Plant Profiler

Bitter melon (Momordica charantia)

Bitter melon (Momordica charantia) Image
Synonyms / Common Names / Related Terms
African cucumber, alpha-momorcharin, ampalaya, balsam-apple, Balsambirne (German), balsam pear, balsambirne, balsamo, beta-momorcharin, bitter apple, bitter cucumber, bitter gourd, bittergurke, bitter melon capsules, bitter melon extract, bitter melon juice, bitter melon malt vinegar, bitter melon seed oil, carilla gourd, cerasse, charantin, chinli-chih, Cucurbitaceae (family), cundeamor, fructus mormordiacea grosvenori, GlyMordica®, goya, kakara, karavella, karela, kareli, kathilla, kerala, Koimidori bitter melon, kuguazi, K'u-kua, Lai margose, MAP30, Mormodica angustifolia, Momordica charantia, Momordica charantia peroxidase, momordique, pavakkachedi, pepino montero, P'u-t'ao, sorosi, sushavi, vegetable insulin, wild cucumber.

Mechanism of Action


  • Constituents: Bitter melon's constituents include Momordica charantia peroxidase39, MAP307,6,8,9, and 9cis,11trans,13trans-conjugated linolenic acid34.
  • Anthelminthic activity: In an assay using free-living nematodes, a crude extract of Momordica charantia produced 96% mortality.13
  • Antineoplastic effects: MAP30, a protein isolated from bitter melon extract, has been reported to possess anti-neoplastic effects in vitro.7,6,8,9 These effects have been attributed to the reduced expression of growth factor receptors such as the transmembrane tyrosine kinase receptor HER2 (also known as neu or c-erb-2), which has been implicated in breast cancer.7 MAP30 was originally identified as a single chain ribosome inactivating protein (SCRIP), but its in vitro activities appear to be unrelated to its effect on ribosomes. Bitter melon has been suggested to potentiate function of natural killer cells in cancer patients.32,33 In addition, 9cis,11trans,13trans-conjugated linolenic acid extracted from bitter melon seed has shown antineoplastic effects in human colon cancer cell lines.34 An in vivo study reported cytostatic activity in IM9 human leukemic lymphocytes due to inhibition of RNA synthesis by an unidentified bitter melon constituent.35 Another study associated the cytotoxicity of bitter melon extract on leukemic lymphocytes to the inhibition of guanylate cyclase, enzymes that are normally present in normal and leukemic lymphocytes. This blockade in the leukemic lymphocytes correlates with these cell death.36 An in vivo study in rats, the constituent, cis(c)9, trans(t)11, t13-conjugated linolenic acid (CLN), inhibited the development of azoxymethane (AOM)-induced colonic aberrant crypt foci (ACF).37
  • Antioxidant effects: An assay found that extracts from bitter melon showed significant antioxidant properties.14
  • Antiviral activity: Antiviral activity observed in vitro has been attributed to a 30kD protein called MAP30, which has been isolated from bitter melon seeds.6 This protein has been reported to inhibit HIV viral integrase and cause irreversible relaxation of supercoiled viral nucleic acids.8 These changes render viruses unable to integrate into host cell genomes. Rates of T lymphocyte infection with HIV-1 and reduced rates of viral replication in infected cells have also been reported in vitro.11,10 The MAP30 gene has been cloned and expressed, and the recombinant protein re-MAP30 possesses similar properties in vitro as native MAP30. However, the antiviral activity of MAP30 (or bitter melon) has not been studied in humans. Rebultan reported the case of a man infected with HIV whose CD4 count and CD4/CD8 ratios improved and eventually returned to normal after drinking 10oz. of bitter melon juices, drinking a combination of juices and decoction, or using a rectal retention enema.38
  • Hepatic activity: In an animal study, bitter melon fruit juice and seed extract increased GGT and alkaline phosphatase levels, although these rises were not associated with significant histopathological changes in the liver.28
  • Hypoglycemic effects: Several low-quality human studies have indicated that bitter melon lowers serum glucose levels1,2,3,4, although one higher quality study found no evidence of this.5 Multiple mechanisms have been proposed as the cause of bitter melon's hypoglycemic properties.40 Components of bitter melon extract appear to have structural similarities to animal insulin, as measured by electrophoresis and infrared spectrum analysis1. Preliminary investigation has reported some insulin-like properties of bitter melon.25,29,30 Other evidence suggests that bitter melon may decrease hepatic gluconeogenesis, increase hepatic glycogen synthesis, and increase peripheral glucose oxidation in erythrocytes and adipocytes.27 One study reported that bitter melon increases pancreatic insulin secretion26, but this was not confirmed by subsequent studies41,42. Although several constituents of bitter melon have been found to possess hypoglycemic properties20,21,22,23,24, most interest has focused on a polypeptide isolated from the seeds called "polypeptide p," and a mixture of two steroid glycosides referred to as "charantin".19,31
  • Hypolipidemic activity: Bitter melon juice in vivo has been associated with reduced apolipoprotein B (apoB) secretion in human hepatoma cells after 24-hour treatment with or without addition of lipids.15,16 In addition, BMJ reduced the secretion of new triglycerides (p<0.05) and decreased microsomal triglyceride transfer protein (MTP) mRNA expression, suggesting that lipid bioavailability and lipidation of lipoprotein assembly are likely involved in decreased apoB secretion A study reported dose-dependent reduction of hepatic triglyceride level in rats with 3.0% supplementation of Koimidori bitter melon extract in methanol.17,18
  • Immunomodulatory activity: Alpha- and beta-momorcharin, the proteins isolated from the seeds of bitter melon, were found to significantly inhibit the mitogenic responses of mouse splenocytes at non-cytotoxic concentrations.12 A clear decrease in the functional capacity of macrophages, such as the cytostatic and phagocytic activities, was also observed under similar conditions. In addition, the alloantigen-induced lymphoproliferation and the in vitro generation of a primary cytotoxic lymphocyte response were severely suppressed in the presence of these proteins.


  • Excretion: In a study of 56 healthy, normotensive, free-living Japanese women aged 18-38 years living in Okinawa, ingestion of 371.4g daily of vegetables, including bitter melon, increased urinary potassium excretion 20.5%.43


  1. Baldwa VS, Bhandara CM, Pangaria A, and et al. Clinical trials in patients with diabetes mellitus of an insulin-like compound obtained from plant source. Upsala J Med Sci 1977;82:39-41.
  2. Leatherdale, B. A., Panesar, R. K., Singh, G., Atkins, T. W., Bailey, C. J., and Bignell, A. H. Improvement in glucose tolerance due to Momordica charantia (karela). Br Med J (Clin Res Ed) 6-6-1981;282(6279):1823-1824. 6786635
  3. Welihinda, J., Karunanayake, E. H., Sheriff, M. H., and Jayasinghe, K. S. Effect of Momordica charantia on the glucose tolerance in maturity onset diabetes. J Ethnopharmacol 1986;17(3):277-282. 3807390
  4. Akhtar, M. S. Trial of Momordica charantia Linn (Karela) powder in patients with maturity-onset diabetes. J Pak Med Assoc 1982;32(4):106-107. 6806502
  5. Dans, A. M., Villarruz, M. V., Jimeno, C. A., Javelosa, M. A., Chua, J., Bautista, R., and Velez, G. G. The effect of Momordica charantia capsule preparation on glycemic control in type 2 diabetes mellitus needs further studies. J Clin Epidemiol 2007;60(6):554-559. 17493509
  6. Wang, Y. X., Jacob, J., Wingfield, P. T., Palmer, I., Stahl, S. J., Kaufman, J. D., Huang, P. L., Huang, P. L., Lee-Huang, S., and Torchia, D. A. Anti-HIV and anti-tumor protein MAP30, a 30 kDa single-strand type-I RIP, shares similar secondary structure and beta-sheet topology with the A chain of ricin, a type-II RIP. Protein Sci 2000;9(1):138-144. 10739256
  7. Lee-Huang, S., Huang, P. L., Sun, Y., Chen, H. C., Kung, H. F., Huang, P. L., and Murphy, W. J. Inhibition of MDA-MB-231 human breast tumor xenografts and HER2 expression by anti-tumor agents GAP31 and MAP30. Anticancer Res 2000;20(2A):653-659. 10810336
  8. Wang, Y. X., Neamati, N., Jacob, J., Palmer, I., Stahl, S. J., Kaufman, J. D., Huang, P. L., Huang, P. L., Winslow, H. E., Pommier, Y., Wingfield, P. T., Lee-Huang, S., Bax, A., and Torchia, D. A. Solution structure of anti-HIV-1 and anti-tumor protein MAP30: structural insights into its multiple functions. Cell 11-12-1999;99(4):433-442. 10571185
  9. Bourinbaiar, A. S. and Lee-Huang, S. The activity of plant-derived antiretroviral proteins MAP30 and GAP31 against herpes simplex virus in vitro. Biochem Biophys Res Commun 2-27-1996;219(3):923-929. 8645280
  10. Lee-Huang, S., Huang, P. L., Chen, H. C., Huang, P. L., Bourinbaiar, A., Huang, H. I., and Kung, H. F. Anti-HIV and anti-tumor activities of recombinant MAP30 from bitter melon. Gene 8-19-1995;161(2):151-156. 7665070
  11. Lee-Huang, S., Huang, P. L., Huang, P. L., Bourinbaiar, A. S., Chen, H. C., and Kung, H. F. Inhibition of the integrase of human immunodeficiency virus (HIV) type 1 by anti-HIV plant proteins MAP30 and GAP31. Proc Natl Acad Sci U.S.A 9-12-1995;92(19):8818-8822. 7568024
  12. Leung, S. O., Yeung, H. W., and Leung, K. N. The immunosuppressive activities of two abortifacient proteins isolated from the seeds of bitter melon (Momordica charantia). Immunopharmacology 1987;13(3):159-171. 3497134
  13. Das, P., Sinhababu, S. P., and Dam, T. Screening of antihelminthic effects of Indian plant extracts: a preliminary report. J Altern Complement Med 2006;12(3):299-301. 16646729
  14. Ansari, N. M., Houlihan, L., Hussain, B., and Pieroni, A. Antioxidant activity of five vegetables traditionally consumed by South-Asian migrants in Bradford, Yorkshire, UK. Phytother Res 2005;19(10):907-911. 16261524
  15. Nerurkar, P. V., Pearson, L., Efird, J. T., Adeli, K., Theriault, A. G., and Nerurkar, V. R. Microsomal triglyceride transfer protein gene expression and ApoB secretion are inhibited by bitter melon in HepG2 cells. J Nutr 2005;135(4):702-706. 15795421
  16. Nerurkar, P. V., Lee, Y. K., Linden, E. H., Lim, S., Pearson, L., Frank, J., and Nerurkar, V. R. Lipid lowering effects of Momordica charantia (Bitter Melon) in HIV-1-protease inhibitor-treated human hepatoma cells, HepG2. Br J Pharmacol 2006;148(8):1156-1164. 16847441
  17. Senanayake, G. V., Maruyama, M., Shibuya, K., Sakono, M., Fukuda, N., Morishita, T., Yukizaki, C., Kawano, M., and Ohta, H. The effects of bitter melon (Momordica charantia) on serum and liver triglyceride levels in rats. J Ethnopharmacol 2004;91(2-3):257-262. 15120448
  18. Senanayake, G. V., Maruyama, M., Sakono, M., Fukuda, N., Morishita, T., Yukizaki, C., Kawano, M., and Ohta, H. The effects of bitter melon (Momordica charantia) extracts on serum and liver lipid parameters in hamsters fed cholesterol-free and cholesterol-enriched diets. J Nutr Sci Vitaminol.(Tokyo) 2004;50(4):253-257. 15527066
  19. Marles R and Farnsworth N. Antidiabetic Plants and Their Active Constituents: An update. Phytomedicine 1997;2(2):137-189.
  20. Chen, Q., Chan, L. L., and Li, E. T. Bitter melon (Momordica charantia) reduces adiposity, lowers serum insulin and normalizes glucose tolerance in rats fed a high fat diet. J Nutr 2003;133(4):1088-1093. 12672924
  21. Virdi, J., Sivakami, S., Shahani, S., Suthar, A. C., Banavalikar, M. M., and Biyani, M. K. Antihyperglycemic effects of three extracts from Momordica charantia. J Ethnopharmacol 2003;88(1):107-111. 12902059
  22. Rathi, S. S., Grover, J. K., and Vats, V. The effect of Momordica charantia and Mucuna pruriens in experimental diabetes and their effect on key metabolic enzymes involved in carbohydrate metabolism. Phytother Res 2002;16(3):236-243. 12164268
  23. Miura, T., Itoh, C., Iwamoto, N., Kato, M., Kawai, M., Park, S. R., and Suzuki, I. Hypoglycemic activity of the fruit of the Momordica charantia in type 2 diabetic mice. J Nutr Sci.Vitaminol (Tokyo) 2001;47(5):340-344. 11814149
  24. Vikrant, V., Grover, J. K., Tandon, N., Rathi, S. S., and Gupta, N. Treatment with extracts of Momordica charantia and Eugenia jambolana prevents hyperglycemia and hyperinsulinemia in fructose fed rats. J Ethnopharmacol 2001;76(2):139-143. 11390126
  25. Wong, C. M., Yeung, H. W., and Ng, T. B. Screening of Trichosanthes kirilowii, Momordica charantia and Cucurbita maxima (family Cucurbitaceae) for compounds with antilipolytic activity. J Ethnopharmacol 1985;13(3):313-321. 4058034
  26. Welihinda, J., Arvidson, G., Gylfe, E., Hellman, B., and Karlsson, E. The insulin-releasing activity of the tropical plant momordica charantia. Acta Biol Med Ger 1982;41(12):1229-1240. 6765165
  27. Shibib, B. A., Khan, L. A., and Rahman, R. Hypoglycaemic activity of Coccinia indica and Momordica charantia in diabetic rats: depression of the hepatic gluconeogenic enzymes glucose- 6-phosphatase and fructose-1,6-bisphosphatase and elevation of both liver and red-cell shunt enzyme glucose-6-phosphate dehydrogenase. Biochem J 5-15-1993;292 ( Pt 1):267-270. 8389127
  28. Tennekoon, K. H., Jeevathayaparan, S., Angunawala, P., Karunanayake, E. H., and Jayasinghe, K. S. Effect of Momordica charantia on key hepatic enzymes. J Ethnopharmacol 1994;44(2):93-97. 7853870
  29. Ng, T. B., Wong, C. M., Li, W. W., and Yeung, H. W. Isolation and characterization of a galactose binding lectin with insulinomimetic activities. From the seeds of the bitter gourd Momordica charantia (Family Cucurbitaceae). Int J Peptide Protein Res 1986;28(2):163-172. 3533814
  30. Ng, T. B., Wong, C. M., Li, W. W., and Yeung, H. W. Insulin-like molecules in Momordica charantia seeds. J Ethnopharmacol 1986;15(1):107-117. 3520153
  31. Khanna, P., Jain, S. C., Panagariya, A., and Dixit, V. P. Hypoglycemic activity of polypeptide-p from a plant source. J Nat Prod 1981;44(6):648-655. 7334382
  32. Pongnikorn, S., Fongmoon, D., Kasinrerk, W., and Limtrakul, P. N. Effect of bitter melon (Momordica charantia Linn) on level and function of natural killer cells in cervical cancer patients with radiotherapy. J Med Assoc Thai 2003;86(1):61-68. 12678140
  33. Cunnick, J. E., Sakamoto, K., Chapes, S. K., Fortner, G. W., and Takemoto, D. J. Induction of tumor cytotoxic immune cells using a protein from the bitter melon (Momordica charantia). Cell Immunol 4-1-1990;126(2):278-289. 2311123
  34. Yasui, Y., Hosokawa, M., Kohno, H., Tanaka, T., and Miyashita, K. Troglitazone and 9cis,11trans,13trans-conjugated linolenic acid: comparison of their antiproliferative and apoptosis-inducing effects on different colon cancer cell lines. Chemotherapy 2006;52(5):220-225. 16899971
  35. Takemoto, D. J., Dunford, C., and McMurray, M. M. The cytotoxic and cytostatic effects of the bitter melon (Momordica charantia) on human lymphocytes. Toxicon 1982;20(3):593-599. 7201686
  36. Takemoto, D. J., Jilka, C., and Kresie, R. Purification and characterization of a cytostatic factor from the bitter melon Momordica charantia. Prep Biochem 1982;12(4):355-375. 6185939
  37. Kohno, H., Yasui, Y., Suzuki, R., Hosokawa, M., Miyashita, K., and Tanaka, T. Dietary seed oil rich in conjugated linolenic acid from bitter melon inhibits azoxymethane-induced rat colon carcinogenesis through elevation of colonic PPARgamma expression and alteration of lipid composition. Int J Cancer 7-20-2004;110(6):896-901. 15170673
  38. Rebultan, S. P. Bitter melon therapy: an experimental treatment of HIV infection. AIDS Asia 1995;2(4):6-7. 12346831
  39. Liu, H. L., Wan, X., Huang, X. F., and Kong, L. Y. Biotransformation of sinapic acid catalyzed by Momordica charantia peroxidase. J Agric Food Chem 2-7-2007;55(3):1003-1008. 17263505
  40. Krawinkel, M. B. and Keding, G. B. Bitter gourd (Momordica Charantia): A dietary approach to hyperglycemia. Nutr Rev 2006;64(7 Pt 1):331-337. 16910221
  41. Day, C., Cartwright, T., Provost, J., and Bailey, C. J. Hypoglycaemic effect of Momordica charantia extracts. Planta Med 1990;56(5):426-429. 2077547
  42. Sarkar, S., Pranava, M., and Marita, R. Demonstration of the hypoglycemic action of Momordica charantia in a validated animal model of diabetes. Pharmacol Res 1996;33(1):1-4. 8817639
  43. Tuekpe, M. K., Todoriki, H., Sasaki, S., Zheng, K. C., and Ariizumi, M. Potassium excretion in healthy Japanese women was increased by a dietary intervention utilizing home-parcel delivery of Okinawan vegetables. Hypertens Res 2006;29(6):389-396. 16940700

Licensed by Natural Standard Copyright © 2010 by Natural Standard Corporation. All Rights Reserved.

back to Plant Profiler
back to top