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

SIMPLE SUMMARY: Intrauterine growth retardation (IUGR) is usually defined as fetal growth below the 10th percentile for gestational age and results in impaired growth and development of the fetus and/or its organs during gestation. IUGR not only has a permanent effect on postnatal growth and long-term health, but also results in high fetal mortality and morbidity. Recent results have demonstrated that IUGR can cause jejunum damage in piglets. The jejunum is not only the main organ for the digestion and absorption of nutrients, but also an immune organ in the body. However, few effective methods to alleviate jejunum damage and oxidative stress in IUGR pigs have been found. In recent years, studies have found that curcumin (CUR) may be an effective and safe feed additive for regulating oxidative stress in the body. Our results indicated that dietary added 200 mg/kg curcumin to the basal diet can increase the antioxidant capacity of the IUGR growing pigs, jejunum and alleviate the damage in jejunum of the IUGR growing pigs. Therefore, the use of curcumin as a feed additive has certain economic value. ABSTRACT: 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.