Metabolic Profiling, Tissue Distribution, and Tolerance Assessment of Bopu Powder in Laying Hens Following Long-Term Dietary Administration

This study aimed to elucidate the metabolic profile and safety of Bopu Powder in laying hens, focusing on its principal alkaloids protopine (PRO) and allocryptopine (ALL). Nine hens received intravenous PRO (1 mg/kg·bw), ALL (1 mg/kg·bw), or saline. Blood (5-120 min post-dose) and feces (48 h collection) were analyzed via LC-Q-TOF-MS, revealing 9 ALL and 12 PRO metabolites, including two novel structures. In a separate 56-day trial, 324 hens were assigned to control, 50 mg/kg Bopu Powder (BP), or 500 mg/kg Bopu Powder (BPX) groups. Post-trial analyses showed PRO and ALL residues primarily in their kidneys (BP: PRO 11.21 ng/g, ALL 6.59 ng/g; BPX: PRO 23.62 ng/g, ALL 7.92 ng/g) and livers (BP: PRO 15.52 ng/g; BPX: PRO 269.49 ng/g, ALL 56.14 ng/g). Residues in eggs occurred exclusively in the BPX group (PRO 26.86 ng/g, ALL 12.29 ng/g). No residues were detected in other tissues (jejunum, ileum, ovaries, oviducts, uterus, muscle, fat, gizzard). Serum biochemical indicators and histopathological examinations were used to evaluate the long-term effects of Bopu Powder. The results confirmed that supplementation at doses up to 500 mg/kg did not induce any significant physiological or histopathological alterations.