Effect of Rubus Occidentalis Extract on Metabolic Parameters in Subjects with Prediabetes: A Proof-of-concept, Randomized, Double-blind, Placebo-controlled Clinical Trial

Phytother Res. 2016 Oct;30(10):1634-1640. doi: 10.1002/ptr.5664. Epub 2016 Jun 9.

Abstract

Rubus occidentalis (RO) has beneficial effects on glucose and lipid profiles in vitro. The aim of the study was to investigate RO extract effect on metabolic parameters in prediabetic patients, adopting a 12-week, randomized, double-blind, placebo-controlled trial. Forty-four patients (age 59.0 ± 8.2 years, 70.5% females, HbA1c 5.8 ± 0.4%) were divided into placebo (n = 13), low-dose RO extract (LRE; n = 14), or high-dose RO extract (HRE; n = 17) groups. Either 900 or 1800 mg per day of RO extract was administered orally. Area under the curve for glucose obtained 2 h after a 75-g oral glucose tolerance test was significantly decreased in the HRE group, compared with the placebo group (-28.1 ± 42.4 vs. +13.4 ± 52.6 mg/dL, p < 0.05). Homoeostasis model assessment-B was increased (+17.11 ± 10.69, +5.24 ± 4.10, and +0.86 ± 6.01 in HRE, LRE, and placebo, respectively, p < 0.05). Serum levels of monocyte chemoattractant protein-1 and oxidized low-density lipoprotein were significantly decreased by treatment in a dose-dependent manner (monocyte chemoattractant protein-1: -35.0 ± 21.2, +8.4 ± 18.1, and +24.2 ± 14.5; oxidized low-density lipoprotein: -19.7 ± 8.5, -13.1 ± 7.2, and -2.2 ± 11.0 in the HRE, LRE, and placebo, respectively, p < 0.05). The results support the beneficial effects of RO extract on the control of glycemia and vascular inflammation in prediabetic patients. (ClinicalTrials.gov: NCT01964703). Copyright © 2016 John Wiley & Sons, Ltd.

Keywords: Rubus occidentalis; atherosclerosis; black raspberry; metabolic syndrome; prediabetes.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Blood Glucose / drug effects*
  • Double-Blind Method
  • Female
  • Humans
  • Male
  • Middle Aged
  • Prediabetic State / metabolism*
  • Rubus / chemistry*
  • Young Adult

Substances

  • Blood Glucose

Associated data

  • ClinicalTrials.gov/NCT01964703