Preventive and ameliorative effects of potato exosomes on UVB-induced photodamage in keratinocyte HaCaT cells

Exosomes isolated from potato (Solanum tuberosum) exhibit the biophysical characteristics of exosomes observed in mammalian cells and microorganisms, as determined by dynamic light scattering analysis and transmission electron microscopy. In the present study, it was shown that potato exosomes (ExoPs) can penetrate keratinocyte HaCaT cells, as determined by confocal microscopy and flow cytometry. In addition, ExoPs can suppress the expression of the collagen-destroying enzymes MMP1, 2 and 9, and the inflammatory cytokines IL6 and TNF-& alpha;, while inducing the expression of glutathione S-transferase & alpha; 4, a cellular detoxifying enzyme, as revealed by reverse transcription-quantitative PCR. Furthermore, ExoPs promote HaCaT cell proliferation, exhibit in vitro antioxidant activity against the free radical 2,2-diphenyl-& beta;-picrylhydrazyl, and protect cells from hydrogen peroxide-induced cytotoxicity. ExoPs can also minimize the induction of photodamage initiated by ultraviolet B (UVB) irradiation, and have the tendency to cure the photodamage already incurred on cells by UVB irradiation. ExoPs also prevent collagen degradation as observed in the culture media of UVB-irradiated HaCaT cells. Collectively, ExoPs may protect and ameliorate photodamage in keratinocyte HaCaT cells.