Utilization of edible poultry slaughter residues: A chicken-liver hydrolysate with glucose-lowering ability and upregulating glycogenesis in type II diabetes

Approximately 10,000 metric tons of broiler livers are yielded every year in Taiwan. However, due to unpleasant odor and health concern, these livers are typically discarded as waste in the slaughtering stream in most developed or developed countries. In alignment with global agrocycle policies, a biofunctional chicken-liver hydrolysate (CLH) has been developed. This study was to investigate the effects of CLHs on glucose homeostasis and complications in type II diabetes. Insulin resistance was induced in liver (FL83B) and muscle (C2C12) cells using 30 and 20 ng TNF-α/mL, respectively, resulting in decreased glucose uptake and lower expressions of IRβ, p-Akt/Akt, and p-GSK3/GSK. CLH supplementation significantly upregulated (p<0.05) glucose uptakes and these proteins. In db/db mice, CLH supplementation improved insulin resistance, as shown by OGTT assay, HOMA-IR value and serum glucose levels, while also reducing serum lipids and liver damage indices (p<0.05). Additionally, CLH ameliorated (p<0.05) decreased hindlimb-gastrocnemius weight, and liver lipid contents, oxidative stress (sera and liver) and inflammatory cytokines. Increased glycogen accumulation was visualized in PAS-stained liver and hindlimb tissues of db/db mice supplemented with CLHs, consistent with upregulated glycogenesis in TNF-α-induced liver and muscle cells through the IRβ-Akt-GSK3 pathway. These findings suggest CLH may offer a mitigation against hyperglycemia and associated complications in type II diabetes, while also highlighting a sustainable solution for utilizing poultry slaughter residues.