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Banaba leaf extract, benefits, sugar level, diabete, medical uses - ZHION.COM
- June 23, 2011
Banaba [Lagerstroemia speciosa] has been used in Philippines to control blood sugar level for years.
Research done with its active ingredient, corosolic acid, suggests its benefit on diabetes. However, clinical
studies are needed to confirm the findings. Since it may possibly interact with other therapeutics, users
must discuss with their healthcare providers before taking this herbal remedy.

The use of banaba for diabetes in the US is relatively new and I don't see many studies done with this

As early as in 1996, Kakuda T and co-workers from Itoen Ltd, Japan, fed non-insulin dependent diabetic
mice with a diet containing extracts of banaba leaves. They found that the elevation of blood plasma
glucose level in non-insulin dependent diabetic mice fed the cellulose as control diet were almost entirely
suppressed by addition of the extracts. [Biosci Biotechnol Biochem. 1996 Feb;60(2):204-8]

In another study, Corosolic acid inhibits gluconeogenesis by increasing the production of
Fructose-2,6-bisphosphate by lowering the cAMP level and inhibiting cAMP-dependent protein kinase
activity in isolated hepatocytes. Furthermore, Corosolic acid increased glucokinase activity in isolated
hepatocytes without affecting glucose-6-phosphatase activity, suggesting the promotion of glycolysis.
These effects on hepatic glucose metabolism may underlie the various anti-diabetic actions of
Corosolic acid. [Diabetes Res Clin Pract. 2008 Apr;80(1):48-55.]

Obesity and triglyceride
An animal study indicates that banaba leaf extract may benefit people with obesity. In this study, KK-Ay
mice were fed a control diet or test diet containing 5% of a hot-water extract from banaba leaves instead of
cellulose for 12 wk. Neither group showed any changes in diet intake during the experimental period. Body
weight gain and parametrial adipose tissue weight were lowered significantly in the banaba diet group.
Furthermore, tthe mice fed banaba extract showed a significant decrease, to 65% of the control level in
total hepatic lipid contents. This decrease was due to a reduction in the accumulation of triglyceride. [J
Nutr Sci Vitaminol (Tokyo). 1999 Dec;45(6):791-5]

One may wonder how banaba extract benefits the obese mice? The same group from ITO EN, Ltd, Japan,
found that Banaba contains valoneaic acid. The alpha-amylase-inhibiting activities of the decoctions were
dependent on the whole valoneaic acid contents. In addition, a strong linear correlation was observed
between the whole valoneaic acid contents and total polyphenol contents. [Yakugaku Zasshi. 2003

In 2005, a group from Korea published a report that mulberry leaf water extract, Korean red ginseng,
banaba leaf water extract, and the combination of above herbs effectively reduced blood glucose, insulin,
TG, and percent HbA1c in diabetic mice. These extracts increased insulin sensitivity, and improve
hyperglycemia possibly through regulating PPAR-mediated lipid metabolism in the study. [Life Sci. 2005
Nov 12;77(26):3344-54. Epub 2005 Jun 23.]

Corosolic acid inhibited the mean blood cholesterol level by 32% nd the liver cholesterol content by 46%
compared with control 10 weeks after the start of dietary intake in a type 2 diabetic mice. Corosolic acid
may have some direct effects on the cholesterol absorption process in the small intestine or/and corosolic
acid may inhibit the activity of cholesterol acyltransferase, which acts in the re-esterification of cholesterol
in the small intestine, in type 2 diabetes. [Biomed Res. 2010;31(4):213-8.]

Corosolic acid, a constituent of banaba leaves, has been reported to have anti-inflammatory and
hypoglycemic activities. In one study, it ameliorated hypertension, abnormal lipid metabolism, and oxidative
stress as well as the inflammatory state in rats (fed with a high fat diet for 14 weeks). (Life Sci. 2006 Nov