Photoprotective effect of Pothomorphe umbellata on UVB radiation-induced biomarkers involved in carcinogenesis of hairless mouse epidermis

Abstract

In this study we assessed the protective effect of topical application of Pothomorphe umbellata extract on ultraviolet B (UVB)-induced skin lesion parameters in hairless mouse epidermis. A single dose of UVB irradiation (0.23 kJ/m²) resulted in a significant decrease in thymine dimer-positive cells and apoptotic sunburn cells, with an increase in p53 and proliferating cell nuclear antigen-positive cells in the epidermis. After 5 weeks (total dose 13.17 kJ/m²) and 15 weeks (total dose 55.51 kJ/m²) of irradiation, P. umbellata treatment inhibited the hyperplasic response and induced an increase in p53-positive cells. These findings suggest that P. umbellata extract affords protection against UVB-induced skin lesions.

Keywords::

• Pothomorphe umbellata
• UVB radiation
• skin
• biomarkers
• tumors

Acknowledgments

This work has been supported by Fundação de Amparo a Pesquisa do Estado de São Paulo – FAPESP (doctoral fellowship to Vanessa Vitoriano da Silva (02/13106-7), postdoctoral fellowship to Cristina Dislich Ropke (03/10917-7), project support grant (04/03507-0). We also would like to thank Prof. Paolo Di Mascio for the radiometry measurements.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.