Health Care Professional Information
Bitter gourd, bitter apple, wild cucumber, bitter cucumber, balsam apple, balsam pear, margose, la-kwa, leprosy gourd, karela, kugua, cerasee.
Bitter melon is a perennial plant that grows in the tropical and subtropical regions of Asia, South America, East Africa, and the Carribean. It is used both as food and in medicine to treat diabetes, cancer, viral infections, and immune disorders. The nutritional value of bitter melon is due to its high mineral and vitamin content, whereas its bitterness is attributed to the presence of alkaloids, momordicosides, and momordicines.
In vitro and animal studies indicate anticancer (3) (7) (8) (13), antiviral (9) (10), and lipid lowering (11) effects. Bitter melon was also shown to exert hypoglycemic effects in both healthy and diabetic patients (1) (2) (20), but further studies are required to recommend its use (14).
Bitter melon had no effect on natural killer cell activity in a study of cervical cancer patients (6).
Bitter melon can have additive effects when combined with insulin or oral hypoglycemic agents.
- Cancer prevention
- HIV and AIDS
- Menstrual disorder
- Glycosides: momordin, charantin
- Alkaloids: momordicin
- Others: polypeptide-P
- Oils (seed only): stearic, linoleic, oleic acids
- Glycoproteins: alpha-momorcharin, beta-momorcharin, lectins
- Others: vicine (pyrimidine nucleoside), protein MAP30
- Cucurbitane triterpenoids
Mechanism of Action
The compounds present in bitter melon including vicine, charantin, and polypeptide-P increase glucose uptake and glycogen synthesis in the liver, muscle, and adipose tissue, and improve glucose tolerance. Studies with hepatic enzymes in mice revealed reduction in glucose-6-phosphatase and fructose-1,6-bisphosphatase activity, and increased glucose oxidation by G6PDH pathway. Bitter melon displays cytotoxic activity against leukemic cells in vitro (guanylate cyclase inhibitor) and has a cytostatic effect on MDA-MB-231 human breast cancer cells xenografted into mice. MAP30 also demonstrates dose-dependent inhibition of HIV-1 integrase leading to poor viral DNA integration, thus inhibiting T lymphocyte and monocytes.
(1) (2) (3). Bitter melon also inhibits P-glycoprotein and can alter the pharmacokinetics of drugs by inhibiting the P-glycoprotein-mediated efflux (12).
It may affect fat and carbohydrate metabolism by stimulating the synthesis and release of thyroid hormones and adiponectin, and by enhancing the activity of AMP-activated protein kinase (AMPK) (21).
Red arils (covering on seed) are reportedly toxic in children, causing vomiting, diarrhea, and death (1).
Bitter melon is contraindicated in pregnant women as it can induce bleeding, contractions, and abortion.
- Hypoglycemia and hepatotoxicity were reported in animal studies (18).
- Toxicity: Ingestion of vicine (seed) may cause favism characterized by headache, fever, abdominal pain, and coma (17).
- A 22-year-old man experienced atrial fibrillation with rapid ventricular response following ingestion of bitter melon two days before his admission for his dyspeptic complaints. He ingested crushed bitter melon and drank two tablespoons of its juice three times a day, and on the morning of admission as well. His symptoms improved after administering antiarrhythmic medication (15).
- A 40-year-old man developed acute gastric ulceration following consumption of half a liter of concentrated homemade liquid extract of bitter melon. His symptoms included severe epigastric pain and hematemesis, which were managed with intravenous fluids, blood transfusion and intravenous rabeprazole (19).
- Gastrointestinal problems have been reported with use of bitter melon (22).
Insulin: Bitter melon may have an additive effect when used concomitantly.
Hypoglycemics: Bitter melon may have additive effect when used concomitantly.
Literature Summary and Critique
Ooi CP, Yassin Z, Hamid TA. Momordica charantia for type 2 diabetes mellitus. Cochrane Database Syst Rev. 2010 Feb 17;2:CD007845.
This review was conducted to determine the antidiabetic potential of bitter melon. The Cochrane Library (issue 4, 2009), MEDLINE, EMBASE, CINAHL, SIGLE and LILACS (all up to November 2009) were searched for studies. Randomized controlled trials that compared bitter melon with a placebo or another intervention, pharmacological or non-pharmacological, were included. Three studies met the inclusion criteria of which two compared preparations from different parts of the plant to placebo; there was no statistically signficant difference between bitter melon and placebo. The third study found the effects of bitter melon to be comparable to glibenclamide, an antidiabetic drug. Serious adverse events were not reported in any of the three trials.
The authors concluded that the current evidence to recommend bitter melon for type 2 diabetes mellitus is insufficient. Additional studies are needed to validate its use.
Dosage (Inside MSKCC Only)
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- DerMarderosian A, editor. The Review of Natural Products. St. Louis: Facts and Comparisons; 1999.
- Huang KC. The Pharmacology of Chinese Herbs, 2nd ed. New York: CRC Press; 1999.
- Lee-Huang S, et al. Inhibition of MDA-MD-231 human breast tumor xenografts and HER2 expression by anti-tumor agents GAP31 and MAP30. Anticancer Res 2000;20:653-9.
- Brinker F. Herb Contraindications and Drug Interactions, 3rd ed. Sandy (OR): Eclectic Medical Publications; 2001.
- Srivastava Y, et al. Antidiabetic and adaptogenic properties of momordica charantia extract: an experimental and clinical evaluation. Phytotherapy Res 1993;7:285-9.
- Pongnikorn S, Fongmoon D, Kasinrerk W, Limtrakul PN. 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 Jan;86(1):61-8.
- Deep G, Dasgupta T, Rao AR, Kale RK. Cancer preventive potential of Momordica charantia L. against benzo(a)pyrene induced fore-stomach tumourigenesis in murine model system. Indian J Exp Biol. 2004 Mar;42(3):319-22.
- Xiong SD, Yu K, Liu XH, et al. Ribosome-inactivating proteins isolated from dietary bitter melon induce apoptosis and inhibit histone deacetylase-1 selectively in premalignant and malignant prostate cancer cells. Int J Cancer. 2009 Aug 15;125(4):774-82.
- Lee-Huang S, Huang PL, Chen HC, et al. Anti-HIV and anti-tumor activities of recombinant MAP30 from bitter melon. Gene. 1995 Aug 19;161(2):151-6.
- Fan JM, Zhang Q, Xu J, et al. Inhibition on Hepatitis B virus in vitro of recombinant MAP30 from bitter melon. Mol Bio Rep 2009 Feb;36(2):381-8.
- Nerurkar PV, Lee YK, Linden EH, et al. Lipid lowering effects of Momordica charantia (Bitter Melon) in HIV-1-protease inhibitor-treated human hepatoma cells, HepG2. Br J Pharmacol. 2006 Aug;148(8):1156-64.
- Konishi T, Satsu H, Hatsugai Y, et al. Inhibitory effect of a bitter melon extract on the P-glycoprotein activity in intestinal Caco-2 cells. Br J Pharmacol. 2004 Oct;143(3):379-87.
- 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 Feb 23. [Epub ahead of print]
- Ooi CP, Yassin Z, Hamid TA. Momordica charantia for type 2 diabetes mellitus. Cochrane Database Syst Rev. 2012 Aug 15;8:CD007845.
- Erden I, Ordu S, Erden EC, Caglar SO. A case of atrial fibrillation due to Momordica charantia (bitter melon). Ann Saudi Med. 2010 Jan-Feb;30(1):86-7.
- Liu JQ, Chen JC, Wang CF, Qiu MH. New cucurbitane triterpenoids and steroidal glycoside from Momordica charantia. Molecules. 2009 Nov 25;14(12):4804-13.
- Cunnick J, Takemoto D. Bitter melon (Mormordica charantia). J Nat Med 1993;4:16-21.
- Tennekoon KH, Jeevathayaparan S, Angunawala P, Karunanayake EH, Jayasinghe KS. Effect of Momordica charantia on key hepatic enzymes. J Ethnopharmacol 1994;44:93-7.
- Nadkarni N, D'Cruz S, Sachdev A. Hematemesis due to bitter melon (Momordica charantia) extract-induced gastric ulcerations. Indian J Gastroenterol. 2010 Jan;29(1):37-8.
Chaturvedi P. Antidiabetic potentials of Momordica charantia: multiple mechanisms behind the effects. J Med Food. 2012 Feb;15(2):101-7.
Saokaew S, Suwankesawong W, Permsuwan U, Chaiyakunapruk N.Safety of herbal products in Thailand: an analysis of reports in the thai health product vigilance center database from 2000 to 2008.Drug Saf. 2011 Apr 1;34(4):339-50.
How It Works
Bottom Line: Bitter melon can lower blood glucose levels, but it is not known how it interacts with insulin or other medications.
Several active substances in bitter melon have been studied in both animals and humans. These experiments show that these substances act in the same way as insulin, by increasing the entry of glucose into cells and promoting its processing and storage in the liver, muscle, and fat. Bitter melon also prevents the conversion of stored nutrients to glucose and the release of this glucose into the blood. However, researchers have not established the correct dosage of bitter melon for effectively treating the high blood glucose levels in diabetes, and therefore it cannot be recommended as a replacement therapy for insulin or hypoglycemic drugs.
Bitter melon extracts are able to kill leukemia cells in the laboratory and slow the growth of breast cancer in mice, but it is unknown whether these effects occur in humans. A study in humans showed bitter melon had little effect on the immune system of cervical cancer patients. In laboratory tests, bitter melon extracts also inhibit the ability of HIV to insert its DNA into the chromosomes of human cells, but it is also not known whether this effect would occur in humans.
- To prevent cancer
A few laboratory studies show that bitter melon extracts can kill certain cancer cells, but it has not been studied in cancer patients.
- To treat type 2 diabetes
A handful of small clinical trials show that bitter melon extracts can lower blood glucose levels, but larger and better-designed clinical trials are needed to fully support this use.
- To reduce fever
No scientific evidence supports this use.
- To treat HIV and AIDS
Preliminary laboratory studies show that bitter melon can slow the ability of HIV to insert its genes into human chromosomes.
- To treat infections
Bitter melon extracts can kill certain viruses on contact in the laboratory, but human data are lacking.
- To relieve menstrual problems
This claim is not backed by research.
A review of three clinical trials was done to find out the antidiabetic effects of bitter melon. Two studies did not find a clinically meaningful difference between bitter melon and placebo. The third study showed bitter melon to be comparable to an antidiabetic drug called glibenclamide. Serious adverse events were not reported in any of the three trials. The authors concluded that there is not enough evidence to recommend bitter melon for type 2 diabetes mellitus. More research is needed.
- The covering on bitter melon seeds (called red arils) are toxic in children, causing vomiting, diarrhea, and death.
Do Not Take If
- You are pregnant (Bitter melon can cause vaginal bleeding, premature contractions, and abortion).
- You are taking insulin (Bitter melon may have additive effects).
- You are taking hypoglycemic medication for diabetes (Bitter melon may have additive effects).
- Low blood sugar
- Liver damage (this has been shown in animals, but not in humans)
- Ingestion of the seeds of bitter melon can cause toxicity to red blood cells, which includes headache, fever, abdominal pain, and coma.
- Reported (Oral): A 22-year-old man experienced atrial fibrillation (rapid irregular heartbeat) following ingestion of bitter melon two days before his admission for his dyspeptic complaints. He ingested crushed bitter melon and drank two tablespoons of its juice three times a day, and on the morning of admission as well. His symptoms improved after administering antiarrhythmic medication.
- Reported (Oral): A 40-year-old man developed acute gastric ulceration following consumption of half a liter of concentrated homemade liquid extract of bitter melon. His symptoms included severe epigastric pain and hematemesis, which were managed with intravenous fluids, blood transfusion and intravenous rabeprazole.
Researchers have not established the correct dosage or long-term effects of bitter melon for treating the high blood glucose levels in diabetes, and therefore it cannot be recommended as a replacement therapy for insulin or hypoglycemic drugs.
Last updated: February 12, 2013