Curcumin Alleviates IUGR Jejunum Damage by Increasing Antioxidant Capacity through Nrf2/Keap1 Pathway in Growing Pigs

The purpose of this study was to explore the effects of curcumin on IUGR jejunum damage. A total of 24 IUGR and 12 normal-birth weight (NBW) female crossbred (Duroc × Landrace × Large White) piglets were randomly assigned into three groups at weaning (26 days): IUGR group, NBW group, and IUGR + CUR group, which were fed diets containing 0 mg/kg (NBW), 0 mg/kg (IUGR) and 200 mg/kg (IUGR + CUR) curcumin from 26 to 115 days of age. Results showed that dietary supplementation with 200 mg/kg curcumin significantly increased the total superoxide dismutase (T-SOD) activity and decreased the malondialdehyde (MDA) content in the jejunum of IUGR pigs (p < 0.05). Results of real-time PCR showed that the IUGR + CUR group significantly increased the gene expression of NF-E2-related factor 2 (Nrf2) (p < 0.05), and increased the glutamate-cysteine ligase catalytic subunit (GCLC), superoxide dismutase 1 (SOD1), glutamate-cysteine ligase modifier subunit (GCLM), and NAD(P)H quinone dehydrogenase 1 (NQO1) mRNA expression compared with the IUGR group (p < 0.05). Western blot results showed that dietary supplementation with 200 mg/kg curcumin significantly increased the protein levels of Nrf2 and NQO1. Compared with the IUGR group, pigs in IUGR + CUR group showed significantly decreased the levels of tumor necrosis factor-α (TNFα), interleukin-6 (IL-6), and interferon gamma (IFNγ) (p < 0.05), and increased the interleukin-2 (IL-2) level (p < 0.05). Dietary supplementation with 200 mg/kg curcumin significantly reduced cysteinyl aspartate specific proteinase 3 (caspase3), BCL2-associated X protein (bax), B-cellCLL/lymphoma 2 (bcl2), and heat-shock protein 70 (hsp70) mRNA expression, and increased occludin (ocln) mRNA expression (p < 0.05). In conclusion, dietary supplementation with 200 mg/kg curcumin can alleviate jejunum damage in IUGR growing pigs, through Nrf2/Keap1 pathway.