Safety Profile of Solanum tuberosum-Derived Exosomes: Evidence from In Vitro Experiments and Human Skin Tests

Repetitive exposure to ultraviolet B (UVB) radiation is known to cause DNA damage and increase levels of reactive oxy-gen species (ROS), which are linked to the upregulation of matrix metallopeptidases (MMPs) and inflammatory cyto-kines. These events lead to collagen breakdown by MMPs, resulting in wrinkles, loss of elasticity, and rough, dry skin—typical signs of photoaging—and may even contribute to skin cancers in the long term. We have previously shown that Solanum tuberosum-Derived Exosomes (SDE) can repress 80% of the expression of MMP1 and tissue necro-sis factor (TNF) at 50 μg/mL without inducing damage to keratinocyte HaCaT cells. In this report, we show that SDEs can be treated to the HaCaT cells up to 1,000 μg/mL without inducing cell death, establishing a safe maximum concen-tration. SDEs can signifcantly promote wound healing in a scratch model of wounds in HaCaT cells and elevate the ex-pression of skin barrier genes in HaCaT and fibroblast cell line Detroit 551, which are known to enhance skin cell integ-rity, prevent water loss, and support natural desquamation. In a skin clinical test including 21 volunteers for 2 weeks, prototypes containing SDEs at 100 μg/mL as the main ingredient significantly enhanced skin elasticity, reduced deep eye wrinkle depth, and decreased melanin content, most importantly, without skin-irritating side effects. These findings suggest that SDEs are a safe, natural complex with antioxidant, anti-inflammatory, and barrier-enhancing effects that can be produced in quantity with relative ease for a potential medical application in humans.