Asaronic Acid Attenuates Macrophage Activation toward M1 Phenotype through Inhibition of NF-κB Pathway and JAK-STAT Signaling in Glucose-Loaded Murine Macrophages

Macrophage polarization has been implicated in the pathogenesis of obesity and type 2 diabetes, which are recognized as chronic proinflammatory diseases. This study investigated that high level of glucose, similar to lipopolysaccharide (LPS), activated macrophages toward M1 phenotypes and 1–20 μM asaronic acid (AA) counteracted diabetic macrophage activation. AA reduced the LPS-promoted secretion of proinflammatory interleukin (IL)-6 and monocyte chemoattractant protein-1. The LPS markedly elevated the macrophage induction of the M1 markers of Toll-like receptor 4 (TLR4), CD36, and CD68, which was attenuated by AA. Also, the LPS significantly enhanced the nuclear factor (NF)-κB transactivation, signal transducers, and activators of transcription 1 (STAT1)/STAT3 activation and suppressor of cytokine signaling 3 (SOCS3) induction in macrophages. However, AA highly suppressed the aforementioned effects of LPS. Glucose-stimulated macrophages expressed advanced glycation end products (AGEs) and receptor for AG...