Abstract

A study in vitro on the antioxidant activity of Portulaca oleracea L. was carried out by HPLC-ESR Spin-trapping System. HPLCESR analysis is performed on monitoring ESR signal intensity of radicals adduct of 5,5-dimethyl-1-pyrroline N-oxide (DMPO/O2). The ESR signal which is recorded from the Portulaca oleracea L. extracts in aqueous buffer by HPLC-ESR system showed that the high antioxidant activity of the extracts reduce the concentration of DMPO/O2 signal to 80 % and the absorbance of reactive oxygen species from 0.08 to 0.06. The ground powder and the extract of Portulaca oleracea were in vivo performed on GMRGAL4/ UAS-hDuox2 flies containing hDuox2 protein which induced high oxidative stress and expressed rough-eye phenotype. Antioxidant activities of Portulaca oleracea were evaluated by comparing the rough-eye area before and after the experiment. At the concentration of 20 %, the ground powder and the extracts induced antioxidant activities to 81.72 % and 87.33 %, respectively. The result showed that both the ground powder and the extracts had antioxidant activities which reduced symptoms of rough-eye phenotypes. In conclusion, the in vitro and in vivo experiments indicated that both ground power and aqueous extract of leaves of Portulaca oleracea possess effective antioxidative abilities.