Effect of Banaba (Lagerstroemia speciosa) on Metabolic Syndrome, Insulin Sensitivity, and Insulin Secretion

To evaluate the effect of Banaba (Lagerstroemia speciosa) on metabolic syndrome (MetS), insulin sensitivity, and insulin secretion. A randomized, double-blind, placebo-controlled clinical trial was carried out in 24 patients with diagnosis of MetS according to the International Diabetes Federation criteria. Body weight, waist circumference, and blood pressure were evaluated. Fasting plasma glucose (FPG) and insulin concentrations were measured every 30 min during 2 h after a 75-g dextrose load. Lipid profile was determined before and after the pharmacological intervention. Twelve patients received Banaba (500 mg) twice a day, before breakfast and dinner for 12 weeks. The remaining 12 patients received placebo at the same dosage. Body mass index, area under the curve (AUC) of glucose and insulin, insulin sensitivity, total insulin secretion, and the first phase of insulin secretion were calculated. After Banaba administration, there were significant decreases in systolic blood pressure (SBP) (121.5 ± 12.9 vs. 116.3 ± 9.8 mmHg, P = .050), FPG (5.9 ± 0.4 vs. 5.7 ± 0.4 mmol/L, P = .034), triglycerides (TG) (2.3 ± 0.4 vs. 1.7 ± 0.5 mmol/L, P = .021), very low-density lipoprotein (VLDL) (0.5 ± 0.1 vs. 0.3 ± 0.1 mmol/L, P = .021), AUC of insulin (50,675 ± 14,309 vs. 37,983 ± 19,298 mmol/L, P = .017), and insulinogenic index (0.4 ± 0.2 vs. 0.3 ± 0.2, P = .047). Eight patients (67%) of the Banaba group showed remission of MetS. In the placebo group, there was a downward trend toward statistical significance in the Stumvoll index (910.3 ± 514.1 vs. 651.0 ± 405.2, P = .062). Banaba administration leads to remission of MetS and a significant decrease in SBP, FPG, TG, VLDL, AUC of insulin, and total insulin secretion. Clinical Trial Registration number: NCT02767869.