Aim: 

Lupin seed is referred to as an antidiabetic product by the traditional medicine. Conglutin-g, a lupin seed glycoprotein, caused a significant plasma glucose reduction when orally administered upon glucose overload trials in rats. The aim of this work was to unveil conglutin-g hypothetical insulin-mimetic cellular mechanism of action. Insulin is the primary hormone responsible for proteosynthesis control through IRS/P70S6k/PHAS1 pathways modulation, glucose homeostasis and muscle differentiation and hypertrophy via muscle-specific MHC (myosin heavy chain) gene transcription control.

Methods and Results: 

To verify if conglutin-g is able to modulate the same insulin-activated kinases, myoblastic C2C12 cells were incubated, after 72h of differentiation, with 100 nM insulin or 0.5 mg/ml conglutin-g. We used cells without stimulation as a negative control and cells stimulated with metformin as a positive control. We evaluated the effect of these treatment after 5, 10, 20, 30 and 240 minutes. We verified that stimulation with insulin or conglutin-g resulted in persistent activation of kinases of the protein synthetic pathway as well as increase of glucose transport and muscle-specific gene transcription regulation.

Conclusion: 

Our results indicate that conglutin-g may regulate the same components of the insulin signaling, suggesting the potential therapeutic oral use of this protein in diabetes treatment and, in particular, the potential conglutin-g influence on muscle cells differentiation and hypertrophy.