J Nutr Sci Vitaminol (Tokyo). 2001 Oct; 47(5): 340-4.

Hypoglycemic activity of the fruit of the Momordica charantia in type 2 diabetic mice.

Miura T, Itoh C, Iwamoto N, Kato M, Kawai M, Park SR, Suzuki I.

Department of Clinical Nutrition, Suzuka University of Medical Science, Mie, Japan.

The antidiabetic activity of Momordica charantia L. (Cucurbitaceae) was investigated in KK-Ay mice, an animal model with type 2 diabetes with hyperinsulinemia. The water extract of the fruit of Momordica charantia L. (MC) reduced the blood glucose of KK-Ay mice 3 weeks after oral administration (p<0.01) and also significantly lowered the serum insulin of KK-Ay mice under similar conditions (p<0.01). However, MC did not affect the blood glucose in normal mice. MC-treated KK-Ay mice blood glucose significantly decreased in an insulin tolerance test. Moreover, the muscle content of facilitative glucose transporter isoform 4 (GLUT4) protein content in the plasma membrane fraction from muscle significantly increased in the orally MC-treated mice when compared with that of the controls (p<0.01). These results suggest that the antidiabetic effect of MC is derived, at least in part, from a decrease in insulin resistance because of the increase of GLUT4 protein content in the plasma membrane of the muscle.