Ferulic and caffeic acids as potential protective agents against photooxidative skin damage

The biological properties and, particularly, the antioxidant activity of pl ant hydroxycinnamic acids, such as caffeic and ferulic acids, are well reco gnised. This preliminary study was designed to estimate the potential utili ty of caffeic and ferulic acids to prevent, when topically applied, photoox idative stress in the skin. With this aim we have evaluated the antioxidant activity of ferulic and caffeic acids in two experimental models: (1) the UV radiation-induced peroxidation in phosphatidylcholine (PC) liposomal mem branes; (2) the scavenging activity against nitric oxide (a radical involve d in oxidative reactions). In addition, given that a suitable percutaneous absorption is an essential requirement for successful topical photoprotecti ve agents, we measured their in vitro permeation through excised human skin . Caffeic and ferulic acids efficiently protected PC liposomes from UV radi ation-induced peroxidation and reacted with nitrogen oxides. In addition, c affeic and ferulic acids were able to permeate through the stratum corneum (the main barrier against the penetration of exogenous substances through t he skin). Taken together, these findings suggest that caffeic and ferulic a cids should be good canditates for successful employment as topical protect ive agents against UV radiation-induced skin damage. (C) 1999 Society of Ch emical Industry.