DIM (3,3'-Diindolylmethane) is thought to be the most important phytochemical found in broccoli.
[1] Estrogen Metabolism.
Some may think it odd to begin with estrogen. Much of the DIM literature relates to its effect on estrogen metabolism, & this is of major interest to women with hormonal cancer, but why should it concern men with PCa?
I recently posted on the subject of estradiol in PCa. An alarming aspect of prostatic epithelial cells that become cancerous is (a) the disappearance of ERbeta - the protective estrogen receptor; (b) the emergence & upregulatio of ERalpha - the growth promoting estrogen receptor, & (c) the appearance of aromatase, the enzyme that converts testosterone [T] to estradiol [E2].
Men generally experience a small but persistent annual decline in T, beginning in their early 30's. With a decline of 1-2% a year, the aging man has a significantly lower T than at age 21. The result is a loss of muscle mass & an increase in body fat. Visceral fat secretes E2. E2 should be in the 20-30 pg/mL range, but can be much higher in men with low T. The body responds to high E2 by reducing T - the putative source of E2 (via aromatization). & so we get a downward spiral, with an increasingly unfavorable E2:T ratio. Complete with gynecomastia ("swelling of the breast tissue in ... men, caused by an imbalance of the hormones estrogen and testosterone" Mayo Clinic [1a]).
Testosterone is a pussycat compared to estradiol. There are two major hydroxylation metabolic pathways for its elimination: the "2" path (2-Hydroxylation) & the "16alpha" path (16α-Hydroxylation). The latter produces metabolites thare thought to be carcinogenic. The "2" path produces benign, & perhaps even protective, metabolites.
The reason that many women take DIM is that it can shunt E2 down the "2" path. Men with elevated E2 should consider it too. In PCa, we can't readily look inside the cancer cells, but E2 looks to be a legitimate target. I use Arimidex to keep E2 close to 20 pg/mL, & DIM to influence the E2 metabolic pathway.
[1b] (2004 - U.S.)
"Pilot study: effect of 3,3'-diindolylmethane supplements on urinary hormone metabolites in postmenopausal women with a history of early-stage breast cancer."
"In this pilot study, DIM increased the 2-hydroxylation of estrogen urinary metabolites."
There was an "increase of 47% in the 2-OHE1/16alpha-OHE1 ratio from 1.46 to 2.14 ..."
i.e. more "2" & less "16alpha" metabolites.
[1c] (2002 - U.S.)
The introduction in this paper summarizes the estrogen danger:
"Estrogens are known for their proliferative effects on estrogen-sensitive tissues resulting in tumorigenesis. Results of experiments in multiple laboratories over the last 20 years have shown that a large part of the cancer-inducing effect of estrogen involves the formation of agonistic metabolites of estrogen, especially 16-alpha-hydroxyestrone. Other metabolites, such as 2-hydroxyestrone and 2-hydroxyestradiol, offer protection against the estrogen-agonist effects of 16-alpha-hydroxyestrone."
[2] Bio-Response DIM [BR-DIM] [DIM-Plus]
This product is the creation of Dr. Michael Zeligs. It has been used in a number of studies. I have used it for at least ten years. Nalakrats is a big fan.
The product contains 9 IU Vitamin E (as Tocophersolan) per 2 caps. I'm not too keen about that. Also, "Protectamins® Vegetable Blend (spinach powder, broccoli powder, cabbage powder)."
2 caps contain 100 mg BioResponse-DIM® Complex, providing, 25% diindolylmethane [25 mg].
"BR-DIM is a dietary supplement which contains pharmaceutically pure DIM, microdispersed in spray-dried starch particles." ("crystalline DIM is highly insoluble in both water and oil") [2a]
There are 12 PubMed hits for <prostate "br-dim">, 11 of which involve Fazlul H Sarkar. There are also 10 other studies by Sarkar that mention Michael Zeligs as the supplier of the DIM. i.e. most of what we know about BR-DIM & PCa comes out of a single lab.
[2a] ( 2010 - U.S. - Phase I study in CRPC men without metastases)
"3, 3'-diindolylmethane (DIM) modulates estrogen metabolism and acts as an anti-androgen which down-regulates the androgen receptor and prostate specific antigen (PSA). We conducted a dose-escalation, phase I study of BioResponse (BR)-DIM with objectives to determine the maximum tolerated dose (MTD), toxicity profile, and phar-macokinetics (PK) of BR-DIM, and to assess its effects on serum PSA and quality of life (QoL)."
"Cohorts of 3-6 patients received escalating doses of twice daily oral BR-DIM providing DIM at 75 mg, then 150 mg, 225 mg, and 300 mg."
"One patient without AH at 225 mg experienced a 50% PSA decline. One patient with BR-DIM dose of 225 mg had PSA stabilization. The other 10 patients had an initial deceleration of their PSA rise (decrease in slope), but eventually progressed based on continual PSA rise or evidence of metastatic disease."
"... the maximum tolerated dose (MTD) was deemed to be 300 mg {6 caps} and the recommended phase II dose ... of BR-DIM was 225 mg twice daily {4-5 caps daily}."
[2b] (2016 - U.S.)
"Castrate-resistant prostate cancer (CRPC) progression after androgen deprivation therapy (ADT) shows up-regulated expression of androgen receptor (AR) splice variants, induced epithelial-to-mesenchymal transition (EMT) phenotypes, and enhanced stem cell characteristics, all of which are associated with resistance to enzalutamide."
"we found that BioRespose 3,3’-Diindolylmethane (BR-DIM) treatment in vitro and in vivo caused down regulation in the expression of wild-type AR, the AR splice variants, Lin28B and EZH2 ..."
"The inhibitory effects of BR-DIM on AR and AR target gene such as prostate-specific antigen (PSA) were also observed in the clinical trial. Our preclinical and clinical studies provide the scientific basis for a “proof-of-concept” clinical trial in CRPC patients treated with enzalutamide in combination with BR-DIM."
[2c] (2016 - U.S. - pre-prostatectomy study.)
"Men with localized prostate cancer were treated with a specially formulated DIM capsule designed for enhanced bioavailability (BR-DIM) at a dose of 225 mg orally twice daily for a minimum of 14 days. DIM levels and AR activity were assessed at the time of prostatectomy. Out of 28 evaluable patients, 26 (93%) had detectable prostatic DIM levels, with a mean concentration of 14.2 ng/gm. The mean DIM plasma level on BR-DIM therapy was 9.0 ng/mL ..."
"After BR-DIM therapy, 96% of patients exhibited exclusion of the AR from the cell nucleus. In contrast, in prostate biopsy samples obtained prior to BR-DIM therapy, no patient exhibited AR nuclear exclusion."
{Proliferation can only occur if AR is able to relocate to the nucleus.}
[2d] (2015 - U.S.)
"Cell migration, clonogenicity, sphere-forming capacity was assessed using PCa cells under all experimental conditions and 3,3'-diindolylmethane (DIM; BR-DIM) treatment. Human PCa samples from BR-DIM untreated or treated patients were also used for assessing the expression of AR3 and stem cell markers."
"Overexpression of AR led to the induction of EMT phenotype, while overexpression of AR3 not only induced EMT but also led to the expression of stem cell signature genes. More importantly, ADT enhanced the expression of AR and AR3 concomitant with up-regulated expression of EMT and stem cell marker genes. Dihydrotestosterone (DHT) treatment decreased the expression of AR and AR3, and reversed the expression of these EMT and stem cell marker genes. BR-DIM administered to PCa patients prior to radical prostatectomy inhibited the expression of cancer stem cell markers consistent with inhibition of self-renewal of PCa cells after BR-DIM treatment."
Interesting that DHT decreased AR3 - aka AR-V7. An indication that BAT therapy might turn back the clock.
Also of interest: "... results suggest that AR3 but not AR is involved in the regulation of stem cell marker gene expression ..."
[2e] (2012 - U.S.)
(Note that a major action of Metformin is AMPK activation.)
"Accumulating evidence suggests that AMP-activated protein kinase (AMPK) plays an essential role in cellular energy homeostasis and tumor development and that targeting AMPK may be a promising therapeutic option for cancer treatment in the clinic."
"Our results showed, for the first time, that B-DIM could activate the AMPK signaling pathway, associated with suppression of the mammalian target of rapamycin (mTOR), down-regulation of androgen receptor (AR) expression, and induction of apoptosis in both androgen-sensitive LNCaP and androgen-insensitive C4-2B prostate cancer cells. B-DIM also activates AMPK and down-regulates AR in androgen-independent C4-2B prostate tumor xenografts in SCID mice."
[2f] (2012 - U.S.)
{PCa achieves much of the changes required for its survival, not by gene mutation but by epigenetic silencing. These are reversible changes.}
"These results suggest, for the first time, epigenetic silencing of miR-34a in PCa, which could be reversed by BR-DIM treatment and, thus BR-DIM could be useful for the inactivation of AR in the treatment of PCa."
[2g] (2011 - U.S.)
"B-DIM Impairs Radiation-Induced Survival Pathways Independently of Androgen Receptor Expression and Augments Radiation Efficacy in Prostate Cancer"
[2h] (2009 - U.S.)
"3,3′-Diindolylmethane Enhances Taxotere-Induced Apoptosis in Hormone-Refractory Prostate Cancer Cells through Survivin Down-regulation"
[2i] (2009 - U.S.)
"Inactivation of uPA and its receptor uPAR by 3, 3'-Diindolylmethane (DIM) leads to the inhibition of Prostate Cancer Cell growth and migration"
[2j] (2009 - U.S.)
"We believe that our results show for the first time the cell cycle-dependent effects of B-DIM on proliferation and apoptosis of synchronized prostate cancer cells progressing from G(1) to S phase. B-DIM inhibited this progression by induction of p27(Kip1) and down-regulation of AR. We also show for the first time that B-DIM inhibits proteasome activity in S phase, leading to the inactivation of NF-kappaB signaling and induction of apoptosis in LNCaP and C4-2B cells."
[3] Non-BR-DIM studies.
Out of kindness to my readers, I'm disinclined to include them. More of the same.
-Patrick
[1a] mayoclinic.org/diseases-con...
[1b] ncbi.nlm.nih.gov/pubmed/156...
[1c] ncbi.nlm.nih.gov/pubmed/119...
[2a] ncbi.nlm.nih.gov/pmc/articl...
[2b] ncbi.nlm.nih.gov/pmc/articl...
[2c] ncbi.nlm.nih.gov/pmc/articl...
[2d] ncbi.nlm.nih.gov/pmc/articl...
[2e] ncbi.nlm.nih.gov/pmc/articl...
[2f] ncbi.nlm.nih.gov/pmc/articl...
[2g] ncbi.nlm.nih.gov/pmc/articl...
[2h] cancerres.aacrjournals.org/...