Protective effect of berberine on serum glucose levels in non-obese diabetic mice

Among the active components in traditional anti-diabetic herbal plants, berberine which is an isoquinoline alkaloid exhibits promising potential for its potent anti-inflammatory and hypoglycemic effects. However, the berberine effect on serum glucose levels in type 1 diabetes (T1D) subjects still remains unknown. This study investigated berberine's effects on serum glucose levels using non-obese diabetic (NOD) mice that spontaneously develop T1D. The NOD mice were randomly divided into four groups, administered water with 50, 150, and 500 mg berberine/kg bw, respectively, through 14 weeks. ICR mice were also selected as a species control group to compare with the NOD mice. Changes in body weight, oral glucose challenge, and serum glucose levels were determined to identify the protective effect of berberine on T1D. After the 14-week oral supplementation, berberine decreased fasting serum glucose levels in NOD mice close to the levels in normal ICR mice in a dose dependent manner. Serum berberine levels showed a significantly (P<0.05) negative and non-linear correlation with fasting glucose levels in berberine-administered NOD mice. Our results suggested that berberine supplemented at appropriate doses for 14 weeks did not cause toxic side effects, but improved hyperglycemia in NOD mice.