Study of the synergistic effects of sulforaphane, epigallocatechin gallate and plumbagin against H2O2 in SH-SY5Y cells

Nutraceuticals are interesting resources for research in preventive medicine and neurodegenerative diseases that are characterized by an extensive oxidative stress. The aim of this study was to investigate whether a co-treatment (SEP) consisting of sulforaphane (SF), epigallocatechin gallate and plumbagin, all able to activate Nrf2-ARE stress response pathway, is able to counteract H2O2 deleterious effects based on a synergistic hypothesis. SEP was more effective, compared to the single compounds, in increasing cell viability (measured by PrestoBlue) after H2O2-induced damage and in enhancing GSH levels (by MCB assay). Only SEP and SF significantly reduced ROS levels (by DCFH-DA assay) upon oxidative stress. The synergistic antioxidant activity of SEP was confirmed by the marked up-regulation of different antioxidant enzymes (by RT-PCR). The protection evoked by SEP against H2O2 was also confirmed in a 3 dimensional model (3D) of differentiated SH-SY5Y cells we developed. In conclusion, we identified a pleiotropic treatment that can prevent neurodegeneration caused by oxidative stress and we also developed a more precise brain model for the study of nutraceutical compounds.