Editor’s Note: Each month, HerbalEGram highlights a conventional or
traditional food and briefly explores its history, traditional uses,
nutritional profile, and modern medicinal research. We also feature a
nutritious recipe for an easy-to-prepare dish with each article to encourage
readers to experience the extensive benefits of these whole foods. With this
series, we hope our readers will gain a new appreciation for the foods they see
at the supermarket and frequently include in their diets.
The basic materials for
this series were compiled by dietetic interns from Texas State University in
San Marcos and the University of Texas at Austin through the American Botanical
Council’s (ABC) Dietetic Internship Program, led by ABC Education Coordinator
Jenny Perez.
By
Hannah Baumana and Brittany Markidesb
a HerbalGram Assistant Editor
b ABC Dietetics Intern (Texas State University, 2015)
History and
Traditional Use
Overview
Bitter
melon (Momordica charantia,
Cucurbitaceae) is a slender-stemmed, warm-climate, herbaceous annual vine. With
palmate, deeply lobed leaves, bitter melon has fragrant yellow flowers and
produces an elongated fruit that is harvested for food when immature.1 The immature fruit has white or
green skin with white flesh, is oblong and pointed at the blossom end, and has
a pebbled texture with smooth, lengthwise ridges; it resembles a small, wrinkly
cucumber (Cucumis sativus,
Cucurbitaceae).2 Chinese varieties of bitter melon
bear fruit that are longer and relatively smooth, while Indian varieties bear
shorter fruit with a more textured skin.3 As the fruits begin to mature,
their bitterness increases and the color gradually turns from green to yellow
or orange. At maturity, the fruit splits open, revealing orange flesh and a
bright red placenta to which the seeds are attached.2
Bitter
melon grows well in wet, tropical areas such as South America, including the
Amazon basin, Brazil, and Guyana; the Caribbean; eastern Africa; and Asian
countries including India, China, the Philippines, Pakistan, Nepal, and Sri
Lanka.4 Domestication of bitter melon began
in eastern Asia, most likely in eastern India or southern China.5 Although early archeological
evidence for the presence of bitter melon in these regions is sparse, Ayurvedic
texts written in Sanskrit from 2000 to 200 BCE mention wild or small-fruited
cultivated forms. In China, the earliest written reference to the fruit dates
back to 1370 CE.
Phytochemicals and Constituents
The
immature bitter melon fruit is a good source of vitamin C and also provides vitamin
A, phosphorus, and iron.6 Bitter melon contains other
phytochemicals including phenolic compounds and flavonoids, cucurbitane-type
triterpenes, and insulin-like peptides.
Triterpenoid
compounds called cucurbitanes, which have cancer chemopreventive properties in
mice, have been identified in Momordica charantia fruit.7 In
vitro tests have shown that these compounds may also inhibit viral infections
such as Epstein-Barr, a virus in the herpes family that causes infectious
mononucleosis (commonly called “mono”).
Historical and Commercial Uses
Bitter
melon is used in traditional medicine practices throughout Asia, Africa, and
Central and South America.1,6 Its primary traditional use is the
regulation of blood glucose in people with diabetes.4*
Bitter
melon has also been traditionally used to relieve gastrointestinal symptoms, to
treat colic, to stimulate menstruation, and as an antiviral for measles and
hepatitis. In Turkish folk medicine, preparations of bitter melon fruit are
used topically to heal wounds and internally to treat peptic ulcers.6 In India, it is used as an
antidiabetic, abortifacient, anti-parasitic, laxative, and contraceptive. It is
also used as a galactagogue (to increase breastmilk flow) and a purgative, and
to treat eczema, malaria, gout, jaundice, abdominal pain, kidney stones, leukorrhea
(vaginal discharge), inflamed hemorrhoids, pneumonia, psoriasis, rheumatism,
fever, and scabies.
The
fruit and seeds are the primary medicinal components of bitter melon; however,
some traditional medicine preparations involve the stem and leaves as well.4 The bitter flavor is considered a
desirable characteristic for medicinal preparations, and domesticated plants
have been selectively bred to produce fruit with a high level of bitterness. Bitter melon dietary supplements
are sold in various forms such as powder, juice, and extracts. Supplement
capsules generally contain extracts made from the fruit, seed, stem, leaf, or some
combination.
Bitter
melon is a popular culinary fruit in Asia.1 The unripe fruits of bitter melon
are cooked alone or with other vegetables, meat, or fruit. They can be stuffed,
stir-fried, or used in small quantities to add bitter flavor to soups and other
preparations.5 Often, the fruits are soaked in salt water or parboiled before cooking in order to reduce the bitter
taste. The fruits also can be pickled or dehydrated. The fruit, flowers, and
young shoots of bitter melon are used as flavoring agents in many Asian dishes.
Young shoots and leaves are cooked and eaten as leafy vegetables, and leaves
and fruit extracts are used to prepare tea. The
unripe fruit often can be purchased in Asian grocery stores for use in culinary
preparations.
Modern Research
The
potential health benefits of bitter melon have been investigated in more than
40 animal studies and human clinical trials. Although the body of literature on
bitter melon presents some conflicting results, many studies support the
traditional use of bitter melon for people with diabetes, as it has been
observed in modern research to have anti-diabetic and anti-inflammatory
actions, aid in the reduction of body fat and visceral adiposity
(intra-abdominal fat), and improve dyslipidemia (abnormal lipid levels) and
hypertension associated with the disease.4,6
In
animal models, bitter melon supplementation has been shown to have
anti-hyperglycemic effects.8-10 Bitter melon is believed to exert
glucose-lowering actions through several mechanisms, such as prevention of
glucose absorption into the blood, enhancement of glucose uptake by peripheral
tissues, and potentiation of insulin.11
Prevention of Glucose Absorption
There
are a variety of glucose transporters in the body, which are expressed in
different tissues, and facilitate the uptake of glucose into these tissues. In
the gastrointestinal tract, one of the glucose transporters is a sodium/potassium
ion pump. Bitter melon juice was observed to inhibit this absorption pathway in
diabetic rats.12 Bitter melon extract also was demonstrated to
inhibit glucose absorption by decreasing the activity of alpha-amylase and
alpha-glucosidase, the primary enzymes responsible for digesting carbohydrate
chains into smaller carbon chains.13
Enhancement of Glucose Uptake
In
individuals with type 2 diabetes mellitus, hyperglycemia is caused, in part, by
a decreased ability of glucose transporters to move glucose from systemic
circulation into peripheral tissues. Bitter melon has been shown to increase
the expression of the primary glucose transporter responsible for transporting
glucose into skeletal muscle cells: glucose transporter type 4 (GLUT4).14
Potentiation
of Insulin
Insulin, which is synthesized in and
released from pancreatic beta-cells, is a vital hormonal regulator of glucose
homeostasis. Type 2 diabetes mellitus is characterized by decreased insulin
function and/or production, which leads to increased serum glucose levels.
Bitter melon was shown to potentiate the actions of insulin by maintaining the
structural integrity of pancreatic beta-cells15 and by increasing insulin
secretion.16,17
Clinical
Trials
Human
trials primarily have investigated the potential of bitter melon as an
antidiabetic treatment. In humans, bitter melon supplementation has been shown
to work synergistically with diabetes medications metformin and glibenclamide,18 decrease incidence of metabolic
syndrome and reduce waist circumference,19 and reduce levels of advanced
glycation end products (AGEs),20 which are the result of sugar
molecules binding to proteins or lipids, a process known as “glycation.” (AGEs play
a role in the development of degenerative diseases, including diabetes.) However,
few of these trials are randomized, double-blind, and placebo-controlled, and
study results from these few trials are conflicting and inconclusive.
Therefore, it would be prudent to conduct additional randomized, placebo-controlled
studies investigating the use of bitter melon among patients with type 2
diabetes mellitus.
Body Fat and Visceral Adiposity
Bitter
melon has been shown to reduce body fat and visceral adiposity in animal
studies via the upregulation of key proteins involved in beta-oxidation and
mitochondrial respiration (mitochondria are the cellular units that provide
energy for each cell in the body). The oxidation of fatty acids allows the body
to use fat cells as fuel rather than allowing them to accumulate.
Fatty
acid oxidation is carried out in the mitochondria within cells.21 Inhibition of long-chain fatty acid
(LCFA) oxidation has been shown to increase fat deposits and insulin resistance
in animals on a high fat diet, while increased expression of the enzymes that
catalyze fatty acid oxidation has been observed to improve lipid-induced
insulin resistance by increasing the mitochondrial fatty acid intake, and
therefore the rate of oxidation, and enhancing insulin sensitivity in muscle
tissue in rats fed a high fat diet.22 Bitter melon supplementation has
been shown to decrease body weight of rats fed a high fat diet by increasing
the expression of oxidative enzymes in liver and muscle cells.23
Dyslipidemia
Dyslipidemia is characterized by abnormal levels of
triglycerides, low-density lipoproteins (LDL), and low levels of high-density
lipoproteins (HDL) in the bloodstream. Dyslipidemia is associated with
development of atherosclerosis (hardening of the arteries) and cardiovascular
disease.
Bitter melon has been shown to lower total
cholesterol, triglycerides, and LDL and increase levels of HDL in rats.24 There are several proposed mechanisms for this action. One of them is
the decreased pancreatic lipase activity observed in rats fed a corn oil-heavy
diet and treated with the saponin fraction of bitter melon.25 Pancreatic lipase is an important enzyme for fat digestion and
absorption. Decreased activity can result in less dietary fat absorbed, which
can lead to decreased serum levels of triglycerides. Bitter melon may also
lower serum lipid levels by decreasing apoB secretion.26 ApoB is one of the protein components of lipoproteins. Elevated levels
of apoB have been correlated with the development of cardiovascular disease.
Hepatoprotective
Effects
Bitter
melon has been observed to protect and enhance liver function, which has been
attributed to its antioxidant capacity to scavenge free radicals.1 Bitter melon supplementation has
been shown to normalize levels of total bilirubin and liver enzymes, while
increasing levels of antioxidants in rats.27,28 In addition to its antioxidant
effects, bitter melon may also protect the liver by reducing fat accumulation
and preventing steatosis (fat accumulation in liver cells).29 Supplementation of bitter melon has
been shown to downregulate fibroblast growth factor (FGF) 21 levels in livers
of mice, which can decrease the risk of developing non-alcoholic fatty liver
disease.30
Consumer Considerations
Bitter
melon is easily cultivated and commonly eaten as a vegetable throughout the
Asian continent and the Pacific Islands region with no serious adverse effects;
however, consumption of large quantities of bitter melon can cause diarrhea and
gastrointestinal upset.31 Consumption of bitter melon is
contraindicated during pregnancy, as bitter melon has been shown to cause
uterine hemorrhage in pregnant rats. As the synergistic effects of bitter melon
with diabetes medications is still not fully understood, patients who take
medication or insulin to manage diabetes should consult their physician before
consuming bitter melon.32
*
While diabetes is a growing problem in modern times, the first mention of it in
the written record occurs in an Egyptian manuscript, the Ebers Papyrus, dated
to approximately 1500 BCE.33 The papyrus is a medical text that describes
a number of ailments, including a mention of a condition that caused “too great
emptying of the urine,” which experts have interpreted as a reference to
diabetes. Indian medical literature from the same time period labeled the
condition “honey urine” and observed the presence of ants attracted to urine
samples. Modern traditional healers in Nigeria still use this diagnostic
technique, in addition to observing the patient’s weight, thirst, and urination
habits.34 The term “diabetes” was coined by Apollonius of Memphis in
230 BCE from the Greek words dia (“through”) and betes (“to go”).33
Nutrient Profile35
Macronutrient Profile: (Per 1 cup 1/2-inch
pieces [approx. 93 g])
87 calories 1 g protein 3.4 g
carbohydrate 0.2 g
fat
Secondary Metabolites: (Per 1 cup 1/2-inch
pieces [approx. 93 g])
Excellent source of: Vitamin
C: 78.1 mg (130.2% DV)
Very good source of: Folate:
67 mcg (16.8% DV) Dietary
Fiber: 2.6 g (10.4% DV)
Good source of: Vitamin
A: 438 IU (8.8% DV) Potassium:
275 mg (7.9% DV) Vitamin
K: 4.8 mcg (6% DV)
Also provides: Magnesium:
16 mg (4% DV) Manganese:
0.08 mg (4% DV) Phosphorus:
29 mg (2.9% DV) Thiamin:
0.04 mg (2.7% DV) Riboflavin:
0.04 mg (2.4% DV) Iron:
0.4 mg (2.2% DV) Vitamin
B6: 0.04 mg (2% DV) Niacin:
0.37 mg (1.9% DV) Calcium:
18 mg (1.8% DV) Vitamin
E: 0.14 mg (1% DV)
DV =
Daily Value as established by the US Food and Drug Administration, based on a
2,000 calorie diet.
Recipe: Bitter
Melon Coconut Curry
Recipe courtesy of
Brittany Markides
Ingredients:
- 4
medium bitter melons
- Kosher
salt
- 1
teaspoon each turmeric and ground cumin
- 1
tablespoon garam masala spice blend
- 1
tablespoon vegetable oil
- 1
medium onion, diced
- 2
cloves garlic, minced
- 1
tablespoon fresh ginger, grated
- 2
jalapeños, stems and seeds removed, chopped finely
- 4
tomatoes, cored and diced
- 1 cup
coconut milk
- Juice
of 1 lime
- Cooked rice, for serving
Directions:
Slice
the melon in half lengthwise, remove the seeds, then slice in 1/2-inch slices.
Combine the turmeric, cumin, and garam masala in a small bowl.
In a
large bowl, salt the melon slices liberally and leave the slices to rest for 20
minutes.
While
the melon rests, bring a saucepan of water to a boil. Add the rested melon
slices and boil for 2 minutes. Both salting and par-boiling help tame the
bitterness of the melon.
Remove
the bitter melon and pat dry. Sprinkle with spice mixture and toss to coat.
In a
medium skillet, heat the oil over medium-high heat until it shimmers. Add the
onion and cook 5-10 minutes, or until translucent but not browned. Lower the
heat to medium, add the garlic, ginger, and jalapeño, and cook until fragrant.
Add
the tomatoes, bitter melon, and coconut milk to the skillet. Bring to a simmer
and cook 10-15 minutes, or until flavors have melded together and the liquid
has thickened slightly.
Remove
from heat and stir in lime juice. Serve over rice.
References
Alam
MA, Uddin R, Subhan N, Rahman MM, Jain P, Reza HM. Beneficial role of bitter melon
supplementation in obesity and related complications in metabolic syndrome. J Lipids. 2015;2015:1-18.
doi:10.1155/2015/496169.
Meyers
C. Specialty and Minor Crops Handbook.
2nd ed. Sacramento, CA: University of California Agriculture & Natural
Resources; 1998:22-24.
Monograph:
Momordica charantia (Bitter melon). Altern Med Rev. December 2007;12(4):360-363.
Singh
J, Cumming E, Manoharan G, Kalasz H, Adeghate E. Medicinal chemistry of the
anti-diabetic effects of Momordica
charantia: active constituents and modes of actions. Open Med Chem J. 2011;5(Suppl 2):70-77.
doi:10.2174/1874104501105010070.
Behera
TJ, Behera S, Bharathi LK. Bitter gourd: Botany, horticulture, breeding. Hortic Rev (Am Soc Hortic Sci).
2010;37:101-141.
Grover
JK, Yadav SP. Pharmacological actions and potential uses of Momordica charantia: A review. J Ethnopharmacol. 2004;93(1):123-132.
doi:10.1016/j.jep.2004.03.035.
Akihisa T, Higo N, Tokuda H, et al.
Cucurbitane-type triterpenoids from the fruits of Momordica charantia and
their cancer chemopreventive effects. Journal of Natural Products. 2007;70(8):1233-1239.
Ojewole JAO, Adewole SO, Olayiwola G. Cardiovascular topics
hypoglycaemic and hypotensive effects of Momordica
charantia Linn (Cucurbitaceae) whole-plant aqueous extract in rats. Cardiovascular Journal of South Africa. 2006;17(5):227-232.
Sridhar MG, Vinayagamoorthi R, Arul Suyambunathan V,
Bobby Z, Selvaraj N. Bitter gourd (Momordica
charantia) improves insulin sensitivity by increasing skeletal muscle
insulin-stimulated IRS-1 tyrosine phosphorylation in high-fat-fed rats. Br J
Nutr. 2008;99:806-812. doi:10.1017/S000711450783176X.
Chaturvedi P, George S. Momordica charantia maintains
normal glucose levels and lipid profiles and prevents oxidative stress in diabetic
rats subjected to chronic sucrose load. J Med Food. 2010;13(3):520-527.
doi:10.1089/jmf.2009.0151.
Chaturvedi P. Antidiabetic
potentials of Momordica charantia:
multiple mechanisms behind the effects. J Med Food. 2012;15(2):101-107.
doi:10.1089/jmf.2010.0258.
Mahomoodally MF, Fakim AG, Subratty AH. Momordica charantia extracts inhibit
uptake of monosaccharide and amino acid across rat everted gut sacs in-vitro. Biol
Pharm Bull. 2004;27(2):216-218.
Ahmad Z, Zamhuri KF, Yaacob A, et al. In vitro
anti-diabetic activities and chemical analysis of polypeptide-k and oil
isolated from seeds of Momordica
charantia (bitter gourd). Molecules. 2012;17(8):9631-9640.
doi:10.3390/molecules17089631.
Shih CC, Lin CH, Lin WL, Wu JB. Momordica charantia extract on insulin resistance and the skeletal
muscle GLUT4 protein in fructose-fed rats. J Ethnopharmacol.
2009;123(1):82-90. doi:10.1016/j.jep.2009.02.039.
Sathishsekar D, Subramanian S. Beneficial effects of Momordica charantia seeds in the
treatment of STZ-induced diabetes in experimental rats. Biol Pharm Bull.
2005;28(6):978-983. doi:10.1248/bpb.28.978.
Yibchok-Anun S, Adisakwattana S, Yao CY, Sangvanich P,
Roengsumran S, Hsu WH. Slow acting protein extract from fruit pulp of Momordica charantia with insulin
secretagogue and insulinomimetic activities. Biol Pharm Bull.
2006;29(6):1126-1131. doi:10.1248/bpb.29.1126.
Keller AC, Ma J, Kavalier A, He K, Brillantes A-MB,
Kennelly EJ. Saponins from the traditional medicinal plant Momordica charantia stimulate insulin secretion in vitro. Phytomedicine.
2011;19(1):32-37. doi:10.1016/j.micinf.2011.07.011.
Tongia A, Tongia S, Dave M. Phytochemical determination
and extraction of Momordica charantia
fruit and its hypoglycemic potentiation of oral hypoglycemic drugs in diabetes
mellitus (NIDDM). Indian J Physiol Pharmacol. 2004;48(2):241-244.
Tsai C-H, Chen EC-F, Tsay H-S, Huang C. Wild bitter
gourd improves metabolic syndrome: a preliminary dietary supplementation trial.
Nutr J. 2012;11(1):4. doi:10.1186/1475-2891-11-4.
Trakoon-osot W, Sotanaphun U, Phanachet P,
Porasuphatana S, Udomsubpayakul U, Komindr S. Pilot study: Hypoglycemic and
antiglycation activities of bitter melon (Momordica
charantia L.) in type 2 diabetic patients. J Pharm Res.
2013;6(8):859-864. doi:10.1016/j.jopr.2013.08.007.
Bonnefont J-P, Djouadi F, Prip-Buus C, Gobin S, Munnich
A, Bastin J. Carnitine palmitoyltransferases 1 and 2: biochemical, molecular
and medical aspects. Mol Aspects Med. 2004;25(5-6):495-520.
doi:10.1016/j.mam.2004.06.004.
Bruce CR, Hoy AJ, Turner N, et al. Overexpression of
carnitine palmitoyltransferase-1 in skeletal muscle is sufficient to enhance
fatty acid oxidation and improve high-fat diet-induced insulin resistance. Diabetes.
2009;58(3):550-558. doi:10.2337/db08-1078.
Chan LLY, Chen Q, Go AGG, Lam EKY, Li ETS. Reduced
adiposity in bitter melon (Momordica
charantia)-fed rats is associated with increased lipid oxidative enzyme
activities and uncoupling protein expression. J Nutr. 2005;135(August):2517-2523.
doi:135/11/2517.
Chaturvedi P, George S, Milinganyo M, Tripathi YB.
Effect of Momordica charantia on lipid
profile and oral glucose tolerance in diabetic rats. Phyther Res.
2004;18(May):954-956.
Oishi Y, Sakamoto T, Udagawa H, et al. Inhibition of increases
in blood glucose and serum neutral fat by Momordica charantia saponin fraction.
Biosci Biotechnol Biochem. 2007;71(3):735-740. doi:10.1271/bbb.60570.
Nerurkar P, Lee YK, Motosue M, Adeli K, Nerurkar VR. Momordica charantia (bitter melon)
reduces plasma apolipoprotein B-100 and increases hepatic insulin receptor
substrate and phosphoinositide-3 kinase interactions. Br J Nutr.
2008;100:751-759.
Ching RHH, Yeung LOY, Tse IMY, Sit W, Li ETS.
Supplementation of bitter melon to rats fed a high-fructose diet during gestation
and lactation ameliorates fructose-induced dyslipidemia and hepatic oxidative stress
in male offspring. J Nutr. 2011;141(9):1664-1672.
doi:10.3945/jn.111.142299.
Thenmozhi JA, Subramanian P. Antioxidant potential of Momordica charantia in ammonium chloride-induced
hyperammonemic rats. Evid Based Complement Alternat Med.
2010;2011(4):1-7. doi:10.1093/ecam/nep227.
Yu Y, Zhang XH, Ebersole B, Ribnicky D, Wang ZQ. Bitter
melon extract attenuating hepatic steatosis may be mediated by FGF21 and
AMPK/Sirt1 signaling in mice. Sci Rep. 2013;3:3142.
doi:10.1038/srep03142.
Morris-Stiff G, Feldstein AE. Fibroblast growth factor
21 as a biomarker for NAFLD: integrating pathobiology into clinical practice. J
Hepatol. 2010;53(5):795-796. doi:10.1016/j.jhep.2010.07.003.
Premila MS, Tyler VM. Ayurvedic Herbs: A Clinical
Guide to the Healing Plants of Traditional Indian Medicine. New York, NY:
Routledge; 2009.
Hudson
T. Bitter Melon: A Review of Its Indications, Efficacy, and Safety. Natural
Dispensary website. Available at: http://cdn.naturaldispensary.com/downloads/A%20Research%20Review%20of%20Bitter%20Melon.pdf.
Accessed September 6, 2016.
Poretsky L. Principles
of Diabetes Mellitus. 2nd ed. New York, NY: Springer Science and Business
Media; 2010.
Abo KA, Fred-Jaiyesimi AA, Jaiyesimi AEA.
Ethnobotanical studies of medicinal plants used in the management of diabetes
mellitus in south western Nigeria. J
Ethno Pharmacol. 2008;115:67-71.
- Basic report: 11024, Balsam-pear
(bitter gourd), pods, raw. USDA Agricultural Research Service website.
Available at: http://ndb.nal.usda.gov/ndb/foods/show/2832. Accessed August 11,
2016.
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