In the present work, human red blood cells (RBC) were used to determine cellular antioxidant activity (CAA-RBC) of pure phytochemicals and botanical extracts, with the aim to predict their bioavailability. Amongst the pure flavonoids, isorhamnetin, tamarixetin, myricetin, and kaempferol showed the highest activity in the CAA-RBC assay; whereas, with the ‘‘chemical” oxygen radical absorbance capacity (ORAC) assay, the compounds that showed the highest activity were isorhamnetin, resveratrol, apigenin and catechin. When the CAA-RBC assay was applied to herbal extracts, the Vitis vinifera showed the highest value, a position that this extract maintained also when the ORAC assay was used. Other extracts showed a different order of effectiveness with the two methods. We also employed the CAA-RBC to assess synergistic or antagonistic effects of combinations of herbal extracts and we again compared the results with the ORAC assay. Punica granatum + Malus domestica synergized in the CAA-RBC assay, but not in the ORAC assay; Aspalathus linearis extract interacted positively with Vaccinium myrtillus, both in the ORAC assay and in the CAA-RBC assay. We concluded that the CAARBC assay, coupled with the ORAC assay, was useful for evaluating intracellular bioactivity and synergy amongst phytochemicals or extracts.
The cellular antioxidant activity in red blood cells (CAA-RBC): A new approach to bioavailability and synergy of phytochemicals and botanical extracts
NINFALI, PAOLINO
2010
Abstract
In the present work, human red blood cells (RBC) were used to determine cellular antioxidant activity (CAA-RBC) of pure phytochemicals and botanical extracts, with the aim to predict their bioavailability. Amongst the pure flavonoids, isorhamnetin, tamarixetin, myricetin, and kaempferol showed the highest activity in the CAA-RBC assay; whereas, with the ‘‘chemical” oxygen radical absorbance capacity (ORAC) assay, the compounds that showed the highest activity were isorhamnetin, resveratrol, apigenin and catechin. When the CAA-RBC assay was applied to herbal extracts, the Vitis vinifera showed the highest value, a position that this extract maintained also when the ORAC assay was used. Other extracts showed a different order of effectiveness with the two methods. We also employed the CAA-RBC to assess synergistic or antagonistic effects of combinations of herbal extracts and we again compared the results with the ORAC assay. Punica granatum + Malus domestica synergized in the CAA-RBC assay, but not in the ORAC assay; Aspalathus linearis extract interacted positively with Vaccinium myrtillus, both in the ORAC assay and in the CAA-RBC assay. We concluded that the CAARBC assay, coupled with the ORAC assay, was useful for evaluating intracellular bioactivity and synergy amongst phytochemicals or extracts.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
