Phenolic contents, cellular antioxidant activity and antiproliferative capacity of different varieties of oats

•Phenolic contents and cellular antioxidant activity of oat varieties were determined.•Longyan 3 and Beiyan 1 exhibited the highest levels of total avenanthramides (AVs).•Shaotong exhibited the highest levels of total phenolic acids.•ORAC values correlated with AVs while CAA values correlated with phenolic acids.•All the oat extracts showed antiproliferative capacities. The objectives of this research were to determine the phenolic contents, oxygen radical absorbance capacities (ORAC), cellular antioxidant activities (CAA), and antiproliferative capacities of nine oat varieties and four brans in China. Of all varieties, Longyan 3 and Beiyan 1 exhibited the highest total avenanthramides (146.94±7.31 and 120.95±6.66µg/g, respectively) and ORAC values (21.03±0.56 and 21.18±1.45µM Trolox/g, respectively), while Shaotong exhibited the highest total phenolic acids (143.52±9.42µg/g) and CAA values (33.38±1.74µM quercetin/100g). The EC50 of antiproliferative capacities ranged from 167.31±6.42 to 233.42±21.31mg/mL, with the lowest in Beixiao 8 while the highest in Jinyan 8. ORAC values correlated with avenanthramides while CAA values correlated with phenolic acids. Moreover, phenolic contents, antioxidant properties, and antiproliferative capacities of oat brans was higher than that of corresponding whole oats in most cases.