Protective Effects Proanthocyanidin Nanoliposome Freeze‐Dried Powder on Oxidative Injury in a p31‐43 Induced Celiac Disease Cell Model

Proanthocyanidins play a crucial role in celiac disease (CD) through their antioxidant and anti-inflammatory properties, effectively regulating oxidative stress and inflammatory responses. However, the poor stability and low bioavailability of proanthocyanidins significantly limit their therapeutic applications. The aim of this study was to investigate the effects of lyoprotectants on proanthocyanidin nanoliposome freeze-dried powder (PCNL-FD), characterize its structural properties, evaluate its in vitro antioxidant capacity and explore its protective effects in a celiac disease cell model. The addition of 4% trehalose as a lyoprotectant effectively maintained the encapsulation efficiency and redispersion stability of PCNL-FD. FTIR and TEM analyses confirmed the successful incorporation of proanthocyanidins into the phospholipid bilayer. In vitro antioxidant assays showed that PCNL-FD exhibited significantly higher DPPH, ABTS, and hydroxyl radical scavenging activities compared to free proanthocyanidins. In the p31-43 peptide-induced celiac disease Caco-2 cell model, PCNL-FD significantly reduced oxidative stress by decreasing ROS and MDA levels while increasing GSH levels and antioxidant enzyme activities (SOD and CAT). The formulation showed anti-inflammatory effects by inhibiting pro-inflammatory cytokines (TNF-α, IL-6) and promoting anti-inflammatory cytokines (IL-4, IL-10). In addition, PCNL-FD activated the Keap1/Nrf2 signaling pathway and upregulated the expression of NQO-1 and HO-1. This nanoliposomal delivery system effectively overcame the bioavailability and stability limitations of free proanthocyanidins, providing new insights into the management of oxidative stress in inflammatory diseases such as celiac disease.