Abstract
The fruit of Momordica charantia (family: Cucurbitacea) is used widely as a hypoglycaemic agent to treat diabetes mellitus (DM). The mechanism of the hypoglycaemic action of M. charantia in vitro is not fully understood. This study investigated the effect of M. charantia juice on either 3H-2-deoxyglucose or N-methyl-amino-a-isobutyric acid (14C-Me-AIB) uptake in L6 rat muscle cells cultured to the myotube stage. The fresh juice was centrifuged at 5000 rpm and the supernatant lyophilised. L6 myotubes were incubated with either insulin (100 nM), different concentrations (1–10 μg ml−1) of the juice or its chloroform extract or wortmannin (100 nM) over a period of 1–6 h. The results were expressed as pmol min−1 (mg cell protein)−1, n= 6–8 for each value. Basal 3H-deoxyglucose and 14C-Me-AIB uptakes by L6 myotubes after 1 h of incubation were (means ± S.E.M.) 32.14 ± 1.34 and 13.48 ± 1.86 pmol min−1 (mg cell protein)−1, respectively. Incubation of L6 myotubes with 100 nM insulin for 1 h resulted in significant (ANOVA, p < 0.05) increases in 3H-deoxyglucose and 14C-Me-AIB uptakes. Typically, 3H-deoxyglucose and 14C-Me-AIB uptakes in the presence of insulin were 58.57 ± 4.49 and 29.52 ± 3.41 pmol min−1 (mg cell protein−1), respectively. Incubation of L6 myotubes with three different concentrations (1, 5 and 10 μg ml−1) of either the lyophilised juice or its chloroform extract resulted in time-dependent increases in 3H-deoxy-D-glucose and 14C-Me-AIB uptakes, with maximal uptakes occurring at a concentration of 5 μg ml−1. Incubation of either insulin or the juice in the presence of wortmannin (a phosphatidylinositol 3-kinase inhibitor) resulted in a marked inhibition of 3H-deoxyglucose by L6 myotubes compared to the uptake obtained with either insulin or the juice alone. The results indicate that M. charantia fruit juice acts like insulin to exert its hypoglycaemic effect and moreover, it can stimulate amino acid uptake into skeletal muscle cells just like insulin. (Mol Cell Biochem 261: 99–104, 2004)
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Zimmet P, Alberti KGMM, Shaw T: Global and societal implications of diabetes epidemic. Nature 414: 782–789, 2001
Amos A, McCarty D, Zimmet P: The rising global burden of diabetes and its complications, estimates and projections to the year 2010. Diabetes Med 14: S1–S85, 1997
Kumar PJ, Clark M: Diabetes mellitus and other disorders of metabolism. Textbook of Clinical Medicine. Saunders,(London) 2002, pp 1069–1152.
Attar-uri Rahman A, Zaman K: Medicinal plants with hypoglycaemic activity. J Elthanopharmacol 26: 1–55, 1989
Platel K, Srinivasan K: Plant foods in the management of diabetes mellitus: Vegetables as potential hypoglycaemic agents. Nahrung 41: 68–74, 1997
Day C, Cartwright T, Provost J, Baily CJ: Hypoglycaemic effect of Momordica Charantia extract. Planta Med 56: 426–429, 1990
Day C: Hypoglycaemic compounds from plants In C. J. Bailey, P.R. Flatt (eds) New Antidiabetic Drugs. Nishimura Ltd, Japan, 1990, pp 267–278.
Sharma AK, Ahmed I, Tadaygon M, Penery AS, Aloamaka P, Absood G, Pallot DJ: The beneficial effects of Momordica Charantia fruit juice on streptozotocin-induced diabetes and hypertension in rats. Int J Diabetes 4: 29–38, 1996
Ahmed I: Effect of Momordica Charantia fruit juice on experimental diabetes and its complications. PhD Thesis, University of Central Lancashire, 1999
Welihinda I, Karunanayake, EH, Sheriff MHR, Jayasinghe KSA: Effect of Momordica charantia on the glucose tolerance in maturity onset diabetes. J Ethnopharmacol 17: 277–282, 1986
Leatherdale BA, Panesar RK, Singh G, Atkins TW, Bailey CJ, Bignell AH: Improvement in glucose tolerance due to Momordica charantia (Karela). Br Med J 282: 1923–1924, 1981
Baldwa VS, Bhandari CM, Pangaria A, Goyal RK: Clinical trial in patients with diabetes mellitus of an insulin-like compound obtained from plant source. Ups J Med Sci 82: 39–41, 1977
Ahmed I, Chandranath I, Sharma AK, Adeghate E, Singh J: Effect of Mormordica charantia fruit juice in normal and diabetic animals. J Physiol 520P–25P, 1999
Ahmed I, Adeghate E, Sharma AK, Pallot DJ, Singh J: Effects of Momordica charantia fruit juice on islet morphology in the pancreas of streptozotocin diabetic rats. Diabetes Res Clin Pract 40: 145–151, 1998
Hundal HS, Ramlall T, Reyes R, Laurence AL, Klip A: Cellular mechanism of metaformin action induces glucose transporters translocation from an intracellular pool to the plasma membrane in L6 muscle cells. Endocrinology 131: 1165–1173, 1992
Hundal HS, Klip A: Regulation of glucose transporters and the Na/K-ATPase by insulin in skeletal muscle. In C.G. Ostenson et al. (eds). New Concepts in the Pathogenisis of NIDDM. Plenum Press, NewYork, 1993, pp 63–77.
Klip A, Logen WJ, Gagalang E: Regulation of amino acid transport in L6 myotblast. II Different chemical properties of transporter after amino acid deprivation. J Cell Physiol 113: 56–66, 1982
Bradford MM: A rapid and sensitive method for the quantification of microgram quantities of protein utilizing the principle of protein-dye-bending. Anal Biochem 72: 248–254, 1976
Zorzano A, Bilan TW, Goodman MN, Luderman NB: Additive effects of prior exercise and insulin on glucose and AIB uptake by muscle. Am J Physiol 251: 21–26, 1986
Tszkirdis T, McDowell HE, Walker T, Downes CP, Hundal, HS, Vranic M, Klip A: Multiple roles of phosphatidylinositol 3-kinase in regulation of glucose transport amino acid transport and glucose transporters in L6 skeletal muscle cells. Endocrinology 136: 4315–4322, 1995
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Cummings, E., Hundal, H., Wackerhage, H. et al. Momordica charantia fruit juice stimulates glucose and amino acid uptakes in L6 myotubes. Mol Cell Biochem 261, 99–104 (2004). https://doi.org/10.1023/B:MCBI.0000028743.75669.ab
Issue Date:
DOI: https://doi.org/10.1023/B:MCBI.0000028743.75669.ab