Prompted by a recent study [1]. {May be a bit heavy going for some. Apologies in advance.}
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Between 1997 & 2002, while he was at UVA, Charlottesville, VA, Dr. Myers co-authored 5 PCa studies involving 5-LOX (5-lipoxygenase).
[2] 1997 "Arachidonic acid stimulates prostate cancer cell growth: critical role of 5-lipoxygenase."
[3] 1998 "Inhibition of arachidonate 5-lipoxygenase triggers massive apoptosis in human prostate cancer cells."
[4] 1999 "Lipoxygenase inhibition in prostate cancer."
[5] 1999 "Central role of arachidonate 5-lipoxygenase in the regulation of cell growth and apoptosis in human prostate cancer cells."
[6] 2002 "Molecular mechanisms of prostate cancer cell death triggered by inhibition of arachidonate 5-lipoxygenase: involvement of Fas death receptor-mediated signals."
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Background.
Many here will know that some of the "healthy" oils that replaced "unhealthy" animal fat for cooking, have high levels of pro-inflammatory omega-6 fatty acid. Specifically linoleic acid [LA]. LA has an 18-carbon backbone, with double bonds at positions 9 & 12 (the carbon chain can bend at those points), to make it a polyunsaturated fatty acid. (The double bond at position 12 - six from the end - makes it an omega-6.)
The issue with LA is said to be that high levels can result in high levels of arachidonic acid [AA]. The body slaps a couple of carbons at the front of LA & adds two more double bonds at positions 5 & 8 to form AA. Lipid rafts in prostatic cells contain AA.
But the body will not create an unlimited amount of AA.
The real issue IMO is that the polyunsaturated fats create an unfavorable omega-3:6 ratio for most people & AA becomes over-represented in lipid rafts. [Corn oil is 52% LA]
When the body suffers viral or bacterial insult that could lead to significant cell death, nuclear factor kappaB [NF-kB] is activated. NF-kB causes scores of pro-survival proteins to be produced. Among them are the COX & LOX enzymes that will act on AA to produce inflammatory metabolites.
One of those enzymes - 5-lipoxygenase [5-LOX]:
"metabolizes arachidonic acid to 5-hydroperoxyicosatetraenoic acid (5-HPETE), which in turn is metabolized to various leukotrienes (i.e. leukotriene B4, leukotriene C4, leukotriene D4, and leukotriene E4 as well as to 5-hydroxyicosatetraenoic acid (5-HETE) which may then be further metabolized to 5-HETE's more potent 5-keto analog, 5-oxo-eicosatetraenoic acid (5-oxo-ETE)" [7]
This is all very well during a short-term illness, but PCa chronically activates NF-kB, & 5-HETE, etc, make the cancer more aggressive.
While NSAIDs target the COX enzymes, they are not effective against 5-LOX.
I have used 5-LOXIN for about a dozen years. It is derived from Boswellia serrata & has a high AKBA (Acetyl-11-keto-β-boswellic acid) content [8].
"... 5-LOXIN® is a selective, non-redox 5-LOX inhibitor, which means that its action is very targeted, not affecting other systems."
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From the recent study:
"Acetyl-11-keto-β-boswellic acid {AKBA} suppresses docetaxel-resistant prostate cancer cells in vitro and in vivo by blocking Akt and Stat3 signaling, thus suppressing chemoresistant stem cell-like properties."
"Acquired docetaxel-resistance of prostate cancer (PCa) remains a clinical obstacle due to the lack of effective therapies. Acetyl-11-keto-β-boswellic acid (AKBA) is a pentacyclic triterpenic acid isolated from the fragrant gum resin of the Boswellia serrata tree, which has shown intriguing antitumor activity against human cell lines established from PCa, colon cancer, malignant glioma, and leukemia. In this study, we examined the effects of AKBA against docetaxel-resistant PCa in vitro and in vivo as well as its anticancer mechanisms. We showed that AKBA dose-dependently inhibited cell proliferation and induced cell apoptosis in docetaxel-resistant PC3/Doc cells; its IC50 value in anti-proliferation was ∼17 μM. Furthermore, AKBA dose-dependently suppressed the chemoresistant stem cell-like properties of PC3/Doc cells, evidenced by significant decrease in the ability of mammosphere formation and down-regulated expression of a number of stemness-associated genes. The activation of Akt and Stat3 signaling pathways was remarkably enhanced in PC3/Doc cells, which contributed to their chemoresistant stem-like phenotype. AKBA (10-30 μM) dose-dependently suppressed the activation of Akt and Stat3 signaling pathways in PC3/Doc cells. In contrast, overexpression of Akt and Stat3 significantly attenuated the inhibition of AKBA on PC3/Doc cell proliferation. In docetaxel-resistant PCa homograft mice, treatment with AKBA significantly suppresses the growth of homograft RM-1/Doc, equivalent to its human PC3/Doc, but did not decrease their body weight. In summary, we demonstrate that AKBA inhibits the growth inhibition of docetaxel-resistant PCa cells in vitro and in vivo via blocking Akt and Stat3 signaling, thus suppressing their cancer stem cell-like properties."
-Patrick
[1] ncbi.nlm.nih.gov/pubmed/301...
[2] ncbi.nlm.nih.gov/pubmed/919...
[3] ncbi.nlm.nih.gov/pubmed/978...
[4] ncbi.nlm.nih.gov/pubmed/103...
[5] ncbi.nlm.nih.gov/pubmed/106...
[6] ncbi.nlm.nih.gov/pubmed/126...