Synergistic Protective Effect of Agastache rugosa and Centella asiatica against UVB-Induced Damage in Human Skin Fibroblasts

Abstract

Ultraviolet B (UVB) irradiation is a major cause of the photoaging of human skin. Centella asiatica (CA) has been used as an effective anti-photoaging agent, mainly because it increases type Ⅰ collagen levels. On the other hand Agastache rugosa (AR) is a source of bioactive compounds that protect human skin fibroblasts against UVB irradiation by restoring the antioxidant defense. In this study, we investigated the synergistic protective effects of CA and AR in combination (CA-AR) against UVB-induced damage in human skin fibroblasts (Hs68 cells). Cell viabilities and protective effects were examined using an MTT assay with or without UVB irradiation (30 mJ/cm2). CA, AR, and CA-AR did not have a cytotoxic effect. The synergistic effects of CA and AR were analyzed using combination indices (CI) and isobologram models, and the optimal CA to AR ratio was 3:7. CA, AR, and CA-AR 3:7 increased cell viability by 87%, 80%, and 98%, respectively in UVB irradiated Hs68 cells, and at this ratio. CA-AR 3:7 had CI values ranging from 0.03 to 0.41 and was 71∼97% more effective than CA or AR alone against UVB-induced photoaging. These results suggest that the CA-AR combination has potential use in functional foods and cosmeceutical preparations.