Mosquito bite, composition of mosquito saliva, inflammation, pro-inflammatory chemical mediators, pro-resolution mediators, phytochemicals, itch, swelling.

1. MOSQUITO BITE:
INFLAMMATION AND RELIEF BY
TOPICAL NATURAL PHYTOCHEMICALS
Update 2020
by
Kevin KF Ng, MD, PhD
Former Assoc. Professor of Medicine
Division of Clinical Pharmacology
University of Miami, FL, USA
Gina Ng
Formulator
and MDNatural Care, Inc.
Snellville, GA, USA
email: kevinng68@gmail.com

2. Outline of Lecture
▪ Mosquitoes: types, distribution
▪ Anatomy of mouth parts
▪ Mosquito saliva composition
▪ Acute inflammation
▪ Chemical mediations
▪ Resolution
▪ Science based topical treatment
▪ Phytochemicals
▪ Summary

3. Different Types of Mosquitoes
▪ More than 3,000 species of mosquitoes inhabit the Earth,
with about 176 species found in North America.
▪ The most common mosquitoes in the U.S. are those of the
following genera:
▪ Aedes: East Coast, Midwest, Pacific Northwest, and Southern U.S.
▪ Culex : All parts of the U.S.
▪ Anopheles: Eastern and Western U.S.
▪ Each has its own unique characteristic, and each has the
potential to transmit various diseases.
https://www.ecolab.com/pages/common-types-of-mosquitoes
Culex

4. Approximate periods when mosquitoes are most active
in the United States
http://www.mosquitoreviews.com/mosquito-season

5. Mosquito bite & perception of pain & itch

6. Time course of a mosquito bite wheal

7. Mosquito bite reactions
Immediate & delayed DelayedImmediate

8. Varieties of mosquito bites

9. What attracts an adult female mosquito to bite?
 Chemical attractants from human body:
▪ Carbon dioxide from exhaled air
▪ Octanol (human breadth & sweat)
▪ Nonanal (human scent)
▪ Sulcatone (human odorant)
 Blood meal (nutrients) for development of ≈ 300 eggs

10. Olfactory receptors in mosquito antenna

11. Mosquito Needle-like Proboscis

12. Mouth parts of a mosquito
How mosquito inserts probosis Cross-section of mouth parts
https://www.google.com

13. Mosquito mouthparts in
transverse and longitudinal sections
S=salivary gland

14. Insertion of probocis into blood vessel
and release of saliva
3. Labium

15. Mosquitoes Use 6 Needles To Suck Blood (2016)
https://www.npr.org/sections/health-shots/2016/06/07/480653821/watch-mosquitoes-use-6-needles-to-suck-your-blood

16. Composition of mosquito Salivary Gland Extracts
 Alpha-gluosidase
 Alpha-amylase
 Enzymes
 Peptides/proteins
 Anticoagulant
: carbohydrate digestion
: carbohydrate digestion
: Apyrase :antiplatlet aggregation
: antigen
: Hamadarin
……………………………………………………………………………………………………
 No histamine until saliva induces its release from mast cells of host.

17. Mosquito saliva is a pharmacological cocktail that
causes the following effects:
https://www.keepinspiring.me/the-natural-wonder-balm-you-need-for-mosquito-bites/

19. Mosquito
saliva Skin
Inflamation
Pain
Warmth
Redness
Swelling
Itch
Interaction of mosquito saliva and skin

20. Players in inflammatory response
White blood cells
Platelets
Plasma
Endothelium
Nerves
Fibroblasts

21. Source of chemical mediators in Inflammation

22. Mechanism of Inflammation:
Release of chemical mediators

23. Mast cell: structure, mediators and exudation

24. Circulating White Blood Cells

25. Circulating and resident blood cells

26. Source of chemical mediators in Inflammation
Mediators ( > 20 )
Amines
Cytokines
Chemokines
Source
 Cellular injury
 Nerves
 Blood vessels
 White blood cells Lipid mediator Receptors Effects
 Platelets
 Plasma
Free radicles
Peptides

27. What is a Mediator and a Receptor ?

28. Mechanism of itch response to mosquito bite
https://www.researchgate.net/publication/42389982_The_role_of_G_protein-
coupled_receptors_in_mast_cell_activation_by_antimicrobial_peptides_Is_there_a_connection/figures?lo=1

29. Sequelae of a mosquito bite
itch

30. Mediators of acute inflammation and itch
itch

31. Mediators of pain
itch

32. Mediators of itch
itch

33. Mediators of swelling
 Histamine
 Prostaglandin D2ₔ, E₂, F2α, I₂,
 Leukotriene A₂, B₂
 Bradykinin
 Nitric oxide
 Platelet activating factor

34. Consequence of mosquito bite

35. Inflammation and Resolution of mosquito bite
http://circres.ahajournals.org/content/119/1/113.figures-only

36. Mediators of inflammation and resolution

37. Treatment of mosquito bite
based on new scientific knowledge

38. Therapeutic Targets of Mosquito Bites

39. What are phytochemicals?
 Phytochemicals are bioactive substances
found in plants.
 Phytochemicals are found in roots, barks,
stems, leaves, flowers, fruits.
 Phytochemicals are beneficial for health.
 Phytochemicals are not vitamins.
 Phytochemicals can be extracted by
water, alcohol or massage oils.

40. Bioactive functions of phytochemicals
Antioxidant
Anti-
inflammatory
Phytochemicals
Anticancer
Immuno-
modulatory

41. Examples of anti-inflammatory phytochemicals
In food, spices and herbs
Product Variety Active ingredient
Fruit Grape Resveratrol
Apple Quercetin
Chili pepper Capsaicin
Leaf Green tea ECGC
Aloe Salicylic acid, emodin
Bark White willow Salicylic acid
Magnolia Honokiol
Root Ginseng Ginsenosides
Galagal Galagin
Tumeric Curcumin
(aspirin)

42. Synthetic blockers on 15 inflammatory mediators

43. 13 Molecular targets of synthetic drugs and phytochemicals

44. A phytochemical formula L35 made from spices and herbs for
Itch, Pain and Swelling

45. Preparation of extracts of phytochemicals with
alcohol and olive oil
Botanical materials + extraction solvent
Temperature controlled treatment
Homogenization
Differential centrifugation
Residue removal
Recovery of filtrate

46. Effects of extracts of spices or herbs on
itch caused by mosquito bites
 Oil extract with one anti-inflammatory herb: no relief
 Oil extract with two anti-inflammatory herbs: slight relief
 Oil extract with three anti-inflammatory herbs: moderate relief
 Oil extract with four or more anti-inflammatory herbs : significant relief

47. Effects of Phytochemical extracts on
itch of mosquito bite
Itch scale
Time

48. Effect of black pepper extract on
size of mosquito bite 2 hr 20 min after treatment

49. Conclusion