Matsuura Y.,University of Miyazaki |
Matsuura Y.,Miyazaki Prefectural Food R and nter |
Kaneko M.,University of Miyazaki |
Hirabaru H.,Unkai Shuzo Co. |
And 6 more authors.
Nippon Shokuhin Kagaku Kogaku Kaishi | Year: 2013
We evaluated the effects of dried blueberry leaves (BL) and its hot-water extract (BLEx) on blood pressure of spontaneously hypertensive rats (SHR). A continuous 3-week administration of BL (3 %) and BLEx (1.5 %) reduced systolic blood pressure compared to the control group from the 2-week feeding point. Additionally, we fractionated BLEx and investigated the compound responsible for the enhanced blood pressure-lowering effect. BLEx were fractionated into 5-fractions using Sephadex LH-20 and Diaion HP20SS chromatography, and assayed for angiotensin-I-converting enzyme (ACE) inhibitory activity in vitro. The fraction composed of proanthocyanidins showed the most potent inhibitory activity (IC50, 0.004 mg/mL) and reduced systolic blood pressure of SHR. These results suggest that BL and BLEx have anti-hypertensive effects and one of the active components has been identified as a proanthocyanidin.
Yuji K.,Miyazaki Prefectural Industrial Support Foundation |
Yuji K.,University of Miyazaki |
Sakaida H.,Unkai Shuzo Co. |
Kai T.,Unkai Shuzo Co. |
And 5 more authors.
Journal of Oleo Science | Year: 2013
The serum and liver lipid-lowering effects of dietary freeze-dried blueberry leaf powder (BL) and its hydrothermal extract (BLHE) were examined in rats fed diets with or without cholesterol supplementation. Administration of 1% and 3% BL had no adverse effects on food intake or growth; however, relative liver weights were reduced in rats fed diets with and without dietary cholesterol. In the absence of dietary cholesterol, a dose-dependent reduction was evident. The effects of dietary BL on the concentration of serum lipids were marginal; however, the effects on liver triacylglycerol (TG) and cholesterol levels were apparently dose-dependent when the animals were fed diets free of cholesterol. Further, BL significantly attenuated dietary cholesterol-dependent accumulation of hepatic cholesterol, but not of TG. Hydrothermal treatment studies suggested that the active component of BL in terms of its liver lipid-lowering activity is relatively stable at high temperatures. Histopathological analysis of hepatic tissues revealed that BL administration suppresses fatty infiltrations induced by an AIN 76-based high-sucrose diet. The results of this study suggest that some of the active components of BL extracts, which are incorporated into the liver, prevent fatty liver in rats. These results provide further support for the investigation of dietary BL and derivatives thereof as functional human foods. © 2013 by Japan Oil Chemists' Society.