Bioimpedance analysis, metabolic effects and safety of the association Berberis aristata/Bilybum marianum: a 52-week double-blind, placebo-controlled study in obese patients with type 2 diabetes.

Berberine, a quaternary isoquinoline alkaloid present in Berberis aristata, is well known in terms of cholesterol-lowering, hypoglycemic, and insulin sensitizing effects. Because of its low oral bioavailability, to improve intestinal absorption it has been recently combined with silymarin (Silybum marianum). The aim of our placebo controlled study was to evaluate the effects of its association with silymarin on abdominal fat in overweight/obese patients with type 2 diabetes mellitus (T2DM). To do so, 136 obese subjects with T2DM and metabolic syndrome were analyzed for fasting blood glucose and insulin, Insulin Resistance index according to the Homeostatic Model Assessment (HOMA-R), total, HDL and LDL cholesterol, triglycerides, uric acid, BMI, waist circumference, waist to hip ratio and underwent bioelectrical impedance to assess % of abdominal fat. All the above-mentioned parameters, as recorded at enrollment, after 6 months and at the end of the study, had significantly improved in the BBR-treated group in respect to baseline and to the control group. A validated national cardiovascular risk score also improved significantly after BBR treatment in respect to placebo. Our results point to a clinically significant effect in obese people with T2DM and metabolic syndrome. Moreover, for the first time, they provide evidence of a significant uric acid lowering activity as an additive beneficial effect of the association BBR + silymarin.