ABSTRACT
Increasing findings devote to searching for natural active compositions as additives to ameliorate health status. Anthocyanin, water-soluble natural pigment, has been concerned due to its favorable antioxidant activity. In this study, we purified anthocyanin from Dioscorea alata L., identified its compounds, and evaluated its antioxidant properties. The results indicated that the purity of anthocyanin increased to 39.59 ± 1.56%, 60.18 ± 1.97%, and 81.08 ± 1.97% after purification via AB-8 macroporous resin, Sep-Pak C18 solid phase, and LH-20 Sephadex stepwise. Ultra-performance liquid chromatography tandem mass spectrometer results indicated that paeoniflorin-3,5-O-dihexoside, petunin-3-O-feruloyl-glucoside-5-O-glucoside, cyanidin-3-O-feruloyl glucoside-5-O-glucoside, cyanidin-3-O-sophoroside, and petunin-3,5-O-dihexoside were the major compounds. The purified anthocyanin exhibited stronger antioxidant activity than the unpurified extract and ascorbic acid, whereas weaker than that of cyanidin-3-O-glucoside in general, which was assessed using DPPH, ABTS, and Fe3+ reducing capacity methods. Moreover, the purified anthocyanin increased GSH-Px, total antioxidant capacity, and superoxide dismutase activities and decreased malondialdehyde concentration on serum in mice after administering lipopolysaccharide for 24 h (p < .05). To summarize, the purified anthocyanin boasts more outstanding antioxidant properties than that of crude extracts. These results provide a reference with source of anthocyanin and it is conducive to use Dioscorea alata L. resources.
ABSTRACT
The purple tubers of Dioscorea alata L. have been found to contain a variety of bioactive chemical components, including anthocyanins, which make it significant to investigate the pre-protective effects of Dioscorea alata L. and its crude extracts on cells prior to oxidative stress. To establish a suitable oxidative damage model, an injured model of IPEC-J2 cells was created using H2O2 as the oxidant. Specifically, when the concentration of H2O2 was 120 µmol/L and the injured time was 8 h, the survival rate of cells decreased to approximately 70%, and the cells exhibited a noticeable oxidative stress reaction. Moreover, the crude extracts of Dioscorea alata L. demonstrated beneficial pre-protective effects on IPEC-J2 cells by increasing the total antioxidant capacity (T-AOC) and catalase (CAT) activities, augmenting the expression of total superoxide dismutase (T-SOD) and its genes, reducing the content of malondialdehyde (MDA) and the activity of glutathione peroxidase (GSH-PX) and its expression of genes, and promoting the expression of glucose transporter SGLT1 gene while reducing that of GULT2 gene, thereby facilitating the entry of anthocyanins into cells. In addition, the 50 µg/mL crude extracts effectively inhibited the phosphorylation of IκB and the p65 protein, thus reducing cellular oxidative stress. Given these findings, Dioscorea alata L. can be considered a natural antioxidant for practical breeding and production purposes, with an optimal concentration of crude extracts in this experiment being 50 µg/mL.
