Medically reviewed on November 13, 2017
Scientific Name(s): Momordica charantia L. Family: Cucurbitaceae
Common Name(s): Bitter melon , balsam pear , bitter cucumber , balsam apple , art pumpkin , cerasee , carilla cundeamor
There is insufficient evidence from quality clinical trials to recommend the use of bitter melon as a therapeutic option in type 2 diabetes.
Bitter melon juice has been recommended for diabetes at daily doses of 50 to 100 mL; 900 mg of fruit given 3 times/day has also been given for the same indication. There is insufficient clinical trial evidence to substantiate these doses.
Patients deficient in glucose-6-phosphate dehydrogenase should avoid consumption of bitter melon preparations due to the presence of vicine in the seeds.
Documented adverse reactions include emmenagogue and abortifacient effects. Avoid use.
None well documented.
Bitter melon generally causes few adverse reactions. GI effects (eg, abdominal pain, diarrhea) and headache have been reported in clinical trials. Case reports exist of hypoglycemic coma and atrial fibrillation associated with bitter melon intake. Increases in liver enzymes have been observed experimentally, but without histological changes. Bitter melon should be used with caution in patients with impaired hepatic function.
The red arils around bitter melon seeds are toxic to children.
Bitter melon is an annual tropical plant growing to 2 m in height that is cultivated in Asia, Africa, South America, and India. The plant has lobed leaves, yellow flowers, and edible but bitter-tasting, orange-yellow fruit. The unripe fruit is green and cucumber-shaped with surface bumps. The fruit, leaves, seeds, seed oil, and roots are used. 1 , 2
Bitter melon as an unripe fruit is commonly eaten as a vegetable. Bitter melon has been used as a folk remedy for tumors, asthma, skin infections, GI problems, hypertension, and diabetes symptoms. The plant has been used as a traditional medicine in China, India, Africa, and the southeastern US. In the 1980s, the seeds were investigated in China as a potential contraceptive. 2 , 3 , 4
Chemical constituents from whole plants, fruits, and seeds of bitter melon have been isolated and described. Bitter melon fruit contains triterpene lycosides, including the characteristic mormordin and charantin. Other triterpene glycosides (the momordicosides), vitamins, including beta carotene, ascorbic acid, niacin, and thiamin, elemental compounds (eg, iron, iodine, magnesium, sodium, calcium), and fatty acids, including stearic, palmitic, and oleic, are also present. 4 Insulin-like compounds, or compounds exerting hypoglycemic activity, have been described. 5 , 6 , 7
Bitter melon seeds and the pericarp contain the phenolics catechin and epicatechin, gallic, gentisic, and vanillic acids, as well as lutein, lycopene, carotenes, xanthins, momordicosides, and vicine. 4 , 8 The seed essential oil contains sesquiterepene, phenylpropanoids, and monoterpenes, including nerolidol. 4 , 9
Uses and PharmacologyDiabetes
The hypoglycemic effects of bitter melon have been established in animal studies. Improved glucose tolerance, suppression of postprandial hyperglycemia, and enhanced insulin sensitivity have been demonstrated in rodents and rabbits. Enhanced beta-cell activity, stimulation of the glycolytic pathway, and inhibition of glucose transportation in the small intestine have also been shown experimentally. 6 , 10 , 11Clinical data
Clinical trials evaluating the effect of bitter melon in type 2 diabetes are largely of poor methodology. A limited number of trials meeting adequate methodological standards show no statistically significant effect versus placebo or glibenclamide, and there is insufficient evidence to recommend the use of bitter melon as a therapeutic option in type 2 diabetes. Further large scale, double-blind, randomized clinical trials are required. 10 , 11Other uses
The bitter melon plant parts roots, leaves, and seeds have shown in vitro antibiotic and antiviral activity, including inhibition of HIV integrase. 4 , 12 Synergism with aminoglycosides has been demonstrated in methicillin-resistant strains of Staphylococcus aureus . 13 Antibacterial activity has been attributed to the nerolidol content of the essential seed oil. 9 Clinical studies are lacking.Antioxidant activity
Free-radical scavenging activity, attributed to the phenolic content, has been demonstrated in vitro. 8 , 14 In hyperammonemic rats, the oxidant-antioxidant imbalance was restored by administration of bitter melon fruit extract. 15Cancer
In vitro studies have evaluated the effect of ribosome-inactivating proteins (MAP30 and MCP30) from the seeds of bitter melon. Antineoplastic effects (reduced cell proliferation and induced apoptosis) have been demonstrated in breast, prostate, and epidermal cancer cell lines. 13 , 16 , 17 , 18 , 19 Clinical studies are lacking.Immune system
Bitter melon juice has been recommended for diabetes at daily doses of 50 to 100 mL; 900 mg of fruit 3 times/day has also been given for the same indication. There is insufficient clinical trial evidence to substantiate these doses. 12
Subcutaneous preparations of bitter melon as a vegetable insulin have also been used in older clinical studies, but safety and efficacy data are lacking. 12
An increased hypoglycemic effect with coadministered pharmaceutical agents can be postulated due to effects observed in animal studies. However, case reports are lacking. 12 Minor effects on cytochrome P450 enzymes and glutathione S-transferase were observed in 1 experiment. 25
The plant is relatively safe at low doses and for a duration of 4 weeks or less. 2 There are no published reports of serious reactions in adults given the usual oral dose of 50 mL. Antifertility action (decreased spermatogenesis) has been observed in rats and dogs fed bitter melon fruit extract. 12 , 24
The red arils around bitter melon seeds are toxic to children. The juice given to a child in 1 report caused vomiting, diarrhea, and eventual death. 4
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6. Raman A, et al. Anti-diabetic properties and phytochemistry of Momordica charantia L. (Cucurbitaceae). Phytomedicine . 1996;2:349-362.
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10. Leung L, Birtwhistle R, Kotecha J, Hannah S, Cuthbertson S. Anti-diabetic and hypoglycaemic effects of Momordica charantia (bitter melon): a mini review. Br J Nutr . 2009;102(12):1703-1708.
11. Ooi CP, Yassin Z, Hamid TA. Momordica charantia for type 2 diabetes mellitus. Cochrane Database Syst Rev . 2010;2:CD007845.
12. Basch E, Gabardi S, Ulbricht C. Bitter melon ( Momordica charantia ): a review of efficacy and safety. Am J Health Syst Pharm . 2003;60(4):356-359.
13. Coutinho HD, Costa JG, Falcão-Silva VS, Siqueira-Júnior JP, Lima EO. Effect of Momordica charantia L. in the resistance to aminoglycosides in methicilin-resistant Staphylococcus aureus . Comp Immunol Microbiol Infect Dis . 2009 Sep 2. [Epub ahead of print].
14. Dong CJ, Yang XD, Liu JY. Enzymatic properties of a recombinant phospholipid hydroperoxide glutathione peroxidase from Momordica charantia and its complementation function in yeast. Biochemistry (Mosc) . 2009;74(5):502-508.
15. Thenmozhi AJ, Subramanian P. Antioxidant Potential of Momordica charantia in Ammonium Chloride-induced Hyperammonemic Rats. Evid Based Complement Alternat Med . 2010 Jan 4. [Epub ahead of print].
16. Ray RB, Raychoudhuri A, Steele R, Nerurkar P. Bitter melon ( Momordica charantia ) extract inhibits breast cancer cell proliferation by modulating cell cycle regulatory genes and promotes apoptosis. Cancer Res . 2010;70(5):1925-1931.
17. Xiang L, Huang X, Chen L, Rao P, Ke L. The reparative effects of Momordica Charantia Linn. extract on HIT-T15 pancreatic beta-cells. Asia Pac J Clin Nutr . 2007;(16)(suppl 1):249-252.
18. Grossmann ME, Mizuno NK, Dammen ML, Schuster T, Ray A, Cleary MP. Eleostearic Acid inhibits breast cancer proliferation by means of an oxidation-dependent mechanism. Cancer Prev Res (Phila) . 2009;2(10):879-886.
19. Li M, Chen Y, Liu Z, Shen F, Bian X, Meng Y. Anti-tumor activity and immunological modification of ribosome-inactivating protein (RIP) from Momordica charantia by covalent attachment of polyethylene glycol. Acta Biochim Biophys Sin (Shanghai) . 2009;41(9):792-799.
20. Huang L, Adachi T, Shimizu Y, et al. Characterization of lectin isolated from Momordica charantia seed as a B cell activator. Immunol Lett . 2008;121(2):148-156.
21. Huang L, Ikejiri A, Shimizu Y, et al. Immunoadjuvant activity of crude lectin extracted from Momordica charantia seed. J Vet Med Sci . 2008;70(5):533-535.
22. Ono T, Tsuji T, Sakai M, et al. Induction of hepatocyte growth factor production in human dermal fibroblasts and their proliferation by the extract of bitter melon pulp. Cytokine . 2009;46(1):119-126.
23. Ernst E. Herbal medicinal products during pregnancy: are they safe? BJOG . 2002;109(3):227-235.
24. Chang F, et al. Studies on the antifertility chemical constituents of balsam pear. Chin Tradit Herb Drugs . 1995;26:281-284.
25. Appiah-Opong R, Commandeur JN, Axson C, Vermeulen NP. Interactions between cytochromes P450, glutathione S-transferases and Ghanaian medicinal plants. Food Chem Toxicol . 2008;46(12):3598-3603.
26. Erden I, Ordu S, Erden EC, Caglar SO. A case of atrial fibrillation due to Momordica charantia (bitter melon). Ann Saudi Med . 2010;30(1):86-87.
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