Abiotic stresses usually result in the overproduction of Reactive Oxygen Species (ROS), which cause oxidative damage. ROS regulation is vital to improve plant resistance to stress and is implemented by a defense system. Higher levels of glutathione (GSH) and Metallothionein (MT) indicate a defense mechanism in response to oxidative stress, participating in ROS detoxification. The abajerú (Chrysobalanus icaco L.) leaf extract is used in folk medicine to control glucose levels in diabetic individuals. This effect may be altered due to abiotic factors that differ according to the region where C. icaco occurs, reflected in oxidative stress biomarker levels. In this context, the aim of this study was to evaluate and compare GSH and MT levels in C. icaco specimens from different Brazilian regions. A statistically significant difference in GSH and MT levels was observed between Southeastern and Northeastern samples, indicating that regionalization may interfere in the biochemistry of C. icaco leaf extracts. Furthermore, a statistically significant correlation between GSH and MT levels was noted, which may be linked to metal exposure, which induces MT expression which then acts against ROS, and corroborates that GSH expression may also be related to metal contamination.