Abstract:In this study, the in vitro antioxidant capacities of the anthocyanin from black wolfberry (BWA) and epigallocatechin gallate (EGCG) were investigated, and the synergistically protective effect of the combination of the two compounds against the oxidative damage of immortalized human keratinocytes (HaCaT) was investigated through constructing a model of oxidative damage induced by UVB. In vitro antioxidant experiments showed that BWA and EGCG had strong DPPH radical scavenging ability, hydroxyl radical scavenging ability and iron ion reducing ability. Isobologram analysis revealed that within the safe dose range, the combinations with different proportions of BWA and EGCG exhibited greater protective effects on the damaged cells compared with BWA or EGCG alone (P<0.05), and the combination with the mass ratio of 6:4 (BWA:EGCG) exerted the strongest synergistic protection, with the synergistic rate being 17.08% and the survival rate of the damaged cells being 89.71%. Compared with the model group, the 6:4 combination increased the activities of catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPX) by 2.66, 1.91 and 2.33 times, respectively, while decreasing the content of malondialdehyde (MDA) by 40% (P<0.05). The results showed that both BWA and EGCG had in vitro strong antioxidant capacities, and their combination exhibited synergistically protective effect against cell oxidative damage. The mechanism might be realized by enhancing the activities of antioxidant enzymes in cells, thereby reducing UVB-induced oxidative damage to HaCaT cells, which may provide a theoretical reference and experimental support for the development and application of the combination of the anthocyanin from black wolfberry and EGCG.
