Evaluation of plant extracts of Senna spp. as photosensitizers in antimicrobial photodynamic therapy against Candida species

Abstract

In the last few decades, the incidence of fungal infections has increased significantly, contributing to high levels of morbidity and mortality. Of the Candida species related to these infections, we highlight C. krusei and C. glabrata, which have intrinsic resistance to fluconazole and are associated with high mortality in patients with fungemia. In view of the difficulties encountered in the treatment of candidiasis, much research has been carried out to seek alternative therapies for the treatment of these infections. Therefore, less invasive, less toxic antimicrobial methods and more effective against microbial resistance need to be strengthened and proposed. In this scenario, antimicrobial photodynamic therapy appears as a promising alternative. Therefore, this work proposes to study the in vitro potential of Senna splendida plant extracts, Senna macranthera and Senna reticulata to be used in antimicrobial photodynamic therapy on suspensions and biofilms of Candida Glabrata and Candida Krusei species. Initially, antimicrobial photodynamic therapy will be performed on microorganisms in suspensions in the presence of sub-inhibitory concentrations of materials of plant origin. Four groups will be studied: the negative control, plant material, only light and photodynamic therapy (light + plant material). The plant materials that present better results of suspension photodynamic therapy will be tested with microorganisms organized in biofilms. The effectiveness of therapy will be assessed by counting viable cells after treatment. The data will be analyzed with the aid of the IBM SPSS version 20.0 program, with a 5% significance level.