MICROENCAPSULATED DIINDOLYLMETHANE-DIM

Background

Diindolylmethane (DIM) is a phytonutrient found in indole rich, cruciferous vegetables such as cabbage, brussel sprouts, cauliflower and broccoli. DIM is one of the most abundant and biologically active cruciferous indoles.[1]

Microencapsulated DIM is a specially designed DIM complex with proven clinical activity. This patented DIM complex features an enhanced bioavailability delivery system. As a supplement it does not need to be catalysed within the digestive system to function effectively.

Accumulating evidence shows supplemental DIM assists the activity of the enzymes that maintain healthy oestrogen hormone levels in both men and women and may be used to support female healthy hormone balance.[2],[3],[4],[5],[6]

Health and Oestrogen Hormone Levels

Oestrogens are a group of three biochemically distinct hormones, oestradiol (E2), oestrone (E1), and oestriol (E3). E2 and E1 are considered the parent oestrogens, whereas E3 is metabolized from 16-alpha hydroxoestrone.[1],[5]

Oestrogen is enzymatically converted to specific oestrogen metabolites such as 16-alpha hydroxyoestrone, 4-hydroxyoestrone, 4-methoxyoestrogens, 2-hydroxyoestrogens and 2-methyoxyoestrogens. A healthy ratio of these oestrogen metabolites plays an important role in supporting hormonal health.[1],[5]

As a supplement microencapsulated DIM has a favourable influence on the healthy ratio of oestrogen metabolites. Improved metabolism of available oestrogen supports healthy expression of this key hormone. A number of the common symptoms attributed to oestrogen excess may be due to over production of unfavourable oestrogen metabolites.[1],[5]

Research shows supplemental DIM specifically assists activity of hepatic cytochrome P450 enzymes, CYP1A2 and to a lesser extent CYP1A1, necessary to promote greater 2-hydroxylation of oestrogens.[1],[5][7] This effect is possible using DIM at physiologically achievable doses.3

Microencapsulated DIM supports favourable changes in oestrogen metabolism toward 2-hydroxylation. The protective 2-hydroxyoestrogen and 2-methyoxyoestrogen metabolites are termed ‘favourable’ oestrogen metabolites.[8] Whereas 4-hydroxyoestrone and 16-alpha-hydroxyoestrone are often termed ‘unfavourable’ oestrogen metabolites when hyperdriven.[5],[8]

The 2-hydroxyestrogen metabolites possess lower hormonal potency than oestradiol, a relatively high clearance rate and O-methylation rate by catechol-O-methyltransferase (COMT). However, DIM should not significantly reduce circulating oestradiol or oestrone levels when appropriately prescribed.[9],[4]

Bioavailable DIM in a Clinical Setting

  • Microencapsulated DIM supports healthy oestrogen activity. For this reason, the use of herbal extracts with phytoestrogenic activity may form an effective dual strategy to help maintain healthy hormone balance.
  • Microencapsulated DIM may assist hormone health when taken with Hormone Replacement Therapy (HRT) and the oral contraceptive pill (OCP). DIM has no action on CYP3A4, the enzyme that metabolises the OCP, therefore, microencapsulated DIM does not affect efficacy of the OCP. Hormonal prescribers should be advised of concomitant DIM use.
  • Microencapsulated DIM may support hormone balance when taken with bioidentical hormone replacement therapy (BHRT). Microencapsulated DIM may assist effective metabolism of increased available oestrogen.

DIM – Key benefits

Support Healthy Hormone Balance

Oestrogen Metabolism

Oestrogen receptors are present throughout the human body. Oestrone (E1) and oestradiol (E2) are potent oestrogens, whereas oestriol (E3) is considered a relatively weak oestrogen. Oestrogens are eliminated from the body by metabolic conversion to various metabolites that are excreted in the urine and/or faeces.[10]

The first step in the metabolism of oestrogens is via hydroxylation by CYP450 enzymes. Since most CYP450 enzymes are abundantly expressed in the liver, metabolism of oestrogens mainly occurs here. Emerging evidence now demonstrates that the major physiological effects of oestrogen are due to the hyroxylated metabolites that are formed from oestradiol and oestrone.[10]

The principal hydroxylation products from oestradiol and oestrone are 2-hydroxyoestrone, 4-hydroxyoestrone and 16-alpha hydroxyoestrone. Individuals who metabolise oestradiol and oestrone to unbalanced ratios of 4-hydroxyoestrone and 16-alpha hydroxyoestrone may be at increased risk of serious health issues. The 16-alpha hydroxyoestrone metabolites retain potent hormonal activity and are associated with symptoms of oestrogen excess. At the same time detrimental effects including reduced bone formation possibly initiated from low oestrogen levels may occur if 16-alpha hydroxoestrone metabolites are too low – balance is the key here.[11]

The concentration of 4-hydroxyoestrone metabolites is smaller, so the impact is considered less than the more abundant 16-alpha hydroxyoestrone metabolites. However, the 4-hydroxyoestrone metabolites may be more potent as they are known to be long acting and have the ability to generate potentially mutagenic free radicals.[12]

The 4-hydroxyoestrone metabolites are specifically catalysed via the CYP1B1 pathway, an enzyme which is highly expressed in the oestrogen target tissues of the breasts, ovaries and uterus. 4-hydroxyoestrone production provides a measure of CYP1B1 activity.[13]

Apart from oestrogen metabolism, CYP1B1 is also involved in the metabolic activation of some environmental carcinogens.[11] Research has indicated for many years that the abnormal elevation of 4-hydroxyoestrones may be linked in part to the activation of Arylhydrocarbon receptor (Ahr). This metabolic imbalance may increase the risk of serious oestrogen related health issues.[14]

Microencapsulated DIM may act as an Ahr modulator and act against epigenetic activation of COX-2 expression by AhR agonists.12 The actions of toxic quinone metabolites produced by high levels of 4-hydroxyoestrone metabolites may have negative implications.[13],[14],[15] Since 4-hydroxyoestradiol generates free radicals from the reductive-oxidative cycling with the corresponding semiquinone and quinone forms, which cause cellular damage, the specific and local formation of 4-hydroxyestradiol may impact breast and endometrial health.[16],[17]

2-hydroxyoestrone and its metabolite 2-methoxyoestrone have opposite biological properties and are generally considered protective. In addition, cell proliferative activity of the 2-hyroxy metabolites is nil, while 16-alpha hydroxyoestrone is a powerful oestrogen agonist. Higher levels of 2-hydroxyoestrone metabolites are associated with improvements in hormone balance. Higher levels of the 2-hydroxyoestrone metabolites are associated with a reduction in symptoms associated with oestrogen dominance.[18],[19],[20]

Optimal hormone balance is dependent on an ideal ratio of 2-hydroxyoestrone, 4-hydroxyoestrone and 16-alpha hydroxyoestrone metabolites and then downstream conversion to 2-methoxyoestrogen and 4-methoxyoestrogen metabolites.[18],[19],[20] Adequate supply of nutrients that support methylation may assist the conversion of hydroxyoestrogen to methoxyoestrogen metabolites. Catechol-O-methyltransferase (COMT) catalyses the methylation of catechol oestrogens to methoxy oestrogens.[21]

Studies suggest greater hydroxylation of oestrogen via the 2-hydroxoestrone-3-methyl ether and 2-methoxyoestradiol pathway for women may lower the risk of post-menopausal breast cancer and reduce breast pain associated with pre-menstrual tension.[4],[22],[23]

A small randomized double-blind crossover intervention study of pre-menopausal women with cyclical mastalgia was published in JANA in 2005. Symptoms were monitored daily in a ‘breast pain dairy’ with significant reductions in the duration, and severity of breast pain noted in microencapsulated DIM participants, but not the placebo group.[4]

Furthermore, microencapsulated DIM demonstrated a carryover effect. Three months after supplementation ceased an improved 2-hydroxyoestrone/16-alpha hydroxyoestrone urinary ratio remained. Researchers proposed this was primarily due to an increase in the 2-hydroxyoestrone fraction.[4]

Microencapsulated DIM is highly indicated for the support of female healthy hormone balance.[5],[6],[17] Supplementation of bioavailable DIM can assist transformation of available oestrogen to 2-hydroxyoestrone and 2-methoxyoestrone, which have less oestrogenic effects. DIM therefore has the potential to greatly reduce oestrogen exposure.[24],[25],[26],[27]

Figure 1. Relationship of serum estrogens and estrogen metabolites to postmenopausal breast cancer risk. Falk et al. Breast Cancer Research 2013, 15:R34:[22] Adapted from Fuhrman et al.[61]

Support for prostate health

Oestrogen has a significant effect on prostate gland homeostasis.[28],[29] There is accumulating evidence that greater conversion of oestrogen down the 2-hydroxylation metabolic pathway may support prostate health. Conversely, elevated 16-alpha hydroxylation and 4-hydroxylation are associated with increased dysfunction.[30],[31]

Reducing activity of both the androgen and oestrogen receptors in the prostate supports the health of this endocrine organ. The biological activity of testosterone and dihydrotestosterone is thought to occur predominantly through binding to the androgen receptor.[32],[33] The oestrogen receptor is also active in the prostate tissue and has shown to contribute to prostate enlargement.[34],[35] Microencapsulated DIM may promote prostate health.[36],[37],[38],[39],[40],[41],[42]

Monitoring oestrogen metabolism

Oestrogen metabolite testing detects the urinary products of oestrogen metabolism. As the oestrogen metabolites are modifiable by diet, lifestyle and nutritional changes, this type of testing is useful for establishing risk, and implementing preventative health strategies.[43]

Human use of absorbable DIM has been shown to promote a dose responsive upward effect on the urinary ratio 2-hydroxyoestrone/16-alpha hydroxyoestrone metabolites, demonstrated by Enzyme-Linked ImmunoSorbet Assay (ELISA) testing of urine before and after use.[4],[16]

While attention in the past has focused on testing 2/16 hydroxyoestrone ratios, substantial evidence suggests that an assessment of 4-hydroxyoestrone and the ratio of methoxyoestrogens is also important.

4-hydroxyoestrone production provides a measure of CYP1B1 activity which metabolises both oestrogen, and environmental chemicals. Overactivity of this CYP 450 enzyme pathway is associated serious health issues. CYP1B1 can activate environmental procarcinogens and catalyse the conversion of oestrogens to genotoxic catechol oestrogens.[44]

A few words about the ‘Estrobolome’

The Estrobolome is defined as ‘the aggregate of enteric bacterial genes capable of metabolizing oestrogens’.[45],[46]     Conjugated oestrogens are excreted within the faeces, urine and bile, however significant amounts of oestrogen are reabsorbed. Certain bacteria, particularly those that contain hydrolytic enzymes, beta-glucuronidases and beta-glucosidases, possess activity in the gut that may lead to the deconjugation of oestrogen and its reabsorption via enterohepatic circulation.[46]

Factors such as age, ethnicity, alcohol, certain drugs, antibiotics and diet may affect estrobolome composition.  High fat and protein diets have been associated with increased fecal beta-glucuronidase activity, whereas high fibre diets have been associated with reduced activity.[46]

Adequate fibre intake supports regular elimination and may reduce 17-epiestriol concentrations.  Fibre intakes over 25g/day are associated with increased 4-methoxyestradiol levels compared to intakes of less than 15g/day in premenopausal women.[46]

DIM the major active of I3C

DIM is the major in vivo condensation product formed after the enzymatic release of indole-3 carbinol (I3C) from glucosinolates found in all cruciferous vegetables.

Following ingestion, I3C is rapidly converted into several compounds.[47] DIM is the dominant metabolite formed from I3C, with research indicating that I3C may simply serve as a precursor to DIM.[10] A number of the biological activities of I3C may not be attributed to the parent compound but rather to DIM and other derivatives.[48],[49]

Notably, I3C is not stable in the low pH, digestive milieu with 84% conversion to a variety of DIM and non-DIM compounds in 24 hours.[50],[51] I3C, the natural precursor to DIM, is formed from a condensation reaction in which one I3C molecule combines with another releasing formaldehyde.[52]

The resulting DIM is a ‘di-indole’ or double molecule, formed from two I3C molecules. Exposure to a highly acidic gastric environment produces less DIM and a variety of other double and triple chemical species, while a less acidic gastric environment produces more DIM from I3C. The reaction is variable and unpredictable.[30],[53],[54] I3C not only converts to DIM, the major acid condensation product, it can also form varying amounts of non-DIM metabolites such as indolocarbazole (ICZ), linear trimer (LTR), cyclic trimer (CTR) and ascorbigen.[24],[55],[56],[57]

The exact mix of metabolites formed from I3C depends upon the acidity of the stomach. This unpredictable process is modulated by achlorhydria, and consumption of proton-pump inhibitors or antacids.[58]

The reaction products from I3C have a complex effect on oestrogen metabolism and some activate the Aryl Hydrocarbon Receptor (AhR). The AhR is a cellular protein which interacts with a multitude of xenoestrogens.[57] The activated AhR induces the cell nucleus to produce more of the CYP1B1 enzyme, which produces 4-hydroxyoestrogen metabolites and other toxic metabolites from poly cyclic aromatic hydrocarbons.[56] Research suggest that DIM may act as an AhR modulator.[14]

Generic Diindolylmethane

In its pure crystalline state DIM is insoluble and therefore poorly absorbed. Greater bioavailability is achieved with an absorption-enhanced formulation.

Microencapsulated DIM utilises solubility enhancing microencapsulation technology for effective absorption of DIM. This has been proven to significantly increase sustained gastrointestinal absorption of DIM.[6] Oral administration of Microencapsulated DIM, a patented formulation of DIM, exhibits approximately fifty percent higher bioavailability than an unformulated crystalline DIM.[59]

Highlights

Microencapsulated Diindolylmethane is a unique and highly absorbable diindolylmethane (DIM) as found in cruciferous sources with demonstrated clinical activity.[1],[30] Microencapsulated diindolylmethane assists the favourable metabolism of oestrogen down the 2-hydroxylation pathway.[1],[5] This beneficial shift in metabolism can help support healthy hormone balance.[5],[24],[25]

Excipients

Cellulose microcrystalline, calcium hydrogen phosphate, silicon dioxide, and magnesium stearate (vegetable source).

Warnings

Microencapsulated Diindolylmethane is not recommended for use if you are pregnant, breastfeeding, or planning a pregnancy.

Precautions & Considerations

  • Harmless changes in urine colour may occur with Microencapsulated Diindolylmethane.

Increased water consumption can reduce this side effect.

  • Symptoms of nausea and/or headaches may occur with Microencapsulated DIM.

Microencapsulated DIM assists activity of hepatic cytochrome P450 enzymes (CYP1A2) pathways. Nutrients required to support phase 2 liver detoxification pathways can assist in reducing these symptoms.

  • A short-term increase in symptoms with Microencapsulated DIM may be due to increased metabolism of available oestrogen.
  • Microencapsulated DIM does not contain goitrogenic compounds which could affect thyroid function.
  • Microencapsulated DIM is not phytoestrogenic and has no inherent oestrogenic activity. Bioavailable DIM can be used in used in conjunction with phytoestrogenic herbs.
  • Microencapsulated DIM may assist hormone health when taken with Hormone Replacement Therapy (HRT)
  • Microencapsulated DIM may assist hormone health when taken with the oral contraceptive pill (OCP). Microencapsulated DIM has no inducing action on CYP3A4, the enzyme that metabolises the OCP. Therefore, Microencapsulated DIM does not affect efficacy of the OCP.
  • Microencapsulated DIM may assist effective metabolism of increased available oestrogen when taken with bioidentical hormone replacement therapy (BHRT).
  • Combined use of Microencapsulated DIM and Tamoxifen is not recommended.[60]
  • Combined use of Microencapsulated DIM and Zoladex is supported.
  • Microencapsulated DIM should be used with caution in patients taking anticoagulation medications.
  • Individuals on prescribed medications that are metabolized down the CYP1A1/1A2 pathways should seek medical advice. Eg. Microencapsulated DIM may lead to a moderate increase in the drug Olanzapine. [61]

 

Health and Oestrogen Hormone Levels

Oestrogens are a group of three biochemically distinct hormones, oestradiol (E2), oestrone (E1), and oestriol (E3). E2 and E1 are considered the parent oestrogens, whereas E3 is metabolized from 16-alpha hydroxoestrone.[1],[5]

Oestrogen is enzymatically converted to specific oestrogen metabolites such as 16-alpha hydroxyoestrone, 4-hydroxyoestrone, 4-methoxyoestrogens, 2-hydroxyoestrogens and 2-methyoxyoestrogens. A healthy ratio of these oestrogen metabolites plays an important role in supporting hormonal health.[1],[5]

As a supplement microencapsulated DIM has a favourable influence on the healthy ratio of oestrogen metabolites. Improved metabolism of available oestrogen supports healthy expression of this key hormone. A number of the common symptoms attributed to oestrogen excess may be due to over production of unfavourable oestrogen metabolites.[1],[5]

Research shows supplemental DIM specifically assists activity of hepatic cytochrome P450 enzymes, CYP1A2 and to a lesser extent CYP1A1, necessary to promote greater 2-hydroxylation of oestrogens.[1],[5][7] This effect is possible using DIM at physiologically achievable doses.3

Microencapsulated DIM supports favourable changes in oestrogen metabolism toward 2-hydroxylation. The protective 2-hydroxyoestrogen and 2-methyoxyoestrogen metabolites are termed ‘favourable’ oestrogen metabolites.[8] Whereas 4-hydroxyoestrone and 16-alpha-hydroxyoestrone are often termed ‘unfavourable’ oestrogen metabolites when hyperdriven.[5],[8]

The 2-hydroxyestrogen metabolites possess lower hormonal potency than oestradiol, a relatively high clearance rate and O-methylation rate by catechol-O-methyltransferase (COMT). However, DIM should not significantly reduce circulating oestradiol or oestrone levels when appropriately prescribed.[9],[4]

Bioavailable DIM in a Clinical Setting

  • Microencapsulated DIM supports healthy oestrogen activity. For this reason, the use of herbal extracts with phytoestrogenic activity may form an effective dual strategy to help maintain healthy hormone balance.
  • Microencapsulated DIM may assist hormone health when taken with Hormone Replacement Therapy (HRT) and the oral contraceptive pill (OCP). DIM has no action on CYP3A4, the enzyme that metabolises the OCP, therefore, microencapsulated DIM does not affect efficacy of the OCP. Hormonal prescribers should be advised of concomitant DIM use.
  • Microencapsulated DIM may support hormone balance when taken with bioidentical hormone replacement therapy (BHRT). Microencapsulated DIM may assist effective metabolism of increased available oestrogen.

 

Excipients

Cellulose microcrystalline, calcium hydrogen phosphate, silicon dioxide, and magnesium stearate (vegetable source).

Warnings

Microencapsulated Diindolylmethane is not recommended for use if you are pregnant, breastfeeding, or planning a pregnancy.

Precautions & Considerations

  • Harmless changes in urine colour may occur with Microencapsulated Diindolylmethane.

Increased water consumption can reduce this side effect.

  • Symptoms of nausea and/or headaches may occur with Microencapsulated DIM.

Microencapsulated DIM assists activity of hepatic cytochrome P450 enzymes (CYP1A2) pathways. Nutrients required to support phase 2 liver detoxification pathways can assist in reducing these symptoms.

  • A short-term increase in symptoms with Microencapsulated DIM may be due to increased metabolism of available oestrogen.
  • Microencapsulated DIM does not contain goitrogenic compounds which could affect thyroid function.
  • Microencapsulated DIM is not phytoestrogenic and has no inherent oestrogenic activity. Bioavailable DIM can be used in used in conjunction with phytoestrogenic herbs.
  • Microencapsulated DIM may assist hormone health when taken with Hormone Replacement Therapy (HRT)
  • Microencapsulated DIM may assist hormone health when taken with the oral contraceptive pill (OCP). Microencapsulated DIM has no inducing action on CYP3A4, the enzyme that metabolises the OCP. Therefore, Microencapsulated DIM does not affect efficacy of the OCP.
  • Microencapsulated DIM may assist effective metabolism of increased available oestrogen when taken with bioidentical hormone replacement therapy (BHRT).
  • Combined use of Microencapsulated DIM and Tamoxifen is not recommended.[60]
  • Combined use of Microencapsulated DIM and Zoladex is supported.
  • Microencapsulated DIM should be used with caution in patients taking anticoagulation medications.
  • Individuals on prescribed medications that are metabolized down the CYP1A1/1A2 pathways should seek medical advice. Eg. Microencapsulated DIM may lead to a moderate increase in the drug Olanzapine. [61]

References

[1] Zeligs MA. Safer Estrogen With Phytonutrition. The Townsend Letter. 1999; 189:83-88.

[2] Zeligs MA. Diet and estrogen status: the cruciferous connection. J of Medicinal Food 1998 Nov 2; 1: 67-82.

[3] Reed, GA, Sunega, JM, Sulivan DK, et al. Single-Dose Pharmacokinetics and Tolerability of Absorption-Enhanced 3,3’-Diindolylmethane in Healthy Subjects. Cancer Epidemiology Biomarkers & Prevention 17, 2619-2624, October 1, 2008.

[4] Zeligs MA, Brownstone PK, Sharp ME, et al. Managing Cyclical Mastalgia with Absorbable Diindolylmethane: A Randomized, Placebo-controlled Trial. JANA. Vol. 8, No.1 2005 Pages 10-20.

[5] Dalessandri KM, Firestone KM, Firestone GL, Fitch MD, et al. Pilot study: effect of 3,3’-diindolylmethane supplements on urinary hormone metabolites in postmenopausal women with a history of early-stage breast cancer. Nutrition and Cancer. 2004;50(2):161-7.

[6] Zeligs M.A, Sepkovic DW, Manrique C, et al. Absorption-enhanced 3,3’-Diindolylmethane: Human Use in HPV-related, Benign and Pre-cancerous Conditions. Proc. Am. Assoc. Cancer Res. 2003, Apr; 44.

[7] Jellinck PH, Forkert PG, Riddick DS, et al. Ah receptor binding properties of indole carbinols and induction of hepatic estradiol hydroxylation. Biochem Pharmacol 1993 Mar 9; 45(5):1129-36.

[8] Bradlow HL, Telang NT, Sepkovic DW, Osborne MP. 2-Hydroxyestrone: the ‘good’ estrogen. J Endocrinol. 1996;150 Suppl:S259-265.

[9] Samvat H, Kruzer M. Estrogen metabolism and breast cancer. Cancer Lett. 2015 Jan 28; 356(2 0 0):231-243.

[10] Kwa M, Plottel C, Blaser M, Adams S. The intestical microbiome and estrogen receptive-positive breast cancer.JNCI J Natl Cancer Inst (2016) 108(8): doi: 10.1093/jnci/djw029

[11] Robinson, J.A., et al., Direct action of naturally occurring estrogen metabolites on human osteoblastic cells. J Bone Miner Res, 2000. 15(3): p. 499-506

[12] Lier, JG and Ricci, MJ. 4-Hydroxylation of estrogens as marker of human mammary tumors. PNAS April 16, 1996 vol. 93.

[13] Cavalieri EL, Li KM, Balu N, et al. Catechol ortho-quinones: the electrophilic compounds that form depurinating DNA adducts and could initiate cancer and other diseases. Carcinogenesis. 2002 Jun;23(6):1071-7.

[14] Degner S, Papoutsis AJ, Selmin O, and Romagnolo DF. Targeting of Aryl Hydrocarbon Receptor-Mediated Activation of Cyclooxygenase-2 Expression by the Indole-3-Carbinol Metabolite 3,3#-Diindolylmethane in Breast Cancer Cells. J.Nutr. 139: 26–32, 2009.

[15] Cavalieri E, Frenkel K, Liehr JG, et al. Estrogens as endogenous genotoxic agents—DNA adducts and mutations. Journal of theNational Cancer Institute Monographs, No. 27, 75-94, 2000.

[16] Lord RS, PhD, Bongiovanni B, Bralley JA. Estrogen Metabolism and the Diet-Cancer Connection: Rationale for Assessing the Ratio of Urinary Hydroxylated Estrogen Metabolites. Alternative Medicine Review. 2002 Apr;7(2):112-29.

[17] Tsuchiya Y, Nakajima M & Yokoi T. Cytochrome P450-mediated metabolism of estrogens and its regulation in human. Caner Lett. 2005 Sep 28;227(2):115-24. Epub 2004 Nov 19.

[18] Dawling, S., N. Roodi, and F.F. Parl, Methoxyestrogens exert feedback inhibition on cytochrome P450 1A1 and 1B1. Cancer Res, 2003. 63(12): p. 3127.

[19] James, J., et al., Phase I safety, pharmacokinetic and pharmacodynamic studies of 2-methoxyestradiol alone or in combination with docetaxel in patients with locally recurrent or metastatic breast cancer. Invest New Drugs, 2007. 25(1): p. 41-8.

[20] Lakhani N, Sarkar M, Venitz J, Figg W. Methoxyestradiol, a Promising Anticancer Agent, first published online: 16 JAN 2012.

[21] Dawling S, Roodi N, Mernaugh R, Wang X, Parl F. Catechol-O-Methyltransferase (COMT)-mediated Metabolism of Catechol Estrogens: Comparison of Wild-Type and Variant COMT Isoforms1 CANCER RESEARCH 61, 6716–6722, September 15, 2001.

[22] Falk R, Brinton L, Dorgan J, Fuhrman B, Veenstra T, Xu X et al. Relationship of serum estrogens and estrogen metabolites  to postmenopausal breast cancer risk: a nested case control study. Breast Cancer Research 2013, 15:R34.

[23] Sampson, J, Falk R, Shairer C, Moore S, Fuhrman B,  Dallal C et al. Association of estrogen metabolism with breast cancer risk in different cohorts of post menopausal women. Cancer Res. 2017 February 15; 77(4): 918–925. doi:10.1158/0008-5472.

[24] Rahman KW, Sarkar FH. Inhibition of nuclear translocation of nuclear factor-{kappa}B contributes to 3,3’-diindolylmethaneinduced apoptosis in breast cancer cells. Cancer Research 65. 2005 Jan 1;65(1):364-71.

[25] Rahman KW, Li Y, Wang Z, et al. Gene expression profiling revealed survivin as a target of 3,3’-diindolylmethane-induced cell growth inhibition and apoptosis in breast cancer cells. Cancer Research 6. 2006 May 1;66(9):4952-60.

[26] Leong H, Firestone GL, Bjeldanes LF. Cytostatic effects of 3,3’-diindolylmethane in human endometrial cancer cells result from an estrogen receptor-mediated increase in transforming growth factor-alpha expression. Carcinogenesis. 2001 Nov;22(11):1809-17.

[27] Savino JA, Evans JF, Rabinowitz D, et al. Multiple, disparate roles for calcium signaling in apoptosis of human prostate and cervical cancer cells exposed to diindolylmethane. Mol Cancer Ther. 2006;5:556-563.

[28] Krieg M, Nass R, Tunn S. Effect of aging on endogenous level of 5 alpha-dihydrotestosterone, testosterone, estradiol, and estrone in epithelium and stroma of normal and hyperplastic human prostate. J Clin Endocrinol Metab 1993 Aug;77(2):375-81.

[29] Partin AW, Oesterling JE, Epstein JI, et al. Influence of age and endocrine factors on the volume of benign prostatic hyperplasia. J Urol 1991 Feb;145(2):405-9.

[30] Muti P, Westerlind K, Wu T, et al. Urinary estrogen metabolites and prostate cancer: a case-control study in the United States.Cancer Causes Control. 2002 Dec;13(10):947-55.

[31] Ercole L. Cavalieri et al. Catechol estrogen metabolites and conjugates in different regions of the prostate of noble rats treated with 4-hydroxoestrdial. Vol. 23, No. 2. pp. 329-333 2002.

[32] Bhuiyan MM, Yiwei L, Banerjee S, et al. Down-regulation of Androgen Receptor by 3,3’-Diindolylmethane Contributes to Inhibition of Cell Proliferation and Induction of Apoptosis in Both Hormone-Sensitive LNCaP and Insensitive C4-2B Prostate Cancer Cells. Cancer Research 66, 10064-10072, October 15, 2006.

[33] Le HT, Schaldach CM, Firestone GL, et al. Plant-derived 3,3’-Diindolylmethane is a strong androgen antagonist in human prostate cancer cells. Cancer Research. J. Biol. Chem., Vol. 278, Issue 23, 21136-21145, June 6, 2003.

[34] Bonkhoff H, Fixemer T. Implications of estrogens and their receptors for the development and progression of prostate cancer.Pathologe. 2005.

[35] Yang GS, Chen ZD. Comparative studies of the expression of estrogen receptor-alpha and estrogen receptor-beta in prostatic carcinoma. Zhonghua Wai Ke Za Zhi. 2004 Sep 22;42(18):1111-5. ) Nov;26(6):461-8.

[36] Zeligs MA. The Doctor’s Research Update. Natural Medicine for Men’s Health. Prostate Health with Diindolylmethane (DIM). Available at: http://dimfaq.com/index.htm. Accessed May 1, 2008.

[37] Garikapaty VP, Ashok BT, Tadi K. et al. 3,3?-Diindolylmethane downregulates pro-survival pathway in hormone independent prostate cancer. Biochemical and Biophysical Research Communications. Volume 340, Issue 2, 10 February 2006, Pages 718-725.

[38] Kong D, Yiwei L, Wang Z, et al. Inhibition of angiogenesis and invasion by 3,3’-diindolylmethane is mediated by the nuclear factor-kappaB downstream target genes MMP-9 and uPA that regulated bioavailability of vascular endothelial growth factor in prostate cancer. Cancer Research 67. 2007 Apr 1;67(7):3310-9.

[39] Nachshon-Kedmi M, Yannai S, Fares FA. Induction of apoptosis in human prostate cancer cell line, PC3, by 3,3’-diindolylmethane through the mitochondrial pathway. British Journal of Cancer (2004) 91, 1358?1363.

[40] Sarkar FH, Li Y. Harnessing the fruits of nature for the development of multi-targeted cancer therapeutics. Cancer Treat Rev. 2009 Nov;35(7):597-607. Epub 2009 Aug 5.

[41] Azzam F, Fares A, Stein A.The potential efficacy of 3,3’-diindolylmethane in prevention of prostate cancer development. Eur J Cancer Prev. 2010 May;19(3):199-203.

[42] Rahman KM, Banerjee S, Ali S, Ahmad A, Wang Z, Kong D, Sakr WA..3,3’-Diindolylmethane enhances taxotere-induced apoptosis in hormone-refractory prostate cancer cells through survivin down-regulation. Cancer Res. 2009 May 15;69(10):4468-75.

[43] Zhu BT, Conney AH. Functional role of estrogen metabolism in target cells: review and perspectives. Carcinogenesis.1998 Jan;19(1):1-27.

[44] Chang BL, Zheng SL, Isaacs SD, et al. Polymorphisms in the CYP1B1 gene are associated with increased risk of prostate cancer. British Journal of Cancer (2003) 89,1524-1529.

[45] Plottel CS Blaser MJ. Microbiome and malignancy. Cell Host Microbe.  2011;10(4):324–335.

[46] Oh H, Smith-Warner S, Tamimi R, Wang M, Xu X, Hankinson S et al. Dietary fibre and fat intakes are not associated with patterns of urinary estrogen metabolites in perimenopausal women.. J Nutr. 2015 Sep;145(9):2109-16. doi: 10.3945/jn.115.212779.

[47] Anderton MJ, Manson MM, Verschoyle RD, et al. Pharmacokinetics and Tissue Disposition of Indole-3-carbinol and Its Acid Condensation Products after Oral Administration to Mice. Clinical Cancer Research. Vol. 10, 5233-5241, August 1, 2004.

[48] Reed GA, Arneson DW, Putnam WC, et al. Single-dose and multiple-dose administration of indole-3-carbinol to women: phar macokinetics based on 3,3’-diindolylmethane. Cancer Epidemiol Biomarkers Prev. 2006 Dec;15(12):2477-81.

[49] Ciska E, Verkerk R, Honke J. Effect of boiling on the content of ascorbigen, indole-3-carbinol, indole-3-acetonitrile, and 3,3’-diindolylmethane in fermented cabbage. J Agric Food Chem. 2009 Mar 25;57(6):2334-8

[50] Bradfield CA, Bjeldanes LF. High performance liquid chromatographic analysis of anticarcinogenic indoles in Brassica oleracea. J Agric. Food Chem. 1987; 35:46-49.

[51] Chen DZ, Qi M, Auborn KJ, et al. Indole-3-Carbinol and Diindolylmethane Induce Apoptosis of Human Cervical Cancer Cells and in Murine HPV16-Transgenic Preneoplastic Cervical Epithelium. J Nutr. 2001 Dec;131(12):3294-3302.

[52] Bradlow HL, Zeligs MA. Diindolylmethane (DIM) spontaneously forms from indole-3-carbinol (I3C) during cell culture experiments. In Vivo. 2010 Jul-Aug;24(4):387-91.

[53] De Kruif CA, Marsman JW, Venekamp JC, Falke HE, Noordhoek J, Blaauboer BJ, Wortelboer HM. Structure elucidation of acid reaction products of indole-3-carbinol: detection in vivo and enzyme induction in vitro. Chem Biol Interact. 1991;80(3):303-15

[54] Rosen CA, Woodson GE, Thompson JW, Hengesteg AP, Bradlow HL. Preliminary results of the use of indole-3-carbinol for recurrent respiratory papillomatosis. Otolaryngol Head Neck Surg. 1998 Jun;118(6):810-5.

[55] Levine, S. Focus. Allergy Research Group Newsletter. October 2005. Pages 5-17.

[56] Grose KR, Bjeldanes LF. Oligomerization of indole-3-carbinol in aqueous acid. Chem Res Toxicol. 1992;5:188-93.

[57] Bjeldanes LF, Kim JY, Grose KR, et al. Aromatic hydrocarbon responsiveness-receptor agonists generated from indole-3-carbinol in vitro and in vivo: comparisons with 2,3,7,8-tetrachlorodibenzo-p-dioxin. Proc Natl Acad Sci U S A 1991 Nov 1;88(21):9543-7.

[58] Bradlow HL. Letter to the Editors of the Townsend Letter for Doctors and Patients. May 2002

[59] Anderton MJ, Manson MM, Verschoyle R, et al. Physiological modeling of formulated and crystalline 3,3’-diindolylmethane pharmacokinetics following oral administration in mice. Drug Metab Disp 2004; 32: 632_8.

[60] Thomson C,  Chow H, Wertheim B, Roe D, Stopeck A, Maskarinec G et al. A randomized, placebo-controlled trial of diindolylmethane for breast cancer biomarker modulation in patients taking tamoxifen.  Breast Cancer Res Treat. 2017 Aug;165 (1):97-107.

[61] Fuhrman BJ, Schairer C, Gail MH, Boyd-Martin J, Xu X, Sue LY, Buys SS, Isaacs C, Keefer LK, Veenstra TD, Berg CD, Hoover RN, Ziegler RG. Estrogen metabolism and risk of breast cancer in postmenopausal women. J Natl Cancer Inst. 2012;15:326–329. doi: 10.1093/jnci/djr531.