Protective Effect of Protocatechuic Acid on Oxidative Damage and Cognitive Impairment in Pb-Induced Rats

Protocatechuic acid (PCA), a class of water-soluble phenolic acid abundant in the human diet, has been shown to be of great nutritional interest and to have medicinal value. However, the protective effects against lead (Pb)-induced body injury have not been elucidated. In this study, we explored the protective effect of PCA on Pb-induced oxidative damage and cognitive impairment in rats. The results showed that PCA could reduce the Pb content in rat bodies (blood, bone, brain, liver, and kidney) after Pb exposure. Moreover, PCA may inhibit Pb-induced oxidative damage by increasing the activity of antioxidant enzymes such as superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) and decreasing the level of malondialdehyde (MDA) in the brain, liver, and kidney. In addition, PCA may alleviate Pb-induced learning and memory impairment by upregulating neurotransmitter levels; maintaining the normal function of N-methyl-D-aspartate receptors (NMDARs); and promoting Ca²⁺ influx, thus activating signaling molecules, related protein kinases, and transcription factors in the cAMP-PKA-CREB pathway. In general, PCA could reduce oxidative stress and ameliorate the learning and memory deficits in Pb-treated rats, indicating that PCA may be an effective preventive agent and treatment or plumbism.