UVA (> 360-400) and UVB (300-325) specific sunscreens

Abstract

UVB radiation of about 300-310 nm wavelength and UVA radiation of about 380-390 nm wavelength, each of which exists in solar light, induces MMPs (matrix metalloproteinases) in human skin that degrade the collagen of the dermal matrix. This degradation contributes to photoaging of human skin, which can be prevented by blocking these wavelengths of solar radiation. In contrast, diseases that result in the overproduction of collagen can be treated by exposing the affected with to radiation having wavelengths in those regions, for these wavelengths not only induce MMPs but also inhibit collagen biosynthesis. For lighter skinned people so affected, the UVA wavelengths are preferred because of the reduced amount of erythema, whereas dark skinned people can be treated with the UVB radiation because they generally do not suffer from erythema.

1 . A method for preventing the induction of MMPs in human skin upon exposure to solar radiation, comprising applying to the person's skin one or more substances that block UVB radiation in the range of about 295-315 nm and block UVA radiation in the range of about 365-395 nm.  
   
   
       2 . The method of  claim 1 , wherein the UVB range is about 300-310 nm.  
   
   
       3 . The method of  claim 1 , wherein the UVA range is about 380-390 nm.  
   
   
       4 . A method for treating a fibrotic condition in a human patient normally having a light skin color, comprising providing a source of UVA radiation emitting in the range of greater than about 360 nm up to about 400 nm and exposing the affected area of the patient's skin to the UVA radiation.  
   
   
       5 . The method of  claim 4 , wherein the UVA range is about 370-390 nm.  
   
   
       6 . A method for treating a fibrotic condition in a human patient normally having a dark skin color, comprising providing a source of UVB radiation emitting in the range of about 295-315 nm and exposing the affected area of the patient's skin to the UVB radiation.  
   
   
       7 . The method of  claim 6 , wherein the UVB range is about 300-310 nm.