For those interested in the future, the promising work being done around botanical-based photoprotective actives is an area worth watching. This emerging class of ingredients shows potential for strengthening the skin’s immune response to photodamage and reversing residual damage from past UV exposure.
Carotenoids are antioxidants that are found in various plants, but are particularly abundant in the micro algae Dunaliella. In vitro studes have shown one carotenoid, phytoene, to absorb light in the UVB range, while another, phytofluene, absorbs in the UVA range. Both have been demonstrated to protect against oxidative damage and inflammation, and to inhibit melanin synthesis in skin exposed to UVA radiation.
A University of Maryland study showed bran extracts known as inositol and inositol hexaphosphate to be capable of protecting human skin cells and the skin of cancer-prone mice from UVB radiation. They also proved effective at preventing reactive molecules from injuring DNA.
Gamma oryzanol, which is highly resistant to UV light, is a natural sunscreen enhancer. Already in use as a UVA/UVB filter in Europe, this rice bran derivative displays a powerful antioxidant effect against UV radiation when combined with tocopherol.
While not a sunscreen, research at Johns Hopkins University has shown that broccoli sprout extract can work inside skin cells to boost enzyme production and protect against UV radiation. Erythema was significantly reduced when the skin of laboratory mice and human volunteers was treated with the broccoli sprout extract sulforaphane. Significantly, the effect lasts for several days, even after the extract has vanished from the skin surface.
Joint research at the University of Washington and Rutgers University to study the effects of topical caffeine on UV exposure has led to preliminary suggestion that caffeine can reduce UV absorption in the skin and inhibit the formation of UV-induced skin cancers.
Caffeine and caffeine sodium benzoate applied to mouse skin after UVB exposure resulted in a significant decrease in UV-induced roughness and wrinkles, and promoted apoptosis of DNA damaged cells. A separate animal study suggested that caffeine in combination with exercise may further boost its cancer-fighting protection.