Effects of purified zearalenone on selected immunological and histopathologic measurements of spleen in post-weanling gilts

Abstract

The present study was aimed at investigating the adverse effects of dietary zearalenone (ZEA) on the lymphocyte proliferation rate (LPR), interleukin-2 (IL-2), mRNA expressions of pro-inflammatory cytokines, and histopathologic changes of spleen in post-weanling gilts. A total of 20 crossbred piglets (Yorkshire × Landrace × Duroc) with an initial BW of 10.36 ± 1.21 kg (21 d of age) were used in the study. Piglets were fed a basal diet with an addition of 0, 1.1, 2.0, or 3.2 mg/kg purified ZEA for 18 d <i>ad libitum</i>. The results showed that LPR and IL-2 production of spleen decreased linearly (<i>P</i> < 0.05) as dietary ZEA increased. Splenic mRNA expressions of interleukin-1β (<i>IL-1β</i>) and interleukin-6 (<i>IL-6</i>) were linearly up-regulated (<i>P</i> < 0.05) as dietary ZEA increased. On the contrary, linear down-regulation (<i>P</i> < 0.05) of mRNA expression of interferon-γ (<i>IFN-γ</i>) was observed as dietary ZEA increased. Swelling splenocyte in 1.1 mg/kg ZEA treatments, atrophy of white pulp and swelling of red pulp in 2.0 and 3.2 mg/kg ZEA treatments were observed. The cytoplasmic edema in 1.1 mg/kg ZEA treatments, significant chromatin deformation in 2.0 mg/kg ZEA treatment and phagocytosis in 3.2 mg/kg ZEA treatment were observed. Results suggested that dietary ZEA at 1.1 to 3.2 mg/kg can induce splenic damages and negatively affect immune function of spleen in post-weanling gilts.