The Effects of Ultraviolet B Radiation on Human Skin And The Role of Antioxidants In Reducing Ultraviolet B Radiation-Induced Skin Damage

The proportion of ultraviolet radiation (UVR) that reaches the Earth’s surface and is eventually absorbed by human skin can generate harmful compounds called free radicals or reactive oxygen species (ROS) that lead to various skin disorders like skin cancer, inflammation, and photoaging. Ultraviolet-A and B waves (UVA and UVB), two of the three components of UV light, account for ۵% of the electromagnetic radiation that reaches the Earth’s surface. From this, a large amount of UVA (about ۹۰ to ۹۵%) and a small percentage of UVB (about ۵ to ۱۰%) radiation reaches the surface of the Earth. Accordingly, most of the health damage caused by UVR on the surface of the Earth is due to UVA and UVB, and the latter is one of the main risk factors for the development of skin cancer in humans as it is generally more carcinogenic than UVA. More precisely, UVB exposure, after affecting proteins, DNA, RNA, and lipids, initiates cancer directly and indirectly: Directly, UVB irradiation causes oxidative damage that induces mutations in DNA, immunosuppression, and inflammatory responses; and indirectly, UVB exposure increases ROS formation.In an effort to decrease the amount of UVB-induced ROS production, some studies center on the topical administration of compounds with antioxidant properties. This strategy, referred to as photochemoprotection, consists of using photoprotectors that inhibit or scavenge the intracellular production of ROS after or during exposure to UVB. Since research on protective substances with antioxidant properties against UVR has been shown to increase the skin's immunity against UVB radiation, this review, after discussing the effects of UVB radiation on the skin and the mechanisms of free radical damage, attempts to evaluate the potential benefit of antioxidants in sunscreens and skin care products.