Effects of direct interaction of betalains with light and with retinal photosensitizers

Author(s)

Caroline de Oliveira Machado

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Conjunto das Químicas (IQ e FCF) (CQ/DBDCQ)
• Defense date: 2022-10-21

Examining board members

Erick Leite Bastos; Mauricio da Silva Baptista; Carla Cristina Schmitt Cavalheiro

• Advisor: Erick Leite Bastos

Abstract

Sunlight provides energy for the maintenance of life and its interaction with matter allows us to see the world around us. However, excessive exposure to light, especially ultraviolet and high-energy visible radiation, can favor deleterious photochemical processes that bleach colored products and negatively affect cell viability. This Doctoral Thesis shows that it is possible to combine natural pigments in small vesicles to modulate the color and antioxidant properties of the system, that the thermal degradation of betalain secondary metabolites is less important than their photodecomposition, and that natural betalains reduce the DNA damage induced by photosensitization of A2E and its isomers with blue light. These findings are important to promote the replacement of coloring additives and synthetic antioxidants with natural products, to understand how natural pigments with different chemical properties work together, and to development new ways to prevent photoinduced oxidative damage in the cellular environment. (AU)

• FAPESP's process: 15/24760-0 - Effect of antioxidant plant pigments on the viability of cells subjected to oxidative photoinduced stress
• Grantee: Caroline de Oliveira Machado
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)