Ultraviolet A (UV-A) Radiation-Induced Damage in the Skin and Vital Organs of Albino Rat: An Indirect Correlation with Melatonin

Ultraviolet radiation is causative of generation of reactive oxygen species (ROS) in the body that significantly affects normal physiology and disturbs homeostasis. In the present study we investigated the effect of UV-A radiation exposure on the first line of defence system such as skin and vital organs such as liver, kidney and spleen of Rattus norvegicus . Adult female rats were exposed to UV-A radiation for seven days at a dose of 6.36 J/cm 2 and the changes in the skin histoarchitecture, oxidative load of spleen, liver and kidney along with cellular ROS levels of splenocyte determined using DCFDA staining were recorded. UV-A exposure severely damaged the histoarchitecture of skin and reduced proliferating cell nuclear antigen (PCNA) expression. The lipid peroxidation (MDA) level in spleen, liver and kidney were increased to significant levels while the activities of the enzymatic antioxidants, SOD and catalase were significantly decreased. Significant decrease of glucose content and increase of LDH of both spleen and liver were found. Cellular damage of splenocyte was observed as evidenced by increase in percentage of intense DCFDA-stained cells in UV-A treated rats. Thus, our results clearly demonstrate that UV-A radiation exposure may have detrimental effects on the antioxidant defence system of the body, including melatonin, leading to disruption of physiology by affecting vital organs.