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

2016-06-09
Phytotherapy research : PTR 30(10)
- Jee Hyun An
- Dong-Lim Kim
- Tae-Bum Lee
- Kyeong Jin Kim
- Sun Hwa Kim
- Nam Hoon Kim
- Hee Young Kim
- Dong Seop Choi
- Sin Gon Kim

PubMed: 27279471
DOI: 10.1002/ptr.5664

Study Design

Type: Randomized Controlled Trial (RCT)
Sample size: n = 17
Population: 44 prediabetic patients (age 59.0 ± 8.2 years, 70.5% females, HbA1c 5.8 ± 0.4%)
Methods: 12-week, randomized, double-blind, placebo-controlled trial; 900 or 1800 mg per day of RO extract administered orally
Blinding: Double-blind
Duration: 12 weeks
Funding: Unclear

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.

Research Insights

Black Raspberry→Improved HOMA-B
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).
Effect
Beneficial
Effect size
Small
Dose
900 or 1800 mg per day
Black Raspberry→Reduced Monocyte Chemoattractant Protein-1 Level
Serum levels of monocyte chemoattractant protein-1 ... 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 ... in the HRE, LRE, and placebo, respectively, p < 0.05).
Effect
Beneficial
Effect size
Small
Dose
900 or 1800 mg per day
Black Raspberry→Reduced Oxidized Low-Density Lipoprotein Level
Serum levels of ... oxidized low-density lipoprotein were significantly decreased by treatment in a dose-dependent manner (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).
Effect
Beneficial
Effect size
Small
Dose
900 or 1800 mg per day
Black Raspberry→Reduced Postprandial Glucose
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).
Effect
Beneficial
Effect size
Small
Dose
900 or 1800 mg per day