Glycyrrhizin's Potential to Modulate Feeding Behaviour by Neutralizing Reduced Feed Intake in Inflamed Arian Broilers

BACKGROUND: The Arian broiler, an important native Iranian breed, shows heightened sensitivity to metabolic disturbances caused by lipopolysaccharide (LPS). This study evaluated whether glycyrrhizin could mitigate LPS-associated physiological disruptions. METHODS: In a controlled trial, 100 Arian broilers (21-day-old, mean weight 750 g) were randomly allocated into five experimental groups: (1) ICV glycyrrhizin dose-response assessment (1, 2 and 4 µg) evaluating feeding behaviour; (2) ICV LPS challenge (12.5, 25 and 50 ng) with 8-h monitoring of feed intake and cloacal temperature; (3) IP glycyrrhizin administration (12.5, 25 and 50 mg/kg) to assess effects on feed consumption; (4) IP glycyrrhizin + ICV LPS interaction study; and (5) ICV glycyrrhizin + LPS co-administration group. RESULTS: LPS administration induced characteristic biphasic temperature dysregulation, with significant hypothermia at 3 h (-1.3 ± 0.4°C vs. controls) followed by hyperthermia at 8 h (+1.1 ± 0.3°C), accompanied by feed intake reduction (p < 0.05). The findings indicated that feed intake increased significantly following the injection via both intraperitoneal and intracerebroventricular of glycyrrhizin in a dose-dependent manner (p < 0.05), but IP delivery (25 and 50 mg/kg) showed comparable effects with 20-30 min delayed onset. Co-administration completely prevented LPS-induced disturbances at optimal doses. CONCLUSIONS: Glycyrrhizin counteracts LPS-induced thermoregulatory and feeding disturbances in Arian broilers through rapid-acting mechanisms. While the physiological improvements align with anti-inflammatory responses observed in other species, direct molecular evidence remains to be established.