Titrated Extract of Centella Asiatica Provides a UVB Protective Effect by Altering MicroRNA Expression Profiles in Human Dermal Fibroblasts

The titrated extract of Centella asiatica (TECA) is a reconstituted mixture comprising of asiatic acid, madecassic acid, asiaticoside and madecassoside, and is used as a therapeutic agent in wound healing and also as an anti-microbial, anticancer and anti-aging agent. Although these properties and the associated cell signaling pathways have been elucidated, the cellular mechanism of anti-photoaging upon ultraviolet (UV) exposure in normal human dermal fibroblasts (NHDFs) remains unknown. In this study, we investigated the photoprotective role of TECA via microRNA (miRNA) expression profiling analysis. Low dose of TECA did not exhibit toxicity and showed a protective effect against UVB irradiation in NDHFs. miRNA microarray experiments revealed that specific miRNAs were altered by TECA stimulation in UVB-irradiated NHDFs. Functional bioinformatic analysis showed that the putative target genes of the altered miRNAs were associated with the positive regulation of cell proliferation, anti-apoptosis, small GTPase- and Ras-mediated signal transduction and activation of MAPKK. Therefore, these results suggest that TECA may serve as a potential natural chemoprotective agent against UVB-mediated damage in NHDFs through changes in the expression of specific miRNAs.