To learn the basics of eicosanoids:
Meet the VIP eicosanoid families and their members
To help understand the effects of eicosanoids, this website color-codes their families and their members by their overall function. Their activities can not be differentiated as "good" and "bad". E.g. promoting inflammation is very necessary to aid repair, if say you've been injured, but can be overly painful and damage tissue if done to excess, or causing the blood to clot can be life-saving if you just cut yourself, but can cause a heart attack if overdone in the arteries, and lastly, cell-proliferation is needed to repair tissue, but when out of control can cause a tumor. Excessive or unresolved inflammation, or overreaction to stimuli can lead to uncontrolled tissue damage and health problems.
"Orange" represents activity altering the status quo, some increasing inflammation.
"Turqoise" represents more of a "calming down" / going-back-to-normal action and/or resolving the inflammation.
"Red" represents generally inflammatory activity.
"Green" represents generally anti-inflammatory activity.
The eicosanoid families
• The PROSTAGLANDIN family (a prostanoid): Produced in most cells;
Series 1 (PGE1) and Series 3 prostaglandins. Counter inflammation
Series 2 prostaglandins. Significant ones are PGD2, PGE2, PGF2α, PGI2 (a.k.a. prostacyclin. a potent vasodilator produced mainly by endothelial cells, which comprise the inner lining of blood and lymphatic vessels, and epithelial cells lining the inside of other hollow organs e.g. bronchial epithelial cells in airways, and the skin's epidermis.
• The THROMBOXANE family (a prostanoid): Produced mainly in platelets, also placenta, lungs;
Mainly thromboxane TXA2. Promotes blood clotting /platelet-aggregation and is a potent vasoconstrictor. Also broncho-constrictive.
• The LEUKOTRIENE family: Produced in leukocytes. i.e. white blood cells: Series 4 and Series 5 leukotrienes
• The EOXIN family: Produced in immune system eosinophils (white blood cells), mast cells, and some other tissues. Generally steps up inflammatory response.
• The LIPOXIN and RESOLVIN families: Deal with reducing excessive tissue injury and the resolution of inflammation.
LIPOXINS ( Produced in platelets, neutrophils, red blood cells and reticulocytes; also by low dose aspirin).
RESOLVINS (Produced in most cells) Potent anti-inflammatory agents that as their name suggests, resolve inflammation. They limit the extent of inflammation by blocking the actions of inflammatory prostanoids (prostaglandins and thromboxanes) and also clear away breakdown products of inflammation process. E.g. RVD1-6
• The PROTECTIN family
Eicosanoid activity is complex
Each family member has specific functions. However, their activity can be confusing, since their tissue location, and which enzyme produced them can sometimes determine whether they either promote or resolve inflammation.
Dietary omega-3 EPA and omega-6 GLA counter the predominately inflammatory effects of omega-6 AA in three ways:
• Competitive inhibition. DGLA and EPA compete with AA for COX and LOX enzymes, such that the presence of DGLA and also EPA in tissues lowers the production of AA's eicosanoids
• Displacement. Increased dietary omega-3 results in decreased AA in brain and other tissue. Green et al, 2005
• Direct counteraction. Some DGLA and EPA-derived eicosanoids counteract their AA derived counterparts. E.g. PGE1 derived from DGLA acts against PGE2 derived from AA.
COX-1 - "The housekeeper"
COX-1 is expressed constitutively in most tissues and regulates basal levels of prostaglandins to maintain general homeostasis. Only COX-1 produces prostaglandins that protect the stomach and intestinal lining.
COX-1 is also actively involved in certain traumatic/stimulated events. Only COX-1 produces prostaglandins that activate platelets and constrict airways.
The human COX-1 gene is located on chromosome 9
COX-2 - "The main activator"
COX-2 enzyme is mostly induced in "times of trouble". Responsible for releasing PROSTAGLANDINS after an infection, injury, or in cancer development, COX-2 expression is induced by the cytokines interleukin (IL)-1, IL-2, and TNF, as well as by lipopolysaccharide (LPS) produced by Gram-negative bacteria. Kang et al, 2007
COX-2 enzyme inhibitors reduce the prostanoids PGI2, PGD2, PGE2 PGF2α, and thromboxane A2
The human COX-2 gene is located on chromosome 1
Traditional NSAIDs (e.g. aspirin, Aleve, Motrin) suppress both COX-1 and COX-2 enzymes
|Chart of significant eicosanoids
and their effects
(Currently adding to this list)
(produced in most cells)
and Thromboxanes via COX-1 (housekeeping) and COX-2 (mostly induced under stress conditions) enzymes
Derived directly from: Omega-6 DGLA (in mother's milk). Derived indirectly with the sufficient presence of omega-3 EPA from: Omega-6 LA (E.g. in nuts, seeds, vegetable oils, grass-fed animal fats or legumes, or from GLA (E.g. in borage /evening primrose oil),
|All cells||Sesame lignans promote conversion of omega-6 DGLA to anti-inflammatory PGE1 in favor of pro-inflammatory omega-6 AA|
|Immune System cells|
Derived from omega-6 AA mostly (in the Western diet) from meat and eggs; inhibited by omega-3 EPA presence;
|PGD2 is a major prostaglandin produced by immune system (IS) mast cells (contain histamine and the anticoagulant heparin). Recruits T-helper (CD4) cells (important in adaptive IS), eosinophils (a type of white blood cell (WBC) that aids IS combat against multicellular parasites and other infections), basophils (another WBC granulocyte responsible for inflammatory reactions during an immune response, and in the formation of acute and chronic allergic diseases).|
|Mast cells in Airways;
|Involved in allergic rhinitis and allergic bronchial asthma. Atttracts
neutrophils (WBCs that fight infection and heal injuries). Involved
in late phase reactions to allergens (6 hrs after exposure).
PGD2 has 10 times higher concentration
in asthma patients compared to control patients.
|Mast cells in PULMONARY and PLACENTAL blood vessels||PGD2 is a potent vasoconstrictor via thromboxane/endoperoxide (TX/E) receptor activation in pulmonary vessels, but this mechanism is not responsible for vasoconstriction in systemic vessels or in airway. King, 1991|
|Mast cells in UTERINE blood vessels||PGD2 can promote mild
vasodilation if TX/E is blocked.
PGD2 dilates uterine blood vessels. Together with its ability to constrict placental blood vessels, it may control utero-placental blood flow.
|Mast cells in brain
||In mamalian organs, large amounts of PGD2 are found only in the brain (and in mast cells)|
|Mast cells in skin||PGD2 is the primary mediator of
vasodilation after taking niacin (vitamin B3) - the so-called "niacin
Involved in urticuria (hives), and balding
- a causal link was found between elevated levels of localized PGD2 and hair growth inhibition (by increasing Prostaglandin D2 synthase). Garza et al, 2012.
Derived from omega-6 AA mostly (in the Western diet) from meat and eggs; inhibited by omega-3 EPA presence;
|PGE2 promotes tumor growth.
PGE2 is the most abundant prostaglandin found
in various human malignancies, including colon, lung, breast, and head
and neck cancer, also often associated with a poor prognosis.
In contrast, the enzyme that catalyzes the degradation of PGE2 (15-PGDH,
an antagonist /suppressor of COX-2) is highly expressed in normal tissues
but is ubiquitously lacking in human colon, gastric, lung and breast
cancer. Lack of 15-PGDH expression in these tumours results in increased
endogenous PGE2 levels. Furthermore there may be a negative feedback
loop, since a product of the COX-2 enzymatic pathway, upregulates the
expression of 15-PGDH in breast cancer MDA-MD-231 cells. 15-PGDH is
being investigated as a potential avenue for tissue regeneration.
PubMed. Prostaglandin E Synthase (PGES) converts PGH to PGE.
COX-1 inhibits PGE2 synthesis
|Promotes all signs of classic inflammation: i.e. redness, swelling
and pain. Redness and edema result from increased blood flow into the
inflamed tissue through PGE2-mediated
increase in arterial dilation and microvascular permeability. Pain results
from the action of PGE2 on peripheral
sensory neurons and on central sites within the spinal cord and the
Quercetin reduces PGE2 (RA joints Link)
|Vascular SMCs (in arteries, veins,
SMCs are also in walls of stomach, intestine and bladder, and other hollow organs;
|Dilates smooth muscles cells (SMCs), which form the supporting tissue of blood vessels and hollow internal organs (e.g. stomach, intestine, and bladder)|
|Protects stomach lining;
🠡 mucous /bicarbonate secretion;
🠡 mucosa blood flow;
🠣 gastric acid /PEPSIN secretion;
Provides gastrointestinal integrity (Cox-2?)
🠡 duodenal mucus secretion
|Involved in fertility|
|Regulates immune responses;|
(Derived via Cox1, Cox2 from omega-6 AA (in the Western diet, this is mostly from meat (especially chicken) and eggs); inhibited by omega-3 EPA presence;
|Airways||Anomaly: Promoted by Cox1 inhibitors (aspirin, traditional NSAIDs) Harrington, 2008|
|Vascular Smooth Muscle Cells (VSMCs) via Cox2||
(Derived from AA via Cox1, Cox2)
cells lining inside of blood and lymphatic vessels
(epithelial cells lining hollow
organs, airways, gastrointestinal lining, skin)
via Cox-1 and
|PGI2 has a beneficial effect on allergic airway responses and pulmonary hypertension. e.g. in asthma. Zhou, 2016|
via Cox1 and
|Gastric mucosa via Cox1||Protects stomach lining|
(TXA2-->TXB2) (from AA e.g. meat, eggs, or indirectly from LA in seed oils)
Vascular Smooth Muscle Cells (VSMCs) via Cox2
|Cell proliferation aids damage repair.
Involved in development of atherosclerosis;
|Involved in thrombosis|
|Airways||An anomaly is that bronchoconstriction is promoted by Cox-1 inhibitors (aspirin, traditional NSAIDs), but not selective Cox-2 inhibitors Harrington, 2008|
|Series 3 PGs
Derived from omega-3 EPA e.g. in salmon,
cod liver or
via Cox1 and
Compete for COX and LOX enzymes
Series 4 LTs
Derived from AA e.g. meat, eggs, or indirectly from LA in seed oils
|Part of the inflammation response, especially in asthma and allergic rhinitis. Attract white blood cells to sites of tissue damage and cause smooth muscles to contract.|
Derived from omega-3 EPA e.g. in fish oil
|Specialized pro-resolving mediators
Deal with reducing excessive tissue injury and resolving inflammation.
|Low dose aspirin can trigger lipoxin synthesis|
(from EPA, DHA, DPA e.g. fish oil)
|Newly discovered resolvins are anti-inflammatory and inflammation resolving.||Clear away inflammation debris
Block prostanoid effects
(from AA e.g. meat, eggs, or indirectly from LA in seed oils)
(white blood cells), mast cells
|Involved in asthma, lymphoma of Hodgkins disease, prostate cancer, colon cancer, and other cancers|
Garza, Luis A.; et al. (2012, Mar 12). "Prostaglandin D Inhibits Hair Growth and Is Elevated in Bald Scalp of Men with Androgenetic Alopecia". Science Translational Medicine. 4 (126): 126ra34. PubMed
Green, P., Gispan-Herman, I., & Yadid, G. (2005). Increased arachidonic acid concentration in the brain of Flinders Sensitive Line rats, an animal model of depression. Journal of lipid research, 46(6), 1093-1096. PubMed
Chronic low-level inflammation (CLII) involved in almost all health problems
"The medical kit of the future"
General electrotherapy health benefits. Used systemically and/or locally at specific problem areas of the body, its effective application has many benefits:
|Detoxification||Wellness / Healthy aging||Pain relief|
|Relief from insomnia||Immune system restoral||Anti-Inflammatory|
|Maximizes cellular energy production||Accelerated tissue /bone
|Muscle relaxation / rehabilitation||Increased blood oxygen
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|Pulsed Electromagnetic Field (PEMF) therapy|
|Near Infrared (NIR) class 4 laser therapy|
Cranial Electrotherapy Stimulation (CES) applies specific frequency patterns to the head area, with the following benefits:
|Balances neurotransmitters||Relieves pain||Treats depression|
|Substance abuse withdrawal||Relieves insomnia||Relieve stress / anxiety|