In an in vivo study in diabetes mellitus mice, oral treatment with 200 mg/kg honokiol for 8 weeks significantly decreased the fasting blood glucose in type 2 mice. From the study it appears that Honokiol both increases insulin signallling factors but also inhibited PTP1B. This PTP1B is a negative regulator of the insulin signaling pathway and is seen as a potential therapeutic target, in particular for treatment of type 2 diabetes. It has also been implicated in the development of breast cancer.
From the study:
The phosphorylations of the IRβ and the downstream insulin signaling factors including AKT and ERK1/2 significantly increase in adipose, skeletal muscle, and liver tissue of the honokiol-treated mice. Moreover, honokiol enhanced the insulin-stimulated phosphorylations of IRβ, AKT, and ERK1/2 in a dose-dependent manner in C2C12 myotube cells. Meanwhile, honokiol enhanced insulin-stimulated GLUT4 translocation. Importantly, honokiol exhibited reversible competitive inhibitory activity against PTP1B with good selectivity in vitro and in vivo. Furthermore, using molecular docking and dynamic simulation approaches, we determined the potential binding mode of honokiol to PTP1B at an atomic level.
These findings indicated the hypoglycemic effects of honokiol and its mechanism that honokiol improved the insulin sensitivity by targeting PTP1B. Therefore, our study may highlight honokiol as a promising insulin sensitizer for the therapy of type 2 diabetes.
You can find the research report here.