Blueberry leaf extract reduces fasting glucose, C-reactive protein and plasma aminotransferases in patients with diabetes type 2.

Abstract

In a 4-week randomized placebo-controlled clinical trial we investigated the effect of 300 mg Blueberin, a phytomedicine containing 250 mg Blueberry leaves (Vaccinium arctostaphylos L, Ericaceae) extract providing minimum 50 mg 3,4-caffeoylquinic (chlorogenic) acid, and 50 mg myricetin, on fasting plasma glucose, alanine aminotransferases (ALT), aspartate aminotransferases (AST), glutamyltransferase (GGT) enzymes levels, and serum inflammatory C-Reactive proteins (CRP) in forty-two volunteer subjects (46+/-15 year of age, BMI 25+/-3 kgs/(m2)) diagnosed with Type 2 diabetes. During the 4-week trial, the Blueberin supplement was administered three times per day, 15-30 minutes prior to a meal along with 100 ml of water. Results of this trial revealed that the supplementation of Blueberin reduced fasting plasma glucose from 143+/-5,2mg/L to 104+/-5,7 mg/L (p<0,001), whereas there was no statistically significant changes in the Placebo group from 138+/-4,8 mg/L to 126+/-5,1mg/L (p>0,05). The reduction of fasting glucose was correlated with the reduction of serum CRP and in the Blueberin group from 5,18+/-1,4 mg/l to 2,14+/-1,8 mg/L (p<0,05), whereas in the Placebo group CRP levels were not significantly reduced from 5,11+/-1,7 mg/l to 4,94+/-1,1mg/L (p>0,05). Furthermore, the Blueberin also significantly reduced the levels of plasma enzymes ALT, AST and GGT, indicating that, in addition to anti-diabetes effects, the Blueberin also possess pharmacologically relevant anti-inflammatory properties.