds, which act as potent in vitro antioxidants in both non-cellular and cellular systems.