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 lipopolysaccharide (LPS)-induced inflammation on cultured hepatocytes and weaning piglets. In vitro studies examined HepG2 cells treated with BOT and challenged with Escherichiacoli LPS for 8 d. BOT treatment reduced IL-6 concentration in cell culture media across time (P < 0.05) and decreased pro-inflammatory cytokine expression on days 1 and 8 of experiment (TNFα, IL-1ß; 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 O55B5 LPS on days 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 (1 animal per pen) and 28 (remaining animals), pigs were sacrificed to collect liver and jejunal tissues. After the challenge, BOT+ pigs had increased BW on days 21 (P < 0.05) and 28 (P < 0.1) compared to CTR+. Similar improvements in average daily gain and FCR on days 14 to 21 (P < 0.05) and 21 to 28 (P < 0.1) were also seen in BOT+ group. In the liver, compared to CTR+ pigs, BOT+ pigs had downregulated 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 days 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 days 21 (P < 0.1) and 28 (P < 0.05), and increased villi-to-crypt ratio on days 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 oxidative stress in liver cells, enhanced intestinal integrity, and as a result improved the growth performance of weaning piglets challenged with LPS.

Piglets are particularly susceptible to stress due to the abrupt changes they face during weaning. These stressors cause a surge of oxidation and inflammation, particularly in the intestinal tract. Inflammation in the intestine causes a loss in its barrier function and facilitates the translocation of harmful compounds. Of particular concern is the translocation of lipopolysaccharide (LPS), which elicits an immune response in the liver, diverting energy from growth to inflammatory processes. Exposure to LPS also has the potential to have long-lasting detrimental effects on piglets' health. Research has identified the potential of many botanicals to minimize weaning stress through diverse modes of action. This study investigated the efficacy of a blend of botanicals (BOT) to help hepatocytes control inflammatory stress in vitro and to ameliorate the effects of an LPS challenge in piglets in vivo. Our in vitro and in vivo models successfully generated an inflammatory state. In vitro, BOT decreased inflammation and oxidation, and similar effects were seen in vivo, where BOT supplementation modulated the expression of cytokines in the liver and maintained intestinal integrity. These effects validate BOT ability to improve the performance of LPS-challenged piglets and support its utilization as a feed supplement to mitigate weaning stress.