Leafy green vegetables; Thylakoids, natural appetite suppressant; hunger hormone ghrelin, appetite suppressant hormone cholecystokinin.

1. NATURAL APPETITE SUPPRESSANT:
THYLAKOIDS
FROM LEAFY GREEN VEGETABLES
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 Professional July 2021
Spinach Kale
Broccoli Bok choy

2. Lecture Outline
▪ Why ae leaves green in color?
▪ Chloroplast and thylakoid
▪ Functions of thylakoid
▪ Thylakoids as appetite suppressant
▪ Clinical studies of thylakoid
▪ Summary
https://pt-br.facebook.com/107561579440734/photos/362382227292000

3. Why are leaves green in color?
https://www.quora.com/Does-development-progress-or-evolution-always-follows-a-linear-trajectory

4. Functions of thylakoids in plant and human
Plant
▪ Photosynthesis
Human
▪ Appetite suppressant
https://biologydictionary.net/ngss-high-school-tutorials/ls1-5-photosynthesis-modeling/

5. What is appetite?
▪ Appetite is the desire to eat food, sometimes due to
hunger.
▪ Appealing foods can stimulate appetite even when
hunger is absent, although appetite can be greatly
reduced by satiety.
▪ Appetite exists in all higher life-forms, and serves to
regulate adequate energy intake to maintain
metabolic needs.
▪ It is regulated by a close interplay between the
digestive tract, adipose tissue and the brain
https://en.wikipedia.org/wiki/Appetite
https://www.dreamstime.com/illustration/appetite.html

6. What is an appetite suppressant?
▪ Appetite suppressants are drugs designed to curb hunger and aids weight loss.
▪ Drugs approved by FDA require a doctor's prescription.
▪ Over-the-counter natural appetite suppressants do not require a prescription.
doctor's prescription natural appetite suppressants

7. SCIENTIFIC STUDIES OF APPETITE SUPPRESSANT

8. Number of publications in PubMed on “appetite suppressant”
from 1864 to 2020 and “thylakoid” from 1950-2020
https://pubmed.ncbi.nlm.nih.gov/?term=APPETITE+SUPPESSANT
appetite suppressant thylakoid

9. Factors affecting appetite

10. Hunger and appetite stimulate the release
of
ghrelin (hunger hormone) and gastrin (digestive hormone ) from the stomach
Adapted from https://courses.lumenlearning.com/wsu-sandbox/chapter/hunger-and-eating/
Sight of
food
Smell of
food
Hormones
Ghrelin
Gastrin
Vagus nerve
80% afferent fibers
20% efferent fibers
hypothalamus

11. The entry of food into the stomach inhibits the release of
ghrelin(hunger hormone)
Adapted from https://courses.lumenlearning.com/wsu-sandbox/chapter/hunger-and-eating/
Sight of
food
Smell of
food
Hormones
Ghrelin
Gastrin
Vagus nerve
Food
80% afferent fibers
20% efferent fibers

12. The entry of food into the duodenum releases
cholecystokinin (CCK) and secretin
Adapted from ://www.sciencelearn.org.nz/resources/1836-hormonal-control-of-digestion

13. The entry of food into the small and large intestine release
GLP-1, GLP-2 and PYY
Adapted from ://www.sciencelearn.org.nz/resources/1836-hormonal-control-of-digestion

14. Summary of hormonal control of digestion in the gut
The gut is the body’s largest hormone-producing organ,
releasing more than 20 different peptide hormones
https://www.sciencelearn.org.nz/resources/1836-hormonal-control-of-digestion
CCK

15. APPETITE SUPPRESSANT:
THYLAKOID
COMPOSITION

16. What is an appetite suppressant?
▪ Appetite suppressants are drugs designed to curb hunger and aids weight loss.
▪ The FDA approved medications require a doctor's prescription.
▪ Over-the-counter natural appetite suppressants do not require a prescription.
doctor's prescription natural appetite suppressants

17. Natural appetite suppressant: thylakoids
▪ All leafy green vegetables contain thylakoids.
▪ Five grams of extracted thylakoids is equivalent to 100 g of spinach.
https://www.sciencedirect.com/science/article/pii/S019566631500197X#:~:text=A
ll%20leafy%20green%20vegetables%20contain,to%20100%20g%20of%20spinach.

18. Location of thylakoids in chloroplast

19. What is thylakoid?
▪ Thylakoid in Greek means “sac-like”
▪ It is a membrane-bound structure found within the chloroplast
of all leafy green vegetables.
▪ Five grams of extracted thylakoids is equivalent to 100 g of
spinach.
▪ It is responsible for the photosynthesis of foods from carbon
dioxide and water and the release of oxygen.
▪ It is made of 50% protein and 50% lipids including vitamins E
and K as well as chlorophyll, carotenoids, zeaxanthin and
lutein.
▪ In thylakoid membranes, chlorophyll pigments are found in
packets called quantasomes. Each quantasome contains 230
to 250 chlorophyll molecPhotosynthetic componentsules
https://www.sciencedirect.com/science/article/pii/S019566631500197X#:~:text=A
ll%20leafy%20green%20vegetables%20contain,to%20100%20g%20of%20spinach.
Photosynthetic components

20. Composition of Thylakoid in fresh spinach (100g)
https://www.semanticscholar.org/paper/Intestinal-regulation-of-hunger-and-reward.-
Studies-Stenblom/094fe1e1a905dab490004b81503bd7c5be752ce1/figure/3

21. Physical Properties of Thylakoids (2018)
▪ Thylakoids are the membranes in the chloroplast of green leaves
responsible for the light reaction in photosynthesis.
▪ They have over100 different proteins which are both intrinsic
and extrinsic ,together with membrane lipids and pigments .
▪ These thylakoids are located in droplets of green leaves and are
at a higher concentration in dark green leaves as compared to
light green leaves
▪ Characteristics of the proteins is that they are membrane
spanning which means they are hydrophobic and attract to
hydrophobic surface like lipids..
▪ In the lumen of the intestine they form large swollen structures
which adhere to mucosal surface .
https://symbiosisonlinepublishing.com/obesity-control-
therapies/obesity-control-therapies44.php

22. PHARMACOLOGY OF THYLAKOIDS

23. Pharmacological actions of Thylakoid
▪ Suppress appetite and increase satiety
▪ Delay stomach and intestinal transit
▪ Decrease secretion of ghrelin
▪ Increase secretion of CCK
▪ Increase secretion of GLP-1
▪ Increase in beneficial microbiome
▪ Other actions:
▪ Antioxidant
▪ Anti-inflammatory
▪ Immuno-modulatory
▪ Anticancer
▪ Hypolipidemic

24. Thykamine Extracts (thylakoids and galactolipids) from Spinach Reduce Acute
Inflammation In Vivo and Downregulate Phlogogenic Functions of
Human Blood Neutrophils In Vitro 2020
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7399895/
Hapten 2,4,6-trinitrobenzenesulfonic acid (TNBS) induced
colitis in rats was measured by (A) the macrocsopic damage
and (B) the ratio weight/length.
Male Wistar rats, after an overnight food deprivation, were
anesthetized with isoflurane before insertion of a colonic
catheter of 8 cm. v
Anti-
inlamation
macrocsopic damage ratio weight/length Carrageenan-induced paw edema in rats.

25. The effect of thylakoids on gastric emptying and
intestinal transit in rats (2016)
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5059972/
decreased by 41 % 34 % in two-week
physiological

26. Effect of Thylakoids on fat digestion (2015)
▪ Thylakoids inhibit lipase/colipase
activity in a dose-dependent way
▪ Binding of thylakoids to the triglyceride
interface
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4539357/
Fat digestion

27. Release of CCK 60 min after a bolus dose of thylakoid in rats (2016)
HFD (control n = 6, thylakoid n = 8 rats).
Bars represent mean + SEM.
No statistical difference between thylakoid
and control-treated rats was observed
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5059972/
CCK release

28. CHOLECYSTOKININ (CCK)

29. Structure of cholecystokinin peptide (58 amino acids)
https://www.researchgate.net/figure/The-release-of-cholecystokinin-
CCK-is-stimulated-by-various-triggers-such-as-the_fig11_323024357

30. Amino acid structure of the human CCK precursos and the
different forms of CCK produced by processing the peptides
https://www.pancreapedia.org/molecules/cholecystoki
nin

31. Cholecystokinin active sites (2016)
https://www.cell.com/trends/endocrinology-metabolism/comments/S1043-2760(16)30017-0

32. 2 Cholecystokinin receptors: CCK1 & CCK2
▪ CCK1 receptors are located primarily in the
▪ pancreas,
▪ gall bladder,
▪ intestine and
▪ vagus nerve
▪ where they play a role in food intake, pancreatic exocrine
secretion, gall bladder contractility and GI motility.
▪ CCK2 receptors are localized in :
▪ acid secreting cells in the oxyntic mucosa of the stomach
▪ extensively throughout the brain
https://bpspubs.onlinelibrary.wiley.com/doi/10.1038/sj.bjp.0705769

33. Effects of cholecystokinin on the gastrointestinal tract.
Cholecystokinin is secreted by I-cells in the small intestine and
• induces contraction of the gallbladder,
• relaxes the sphincter of Oddi,
• increases bile acid production in the liver,
• delays gastric emptying, and
• induces digestive enzyme production in the pancreas.
https://en.wikipedia.org/wiki/Cholecystokinin

34. Half-life of CCK in plasma
▪ The half-life of CCK in the plasma is very short.
▪ In dogs the half-life of CCK-58 was 4.4 ± 0.6 minutes and
that of CCK-8 was shown to be 1.3 ± 0.1 minutes.
▪ CCK is cleared from the circulation as it passes through the
liver and by neutral endopeptidases in capillary endothelial
cells.
https://www.pancreapedia.org/molecules/cholecystoki
nin

35. CLINICAL STUDIES OF THYLAKOIDS

36. Clinical evaluations of effects of thylakoids
▪ Satiety:
▪ Hunger
▪ Fullness
▪ Longing for food
▪ Prospective intake
▪ Satisfaction
▪ Gut hormones:
▪ Ghrelin (hunger hormonee)
▪ CCK
▪ GLP-1
▪ Metabolic profile:
▪ Glucose
▪ Insulin
▪ Lipids
▪ Body weight

37. Satiety (feeling of fullness after eating) effects of a
physiological dose of cholecystokinin in humans (1995)
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1382399/?page=2
less desire less hunger
more fullness less feeding intentions

38. Effects of supplementation with green-plant membranes
on blood lipids (2014)
https://www.multivu.com/players/English/7426951-appethyl-spinach-extract/links/7426951-
MONTELIUS-Appethyl-wt-loss-cravings-GLP-1-Appetite-2014-81-295-304.pdf
Green-plant membranes decreased total and LDL-cholesterol while
HDLcholesterol and TG were unaltered.

39. Suppressed urge for sweet and release of GLP-1 (glucagon-like peptide 1)
with and without the consumption of thylakoids (2015)
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4539357/

40. The release of CCK following a meal with thylakoids in human. (2015)
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4539357/

41. Body weight loss with and without green-plant membrane
supplementation for 12 weeks. (2014)
38 women (40–65 years of age, body mass index 25–33 kg/m2)
https://www.multivu.com/players/English/7426951-appethyl-spinach-extract/links/7426951-
MONTELIUS-Appethyl-wt-loss-cravings-GLP-1-Appetite-2014-81-295-304.pdf
weight loss (6.3%)

42. The effects of spinach-derived thylakoid supplementation in combination with calorie
restriction on anthropometric parameters and metabolic profiles in
obese women with polycystic ovary syndrome:
a randomized, double-blind, placebo-controlled 12 weeks clinical trial (2020)
https://nutritionj.biomedcentral.com/articles/10.1186/s12937-020-00601-4
WC: Waist circumference,
WHR: Waist-to-hip ratio,
FM: Fat mass,
FFM: Fat free mass

43. Effects of thylakoid intake on appetite and weight loss:
a systematic review in 8 studies (2020)
▪ Conclusion
▪ In conclusion, our results may approve this postulation that
receiving a thylakoid-enriched meal can decrease appetite
and probably food intake in short term.
▪ More studies are needed to explore the effects of long term
supplementation with thylakoids on weight loss in human
subjects.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7270222/

44. MECHANISM OF ACTION OF CCK
EFFICACY OF THYLAKOIDS

45. The mechanism of action of thylakoids in appetite regulation (2015)
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4539357/

46. Can Thylakoids Replace Bariatric Surgery for Long Term
Maintenance of Weight Loss in Obesity? (2018)
https://symbiosisonlinepublishing.com/obesity-control-therapies/obesity-control-therapies44.php

47. Efficacy of weight loss therapies (2016)
Commercial programs
Prescription drugs
Bariatric surgery
https://www.semanticscholar.org/paper/Intestinal-regulation-of-hunger-and-reward.-
Studies-Stenblom/094fe1e1a905dab490004b81503bd7c5be752ce1/figure/2

48. COMMERCIAL THYLAKOID PRODUCTS

49. Commercial thylakoid products
▪ Green leafy vegetables
▪ Green leaf vegetable powder
▪ Spinach leaf extract
▪ Spinach leaf powder
▪ Spinach leaf capsule

50. Safety issues
▪ Thylakoids is present in green leafy vegetables
▪ Since vegetable is a source of food, there is no
official recommendation for thylakoids.
▪ No side effects of thylakoids have been reported
Spinach Kale Broccoli Bok Choy

51. Summary
▪ The green color of leafy vegetable such as kale and spinach
is due to the presence of thylakoids within the chloroplast.
▪ In plants, thylakoids function as a photosynthetic apparatus
for the manufacture of glucose from sunlight, carbon dioxide
and water with the release of oxygen.
▪ In man, thylakoids stimulate the release of cholecystokinin
from the duodenum which acts as an appetite suppressant
and aid in weight loss.
▪ However, studies on the efficacy of thylakoids in weight loss
is limited at this time. More studies need to be done.

52. ANY QUESTION?
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