Model of Experimentation for Photoprotective Properties of Natural Products Against Ultraviolet C (UVC) Damage: A Case Study On Rosmarinic Acid

UVC is one of the three forms of ultraviolet radiation that is produced by the sun and is harmful to those who are exposed to it. On earth, our ozone layer acts as a filter against UVC (solar UVC) from the sun. However, this is not the case for those exploring space as there would not be any filter for solar UVC once out of Earth’s atmosphere. Additionally, although our ozone layer is able to filter solar UVC, non-solar UVC created by mankind can still pose a threat to those who utilize it for sterilization, research studies, medicine, etc. Identifying substances that could protect against this harmful form of radiation has significant potential; hence, we developed an experimental model to test a bioactive compound, romarinic aid (RA) in order to determine if it has photoprotective properties against UVC. To study the photoprotective properties of the compound, an experimental model using UVC lamp was set up and the cell viability of human keratinocyte cells treated with RA were measured with MTT and flow cytometry based apoptosis assays. The results obtained showed that RA was indeed able to attenuate the damaging effect of UVC, thus making it a potential candidate for further studies of photoprotection against solar and non-solar UVC. The model that was designed was shown to be reliable, reproducible and effective in screening UVC photoprotective properties in natural products. Thus, this opens up a new platform of natural product screening in the development of functional-cosmetics for astronauts and non-solar UVC users.