Importantly, the expression of nuclear factor kappa-B kinase subunit β (IKKβ), which inhibits insulin signaling and is associated with hepatic insulin resistance [49], is significantly increased in the livers of the Veh-treated old mice and this is reverted by hesperetin treatment (Additional file 1: Fig. S7B), which suggests that hesperetin appears to improve hepatic insulin sensitivity. This evidence concerns the gene INS and Insulin resistance.