Punicalagin Activates AMPK/PGC-1α/Nrf2 Cascade in Mice: The Potential Protective Effect against Prenatal Stress.

Abstract

Prenatal stress is closely associated with poor health outcomes for offspring, yet the specific mechanisms and effective interventions remain limited. In the present study, both male and female rat offspring exposed to prenatal restraint stress (PRS) are confirmed to have impaired spatial learning and memory, accompanied by reduced AMP-activated protein kinase (AMPK) activity and decreased protein expression of mitochondrial biogenesis and antioxidant pathways in the hippocampus. Interestingly, a deficiency in the AMPK cascade also occurs in liver, heart, and adipose tissues, suggesting that the systemic deactivation of AMPK in the offspring is potentially attributed to increased maternal glucocorticoid levels under PRS. Punicalagin (PU), a major ellagitannin in pomegranate, is found to effectively induce mitochondrial biogenesis and phase II enzymes through activation of AMPK in both HT22 and primary hippocampal neurons, thereby inhibiting glutamate-induced cell viability and mitochondrial membrane potential loss. Meanwhile, the activation of AMPK cascade is also confirmed in mice administrated with PU for three days. Altogether, these results indicate that the systemic deficiency of the AMPK cascade can be the key factor that contributes to poor outcomes of PRS, and PU may be used as an effective maternal nutritional intervention.