Growth promotion in broilers by both oxytetracycline andMacleaya cordataextract is based on their anti-inflammatory properties

Abstract

The non-antibiotic anti-inflammatory theory of antimicrobial growth promoters (AGP) predicts that alternatives can be selected by simple in vitro tests. In vitro, the known AGP oxytetracycline (OTC) and a Macleaya cordata extract (MCE) had an anti-inflammatory effect with a half-maximal inhibitory concentration of 88 and 132 mg/l, respectively. In vivo, chickens received three different concentrations of MCE in drinking-water, OTC in feed and a control. Body weight (BW), feed intake (FI) and gain:feed (G:F) ratio were determined on days 14, 21 and 35. On day 35, body composition was determined. Plasma a 1 -acid glycoprotein (a 1 -AG) concentration was measured on days 21 and 35, and the expression of several jejunal inflammatory genes was determined on day 35. OTC-fed chickens showed a significantly higher BW, FI and G:F ratio compared with the control group at all time points. MCE had a significant linear effect on BW on days 21 and 35, and the G:F ratio was improved only over the whole period, whereas FI was not different. Only MCE but not OTC decreased the percentage of abdominal fat. Plasma a 1 -AG concentration increased from day 21 to 35, with the values being lower in the treatment groups. Both OTC and MCE significantly reduced the jejunal mucosal expression of inducible NO synthase. For most parameters measured, there was a clear linear dose -response to treatment with MCE. In conclusion, the results are consistent with the anti-inflammatory theory of growth promotion in production animals.

<i>Macleaya cordata</i> Extract Reduces Inflammatory Responses of Intestinal Epithelial Cells <i>in Vitro</i>

“…The mechanism by which ASA exerts its activity in cells is not entirely clear [11], and the same is the case for MCE [10]. Still, MCE and ASA have clear anti-inflammatory effects on different cell types including enterocytes as demonstrated here.…”

“…This is consistent with the anti-inflammatory effects described by others in vitro and in vivo, although there are certainly differences concerning the expression of particular anti-inflammatory genes. For instance, as opposed to in vitro, in jejunal mucosa of broilers there was no effect of in feed MCE on IL-10 expression, and only a small quadratic effect on IL-1β [10]. Differences with other in vitro studies may be due to different cell types, incubation conditions and time et cetera.…”

“…Experiments were performed in triplicate. Anti-inflammatory treatments included a commercial Macleaya cordata extract (MCE) (Sangrovit WS SV Phytobiotics GmbH, Eltville, Germany containing 12,235 mg/kg of sanguinarine and 4073 mg/kg of chelerythrine, of which sanguinarine is the active component [10]) and acetylsalicylic acid (ASA, Sigma Aldrich, St. Louis, USA), both diluted in sterile PBS at 0.001% (w/v), which is in the range of the intestinal concentration expected by in feed use of the compounds as AGP. One mL of each E. coli strains cultures (2 × 10 8 CFU/mL) was mixed with 1 mL of MCE, ASA or PBS (control) solutions and pre-incubated for 30 minutes at RT [14].…”

“…However, it is clear that the major cell types in the intestines are enterocytes which play an important role in modulating intestinal inflammatory responses working in close concert with inflammatory cells (for recent reviews see [8] [9]). Recently, we have demonstrated that growth promoting effects of AGP and the phytobiotic alternative Macleaya cordata extract (MCE) coincide with a reduction of inflammatory responses in small intestinal mucosa in broilers [10]. Because the mucosa contains a multitude of different cell types, no conclusions could be drawn on the role of enterocytes.…”

“…Therefore, in the current study we tried to establish the inflammatory response of a monoculture of enterocytes to MCE using the non-antibiotic anti-inflammatory compound acetylsalicylic acid (ASA) [11] with known growth promoting activity [12] as a control. MCE is an extract of Macleaya cordata (commonly known as plume poppy), and the active anti-inflammatory component is sanguinarine [10]. Co-culture with enterotoxigenic E. coli (ETEC) was used to stimulate inflammation and gene expression was compared with co-culture with a non-pathogenic non-adhesive E. coli strain (EC), using the porcine intestinal cell line IPEC-J2.…”