Confirmation of plant-derived exosomes as bioactive substances for skin application through comparative analysis of keratinocyte transcriptome

Plant exosomes are nanosized (30–150 nm) membrane vesicles that contain biomolecules and influence the development of a plant and protect the plant from pathogens. Recently, plant exosomes are in the spotlight as a new biologically active substance. However, whether plant exosomes have similar efficacy to conventional secondary metabolites of plants is unknown. In this study, the difference in efficacy between plant exosomes and conventional secondary metabolites was analyzed with three or four types of plant extracts, including ginseng (Panax ginseng) and green tea (Camellia sinensis). After 6 h of treatment, the analysis of gene expression pattern of each sample showed that the exosome treatment group and the extract treatment group were clearly distinguished. After selecting the genes that showed differential expression of > twofold change, the number of genes that were up- or downregulated appeared to be 398 or 438 for the extract and 861 or 648 for the exosome, on average. This suggests that the change in transcriptome is more expressed in the exosome treatment group than in the extract treatment group. In addition, in the comparative analysis of expression of genes that are known to affect aging, regeneration, skin barrier, and moisturization—MMP12, MMP13, NOTCH3, FGF12, HS3ST3A1, LOX, VIM, ELOVL3, and KRTI—the exosome treatment group was predicted to more effectively contribute to maintaining a healthy skin when compared to the extract treatment group. The number of genes that were identified to specifically react to the Panax ginseng or Camellia sinensis treatment group during the transcriptome change phase was 11 and 8, respectively. This suggests that exosomes bear its specific effect according to the plant it is derived from. In conclusion, the results of this study indicate that plant exosomes, as natural biologically active substances, have different effects from conventional plant extracts, and have the potential to be commercialized as a cosmeceutical product.