Corosolic Acid Induces GLUT4 Translocation in Genetically Type 2 Diabetic Mice

Abstract

The effect of corosolic acid (CA) on blood glucose was studied in KK-Ay mice, an animal model of type 2 diabetes. CA (10 mg/kg) reduced the blood glucose (pϽ0.05) of KK-Ay mice 4 h after single oral administration when compared with the control group. However, CA did not change the plasma insulin. The muscle facilitative glucose transporter isoform 4 (GLUT4) translocation from low-density microsomal membrane to plasma membrane was significantly increased in the orally CA-treated mice when compared with that of the controls (pϽ0.05). These results suggest that the hypoglycemic effect of CA is derived, at least in part, from an increase in GLUT4 translocation in muscle. Therefore, it may be that CA has beneficial effects on hyperglycemia in type 2 diabetes.

Effect of Corosolic Acid on the Hydrolysis of Disaccharides

“…Animals were tested in accordance with the Guideline for the Care and Use of Laboratory Animals (the Prime Minister's Office Directive no. 6,1980).…”

“…The hypoglycemic effect of CA has been reported by various experiments (2)(3)(4)(5). The decrease in insulin resistance due to the increase in GLUT4 translocation has been reported as a mechanism of action ( 6 ). On the other hand, there is no report that reviews brief direct action.…”

11β-Hydroxysteroid dehydrogenase type 1 inhibitors with oleanan and ursan scaffolds

“…Clinical interest in pentacyclic ursan and oleanan type triterpenes relate to their anti-inflammatory, anti-viral, apoptosis inducing and hypoglycemic properties, although the underlying mechanism in most cases is still unknown (Bühler et al, 1991;Matsuda et al, 1998). Corosolic acid, an ursan type triterpene isolated from the leaf of Banaba (Lagerstroemia speciosa), a traditional oriental medicine to treat diabetes, induces GLUT4 translocation and lowers plasma insulin levels in KK-Ay mice (Miura et al, 2004). Oleanoic acid, an oleanan type triterpene found in many plants with hypoglycemic activity e.g.…”

Triterpenoids Isolated from <i>Ziziphus jujuba</i> Enhance Glucose Uptake Activity in Skeletal Muscle Cells

“…It is possible that triterpenoids activate the insulin signaling, but the underlying mechanism remains to be clarified. Corosolic acid (2a-hydroxyursolic acid) from banana leaves acts as a hypoglycemic compound in KK-Ay type 2 diabetic mice (15). This compound induces the translocation of GLUT4 in hindlimb muscle of KK-Ay mice (15), probably via inhibition of protein tyrosine phosphatases (PTPs) (16).…”