Skin cancer incidences are rising worldwide, and one of the major causative factors is excessive exposure to solar ultraviolet radiation (UVR). Annually, ~5 million
skin cancer patients are treated in United States, mostly with nonmelanoma
skin cancer (NMSC), which is also frequent in other Western countries. As
sunscreens do not provide adequate protection against deleterious effects of UVR, additional and alternative
chemoprevention strategies are urgently needed to reduce
skin cancer burden. Over the last couple of decades, extensive research has been conducted to understand the molecular basis of skin
carcinogenesis, and to identifying novel agents which could be useful in the
chemoprevention of
skin cancer. In this regard, several natural non-toxic compounds have shown promising efficacy in preventing skin
carcinogenesis at initiation, promotion and progression stages, and are considered important in better management of
skin cancer. Consistent with this, we and others have studied and established the notable efficacy of natural flavonolignan
silibinin against UVB-induced skin
carcinogenesis. Extensive pre-clinical animal and cell culture studies report strong anti-inflammatory,
anti-oxidant, DNA damage repair, immune-modulatory and anti-proliferative properties of
silibinin. Molecular studies have identified that
silibinin targets pleotropic signaling pathways including mitogenic, cell cycle, apoptosis, autophagy, p53, NF-κB, etc. Overall, the
skin cancer chemopreventive potential of
silibinin is well supported by comprehensive mechanistic studies, suggesting its greater use against UV-induced cellular damages and photocarcinogenesis.