Figure 1.

Prisma flow diagram details the methodology that was applied to choose the preclinical studies that were used for the writing of the review. Duplicate articles were excluded from the total number of studies that were recorded. Instead, we selected the articles that describe the role of natural compounds in the activation of Nuclear Factor Erythroid-2 Related Factor 2 (Nrf-2) signaling, which is important to promote injury repair and restore functional deficits (The PRISMA Statement is published in [23]).