Abstract:

The antioxidant activity of free phenols and anti-proliferation activity of polyphenols in Lentinus edodes stipe
powder after different crushing treatments on human liver cancer HepG2 cells were investigated in this study. The results
showed that the cellular antioxidant activity (CAA) decreased with the decrease in power size. Specifically, the CAA value
of free phenols from Lentinus edodes stipe powder ranged from 9.90 to 24.22 μmol QE/100 g; the coarse-ground group
indicated the highest CAA value, while and the nano-ground group exhibited the lowest CAA level. The CAA of free
phenols in Lentinus edodes stipe powder without washing with phosphate buffer saline (PBS) became lower with decreasing
particle size. With PBS washing, only the jet-milled group had antioxidant activity with a CAA value of 0.65 μmol QE/100 g.
The antiproliferative activity assay showed that EC50 values of free phenols from Lentinus edodes stipe powder were
1.888–5.213 mg/mL while those of bound phenols were 2.225–4.751 mg/mL. This study shows that jet milling can improve
the antiproliferative activity of Lentinus edodes stipe powder.

Key words: Lentinus edodes stipe powder, polyphenols, cellular antioxidant activity, antiproliferative activity