Eugenol protects cells against oxidative stress via Nrf2

Eugenol is a naturally occurring compound that is present in a variety of plants and has previous been demonstrated to exert a number of bioactivities. However, the potential effects of Eugenol on cellular protection against oxidative stress remain poorly understood. In the present study, HEK-293 cells and the mouse fibroblast cell line NIH-3T3 cells were used as models to explore the effects of eugenol on H2O2-induced damage. Among the three natural compounds tested, namely eugenol, methyleugenol and acetyleugenol, eugenol was found to increase the transcriptional activity and expression level of nuclear factor erythroid 2-related factor 2 (Nrf2), a central regulator of cellular responses to oxidative stress, in a dose-dependent manner. The mRNA levels of Nrf2 target genes glutamate-cysteine ligase modifier regulatory subunit and glutathione S-transferase A1, were also found to be upregulated following eugenol treatment. Further study revealed that eugenol enhanced the stabilization and nuclear translocation of Nrf2. Additionally, treatment with eugenol was found to reduce intracellular ROS levels while increasing cellular resistance to H2O2, in a manner that was dependent on Nrf2. In conclusion, data from the present study suggest that eugenol is a protective agent against oxidative stress that exerts its effects through a Nrf2-dependent pathway, rendering eugenol and its derivatives to be promising candidates for the future development of antioxidants.