Lysine Carboxymethyl Cysteinate, as a Topical Glutathione Precursor, Protects Against Oxidative Stress and UVB Radiation-Induced Skin Damage.

Lysine carboxymethyl cysteinate (LCC) is a synthetic substance obtained via lysine salification of S-carboxymethyl-cysteine. LCC has emerged as a promising glutathione (GSH) precursor. In this study, we sought to determine whether LCC could boost GSH levels and protect skin against oxidative stress. Experiments utilizing primary human keratinocytes and skin tissue samples revealed that LCC significantly increased endogenous GSH levels. LCC was able to pass through the stratum corneum and reach deep into the epidermis, where it enhanced the production of key metabolites involved in GSH biosynthesis. Then, the efficacy of LCC on skin protection was explored. LCC demonstrated protective effects by shielding keratinocytes from blue-light-induced oxidative stress and preventing ultraviolet B (UVB)-induced barrier disruption and pigmentation in a pigmented living skin equivalent (pLSE) model. In addition to its antioxidant properties, LCC also reduced the production of inflammatory mediators. Together, these findings underscore the multifaceted role of LCC in bolstering the natural antioxidant defenses of skin and preventing the accumulation of irreversible damage from the environment, thereby positioning it as a promising candidate for advancing skin health.