The effects of aqueous and ethanolic extracts of Rheum ribes on insulin-resistance and apolipoproteins in patients with type 2 diabetes mellitus: a randomized controlled trial

BACKGROUND AND AIM: Previous studies have shown that Rheum ribes (R. ribes) could be effective in controlling the blood glucose levels. This study was conducted to determine the effects of R. ribes supplementation on glycemic indices and apolipoproteins in patients with type 2 diabetes mellitus (T2DM). METHODS: In the present randomized double-blind controlled trial, 60 type 2 diabetic patients aged 30–60 years with a body mass index (BMI) of 20–30 kg/m(2) and hemoglobin A1c (HbA1c) of 6–8% were enrolled. Patients were randomly assigned to receive 450 mg of aqueous R. ribes extract (AG), 450 mg of ethanolic R. ribes extract (EG), or placebo (PG) three times daily for 6 weeks. At the baseline and at the end of the study, blood glucose levels, homeostatic model assessment of insulin resistance (HOMA-IR) and the homeostatic model assessment of β-cell dysfunction (HOMA-B), as well as apolipoprotein A-I (ApoA1) and apolipoprotein B (ApoB) were measured. RESULTS: There was a significant decrease in the serum levels of insulin in AG and EG groups (P = 0.003 and P = 0.001, respectively), HOMA-IR (P = 0.01 and P = 0.001, respectively), HOMA-B (P = 0.002 and P = 0.001, respectively), ApoB (P = 0.006 and P = 0.03, respectively), ApoB/ApoA1 ratio (P = 0.016 and P = 0.04, respectively). However, a significant increase in ApoA1 (P = 0.08 and P = 0.05, respectively) with no significant changes in blood glucose, at the end of study compared to beginning values, were observed. None of the variables showed a significant change in PG. At the end of the study; while there were significant differences in insulin (P = 0.04), HOMA-IR (P = 0.03), HOMA-B (P = 0.01), ApoB (P = 0.02), and ApoB/ApoA1 ratio (P = 0.03) among the groups but ApoA1 had no significant change. CONCLUSION: Consumption of R. ribes intake could have beneficial effects on insulin resistance and apolipoproteins in type 2 diabetic patients. (Registered at en.irct.ir, identification number: IRCT201410142709N31).