Effects of Acanthopanax senticosus Polysaccharide Supplementation on Growth Performance, Immunity, Blood Parameters and Expression of Pro-inflammatory Cytokines Genes in Challenged Weaned Piglets

다국어 초록 (Multilingual Abstract)

To investigate the effect of dietary Acanthopanax senticosus polysaccharide (ASPS) on growth performance, immunity, blood parameters and mRNA expression of pro-inflammatory cytokines in immunologically challenged piglets, an experiment employing $2{\times}2$ factorial arrangement concerning dietary ASPS treatment (0 or 800 mg/kg) and immunological challenge (lipopolysaccharide [LPS] or saline injection) was conducted with 64 crossbred piglets (weaned at 28 d of age, average initial body weight of $7.25{\pm}0.21kg$) assigned to two dietary ASPS treatments with 8 replicates of 4 pigs each. Half of the piglets of per dietary treatment were injected with LPS or saline on d 14. Blood samples were obtained at 3 h after immunological injection on d 14 and piglets were slaughtered to obtain spleen samples on d 21. Dietary ASPS did not affect average daily gain (ADG) (p = 0.634), average daily feed intake (ADFI) (p = 0.655), and gain:feed (p = 0.814) prior to LPS challenge. After LPS challenge, for LPS-challenged pigs those fed ASPS had higher ADG and ADFI than the non-supplemented group (p<0.05), and an interaction between $LPS{\times}ASPS$ was observed on the two indices (p<0.05). Dietary ASPS improved lymphocyte proliferation among saline-injected and LPS-injected pigs (p<0.05). Interaction between $LPS{\times}ASPS$ was also revealed on lymphocyte proliferation (p<0.05). Circulatory concentration of IgG was influenced neither by ASPS (p = 0.803) or LPS (p = 0.692), nor their interaction (p = 0.289). Plasma concentration and spleen mRNA expression of interleukin-1beta (IL-$1{\beta}$), interleukin-6 (IL-6), and tumor necrosis factor (TNF)-${\alpha}$ were induced to increase (p<0.05) by LPS challenge, in contrast, these indices were decreased by dietary ASPS (p<0.05), and interactions were found on these cytokines (p<0.05). For LPS-challenged pigs, dietary ASPS also reduced the circulating concentration and spleen mRNA expression of IL-$1{\beta}$, IL-6 as well as TNF-${\alpha}$ (p<0.05). The interaction between $LPS{\times}ASPS$ was also observed on the circulating concentration of insulin-like growth factor-I, ${\alpha}$-acid glycoprotein (${\alpha}$-AGP), nonesterified fatty acid, and glucose (p<0.05). The results of this study demonstrate that dietary ASPS can modulate the release of pro-inflammatory cytokines during immunological challenge, which might enable piglets to achieve better growth performance.