Berberine lowers blood glucose in type 2 diabetes mellitus patients through increasing insulin receptor expression

Our previous work demonstrated that berberine (BBR) increases insulin receptor (InsR) expression and improves glucose utility both in vitro and in animal models Here, we study the InsR up-regulating and glucose-lowering activities of BBR in humans Our results showed that BBR increased InsR messenger RNA and protein expression in a variety of human cell lines, including CEM, HCT-116, SW1990, HT1080, 293T, and hepatitis B virus-transfected human liver cells Accordingly, insulin-stimulated phosphorylanons of InsR beta-subunit and Akt were increased after BBR treatment in cultured cells In the clinical study, BBR significantly lowered fasting blood glucose (FBG), hemoglobin Ate, triglyceride, and insulin levels in patients with type 2 diabetes mellitus (T2DM) The FBG- and hemoglobin A(tc)- lowering efficacies of BBR were similar to those of metformin and rosiglitazone In the BBR-treated patients, the percentages of peripheral blood lymphocytes that express InsR were significantly elevated after therapy Berberine also lowered FBG effectively in chronic hepatitis B and hepatitis C patients with T2DM ot impaired fasting glucose Liver function was improved greatly in these patients by showing reduction of liver enzymes Our results confirmed the activity of BBR on InsR in humans and its relationship with the glucose-lowering effect Together with our previous report, we strongly suggest BBR as an ideal medicine for T2DM with a mechanism different from metformin and rosiglitazone (C) 2010 Elsevier Inc All rights reserved