Abstract
- Background
The human body's endogenous antioxidant defense system plays a crucial physiological role in maintaining systemic redox homeostasis and fulfilling essential protective functions against oxidative damage. Among circulating antioxidants, carotenoids exhibit pronounced antioxidant properties, specifically acting as efficient neutralizers of reactive free radicals. Within human cutaneous tissues, carotenoids accumulate at high concentrations within the stratum corneum (SC)—the outermost horny layer of the epidermis—where they specifically incorporate into the intercellular lipid lamellae. Non-invasive optical and spectroscopic techniques, notably resonance Raman spectroscopy and diffuse reflectance spectroscopy, are widely utilized to quantitatively determine human SC carotenoid concentrations in vivo. Electron paramagnetic resonance (EPR) spectroscopic investigations have further demonstrated that carotenoids bolster the total antioxidant capacity of the human stratum corneum in vivo by scavenging free radicals and effectively counteracting the onset of oxidative stress. This comprehensive review is dedicated to synthesizing the kinetic behaviors of carotenoids within the human stratum corneum in vivo using advanced non-invasive optical and spectroscopic methodologies.
- Methods
A systematic evaluation of biophysical, optical, and clinical literature was conducted to compile data concerning carotenoid kinetics in the human stratum corneum in vivo. Factors contributing to fluctuations in cutaneous carotenoid concentrations, their direct impact on the antioxidant status of the stratum corneum, and the specific physiological and clinical implications of these shifts were systematically analyzed. Particular emphasis was placed on examining the biochemical alterations induced by pharmacological treatments, such as the impact of chemotherapy on SC carotenoid levels in oncological patients.
- Results
Synthesized evidence highlights that non-invasive spectroscopic tools reliably map stratum corneum carotenoid kinetics and antioxidant status in vivo. Furthermore, clinical evaluations reveal that systemic chemotherapy significantly depletes cutaneous carotenoid concentrations in cancer patients, directly compromising their epidermal antioxidant defense. Building upon these findings, a potential antioxidant-based pathomechanism underlying chemotherapy-induced hand-foot syndrome (palmar-plantar erythrodysesthesia) is elucidated, alongside non-invasive monitoring approaches and targeted antioxidant strategies designed to reduce the frequency and severity of this debilitating dermatological toxicity.
- Conclusions
Carotenoids within the human stratum corneum serve as vital components of the cutaneous antioxidant network in vivo. Understanding their kinetics through non-invasive optical methods provides critical clinical insights into managing chemotherapy-induced cutaneous toxicities such as hand-foot syndrome, underscoring the therapeutic value of preserving skin carotenoid status during oncological care.
https://www.mdpi.com/2076-3921/11/8/1451