Abstract:Roselle was used as raw material for the preparation of anthocyanins. The anthocyanins were purified using Amberlite XAD-7 macroporous resin, identified by Fourier-transform infrared spectroscopy, and ultrahigh-performance liquid chromatography-quadrupole time-of-flight mass spectrometry. Moreover, the antioxidant activity of anthocyanins in vitro and in HepG2 cells was evaluated. The results showed that the anthocyanin content in the purified product (Purified Roselle Anthocyanins, PRA) was 6.35-fold increased with a value of 175.27 mg/g. PRA contains five anthocyanins, of which delphinidin-3-sambubioside was the most abundant, accounting for 57.35% (w/w) of the total anthocyanins. PRA possessed good antioxidant activity in vitro. The scavenging rate of 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical reached 90% when the PRA concentration was 0.23 mg/mL, and the scavenging rate of hydroxyl radical reached 97.85% when the PAR concentration was 2.0 mg/mL. PRA also possessed good intracellular antioxidant activity. PRA of 200 μg/mL treatment significantly reduced the H2O2-induced HepG2 intracellular reactive oxygen species level and nitric oxide content from 117.47% (the 2',7'-dichlorofluorescein fluorescence intensity of the control group as 100%) and 53.18 nmol/mL to 102.09% and 45.79 nmol/mL, respectively. The PRA treatment significantly increased the H2O2-induced HepG2 intracellular superoxide dismutase activity and catalase activity from 18.19 U/mg prot and 10.10 U/mg prot to 35.05 U/mg prot and 19.38 U/mg prot, respectively. In conclusion, the PRA anthocyanins were dominated by delphinidin-3-sambubioside and had good antioxidant activity in vitro and anti-oxidative stress capacity in vivo. These results provide a theoretical basis for the high-value development and the potential health benefits of Roselle anthocyanins.