Author: Anthony Russano Last Edited: April 2nd 2019, 11:52:04 PM

Bitter Melon or Bitter cucumber (also known as the balsam pear, bitter gourd, and karela) is the fruit of the Momordica charantia plant. It is a part of the gourd family (Cucurbitaceae), which includes melon, pumpkin, squash, and cucumber.

The fruit has a distinct warty 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. The fruit is most often eaten green, or as it is beginning to turn yellow. At this stage, the fruit's flesh is crunchy and watery in texture, similar to cucumber, chayote or green bell pepper, but bitter. The skin is tender and edible. Seeds and pith appear white in unripe fruits; they are not intensely bitter and can be removed before cooking.

Composition

Bitter Melon contains a number of chemical compounds including nutritionally important vitamins and minerals, antioxidants, and many other phytochemicals,that include: saponins, phenolic constituents, glycosides, fixed oils, alkaloids, resins, reducing sugars, and free acids.

  • Bitter Melon is a good source of vitamins A and C, iron, phosphorus, proteins, fibers, carbohydrates, zinc, calcium, and magnesium.[1]
  • The pulp around the seeds of the mature Bitter Melon is rich in the carotenoid lycopene.[1]

Healing Properties

  • Antibacterial: (antibiotic)
  • Anti-inflammatory: Purified compounds from the bitter melon fruit showed significant anti-inflammatory activity.[2]
  • Immunomodulator: Bitter melon is known to interact with immune cells. Multiplestudies have shown that various extracts of MC can act asimmunomodulators and, hence, can also act as anti-inflammatory agents.[1]
  • Antiviral:
  • Antidiabetic: Different mechanisms contribute to the antidiabetic activities of M. charantia, these include increasing pancreatic insulin secretion, decreasing insulin resistance and increasing peripheral and skeletal muscle cell glucose utilization, inhibition of intestinal glucose absorption and suppressing of key enzymes in the gluconeogenic pathways.[3]
    • Glucose Regulation: Momordica charantia is a plant‐based medicine used for improving glycemic control.[3]
    • Glucose Tolerance: Bitter Melon has been used to improve glucose tolerance.[3]
    • Hypoglycemic: The insulin‐like peptide, charantin, and the alkaloid vicine are two compounds which have been derived from the bitter melon plant, both have been reported to have hypoglycemic effects.[3]
  • Exercise & Training: Bitter Mellon Improves running endurance.
  • Increases mitochondrial content in gastrocnemius muscle (the gastrocnemius forms half of the calf muscle. Its function is plantar flexing the foot at the ankle joint and flexing the leg at the knee joint.).[4]
  • Improved endurance capacity via stimulation of mitochondrial biogenesis and function, potentially influencing muscle metabolism and fiber-type composition.[4]
  • Anticancer: Momordica charantia L. (Cucurbitaceae) extract has been demonstrated to play a role in oncogenesis, and accumulated evidence has evaluated its anticancer effects, such as anti-proliferation and anti-migration activity.[5]
    • Isolated cucurbitane triterpenoids and their glycosides have been reported to have significant anticancer and antitumor activity.[2]

Disease / Symptom Treatment

  • Diabetes: Various in vitro and in vivo studies have indicated that extracts of bitter melons have anti-diabetic properties.[2] The anti-diabetic activity of bitter melon has been related to various triterpenoids.[2]
    • Carbohydrate Digestion: Compounds which were isolated from the bitter melon fruit exhibit significant inhibition of α-amylase and α-glucosidase, glucosidases required for starch digestion. The overall effect of inhibition is to help reduce the flow of glucose from complex dietary carbohydrates into the bloodstream, diminishing the postprandial effect of starch consumption on blood glucose levels. The effects exhibited by these compounds were comparable to acarbose (an anti-diabetic drug used to treat diabetes mellitus type 2 and, in some countries, prediabetes).[2]

Adverse Effects

  • Sex-related variations in responses to dietary supplementation (aimed at combating metabolic syndrome): Dietary intake of Bitter Melon supplements was tested for its ability to ameliorate obesity-induced insulin resistance and metabolic inflexibility on mice challenged with a high-fat diet. Bitter melon supplementation was shown to evoke a divergent, and generally less favorable, set of metabolic responses in females compared to males.[6]

Sources:

  1. Study Type: Review
    Title: Bitter Melon as a Therapy for Diabetes, Inflammation, and Cancer: a Panacea?
    Author(s): Deep Kwatra, Prasad Dandawate, Subhash Padhye, Shrikant Anant
    Institution(s): Department of Surgery, University of Kansas Medical Center, Kansas City, USA; The University of Kansas Cancer Center, University of Kansas Medical Center, Kansas City, USA; Interdisciplinary Science and Technology Research Academy, Abeda Inamdar College University of Pune, Pune, India
    Publication: Current Pharmacology Reports
    Date: January 2016
    Abstract: Natural products have been used for centuries for cures prevention, treatment, and cure of multiple diseases. Some dietary agents are present in multiple systems of medicines as proposed treatments for chronic and difficult to treat diseases. Once such natural product is Momordica charantia or bitter melon. Bitter melon is cultivated in multiple regions across the world, and various parts of the plant, such as fruit, leaves seed, etc. have been shown to possess medicinal properties in ancient literature. Over the last few decades, multiple well-structured scientific studies have been performed to study the effects of bitter melon in various diseases. Some of the properties for which bitter melon has been studied include: antioxidant, antidiabetic, anticancer, anti-inflammatory, antibacterial, antifungal, antiviral, anti-HIV, anthelmintic, hypotensive, anti-obesity, immuno-modulatory, antihyperlipidemic, hepato-protective, and neuro-protective activities. This review attempts to summarize the various literature findings regarding medicinal properties of bitter melon. With such strong scientific support on so many medicinal claims, bitter melon comes close to being considered a panacea.
    Link: Source
    Citations:

  2. Study Type: Human Study: In Vitro, In Silico
    Title: Cucurbitane-type compounds from Momordica charantia : Isolation, in vitro antidiabetic, anti-inflammatory activities and in silico modeling approaches
    Author(s): Siddanagouda R.S, Wilmer H. Perera, Jose L Perez, Giridhar Athrey, Yuxiang Sun, G.K. Jayaprakasha, Bhimanagouda S. Patil
    Institution(s): Vegetable and Fruit Improvement Center, Department of Horticultural Sciences, Texas A&M University, 1500 Research Parkway, Suite A120, College Station, TX 77845; Department of Poultry Science, Texas A&M University, College Station, TX 77845; Department of Nutrition and Food Sciences, Texas A&M University, College Station, TX 77843
    Publication: Bioorganic Chemistry
    Date: January 2019
    Abstract: Momordica charantia L., commonly known as bitter melon, belongs to the Cucurbitaceae family. Various in vitro and in vivo studies have indicated that extracts of bitter melons have anti-diabetic properties. However, very little is known about the specific purified compounds responsible for these antidiabetic properties. In the present study, 3β,7β,25-trihydroxycucurbita-5,23(E)-dien-19-al, charantal, charantoside XI, and 25ξ-isopropenylchole-5, 6-ene-3-O-D-glucopyranoside were isolated from bitter melon fruit. The structures of the purified compounds were elucidated by HR-ESIMS, 1D, and 2D NMR experiments. All compounds exhibited significant inhibition of α-amylase and α- glucosidase comparable to acarbose. Molecular docking studies demonstrated that purified compounds were able to bind to the active sites of proteins. Additionally, the purified compounds showed significant anti-inflammatory activity, downregulating the expression of NF-κB, INOS, IL-6, IL-1β, TNF-α, and Cox-2 in lipopolysaccharide-activated macrophage RAW264.7 cells. Our findings suggest that the purified compounds have potential anti-diabetic and anti-inflammatory activities and therefore hold promise for the development of plant-based treatments for diabetic and inflammatory conditions.
    Link: Source
    Citations:

  3. Study Type: Review
    Title: Possible molecular mechanisms of glucose‐lowering activities of Momordica charantia(karela) in diabetes
    Author(s): Naseh Pahlavani, Fatemeh Roudi, Mohsen Zakerian, Gordon A Ferns, Jamshid Gholizadeh Navashenaq, Amir Mashkouri, Majid Ghayour‐Mobarhan, Hamidreza Rahimi
    Institution(s): Students Research Committee, Mashhad University of Medical Sciences, Mashhad, Iran; Department of Nutrition, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran; Department of Persian Medicine, School of Persian and Complementary Medicine, Mashhad University of Medical Sciences, Mashhad, Iran; Brighton & Sussex Medical School, Division of Medical Education, Brighton, Sussex, UK; Immunology Research Center, Mashhad University of Medical Sciences, Mashhad, Iran; Students Research Committee, Imam Reza International University, Mashhad, Iran; Cardiovascular Research Center, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran; Department of Modern Sciences and Technology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran; Neurogenic Inflammation Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
    Publication: Journal of Cellular Biochemistry
    Date: December 2018
    Abstract: Diabetes mellitus is a highly prevalent metabolic disorder which is characterized by impaired glucose tolerance, with a relative or absolute insulin deficiency and profound changes in the metabolism of macronutrients. Traditional and complementary medicine is therapeutic strategies that have both been applied to improving glycemic control. Momordica charantia is one of the plant‐based, folk medicines that used for improving glycemic control. We aimed to review, the effects of M. charantia on blood glucose with a clarification of the molecular pathways involved. Of the compounds derived from the plants, the insulin‐like peptide, charantin, and the alkaloid vicine, have been reported to have hypoglycemic effects. Different mechanisms contribute to the antidiabetic activities of M. charantia, these include increasing pancreatic insulin secretion, decreasing insulin resistance and increasing peripheral and skeletal muscle cell glucose utilization, inhibition of intestinal glucose absorption and suppressing of key enzymes in the gluconeogenic pathways.
    Link: Source
    Citations:

  4. Study Type: Animal Study
    Title: Bitter melon seed oil increases mitochondrial content in gastrocnemius muscle and improves running endurance in sedentary C57BL/6 J mice
    Author(s): Fei Koon Chana, Chin Hsub, Tsai-Chung Lic, d, Wen-Hung Chene, Kuo-Tang Tsenge, Pei-Min Chao
    Institution(s): Department of Nutrition, China Medical University, Taichung, Taiwan, Department of Exercise Health Science, National Taiwan University of Sport, Taichung City, Taiwan, Department of Public Health, College of Public Health, China Medical University, Taichung, Taiwan, Department of Healthcare Administration, College of Medical and Health Science, Asia University, Taichung, Taiwan, Aquavan Technology Co., Ltd., Taipei City, Taiwan
    Publication: The Journal of Nutritional Biochemistry
    Date: 6 June 2018
    Abstract: The α-eleostearic acid (α-ESA) in bitter melon seed oil (BMSO) is efficiently converted by the body into rumenic acid. The objective of this study was to investigate effects of BMSO on skeletal muscle fiber-type switch and endurance capacity in mice, with or without exercise training. In a 3 x 2 factorial design, C57BL/6 J mice were fed a 30% high-fat diet composed of soybean oil, butter or a 1:1 mixture of BMSO and soybean oil, i.e. SB, BT and BM diets respectively and were allocated to be sedentary or undergo exercise (Ex). The Ex groups received a 15-min training regimen on a motorized treadmill 5 times a week. After 3-wk intervention, endurance capacity was evaluated (total running time and distance until exhaustion). Mice fed a BM diet had significantly less body fat, with increased muscle percentage and improved endurance capacity. Combining sedentary and Ex groups, mice fed a BM diet ran 33% longer and 50% further than those fed SB, or 25% longer and 36% further than those fed BT (P<.01). The BM diet-increased gastrocnemius cytochrome c protein and mitochondrial DNA content was more prominent in sedentary than in trained mice. Histochemical staining shows sedentary BM-fed mice had a higher succinate dehydrogenase activity among groups. Based on a reporter assay, rumenic acid, rather than α-ESA itself, activated PPARδ ligand binding domain. We concluded that BMSO, improved endurance capacity via stimulation of mitochondrial biogenesis and function, potentially influencing muscle metabolism and fiber-type composition in sedentary mice.
    Link: https://doi.org/10.1016/j.jnutbio.2018.05.008
    Citations:

  5. Study Type: Human Study: In Vitro
    Title: Structural characterization of Momordica charantia L. (Cucurbitaceae) oligopeptides and the detection of their capability in non-small cell lung cancer A549 cells: induction of apoptosis
    Author(s): Jiao Dong, Xianxin Zhang, Chunxiao Qu, Xuedong Rong, Jie Liu, and Yiqing Qu
    Institution(s): Department of Respiratory Medicine, Qilu Hospital of Shandong University, Jinan, Shandong 250012, China.; Department of Respiratory Medicine, Shandong Provincial Chest Hospital, Jinan, 250013, China; The Research Center of Allergy & Immunology, Shenzhen University School of Medicine, Shenzhen, 518060, China.
    Publication: The Royal Society of Chemistry
    Date: March 2019
    Abstract: Oligopeptides are rarely reported from Chinese herbal medicine because they are often present in very low concentrations in a complex matrix. Twenty-eight oligopeptides were recently identified by high-performance liquid chromatography and quadrupole-time-of-flight-mass spectrometry (HPLC-Q-TOF-MS) from Momordica charantia L. (Cucurbitaceae), and a septapeptide, FHGKGHE (Phe-His-Gly-Lys-Gly-His-Glu), named MCLO-12, showed the best anticancer activity against the non-small cell lung cancer A549 cell line in vitro, with an IC50 value of 21.4 ± 2.21 mM. The anti-proliferative activity assay results showed that MCLO-12 induced apoptosis of A549 cells in a concentration-dependent manner. Treatment of the cells with MCLO-12 (10.7–42.8 mM mL−1) caused strong intracellular reactive oxygen species (ROS) up-regulating activities and activated caspase expression. MCLO-12 also suppressed the Trx system and subsequently activated a number of Trx-dependent pathways, including the ASK1, MAPK-p38 and JNK pathways. Thus, our research provides a good reference point for anti-NSCLC research into oligopeptides.
    Link: Source
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  6. Study Type: Animal Study
    Title: Potential adverse effects of botanical supplementation in high-fat-fed female mice
    Author(s): Scott Fuller, Yongmei Yu, Tamra Mendoza, David M. Ribnicky, William T. Cefalu, Z. Elizabeth Floyd
    Institution(s): Pennington Biomedical Research Center Louisiana State University System Baton Rouge USA; School of Kinesiology University of Louisiana at Lafayette Lafayette USA; Biotech Center Rutgers University New Brunswick USA
    Publication: Biology of Sex Differences
    Date: September 2018
    Abstract: Background: Insulin resistance underlies metabolic syndrome and is associated with excess adiposity and visceral fat accumulation, which is more frequently observed in males than females. However, in young females, the prevalence of metabolic syndrome is rising, mainly driven by accumulation of abdominal visceral fat. The degree to which sex-related differences could influence the development of insulin resistance remains unclear, and studies of potential therapeutic strategies to combat metabolic syndrome using rodent models have focused predominantly on males. We therefore evaluated the effects of two nutritional supplements derived from botanical sources, an extract of Artemisia dracunculus L. (termed PMI5011) and Momordica charantia (commonly known as bitter melon), on female mice challenged with a high-fat diet in order to determine if dietary intake of these supplements could ameliorate obesity-induced insulin resistance and metabolic inflexibility in skeletal muscle. Methods: Body composition, physical activity and energy expenditure, fatty acid oxidation, insulin signaling, and gene and protein expression of factors controlling lipid metabolism and ectopic lipid accumulation were evaluated in female mice fed a high-fat diet supplemented with either PMI5011 or bitter melon. Statistical significance was assessed by unpaired two-tailed t test and repeated measures ANOVA. Results: PMI5011 supplementation resulted in increased body weight and adiposity, while bitter melon did not induce changes in these parameters. Pyruvate tolerance testing indicated that both supplements increased hepatic glucose production. Both supplements induced a significant suppression in fatty acid oxidation in skeletal muscle homogenates treated with pyruvate, indicating enhanced metabolic flexibility. PMI5011 reduced lipid accumulation in skeletal muscle, while bitter melon induced a downward trend in lipid accumulation in the skeletal muscle and liver. This was accompanied by transcriptional regulation of autophagic genes by bitter melon in the liver. Conclusions: Data from the current study indicates that dietary supplementation with PMI5011 and bitter melon evokes a divergent, and generally less favorable, set of metabolic responses in female mice compared to effects previously observed in males. Our findings underscore the importance of considering sex-related variations in responses to dietary supplementation aimed at combating metabolic syndrome.
    Link: Source
    Citations: