Abstract:

Purpose: To establish the best purification conditions for anthocyanins from the fruit pulp of Padus racemosa
with AB-8 macroporous resin and detect the in vitro antioxidant activity of the extracted anthocyanins. Methods: The adsorption
and desorption properties of macroporous resin AB-8 for anthocyanins from Padus racemosa were investigated to optimize the
purification procedure, and the antioxidant activity in vitro was detected by nitroblue tetrazolium (NBT) photochemical reduction
method. The protective effect of the extracted anthocyanins against oxidative stress induced by H2O2 in N2A cells was analyzed
by 2’,7’-dichlorodihydrofluorescein diacetate (DCFH-DA) fluorescent probe assay. Results: The best purification conditions were
achieved by adsorption performed twice with at a flow rate of 0.01 mL/s after adjustment of the crude extract concentration to
8 mg/mL and subsequent desorption with 70% ethanol acidified to pH 3 at a flow rate of 0.01 mL/s. The color value after
purification was 57.1, achieving a 16.31-fold purification factor. The anthocyanins had a strong superoxide anion radical
scavenging capacity in a dose-dependent manner. N2A cells could be protected by the anthocyanins at a concentration of
0.025 mg/mL, and the level of reactive oxide species in N2A cells could be reduced by the anthocyanins at 0.05 mg/mL.
Conclusion: Macroporous resin AB-8 is an effective adsorbent for the purification of Padus racemosa anthocyanins, and Padus
racemosa anthocyanins have strong antioxidant activity in vitro in a certain concentration range.

Key words: Padus racemosa, anthocyanin, purification, macroporous resin, antioxidant, reactive oxide species