TNF and type 2 diabetes mellitus: Additionally, our results revealed that B. vernae extract or metformin treatment for 30 days significantly decreased (P < 0.01) serum FBG, INS, HOMA-IR, GSP, TNF-α, IL-1β, and IL-6 levels, whereas increased serum ISI levels (P < 0.01) in type 2 diabetic rats, compared with the model group.