A microencapsulated blend of botanicals supports weaning piglets during a lipopolysaccharide challenge by modulating liver inflammation and intestinal integrity

Abstract

This study examined the action of a blend of botanicals (BOT) against LPS-induced inflammation on cultured hepatocytes and weaning piglets. In vitro studies examined HepG2 cells treated with BOT and challenged with E. coli lipopolysaccharide (LPS) for 8 days. BOT treatment reduced IL-6 concentration in cell culture media across time (p < 0.05) and decreased pro-inflammatory cytokine expression on day 1 and 8 of experiment (TNFα, IL-1β; p < 0.05). BOT also increased the expression of antioxidant enzymes (GPX-2, SOD, CAT) on day 8 (p < 0.05), which was supported by lowered reactive oxygen species concentration after LPS challenge (p < 0.1). The in vivo study was conducted with 72 weaning pigs, allotted into 24 pens and divided into 3 groups: a negative control (CTR-, basal diet), a challenged control (CTR+) that received an intraperitoneal injection of E. coli O55:B5 LPS on day 14 and 16, and a challenged treated group which received a diet containing 1.5 g/Kg of microencapsulated BOT (BOT+) for the whole duration of the study. Growth performance was determined weekly and, on days 21 (one animal per pen) and 28 (remaining animals), pigs were sacrificed to collect liver and jejunal tissues. After challenge, BOT+ pigs had increased BW on day 21 (p < 0.05) and 28 (p < 0.1) compared to CTR+. Similar improvements in ADG and FCR on day 14-21 (p < 0.05) and 21-28 (p < 0.1) were also seen in BOT+ group. In the liver, compared to CTR+ pigs, BOT+ pigs downregulated the expression of TLR-4, IL-6, IFN-γ on day 21 (p < 0.05), and TLR-4, TNF-α, IL-8 on day 28 (p < 0.05). BOT+ also increased GPX-2 expression on day 21 and 28 (p < 0.05), while also upregulating SOD-1 and SOD-2 on day 21 (p < 0.05) and CAT on day 28 (p < 0.05) compared to CTR+. In the jejunum, BOT+ reduced inflammation by affecting cytokine expression (p < 0.05) and increasing the expression of tight-junction proteins, ZO-1 on day 21 and CLD-1 on day 28 (p < 0.05). Furthermore, BOT+ pigs had lower crypt depth on day 21 (p < 0.1) and day 28 (p < 0.05), and increased villi to crypt ratio on day 21 and 28 (p < 0.05). By day 28, BOT+ intestinal measurements were restored to values similar to the CTR-. Finally, BOT+ also reduced mast cell activation on day 21 (p < 0.05) compared to CTR+. Considering all the findings, BOT controlled inflammatory activation and the oxidative stress in liver cells, enhanced intestinal integrity, and as a result improved the growth performance of weaning piglets challenged with LPS.