Allicin Promotes Glucose Uptake by Activating AMPK through CSE/H₂S-Induced S-Sulfhydration in a Muscle-Fiber Dependent Way in Broiler Chickens

Scope Allicin, a product of enzymatic reaction when garlic is injured, plays an important role in maintaining glucose homeostasis in mammals. However, the effect of allicin on glucose homeostasis in the state of insulin resistance remains to be elucidated. This study investigates the effect of allicin on glucose metabolism using different muscle fibers in a chicken model. Methods and results Day-old male Arbor Acres broilers are randomly divided into three groups and fed a basal diet supplemented with 0, 150, or 300 mg kg(-1) allicin for 42 days. Results show that allicin improves the zootechnical performance of broilers at the finishing stage. The glucose loading test (2 g kg(-1) body mass) indicates the regulatory role of allicin on glucose homeostasis. In vitro results demonstrate allicin increases glutathione (GSH) level and the expression of cystathionine gamma lyase (CSE), leading to endogenous hydrogen sulfide (H2S) production in M. pectoralis major (PM) muscle-derived myotubes. Allicin stimulates adenosine monophosphate-activated protein kinase (AMPK) S-sulfhydration and AMPK phosphorylation to promote glucose uptake, which is suppressed in the presence of d,l-propargylglycine (PAG, a CSE inhibitor). Conclusion This study demonstrates that allicin induces AMPK S-sulfhydration and AMPK phosphorylation to promote glucose uptake via the CSE/H2S system in a muscle fiber-dependent manner.