Dual Role of Stratum Corneum Carotenes/Lycopene Against the Development of Chemotherapy-induced PPE in Patients With Cancer

Palmar-plantar erythrodysaesthesia (PPE) is a common side effect of chemotherapy treatment in patients with cancer. The exact pathophysiologic mechanisms of the development of PPE remain unclear. Here, we report two important physiological functions of carotenoids without hydroxyl groups (α-carotene, β-carotene, γ-carotene, Ξ- carotene, lycopene, phytoene, phytofluene and their isomers) in the stratum corneum (SC) of glabrous skin: The powerful antioxidant protection of the integrity of the SC components against the destructive action of free radicals and maintaining the skin barrier function by the creation of an orthorhombic organization of intercellular lipids within lamellae using carotenoids as a skeleton. The dual protective role of carotenoids without hydroxyl groups is important for both healthy skin and, in the authors' opinion, for the skin of chemotherapy-treated patients against the development of PPE, as the chemotherapy-induced reduction of the carotenoid concentration in the stratum corneum considerably weakens the skin resistance to cytotoxic and other adverse reactions.