Bitter melon

Bitter melon
Scientific classification
Kingdom: Plantae
Division: Magnoliophyta
Class: Magnoliopsida
Order: Cucurbitales
Family: Cucurbitaceae
Genus: Momordica
Species: M. charantia
Binomial name
Momordica charantia
Descourt.

Momordica charantia is a tropical and subtropical vine of the family Cucurbitaceae, widely grown for edible fruit, which is among the most bitter of all fruits. Names for the plant and its fruit include bitter melon, bitter gourd (translated from Chinese: 苦瓜; pinyin: kǔguā), goya (ゴーヤー?) from an Okinawan language or Karela/Karella in India, ampalayá from Tagalog, and cerasee[1] (Caribbean and South America; also spelled cerasse).

The original home of the species is not known, other than that it is a native of the tropics. It is widely grown in India and other parts of the Indian subcontinent, Southeast Asia, China, Africa, and the Caribbean.

Contents

Description

China phenotype bitter melons
Sub-continent phenotype bitter melon
Ripe fruit

The herbaceous, tendril-bearing vine grows to 5 m. It bears simple, alternate leaves 4–12 cm across, with 3–7 deeply separated lobes. Each plant bears separate yellow male and female flowers.

The fruit has a distinct warty looking exterior and an oblong shape. It is hollow in cross-section, with a relatively thin layer of flesh surrounding a central seed cavity filled with large flat seeds and pith. Seeds and pith appear white in unripe fruits, ripening to red; they are not intensely bitter and can be removed before cooking. However, the pith will become sweet when the fruit is fully ripe, and the pith's color will turn red. The pith can be eaten uncooked in this state, but the flesh of the melon will be far too tough to be eaten anymore. Red and sweet bitter melon pith is a popular ingredient in some southeast Asian salads. The flesh is crunchy and watery in texture, similar to cucumber, chayote or green bell pepper. The skin is tender and edible. The fruit is most often eaten green. Although it can also be eaten when it has started to ripen and turn yellowish, it becomes more bitter as it ripens. The fully ripe fruit turns orange and mushy, is too bitter to eat, and splits into segments which curl back dramatically to expose seeds covered in bright red pulp.

Bitter melon comes in a variety of shapes and sizes. The typical Chinese phenotype is 20–30 cm long, oblong with bluntly tapering ends and pale green in color, with a gently undulating, warty surface. The bitter melon more typical of India has a narrower shape with pointed ends, and a surface covered with jagged, triangular "teeth" and ridges. Coloration is green or white. Between these two extremes are any number of intermediate forms. Some bear miniature fruit of only 6–10 cm in length, which may be served individually as stuffed vegetables. These miniature fruit are popular in Southeast Asia as well as India.

Bitter melon contains a bitter compound called momordicin that is said to have a stomachic effect.

Culinary uses

A small green bitter melon (front) and a scoop of Okinawan gōyā chanpurū stirfry (back)
Bitter gourd (boiled, drained, no salt)
Nutritional value per 100 g (3.5 oz)
Energy 79 kJ (19 kcal)
Carbohydrates 4.32 g
Sugars 1.95 g
Dietary fiber 2.0 g
Fat 0.18 g
saturated 0.014 g
monounsaturated 0.033 g
polyunsaturated 0.078 g
Protein 0.84 g
Water 93.95 g
Vitamin A equiv. 6 μg (1%)
Thiamine (Vit. B1) 0.051 mg (4%)
Riboflavin (Vit. B2) 0.053 mg (4%)
Niacin (Vit. B3) 0.280 mg (2%)
Vitamin B6 0.041 mg (3%)
Folate (Vit. B9) 51 μg (13%)
Vitamin B12 0 μg (0%)
Vitamin C 33.0 mg (55%)
Vitamin E 0.14 mg (1%)
Vitamin K 4.8 μg (5%)
Calcium 9 mg (1%)
Iron 0.38 mg (3%)
Magnesium 16 mg (4%)
Phosphorus 36 mg (5%)
Potassium 319 mg (7%)
Sodium 6 mg (0%)
Zinc 0.77 mg (8%)
Percentages are relative to US recommendations for adults.
Source: USDA Nutrient database
A soft drink made from bitter melon, with a bitter melon mascot
An Indonesian-style bitter melon dish, cooked with sambal, onion, and red bird's-eye chili peppers

Medicinal uses

Bitter melons being fried in Kaohsiung, Taiwan.

Bitter melon has been used in various Asian traditional medicine systems for a long time.[2] Like most bitter-tasting foods, bitter melon stimulates digestion. While this can be helpful in people with sluggish digestion, dyspepsia, and constipation, it can sometimes make heartburn and ulcers worse. The fact that bitter melon is also a demulcent and at least mild inflammation modulator, however, means that it rarely does have these negative effects, based on clinical experience and traditional reports.

Though it has been claimed that bitter melon's bitterness comes from quinine, no evidence supports this claim. Bitter melon is traditionally regarded by Asians, as well as Panamanians and Colombians, as useful for preventing and treating malaria. Laboratory studies have confirmed that various species of bitter melon have anti-malarial activity, though human studies have not yet been published.[3]

In Panama bitter melon is known as Balsamino. The pods are smaller and bright orange when ripe with very sweet red seeds, but only the leaves of the plant are brewed in hot water to create a tea to treat malaria and diabetes. The leaves are allowed to steep in hot water before being strained thoroughly so that only the remaining liquid is used for the tea.

Laboratory tests suggest that compounds in bitter melon might be effective for treating HIV infection.[4] As most compounds isolated from bitter melon that impact HIV have either been proteins or glycoproteins lectins, neither of which are well-absorbed, it is unlikely that oral intake of bitter melon will slow HIV in infected people. It is possible oral ingestion of bitter melon could offset negative effects of anti-HIV drugs, if a test tube study can be shown to be applicable to people.[5] In one preliminary clinical trial, an enema form of a bitter melon extract showed some benefits in people infected with HIV (Zhang 1992). Clearly more research is necessary before this could be recommended.

The other realm showing the most promise related to bitter melon is as an immunomodulator. One clinical trial found very limited evidence that bitter melon might improve immune cell function in people with cancer, but this needs to be verified and amplified in other research. If proven correct this is another way bitter melon could help people infected with HIV.

Folk wisdom has it that bitter melon helps to prevent or counteract type-II diabetes. A recent scientific study at the Jawaharlal Institute of Postgraduate Medical Education and Research, India, has proved that bitter melon increases insulin sensitivity.[6] Also, in 2007, the Philippine Department of Health issued a circular stating that bitter melon, as a scientifically validated herbal medicinal plant, can lower elevated blood sugar levels. The study revealed that a 100 milligram per kilo dose per day is comparable to 2.5 milligrams of the anti-diabetes drug Glibenclamide taken twice per day.[7] Bitter melon is sold in the Philippines as a food supplement and marketed under the trade name Charantia. Charantia capsules and tea are being exported to the United States, Canada, Europe, Mexico, Japan, Korea, and parts of the Middle East.[7]

Bitter melon transformed into capsule form and sold as a food supplement.

Bitter Melon contains four very promising bioactive compounds. These compounds activate a protein called AMPK, which is well known for regulating fuel metabolism and enabling glucose uptake, processes which are impaired in diabetics. "We can now understand at a molecular level why bitter melon works as a treatment for diabetes," said David James, director of the diabetes and obesity program at the Garvan Institute of Medical Research in Sydney. "By isolating the compounds we believe to be therapeutic, we can investigate how they work together in our cells."[8][9][10][11] [12] [13]

Bitter melon contains a lectin that has insulin-like activity. The insulin-like bioactivity of this lectin is due to its linking together 2 insulin receptors. This lectin lowers blood glucose concentrations by acting on peripheral tissues and, similar to insulin's effects in the brain, suppressing appetite. This lectin is likely a major contributor to the hypoglycemic effect that develops after eating bitter melon and why it may be a way of managing adult-onset diabetes. Lectin binding is non-protein specific, and this is likely why bitter melon has been credited with immunostimulatory activity - by linking receptors that modulate the immune system, thereby stimulating said receptors.

Various cautions are indicated. The seeds contains vicine and therefore can trigger symptoms of favism in susceptible individuals. In addition, the red arils of the seeds are reported to be toxic to children, and the fruit is contraindicated during pregnancy.[14]

Consuming bitter melon juice has proved to be dangerous at least in one case. In India, a 60 year old man died after consuming bitter melon juice.[15].This raises the question whether the death was due to excessive amount of the juice or was due to consuming bitter melon in empty stomach. The article also says that there are some parts of the bitter melon that can be harmful when consumed uncooked.

See also

Multilingual list of Indian Vegetables, spices & grains

Gallery

References

  1. Drugs.com: Bitter Melon
  2. Grover JK, Yadav SP (July 2004). "Pharmacological actions and potential uses of Momordica charantia: a review". J Ethnopharmacol 93 (1): 123–32. doi:10.1016/j.jep.2004.03.035. PMID 15182917. http://linkinghub.elsevier.com/retrieve/pii/S037887410400159X. 
  3. Waako PJ, Gumede B, Smith P, Folb PI (May 2005). "The in vitro and in vivo antimalarial activity of Cardiospermum halicacabum L. and Momordica foetida Schumch. Et Thonn". J Ethnopharmacol 99 (1): 137–43. doi:10.1016/j.jep.2005.02.017. PMID 15848033. http://linkinghub.elsevier.com/retrieve/pii/S0378-8741(05)00169-8. 
  4. Jiratchariyakul W, Wiwat C, Vongsakul M, et al. (June 2001). "HIV inhibitor from Thai bitter gourd". Planta Med. 67 (4): 350–3. doi:10.1055/s-2001-14323. PMID 11458453. http://www.thieme-connect.com/DOI/DOI?10.1055/s-2001-14323. 
  5. Nerurkar PV, Lee YK, Linden EH, et al. (August 2006). "Lipid lowering effects of Momordica charantia (Bitter Melon) in HIV-1-protease inhibitor-treated human hepatoma cells, HepG2". Br. J. Pharmacol. 148 (8): 1156–64. doi:10.1038/sj.bjp.070682110.1038/sj.bjp.0706821. PMID 16847441. 
  6. Sridhar MG, Vinayagamoorthi R, Arul Suyambunathan V, Bobby Z, Selvaraj N (2008-04-01). "Bitter gourd ( Momordica charantia) improves insulin sensitivity by increasing skeletal muscle insulin-stimulated IRS-1 tyrosine phosphorylation in high-fat-fed rats". British Journal of Nutrition 99 (04): 806. doi:10.1017/S000711450783176X. http://journals.cambridge.org/article_S000711450783176X. 
  7. 7.0 7.1 http://www.gmanews.tv/story/35962/Ampalaya-tablets-out-soon-for-diabetics
  8. http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6VRP-4S3PX1T-F&_user=1730128&_coverDate=03%2F21%2F2008&_rdoc=13&_fmt=summary&_orig=browse&_srch=doc-info(%23toc%236240%232008%23999849996%23683673%23FLA%23display%23Volume)&_cdi=6240&_sort=d&_docanchor=&_ct=16&_acct=C000054345&_version=1&_urlVersion=0&_userid=1730128&md5=f22536d9e1bb29082e6da6bba59eb127
  9. Rao BK, Kesavulu MM, Giri R, Appa Rao C (October 1999). "Antidiabetic and hypolipidemic effects of Momordica cymbalaria Hook. fruit powder in alloxan-diabetic rats". J Ethnopharmacol 67 (1): 103–9. doi:10.1016/S0378-8741(99)00004-5. PMID 10616966. 
  10. Virdi J, Sivakami S, Shahani S, Suthar AC, Banavalikar MM, Biyani MK. (September 2003). "Antihyperglycemic effects of three extracts from Momordica charantia". J Ethnopharmacol 88 (1): 107–11. doi:10.1016/S0378-8741(03)00184-3. PMID 12902059. 
  11. Shetty AK, Kumar GS, Sambaiah K, Salimath PV (September 2005). "Effect of bitter gourd (Momordica charantia) on glycaemic status in streptozotocin induced diabetic rats". Plant Foods Hum Nutr. 60 (3): 109–12. doi:10.1007/s11130-005-6837-x. PMID 16187012. 
  12. Krawinkel MB, Keding GB (July 2006). "Bitter gourd (Momordica Charantia): A dietary approach to hyperglycemia". Nutr Rev. 64 (7 Pt 1): 331–7. PMID 16910221. 
  13. Miura T, Itoh C, Iwamoto N, Kato M, Kawai M, Park SR, Suzuki I (October 2001). "Hypoglycemic activity of the fruit of the Momordica charantia in type 2 diabetic mice". J Nutr Sci Vitaminol (Tokyo) 47 (5): 340–4. PMID 11814149. 
  14. "About Herbs: Bitter Melon". Memorial Sloan-Kettering Cancer Center. http://www.mskcc.org/mskcc/html/69138.cfm. Retrieved 2007-12-27. 
  15. "Man dies after drinking bitter melon juice". The Times of India. http://timesofindia.indiatimes.com/City/Delhi/Man-dies-after-drinking-lauki-juice-/articleshow/6149952.cms. Retrieved 2010-7-10. 

External links