Berberine (BBR) is a traditional Chinese medicine used to treat diabetes mellitus for
thousands of years in China. The glucose-lowering effect of BBR has been confirmed in
numerous studies. Nevertheless, the detailed mechanisms of action through which BBR exerts
its effects are not yet fully elucidated. In previous data, Jin-Kui Yang found that BBR could
promote insulin secretion in mice and isolated islets. In this current study, investigators
plan to examine the insulinotropic effect of BBR in human through hyperglycemic clamp method.