Modified Si-Miao-San ameliorates pancreatic B cell dysfunction by inhibition of reactive oxygen species-associated inflammation through AMP-kinase activation

Abstract

Aim: To observe the effect of modified Si-Miao-San (mSMS) on advanced glycation end products (AGEs)-induced pancreatic B cell dysfunction, as well as examining the underlying mechanisms.

Method: Pancreatic B cells (INS-1) were stimulated with advanced glycation end products (AGEs, 200 μg·mL(-1)) for 24 h to produce dysfunction in pancreatic B cells and the effects of mSMS observed on insulin secretion, NF-κB (p65) phosphorylation, reactive oxygen species (ROS) production, mitochondria membrane potential (Δψm), cell apoptosis, phosphorylation of AMP-kinase (AMPK), and caspase 3 activity.

Results: The AGEs challenge resulted in increased basal insulin secretion, but decreased insulin secretion in response to high glucose, whereas this situation was reversed by mSMS treatment. AGEs stimulation induced NF-κB (p65) phosphorylation and reactive oxygen species (ROS) production, as well as Δψm collapse and cell apoptosis. mSMS inhibited ROS production and inhibited NF-κB activation by attenuating p65 phosphorylation. Meanwhile, AGEs-induced Δψm collapse and cell apoptosis were also reversed by mSMS treatment. Compound C, an inhibitor of AMP-Kinase (AMPK), abolished the beneficial effects of mSMS on the regulation of B cell function, indicating the involvement of AMPK.

Conclusion: mSMS ameliorated AGEs-induced B cell dysfunction by suppressing ROS-associated inflammation, and this action was related to its beneficial regulation of AMPK activity.

Keywords: AMP-kinase; Advanced glycation end products; Inflammation; Modified Si-Miao-San; Pancreatic B cells.