Bitter melon, categorized as a superior food in the ancient Chinese text 'Divine Farmer’s Materia Medica,' has been used for thousands of years for its medicinal properties. It contains over 225 bioactive compounds that contribute to various health benefits, particularly its antidiabetic effects through mechanisms involving insulin release and glucose regulation. Clinical research on its efficacy for conditions like diabetes and obesity remains inconclusive, highlighting the need for further investigation while it continues to be consumed as a nutritious food.

1. BITTER MELON
IS
A SUPERIOR FOOD
By
Kevin KF Ng, MD, PhD.
Former Associate Professor of Medicine
Division of Clinical Pharmacology
University of Miami, Miami, FL.,USA
Email: kevinng68@gmail.com
A Slide Presentation for HealthCare Providers Aug 2022

2. Presentation Outline
▪ The origin of bitter melon as medicine.
▪ What is bitter melon?
▪ Nutrient composition of bitter melon.
▪ Bioactive compounds.
▪ Mechanism of antidiabetic property.
▪ Preclinical studies.
▪ Clinical studies.
▪ Safety issues.
▪ Summary.
“Good medicine tastes bitter.”
Chinese proverb

3. Origin of the Divine Farmer’s Materia Medica
(Shen Nong Ben Cao Jin, 200-250 AD)
• Legend states that Shen Nong, the Divine Farmer
tasted 365 herbs and documented his findings.
• However, the original text was lost.
• 2,000 years later, his notes were compiled into a book
called Shen Nong Ben Cao Jin now known as the
Divine Farmer’s Materia Medica.
• There are three volumes in the Materia Medica:
https://uprootinglyme.com/cannabis-beneficial-lyme-disease-look-history-reveals-truth/shen-nong/
Shen Nong (ca 2695 BC))

4. Three volumes of “herbs” were graded in
Shen Nong Ben Cao Jin,
the Divine Farmer’s Materia Medica (200-250 AD)
©DRKEVINNG
Shen Nong (Divine Farmer) Divine Farmer’s Materia Medica

5. Sub-classification of Herbs in The Divine Farmer's Materia Medica:
Shen Nong Ben Cao Jin (200-250 AD)
©DRKEVINNG
Divine Farmer’s Materia Medica

6. Bitter melon is classified as a superior food in
Shen Nong Ben Cao Jin (200-250 AD)
Bitter melon
©DRKEVINNG
Divine Farmer’s Materia Medica

7. • WHAT IS A BITTER MELON
• GLOBAL DISTRIBUTION
• NUTRIENT COMPOSITION
• SCIENTIFIC CLASSIFICATION

8. What is bitter melon?
▪ Bitter melon originated in India and spread to China in the 14th Century,
▪ Bitter melon is a tropical and subtropical vine of the family Cucurbitaceae,
widely grown in Asia, Africa, and the Caribbean for its edible fruit.
▪ Bitter melon has many other names
▪ bitter apple
▪ bitter gourd
▪ bitter squash
▪ balsam-pear
https://en.wikipedia.org/wiki/Momordica_charantia

9. Global distribution (dark red color) of bitter melon (Momordica charantia)
https://www.cabi.org/isc/datasheet/34678#toDistributionMaps

10. Scientific classification of bitter melon
https://en.wikipedia.org/wiki/Momordica_charantia

11. Number of publications “bitter melon” in PubMed from
1962 to 2021
https://pubmed.ncbi.nlm.nih.gov/?term=bitter+melon
bitter melon

12. • NUTRIENT COMPOSITION
• BIOACTIVE COMPOUNDS
• GRADING OF BITTERNESS
• ANTIDIABETIC COMPOUNDS

13. Nutrient composition of bitter melon (2018)

14. Proximate constituents and nutrient composition (per 100 g) of
bitter gourd (Momordica charantia L.) fruits (2015)
International Journal of Pharmacology 11 (5): 405-413, 2015
Macronutrients
Minerals
Vitamins

15. Phytochemical composition of bitter melon (2018)

16. Grading of bitterness of M. charantia species (2016)
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC527671
1/

17. Antidiabetic compounds of Momordica charantia (bitter melon)
There are more than 220 phytochemical
compounds in a bitter melon.
The main antidiabetic compounds are:
▪ Alkaloid (momordin)
▪ polypeptide-p (insulin-like)
▪ steroids
▪ lipids
▪ phenolic acids
▪ triterpenes
▪ cucurbitane-type triterpenoids
▪ No study has been done to compare the potency
of individual antidiabetic compound.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4027280/#:~:t
ext=Phytochemistry,been%20isolated%20from%20the%20M.

18. Chemical structures of momordicin and charantin
2 widely studied antidiabetic compounds (2019)
https://www.actascientific.com/ASPS/pdf/ASPS-03-0246.pdf
Bitter momordin
Tasteless charantin
alkaloid
Cucurbitane type triterpenoid

19. BITTER TASTE RECEPTORS

20. Classification of Taste Receptors (2016)
https://link.springer.com/referenceworkentry/10.1007/978-1-4614-6438-9_101498-1

21. Family of bitter taste receptors (TAS2R)
https://www.mdpi.com/1422-0067/21/14/5156/htm
25 bitter taste receptors

22. Extraoral bitter taste receptors
©DRKEVINNG

23. Location of bitter taste receptors in enteroendocrine cells
in the intestine(2021)
Bitter taste receptors
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8224828/

24. Nutrient sensing by enteroendocrine cells (2009)
Adapted from https://www.researchgate.net/figure/Nutrient-sensing-by-
enteroendocrine-cells-Luminal-nutrients-can-act-by-1-of-3-pathways_fig1_244950059
Bitter melon
Peptide YY (PYY) is a 36-amino-acid gut hormone released by
L cells of the ileum/colon in proportion to ingested calories.

25. Action of GLP-1(glucagon-like peptide-1)
on the pancreas
GLP-1
(glucagon-like peptide-1
Glucagon

26. M. charantia induces the secretion of insulin from the β-cell of the islet of Langerhans in
the pancreas. The released insulin recruits GLUT-4 transporters which allow the
absorption of glucose into the liver. (2022)
https://www.cell.com/heliyon/pdf/S2405-8440%2822%2900541-2.pdf

27. Release of gut hormones by bitter compounds from
bitter melon: momordin (2021)
https://www.sciencedirect.com/science/article/abs/pii/S1043661821002772
momordin

28. Current concept of anti-diabetic and anti-obesity
actions of momordin and charantin (2021)
Adapted from https://pubmed.ncbi.nlm.nih.gov/29764719/

29. PRECLINICAL STUDIES
● REPORTS
● DIABETES
● HYPERLIPIDEMIA
● FAT TISSUE
● CYTOKINES
● GLP1

30. Reports of Pre-clinical studies using bitter melon extracts
▪ Anti-microbial & antiviral activity
▪ Antioxidant activity
▪ Immuno-modulatory activity
▪ Anti-inflammatory activity
▪ Anti-cancer activity
▪ Anti-hypertension: ACE inhibition
▪ Anti-diabetes: α-amylase inhibition; GLP-1 release
▪ Anti-obesity activity
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4306384/#:~:text=Apart%20from%20its%
20potential%20antibacterial,psoriasis%2C%20dyslipidemia%2C%20and%20hypertension.

31. Percent decrease in glucose level after feeding bitter gourd
on 56th day. 2021
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8070166/
% decrease in glucose
SF—Skin fed rats;
FF—Flesh fed rats;
WF- Whole fruit fed rats;
L—Lower amount of bitter melon in experimental
diet (150 mg/kg body weight),
H—High amount of bitter melon in experimental
diet (300 mg/kg body weight);

32. Percent increase in insulin level after feeding bitter gourd
on 56th day. 2021
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8070166/
SF—Skin fed rats;
FF—Flesh fed rats;
WF- Whole fruit fed rats;
L—Lower amount of bitter melon in experimental
diet (150 mg/kg body weight),
H—High amount of bitter melon in experimental
diet (300 mg/kg body weight);
% increase in insulin

33. Oral glucose tolerance and insulinogenic index of mice fed the
BGP (bitter gourd powder) diet for 5 weeks (2013)
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3621175/
OGTT serum insulin insulinogenic index

34. Bitter melon (BM) ameliorated fat deposition and insulin
resistance in mice fed with HFD (high fat diet)2013
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3866167/

35. Suppression of Inflammatory Cytokines Expression with Bitter Melon
(Momordica Charantia) in TNBS-induced ulcerative colitis (2020)
Adapted from https://www.researchgate.net/publication/344430323
NC=control
UC=ulcerative colitis
MCh=M Charactin

36. Effects of various BG (Bitter gourd powder) extracts on
GLP-1 secretion in STC-1 cells. (2013)
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3621175/
(STC-1): intestinal secretin tumor cell line

37. ANTI-INFLAMMATION
ANTICANCER
POLYSACCHARIDES

38. Adding wild bitter gourd to diets of sepsis-induced mice
reduced expression of proteins COX-2, iNOS, and NF-κB, all associated with inflammation (2014)
. .
N: Normal group,
S: Sepsis group (i.p. LPS),
L: Sepsis group with low-dose WBG,
M: Sepsis group with moderate-dose WBG,
H: Sepsis group with high-dose WBG,
P: Positive control group (i.p. PDTC)
https://www.researchgate.net/publication/267756681_Anti-
Inflammatory_Effect_of_Momordica_Charantia_in_Sepsis_Mice
COX-2 protein NF-κB protein iNOS protein

39. In vitro assay of anti-inflammatory activity of bitter ethanol
extract by using a protein denaturation method (2020)
https://www.researchgate.net/publication/344033127_In_Vitro_Anti-
Inflammatory_Assay_of_Bitter_Melon_Momordica_charantia_L_Ethanol_Extract
Low anti-inflammatory activity

40. Reports of anticancer activities of bitter melon extracts
on cancer cell lines(2015)
▪ Breast cancer
▪ Colon cancer
▪ Pancreas cancer
▪ Liver
▪ Prostate
▪ Skin cancer
▪ Cervical cancer
▪ Leukemia
▪ Miscellaneous cancer
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5276711/

41. Polysaccharides isolated from Momordica charantia,
their characteristics, and biological functions. (2022)
https://www.cell.com/heliyon/pdf/S2405-8440(22)00541-2.pdf

42. CLINICAL STUDIES
● DIABETES
● LIPIDS
● HYPERTENSION
● OBESITY

43. Comparison of bitter gourd, Knol khol and ash gourd juice levels in patients
with type 2 diabetes mellitus (2017)
(n=30;duration 120 minutes)
https://www.sciencedirect.com/science/article/pii/S2225411017300147#fig2
glucose

44. The effect of bitter melon (Mormordica charantia) in patients with
diabetes mellitus:
a systematic review and meta-analysis (2014)
Overall, the evidence regarding the use of bitter melon on glycemic outcomes in patients with DM is inconclusive.
Additional evidence in a larger sample of patients evaluated over a longer duration of time is needed to determine
whether bitter melon is truly ineffective in patients with DM.
https://www.nature.com/articles/nutd201442

45. Effect of Bitter Melon Extracts on Lipid Levels in Japanese Subjects:
A Randomized Controlled Study (2018)
https://www.researchgate.net/publication/328833996_Effect_of_Bitter_Melon_Extra
cts_on_Lipid_Levels_in_Japanese_Subjects_A_Randomized_Controlled_Study
Before
After
After

46. Change in metabolic parameters after 30-day intervention
with bitter melon (2018)
Adapted from https://www.researchgate.net/publication/328833996_Effect_of_Bitter_Melon_Extracts_
on_Lipid_Levels_in_Japanese_Subjects_A_Randomized_Controlled_Study

47. Effects of Momordica charantia L on blood pressure:
a systematic review and meta- analysis of randomized clinical trials (2020)
▪ Consumption of MC preparations was not associated with a significant reduction in either SBP or DBP
SBP. DBP
https://www.tandfonline.com/doi/pdf/10.1080/109429
12.2020.1833916?cookieSet=1

48. Effect of bitter melon on body weight, obesity, and adipocyte dysfunction. (2015)
▪ Diabetes, obesity, and metabolic syndrome are becoming epidemic both in developed and
developing countries in recent years. Complementary and alternative medicines have
been used since ancient era for the treatment of diabetes and cardiovascular diseases.
Bitter melon is widely used as vegetables in daily food in Bangladesh and several other
countries in Asia. The fruits extract of bitter melon showed strong antioxidant and
hypoglycemic activities in experimental condition both in vivo and in vitro. Recent
scientific evaluation of this plant extracts also showed potential therapeutic benefit in
diabetes and obesity related metabolic dysfunction in experimental animals and clinical
studies. These beneficial effects are mediated probably by inducing lipid and fat
metabolizing gene expression and increasing the function of AMPK and PPARs, and so
forth. This review will thus focus on the recent findings on beneficial effect of Momordica
charantia extracts on metabolic syndrome and discuss its potential mechanism of actions.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4306384/

49. • ADVERSE EFFECTS
• COMMERCIAL PRODUCTS
• DELICIOUS CUISINES

50. Safety of bitter melon (M. charantia)
▪ Bitter melon has been consumed as food in many countries for
thousands of years.
▪ The incidence of severe adverse reaction is rare.
▪ There is no report of favism caused by bitter melon.
▪ The most serious adverse effects in humans were reported in two
small children that experienced a strong reduction of glycaemia
after drinking M. charantia based beverage on an empty stomach.
▪ A case of acute interstitial nephritis was reported in a 60-years
male with T2DM and hypertension that used hyponidd, an ayurvedic
drug containing M. charantia.
https://www.frontiersin.org/articles/10.3389/fphar.2019.00486/full

51. Commercial bitter melon products

52. Some delicious bitter melon cuisines

53. Summary
▪ Bitter melon has been used as food and medicine in China for thousands of years.
▪ The bitterness of bitter melon was discovered by Shen Non (Divine Farmer) more than 5,000
years ago.
▪ Bitter melon was classified as a superior herb in the Divine Farmer’s Materia Medica
published in 200-250 AD.
▪ 1,438 Scientific articles were published in English from 1962 to 2021 in PubMed.
▪ Laboratory studies showed that there are more than 225 bioactive compounds in bitter
melon fruit that showed many pharmacological activities beneficial for health.
▪ The bitter compounds in the fruit stimulate bitter taste receptors in the intestine releasing
GLP-1 which increases insulin release but diminishes glucagon release in the pancreas.
▪ Clinical studies on the efficacy of bitter melon on diabetes, hyperlipidemia, hypertension
and obesity are mixed.
▪ While waiting for more research, bitter melon continues to be enjoyed as a superior food.

54. ANY QUESTIONS?
Other slide presentations available at:
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