Grape Seed Proanthocyanidin Extract Alleviates AflatoxinB1-Induced Immunotoxicity and Oxidative Stress via Modulation of NF-B and Nrf2 Signaling Pathways in Broilers

Aflatoxin B-1 (AFB(1)) is a widely spread mycotoxin contaminates food and feed, causing severe oxidative stress damages and immunotoxicity. Grape seed proanthocyanidin (GSPE), a natural antioxidant with wide range of pharmacological and medicinal properties. The goal of the present study was to investigate the protective effects of GSPE against AFB(1)-induced immunotoxicity and oxidative stress via NF-B and Nrf2 signaling pathways in broiler chickens. For the experiment, 240 one-day old Cobb chicks were allocated into four dietary treatment groups of six replicates (10 birds per replicate): 1. Basal diet (control); 2. Basal diet + AFB(1) 1mg/kg contaminated corn (AFB(1)); 3. Basal diet + GSPE 250 mg/kg (GSPE); 4. Basal diet + AFB(1) 1 mg/kg + GSPE 250 mg/kg (AFB(1) + GSPE). The results showed that GSPE significantly decreased serum inflammatory cytokines TNF-, IFN-, IL-1, IL-10, and IL-6 induced by AFB(1). Similarly, GSPE + AFB(1) treated group revealed a significant decrease in mRNA expressions of pro-inflammatory cytokines (TNF-, IFN-, IL-1, and IL-6) in the splenic tissue compared to the AFB(1) treatment group. In addition, western blotting results manifested that GSPE treatment normalized the phosphorylation of nuclear factor kappa B (p65) and the degradation of IB protein induced by AFB(1). Furthermore, GSPE enhanced the antioxidant defense system through activating the nuclear factor-erythroid-2-related factor (Nrf2) signaling pathway. The mRNA and protein expression level of Nrf2 and its down streaming associated genes were noted up-regulated by the addition of GSPE, and down-regulated in the AFB(1) group. Taken together, GSPE alleviates AFB(1)-induced immunotoxicity and oxidative damage by inhibiting the NF-B and activating the Nrf2 signaling pathways in broiler chickens. Conclusively, our results suggest that GSPE could be considered as a potential natural agent for the prevention of AFB(1)-induced immunotoxicity and oxidative damage.