Procyanidin A₁ and its digestive products alleviate acrylamide-induced IPEC-J2 cell damage through regulating Keap1/Nrf2 pathway

Our previous study has revealed that procyanidin A₁ (A₁) and its simulated digestive product (D-A₁) can alleviate acrylamide (ACR)-induced intestine cell damage. However, the underlying mechanism remains unknown. In this study, we elucidated the molecular mechanism for A₁ and D-A₁ to alleviate ACR-stimulated IPEC-J2 cell damage. ACR slightly activated nuclear factor erythroid 2-related factor 2 (Nrf2) signaling and its target genes, but this activation could not reduce intestine cell damage. A₁ and D-A₁ could alleviate ACR-induced cell damage, but the effect was abrogated in cells transiently transfected with Nrf2 small interfering RNA (siRNA). Further investigation confirmed that A₁ and D-A₁ interacted with Kelch-like ECH-associated protein 1 (Keap1), which boosted the stabilization of Nrf2, subsequently promoted the translocation of Nrf2 into the nucleus, and further increased the expression of antioxidant proteins, thereby inhibiting glutathione (GSH) consumption, maintaining redox balance and eventually alleviating ACR-induced cell damage. Importantly, there was no difference between A₁ and D-A₁ treated groups, indicating that A₁ can tolerate gastrointestinal digestion and may be a potential compound to limit the toxicity of ACR.