Zinc and broccoli sprouts – a winning combination

This 2019 study deserved better coverage than a one sentence mention in Reversal of aging and immunosenescent trends with sulforaphane:

“Obstructive sleep apnea syndrome is one of the most common breathing disorders in sleep, with a high prevalence of 3–7% and severe consequences. It is characterized by intermittent hypoxia (IH) due to recurrent episodes of partial or complete collapse of the upper airway during sleep, leading to blood hypoxemia, hypercapnia, sleep fragmentation, augmented respiratory efforts, and increased sympathetic activity.

Our study is the first investigation of the combination of BSE [broccoli sprout extract] and Zn [zinc], Nrf2, and MT [metallothionein] inducers, to protect against IH-induced cardiomyopathy. By effectively activating Nrf2, its downstream targets, and MT, this combination can ameliorate defects associated with IH-induced cardiomyopathy more effectively than monotherapies.

Mice were administered with BSE (equivalent to SFN [sulforaphane] 2 mg/kg) and/or Zn sulfate heptahydrate (5 mg/kg) by gavage from 8 weeks of age at a frequency of once every other day for 8 weeks. Doses used in this study are safe to convert to human doses. [2 mg x .081 x 70 kg = 11 mg sulforaphane; 5 mg x .081 x 70 kg = 28 mg zinc]

  • Heart mass was significantly lower in the IH-BSE/Zn group than in IH and IH-BSE groups. Heart mass / tibia length ratio was significantly lower in the IH-BSE/Zn group than in IH and monotherapy groups.
  • Treatment with BSE and/or Zn can ameliorate myocardial fibrosis associated with IH, to a certain extent, and combination therapy has the best antifibrotic effect among treatments.
  • BSE or Zn can significantly ameliorate myocardial inflammation induced by IH, but the combination provides a better anti-inflammatory effect.
  • We used 3-NT as an indicator of the severity of oxidative stress. 3-NT protein levels were significantly reduced in IH mice for all treatment groups, and reduction was greater in the combination treatment group.
  • Combination is more effective than monotherapies to activate Nrf2-mediated antioxidant function.

  • In Zn-treated and combination treatment groups, MT protein expression was significantly higher than in the IH group, and there was only a slight increase in the IH-BSE group.”

Combination of Broccoli Sprout Extract and Zinc Provides Better Protection Against Intermittent Hypoxia-Induced Cardiomyopathy Than Monotherapy in Mice

One way to improve broccoli sprout compounds’ effects is to eat them with zinc. One way to improve zinc’s actions is to take it with broccoli sprouts.

Week 34 of Changing to a youthful phenotype with broccoli sprouts

1. Thank you to readers of this blog who find the 650+ curations and other posts worth their time. I reread blog posts after you read them, and sometimes improve them for our mutual benefit.

One such post this week was Broccoli sprout compounds include sinapic acid derivatives. Although it was already fairly detailed, it received a half-dozen improvements.

  • Those researchers measured composition changes of 31 compounds (18 sinapic acid derivatives, 8 glucosinolates, and 5 flavonoids) identified in seed-2-4-6-day germination stages of one cultivar. They provided convertible dry weight and fresh weight measurements in mg / g.
  • It complemented the 3-day-old broccoli sprouts have the optimal yields study comparisons of six cultivated varieties’ seed-3-5-7-day germination stage weights and measurements with their origins using a milligram-per-gram-of-seeds scale:

    “To be comparable, the content of these bioactive compounds from 100 fresh sprouts was divided by the weight (g) of 100 seeds, and then this value was compared with their content from one gram seeds.”

  • The sinapic acid study discussed another study for:

    “In a study, diminishing amounts of total phenolic acids in sprouts of three broccoli cultivars was observed only between 3rd and 7th day of germination under photoperiod conditions and only when expressed on fresh weight basis. After recalculating results to dry weight, amounts were increasing during the whole 14-day observation period.”

All studies were scientifically informative. Still, results depended on researchers’ operative paradigms, and human behavior such as unconscious act-outs of unsatisfied needs to feel important.

2. Speaking of which, I viewed a 1:48 video with broccoli sprout experts who disparaged microwaving around the 1:10 mark. I’m not an expert, but I’ve eaten a clinically-relevant dose of microwaved broccoli sprouts every day for 34 weeks now.

Here are a few studies of microwaving’s effects on phenolic, glucosinolate, and flavonoid broccoli compounds. Just for those who value evidence more than opinion.

  • Microwaving broccoli sprouts may not affect phenolic levels found four of five test cases didn’t significantly diminish total phenolic fresh weight contents of whole broccoli. They blended 100 grams broccoli in 200 ml water, halved the purée, then microwaved half on 700W power for 30 seconds. No disclosure of what temperature was achieved, but it was probably < 60°C (140°F). Microwaving significantly increased the glucosinolate hydrolysis product indole-3-carbinol:

    “I3C in broccoli was increased by 3.1, 9.1 and 1.9 folds respectively using blenders 1, 2 and 5 with microwaving.”

  • Microwave broccoli to increase flavonoid levels study design was “Broccoli florets (150 g) were put in a microwave safe bowl with a 1 tablespoon [15 ml] of water” and a 1200W microwave on full power for one minute. Although this may have produced temperatures > 60°C, flavonoid fresh weight contents increased > 30%:

    Microwaving may increase extractability and/or release from binding to other compounds as a result of matrix softening.

  • Microwave broccoli to increase sulforaphane levels demonstrated significant differences for 450W (LL) and 900W (HL) power settings in glucoraphanin and sulforaphane dry weight amounts when broccoli florets were microwaved to the same temperatures. Compare white bar sulforaphane amounts for LL60 and HL60 (both 60°C), annotated as E and F:

    “Microwave treatment causes a sudden collapse of cell structure due to the increase in osmotic pressure difference over vacuole membrane. Microwave irradiation might help to release more conjugated forms of glucosinolates and then get hydrolyzed by released myrosinase.

  • Enhancing sulforaphane content confirmed the above 60°C finding with broccoli florets:

    “The best treatment temperature for maximizing sulforaphane yield was 60 °C. The slightly higher sulforaphane yield than would be predicted from the level of glucoraphanin in raw broccoli requires further investigation. The sulforaphane yield of broccoli after 5 min thermal treatment at 65 °C was even lower than the value obtained for raw broccoli.”

3. I see socialistic animal behavior often during beach walks. If one seagull pecks a food morsel, a half-dozen others immediately position themselves to take it. It’s a race to the bottom of existence.

Too bad we humans don’t learn pertinent lessons from others’ experiences, much less our own. Today’s US Thanksgiving provides one example.

Richard Ebeling presented the factual Thanksgiving story a while back. Have you read about collectivism that arrived with the Mayflower in 1620? Do you think we’ve learned what we needed to learn about communism from four centuries ago through today?

4. Seagulls are also inspirational in their flock behavior of joie de vivre predawn flying.

Part 2 of Eat broccoli sprouts for your eyes

I was a little bothered by an unreferenced statement in Eat broccoli sprouts for your eyes that:

“Once AGEs are formed, most are irreversible.”

I searched curated 2020 studies for “revers” and found that recent blog studies favored reversibility of epigenetic changes 12-to-2. Do they reflect my selection bias, or is there something different about AGEs?

Let’s start with this statement:

“Although AGEs are irreversible adducts and cross-links in our tissues, these can be removed through different proteolytic capacities:

  • The ubiquitin proteasome system (UPS) – Ubiquitin is a protein that when conjugated to a protein substrate can facilitate degradation of that substrate by the proteasome. Obsolete or damaged proteins are tagged with ubiquitin and these ubiquitinated substrates are degraded by the proteasome. Operates mainly on soluble substrates.
  • Autophagy – Can operate on insoluble substrates, including organelles such as mitochondria. Autophagy requires macromolecular assemblies and organelles to identify, sequester, and eventually degrade substrates via the lysosome.

Unfortunately, the function of both proteolytic pathways declines with extensive glycative stress and upon aging in many tissues, resulting in intracellular accumulation of protein aggregates (also glycated conjugates) and dysfunctional organelles. This thwarts strategies to lower AGEs accumulation by boosting proteolytic capacities.”

https://www.mdpi.com/2076-3921/9/11/1062/htm “Glyoxalase System as a Therapeutic Target against Diabetic Retinopathy”

So humans can remove irreversible AGE epigenetic changes as long as the individual isn’t too stressed or old? Studies from 2008 to 2012 were cited for the above statement and graphic.

Citation 211 Sulforaphane delays diabetes-induced retinal photoreceptor cell degeneration (not freely available) 2020 findings were instructive:

“SF [sulforaphane] can delay photoreceptor degeneration in diabetes. The underlying mechanism is related to:

  • Inhibition of ER [endoplasmic reticulum] stress;
  • Inflammation; and
  • Txnip [thioredoxin-interacting protein] expression through activation of the AMPK [adenosine 5′-monophosphate (AMP)-activated protein kinase] pathway.

Function of the retina in diabetic [DM] mice as determined by ERG [electroretinography].”

This chart demonstrated that preventing diabetes’ retinal effects (non-diabetic control bar) was measurably better than trying to fix them. Are future choices of humans who give themselves this non-communicable disease also limited to addressing symptoms?

The AMPK pathway was mentioned in:

  1. Reversal of aging and immunosenescent trends with sulforaphane:”

    Dihydroxyvitamin D3 and sulforaphane are compounds that safely induce AMPK activation, and may have wide-ranging implications for both normal and pathological aging.”

  2. Part 2 of Reversal of aging and immunosenescent trends with sulforaphane:

    “NQO1 plays a key role in AMPK-induced cancer cell death through the CD38/cADPR/RyR/Ca2+/CaMKII signaling pathway. Expression of NQO1 is elevated by hypoxia / reoxygenation or inflammatory stresses through nuclear accumulation of the NQO1 transcription factor, Nrf2. Activation of the cytoprotective Nrf2 antioxidant pathway by sulforaphane protects immature neurons and astrocytes from death caused by exposure to combined hypoxia and glucose deprivation.”

This first example was vitamin D3’s separate yet connected signaling pathway that acts both additively and synergistically with broccoli sprout compound effects. Followed by signaling pathways becoming cascadingly activated from sulforaphane’s main effect, Nrf2 signaling pathway activation.

Eat broccoli sprouts for your eyes

This 2020 review subject concerned a leading cause of blindness:

“Advanced glycation end products (AGEs) are toxic compounds that have adverse effects on many tissues including the retina and lens. AGEs promote the formation of reactive oxygen species (ROS), which, in turn, boost the production of AGEs, a vicious cycle.

Diabetic retinopathy (DR) is a devastating microvascular complication of diabetes mellitus and the leading cause of blindness in working-age adults. The onset and development of DR is multifactorial. Lowering AGEs accumulation may represent a potential therapeutic approach.

Once AGEs are formed, most are irreversible. Cataracts are perhaps the earliest pathobiology of AGEs:

Nε-(carboxymethyl)-lysine (CML) [a representative AGE] in lens crystallins from diabetic (■) and non-diabetic (♦) subjects as a function of age.

The glyoxalase system is a protective mechanism that slows down synthesis of AGEs by limiting reactive dicarbonyls formed during sugar metabolism. Glutathione (GSH) in the eye is present at concentrations many times blood levels, and is a critical component of the glyoxalase system.

Proteomic analysis identified GLO1 [glyoxalase 1] as a protein differentially expressed in cells treated with sulforaphane. Sulforaphane inhibited AGEs-derived pericyte damage and delayed diabetes-induced retinal photoreceptor cell degeneration.

No AGE inhibitors have reached clinical use. The glyoxalase system and discovery of compounds that enhance this detoxifying activity represent a therapeutic alternative to fight glycation-derived damage.”

https://www.mdpi.com/2076-3921/9/11/1062/htm “Glyoxalase System as a Therapeutic Target against Diabetic Retinopathy”

The above graph – plotting a cataract AGE level against chronological age – represented life stage progression without effective personal agency, without taking responsibility for your one precious life.

Citation 156 was Activation of Nrf2 attenuates carbonyl stress induced by methylglyoxal in human neuroblastoma cells: Increase in GSH levels is a critical event for the detoxification mechanism (not freely available):

“The present study focused on the methylglyoxal (MG) detoxification mechanism. MG treatment resulted in accumulation of modified proteins bearing the structure of AGEs.

This accumulation was suppressed by activation of the Nrf2 pathway prior to MG exposure via pre-treatment with an Nrf2 activator:

Although pre-treatment with the Nrf2 activator did not affect mRNA levels of GLO1, expressions of GCL and xCT mRNA, involved in GSH synthesis, were induced prior to increase in GSH levels.

These results indicated that increase in GSH levels promoted formation of the GLO1 substrate, thereby accelerating MG metabolism via the glyoxalase system and suppressing its toxicity. Promotion of GSH synthesis via the Nrf2/Keap1 pathway is important in MG detoxification.”

Continued in Part 2.


Nrf2 and Parkinson’s disease

This 2020 rodent study investigated a long non-coding RNA (lncRNA) in Parkinson’s disease:

“Knockdown of MALAT1 (metastasis-associated lung adenocarcinoma transcript 1) lncRNA inhibited elevated nuclear factor (erythroid-derived 2)-like-2 factor (NRF2) expression, thereby inhibiting inflammasome activation and ROS (reactive oxygen species) production. MALAT1 was shown to promote neuroinflammation by recruiting enhancer of zeste homologue 2 (EZH2) to the promoter of NRF2, suppressing Nrf2 expression.

EZH2 catalyses generation of trimethylated H3K27 (H3K27me3) from histone H3 at lysine 27 (H3K27). EZH2 plays an important role in regulating the essential genes for inflammation in microglial activation, which induces neurodegeneration in the central nervous system.

Our results also validated MALAT1 binding to EZH2 in LPS-treated BV2 cells, which further recruited H3K27me3 to the gene promoter loci of Nrf2 to repress Nrf2 transcription. Although silencing MALAT1 did not alter global EZH2 expression levels, decreased binding between EZH2 and the Nrf2 promoter was observed. Previous studies have revealed that lncRNAs regulate the function of EZH2 in a similar manner.

MALAT1 epigenetically inhibits NRF2, thereby inducing inflammasome activation and ROS production in PD mouse and microglial cell models. To the best of our knowledge, it is first report of the important role of EZH2 in regulating the expression of Nrf2 to activate microglial inflammation.”

https://molecularbrain.biomedcentral.com/articles/10.1186/s13041-020-00656-8 “LncRNA MALAT1 facilitates inflammasome activation via epigenetic suppression of Nrf2 in Parkinson’s disease”

Eat broccoli sprouts today! referenced a letter to the editor that cited The Ezh2 Polycomb Group Protein Drives an Aggressive Phenotype in Melanoma Cancer Stem Cells and is a Target of Diet Derived Sulforaphane which found:

“SFN treatment is associated with reduced Ezh2 level and H3K27me3 formation.”

However, that study didn’t link sulforaphane’s main effect of Nrf2 signaling pathway activation to these specific treatment effects.

This post was inspired by our latest subscriber, Dr. Albert F. Wright, who is battling PD with – among other treatments – broccoli seeds.

Mild stress improves broccoli compound yields

This 2020 plant study by the same university as Our model clinical trial for Changing to a youthful phenotype with broccoli sprouts investigated seasonal and stressful effects on broccoli compounds:

“In this study, three crop trials were carried out to evaluate effects of cultivation season, application of different dosages of methyl-jasmonate (MeJA) on overall quality and on total content of bioactive compounds of ‘Parthenon’ broccoli cultivated under field conditions of southeastern Spain.

Elicitation is the main tool used to increase content of secondary metabolites in vegetables, as it induces stress responses in plants. Several studies have involved application of elicitors to broccoli plants in order to improve their nutritional properties (although this application is more common for seeds and sprouts).

Content of total carotenoids, phenolic compounds and glucosinolates were higher in autumn compared with spring, showing increases of 2.8-fold, 2-fold and 1.2-fold, respectively. Moreover, a double application of MeJA increased contents of total carotenoids, phenolic compounds and glucosinolates by 22%, 32% and 39%, respectively, relative to untreated samples.

Controlled and timely (four days before harvest) application of 250 µM MeJA as an elicitor to aerial parts of plants, on two consecutive days, yielded florets of Parthenon broccoli with higher contents of bioactive compounds, without changing its overall quality.”

https://www.mdpi.com/2304-8158/9/10/1371/htm “Seasonal Variation of Health-Promoting Bioactives in Broccoli and Methyl-Jasmonate Pre-Harvest Treatments to Enhance Their Contents”

Findings by broccoli compound category were:


“Total content of GLSs was 2-fold higher in autumn than in spring. Total precipitation [2018] in spring was 361 mm compared with 185 mm in autumn. The water deficit in autumn could have contributed to the increase in total GLS content.

The main compound in samples of plants cultivated in spring (first and third assays) was glucoiberin (GIB), followed by glucoraphanin (GRA). The order was reversed in broccoli cultivated in autumn, with GRA being the main compound, followed by GIB, for all treatments.

Aliphatic GLSs were predominant in our Parthenon samples, representing on average 76%, 86% and 83%, of total GLSs in the first, second and third assays, respectively. In relation to the effect of MeJA on content of GLSs, neoglucobrassicin (NGB) was the only compound that showed a significant increase after application of MeJA in seasonal trials, since other GLSs decreased or did not differ with respect to the control group.

NGB increased significantly, from 0.3 mg/kg f.w., to 175 mg/kg f.w. in broccoli treated with two consecutive doses of 250 μM MeJA, and contents of GBSs, total indole GLSs and total GLSs also increased. In contrast, one single dose of 500 μM MeJA did not enhance contents of these compounds.”


“Contents of flavonols and chlorogenic acids were higher in autumn than in spring, whereas content of sinapic acid derivatives was higher in spring. Influence of light on individual phenolic compounds could explain the increase in flavonols and chlorogenic acid derivatives in autumn.

Although MeJA altered contents of phenolic compounds, this effect was not clearly associated solely with MeJA. We found a greater effect of the excipient and MeJA in autumn. When we added an extra stress factor – namely, MeJA – the impact was not as great as in autumn.”


“In broccoli cultivated in spring, the order was β-carotene > lutein > violaxanthin > neoxanthin, while in autumn the order was β-carotene > violaxanthin > lutein > neoxanthin. Content of total carotenoids in broccoli cultivated in autumn (26 mg/kg) represented a 2.8-fold increase compared to broccoli grown in spring (9 mg/kg).

Treatment with MeJA significantly reduced total content of carotenoids in broccoli cultivated in autumn, whereas it did not show any effect on plants cultivated in spring, and in some cases even led to an increase in carotenoid content. Plants that received two applications of 250 µM MeJA content of carotenoids (34 mg/kg f.w.) increased in comparison with plants without this treatment (28 mg/kg f.w.) as well as those receiving one application of 500 µM MeJA (28 mg/kg f.w.).

Chlorophyll content was directly related to carotenoids content, with a strong correlation in autumn. Carotenoids absorb solar light in the spectral region not covered by chlorophylls and pass light energy to chlorophyll a, protecting it from harmful reactions that occur in conditions of excessive light, in the presence of oxygen. When high temperatures reduce content of carotenoids in spring, a reduction in total chlorophylls is also observed, possibly due to the photo-oxidation process.”

DEET and permethrin cause transgenerational diseases

This 2020 rodent study from the labs of Dr. Michael Skinner at Washington State University examined how great-grandmothers’ insect repellent exposures produced diseases in their great-grand offspring:

“Permethrin and DEET are the pesticides and insect repellent most commonly used by humans. These pesticides have been shown to promote the epigenetic transgenerational inheritance of disease in rats.

Direct exposure impacts an individual and their germ line. If germline epigenetics are modified, offspring generated with the affected germ cell can have epigenetic impacts on health and physiology.

Negative health effects of pesticides exposure do not stop with the individuals directly exposed. Epigenetic transgenerational inheritance occurs when future generations without exposure also exhibit alterations and disease. Epigenetic alterations are more common among individuals with disease than specific genetic alterations or mutations.

Pathologies examined are relevant to human populations including prostate, testis and kidney disease, as well as multiple disease incidence. No common DMR [differential DNA methylation region] among the different transgenerational disease DMR biomarkers was identified.

Observations suggest a common set of epimutations is not present between different diseases to alter general disease susceptibility. Although suggestions of such general molecular impacts for disease susceptibility may exist, the current study suggests predominately disease specific epimutations.

DMRs are present for each individual disease on all chromosomes, except the Y chromosome and mitochondrial DNA. The multiple disease signatures are present on the Y chromosome, as well as all other chromosomes. These results support the idea that transgenerational epigenetic effects of ancestral pesticides exposure are genome-wide.

The current study used an epigenome-wide association analysis to identify an epigenetic signature of transgenerational disease present in sperm. Biomarkers identified herein may potentially be used to assess paternal transmission of disease susceptibilities to future generations.”

https://ehjournal.biomedcentral.com/articles/10.1186/s12940-020-00666-y “Epigenome-wide association study for pesticide (Permethrin and DEET) induced DNA methylation epimutation biomarkers for specific transgenerational disease”

Don’t understand how studies on long-term effects of day-to-day human actions like applying insect repellent aren’t front page news. Everyone could benefit from this knowledge. When I explained this study to coworkers, they had a lot of questions and feedback.

An interesting side note was peer review exchanges. A human behavior indicator was pushback regarding repetition of key points among sections, which the researchers justified with:

“The reader does not have to skip back and forth between sections to understand the basic design and methods used.”

Behavioral aspects of epigenetic inheritance haven’t been investigated by this research group. Wouldn’t inherited conditions produce behavioral evidence of their consequences?

Sulforaphane in the Goldilocks zone

This 2020 paper reviewed hormetic effects of a broccoli sprout compound:

“Sulforaphane (SFN) induces a broad spectrum of chemoprotective effects across multiple organs that are of importance to public health and clinical medicine. This chemoprotection is dominated by hormetic dose responses that are mediated by the Nrf2/ARE pathway and its complex regulatory interactions with other factors and pathways, such as p53 and NF-κB.

The stimulatory zone for in vitro studies proved to be consistently in the 1-10 μM range. Hormetic studies of SFN strongly targeted activation of Nrf2.

Capacity to activate Nrf2 diminishes with age, and may affect capacity of SFN to effectively enhance adaptive responses.

A 4-hour exposure induced a 24 hour Nrf2-mediated increase in enzymes that reduce free-radical damage in neurons and astrocytes. Repeated 4-hour treatment for four days affected an accumulation along with a persistent protection.

In the case of continuous exposure to SFN, such as taking a daily supplement, SFN treatment did not result in an accumulation of HMOX1 [heme oxygenase (decycling) 1 gene] mRNA or protein. This suggested that HMOX1 response may experience feedback regulation, avoiding possible harmful overproduction.”

https://www.sciencedirect.com/science/article/abs/pii/S1043661820315917 “The phytoprotective agent sulforaphane prevents inflammatory degenerative diseases and age-related pathologies via Nrf2-mediated hormesis” (not freely available)

One coauthor has been on a crusade to persuade everybody of this paradigm. Hormesis’ hypothesis isn’t falsifiable in all circumstances, however.

Hormetic effects may be experimental considerations. But what’s the point of performing sulforaphane dose-response experiments in contexts that are physiologically unachievable with humans? Two examples:

  1. Autism biomarkers and sulforaphane:

    “There was no concentration-dependence in the induction of any of the genes examined, with the higher (5 μM) concentration of SF even showing a slightly diminished effect for the induction of AKR1C1 and NQO1. Although this concentration is achievable in vivo, more typical peak concentrations of SF (and its metabolites) in human plasma are 1-2 μM.”

  2. Human relevance of rodent sulforaphane studies:

    “Over two-thirds of the animal studies have used doses that exceed the highest (and bordering on intolerable) doses of sulforaphane used in humans. The greater than 4-log spread of doses used in mice appears to be driven by needs for effect reporting in publications rather than optimization of translational science.”

This paper cited many hormetic effects that were human-irrelevant without making a distinction. It also had parts such as:

“The capacity for high concentrations of AITC [allyl isothiocyanate] to enhance genetic damage is not relevant since such high concentrations are not realistically achievable in normal human activities.

Humans ingest only the R-isomer of SFN via diet. Their dosing strategy adopted concentrations of R-SFN that were less than those employed to induce cytotoxic effects in cancer cells and that simulated its consumption as a dietary supplement.”

Landing eagle

Microwaving broccoli sprouts may not affect phenolic levels

Three papers investigated microwaving plant material for phenolic compounds. The first was a 2020 review that compared industry techniques:

“Phenolic compounds are widely used as natural antioxidants and antimicrobial agents. They also exhibit antiallergenic, antiatherogenic, and anti-inflammatory activities.

Although the nature and properties of raw materials strongly influence extraction, all extraction processes share major parameters:

  • Solubility of phenolic compounds is higher in polar solvents such as water and ethanol or their mixtures;
  • Diffusion of compounds and mass transfer rates are enhanced by increased temperature; and
  • Longer extraction times allow for a more intimate and effective contact between solvent and matrix.

MAE [microwave-assisted extraction] is an efficient technique due to its ability to heat a matrix internally and externally without a thermal gradient. Phenolic compounds and ionic solutions strongly absorb microwave energy. Microwaves cause internal superheating of water molecules of a sample, promoting cellular disruption and enhancing the recovery of target compounds from the matrix.

MAE produces the highest total phenolic content, 227.63 mg GAE [gallic acid equivalent] /g dry basis.”

https://link.springer.com/article/10.1007%2Fs13197-020-04433-2 “Recent advances and comparisons of conventional and alternative extraction techniques of phenolic compounds” (not freely available)

I didn’t see any studies in the first paper that I could directly use. Either temperature was too high, or microwave power too low, or was something I’m not going to do, like substitute ethanol for water.

A second 2020 paper compared three industry techniques to extract phenolics from olive and wine post-processing plant material:

“In the case of olive pomace, TPC [total polyphenol content] improved by increasing the ethanol concentration from 20 to 50%, and temperature from 60 to 90°C. No significant improvement was observed when increasing time from 5 to 15 min.

The best extraction efficiency for olive pomace residues was provided by MAE.”

https://www.mdpi.com/2076-3921/9/11/1074/htm “Olive Mill and Winery Wastes as Viable Sources of Bioactive Compounds: A Study on Polyphenols Recovery”

The second study demonstrated that polyphenols weren’t harmed by temperatures up to 90°C. Microwave power was 500W per correspondence with the authors.

Microwave broccoli to increase sulforaphane levels demonstrated significant differences for 450W (LL) and 900W (HL) power settings in glucoraphanin and sulforaphane amounts when microwaved to the same temperatures. Compare sulforaphane amounts for LL60 and HL60 (both 60°C), annotated as E and F:

A third study from 2017 measured total phenolic contents, but primarily used indole-3-carbinol to probe food preparation methods:

“This study evaluated the effects of grinding and chopping with / without microwaving on the health-beneficial components, and antioxidant, anti-inflammation and anti-proliferation capacities of commercial kale and broccoli samples. The availability of indole-3-carbinol (I3C) and total phenolic contents [TPC] were evaluated.

Fifty grams and 100 g of commercial fresh kale and broccoli (including stem and leaves) samples were ground for 15 s with 200 mL of water in 5 different commercial available blenders. The ground vegetables were divided into two parts, and one part was microwaved at 700 watts for 30 s.

Availability of I3C was significantly enhanced with grinding as compared to chopping (below the limit of detection), suggesting the effect of particle size on food factor release. Particle sizes of ground kale and broccoli were 10 times smaller than chopped counterparts. Grinding [in broccoli] not only resulted in difference of particle size, but might also break plant cell walls and release enzymes such as myrosinase, which might have hydrolyzed glucobrassicin and caused a greater releasable I3C level.

Significant difference was observed in I3C availability with or without microwaving. Microwaving significantly elevated the extractable amount of I3C from broccoli regardless of the blenders used. For instance, availability of I3C in broccoli was increased by 3.1, 9.1 and 1.9 folds respectively using blenders 1, 2 and 5 with microwaving as compared to their unmicrowaved counterparts.

TPC from blended broccoli samples ranged from 0.28-0.47 mg gallic acid g-1 of fresh weight. This range was lower than a reported mean of 0.99 mg gallic acid g-1 of fresh broccoli [in another study], suggesting different cultivars, locations (USA versus France) and extraction methods (water extraction versus 70% acetone extraction) might affect releasable TPC from broccoli.”

https://www.sciencedirect.com/science/article/abs/pii/S0308814617318484 “Home food preparation techniques impacted the availability of natural antioxidants and bioactivities in kale and broccoli” (not freely available)

1. Funny that I found this third paper in a PubMed “microwave phenolic broccoli” search, but not in any Part 2 of Do broccoli sprouts treat migraines? I3C combination searches. A plain “I3C” search term like how I search PubMed weekly on “sulforaphane” would have found it.

2. Don’t understand why blenders 1-5 makes and models weren’t stated in the study. Using blender 1 made a significant difference in TPC in the above graphic, but that was the effect. What could have been the cause? Aren’t researchers obligated to provide such explanations?

And why didn’t the study text support the graphic and address all TPC results with microwaved broccoli? Microwaving produced neither significant TPC differences among blenders 2-5 broccoli samples, nor in any of the kale samples.

3. Also don’t understand why these researchers didn’t microwave chopped broccoli samples and measure them for TPC and I3C. Maybe that wouldn’t have produced anything for TPC if phenolics aren’t produced from the myrosinase hydrolysis chain of events.

But I3C is a myrosinase hydrolysis product. Testing microwaved chopped samples for I3C may have changed the above bolded statement to:

“Microwaving significantly elevated the extractable amount of I3C from broccoli regardless of the blenders used. [food preparation method.]

4. One broccoli treatment was blending 100 grams broccoli in 200 ml water, halving the purée, then microwaving half on 700W power for 30 seconds. The study didn’t say what temperature was achieved, but it was probably < 60°C because that’s similar to what I do.

Twice every day I microwave an average 65.5 grams of 3-day-old broccoli sprouts in 100 ml water on 1000W full power for 35 seconds to achieve up to but not exceeding 60°C. I use the same 100 ml water, but more broccoli sprout weight and microwave wattage to initiate myrosinase hydrolization of glucoraphanin and other glucosinolates into sulforaphane and other healthy compounds.

5. My son encouraged me to try blending microwaved broccoli sprouts this summer. I stopped after two weeks as I consistently had trouble swallowing them.

6. The study design required microwaving broccoli sprouts after blending. I don’t think people would do it in this order at home.

It would be too messy to scrape a broccoli sprout purée out of a blender and into a microwavable dish, while maintaining a desired water volume for microwaving. The reverse order is easier – measure the desired water volume into the broccoli sprouts dish, microwave, then plop microwaved broccoli spouts into a blender.

Broccoli sprout compounds include sinapic acid derivatives

This 2020 study provided details about healthy sinapic acid broccoli sprout compounds:

“Anti-inflammatory effects of broccoli sprouts have been demonstrated in vivo, but the connection with composition is not yet fully explained. The aim of the present study was:

  • Provide a complex qualitative / quantitative insight into variability of SADs [sinapic acid derivatives] during germination of broccoli sprouts; and
  • Investigate their antioxidant and anti-inflammatory properties that might result from the presence of phenolics.

Sprouting in darkness results in overall decrease in total content of SADs with growth time, but promotes replacement of relatively low active constituents, such as sinapine, by stronger antioxidants. These structural changes are beneficial for total antioxidant capacity of broccoli sprouts, and are correlated with their increasing ability to scavenge free radicals, reduce transition metal ions, and inhibit lipid peroxidation.”

The graphic’s dotted line is sinapine.

“Anti-TNF-α activity of broccoli sprout extract and sinapic acid was less relevant than that of an anti-inflammatory drug DEX [dexamethasone]. However, contrary to DEX, they significantly stimulated release of IL-10, which is an anti-inflammatory and immunosuppressive factor. By downregulating secretion of pro-inflammatory cytokines, IL-10 may impede immunopathology by inhibiting activity of macrophages, natural killer cells and lymphocytes.

Most of the previous studies ascribed anti-inflammatory effects of broccoli sprouts to their sulfur compounds only. Research data from in vivo models confirmed that glucosinolates may stimulate IL-10 release while isothiocyanates do not influence significantly or even decrease its production.

The present study indicates that phenolic constituents may also be responsible for anti-inflammatory effects of broccoli sprouts, and stimulation of IL-10 might be most relevant in this context.”

https://pubs.rsc.org/en/content/articlelanding/2020/FO/D0FO01387K “Variability of sinapic acid derivatives during germination and their contribution to antioxidant and anti-inflammatory effects of broccoli sprouts on human plasma and human peripheral blood mononuclear cells” (not freely available)

Some aspects of this study:

1. Seed-2-4-6 day measurements complemented seed-3-5-7 day measurements of the superb 3-day-old broccoli sprouts have the optimal yields. Both studies used standard methodologies, provided convertible dry weight and fresh weight measurements in mg / g, and grew their sprouts in darkness, with the current study watering every 12 hours.

The current study measured composition changes of 31 compounds (18 sinapic acid derivatives, 8 glucosinolates, and 5 flavonoids). It was too complicated for me to sum up and convert these granular dry weight measurements to make them directly comparable with 3-day study total phenolics (TP below, and TF is total flavonoids). They decreased similarly to TP mg / g fresh weight measurements.

The 3-day study also compared each cultivated variety’s germination stage weights and measurements with its origin using a milligram-per-gram-of-seeds scale:

“To be comparable, the content of these bioactive compounds from 100 fresh sprouts was divided by the weight (g) of 100 seeds, and then this value was compared with their content from one gram seeds.

The seed weight of XM was nearly twice that of other varieties and its sprouts weight also had the highest increasing rate. LWW and LY had the lowest weight of seeds as well as sprouts.”

phenolics and flavonoids

Different lowercase letters meant significant differences in the same cultivar among sampling days, and uppercase in the same sampling day among cultivars.

A. That study’s mg / g fresh weight trend favored broccoli seeds, a subject explored in Microwave broccoli seeds to create sulforaphane. Seeds of all six cultivars were significantly higher than their sprouts in TP, TF, and sulforaphane in this paradigm.

B. The mg / g seed trend favored 3-day-old broccoli sprouts for TP (five of six cultivars), TF (all), but not sulforaphane (two of six). Both trends were scientifically informed.

Which paradigm suits you?

2. A 2005 study was cited for:

“Total glucosinolate content in fresh broccoli sprouts were reported to reach 4.02 μmol/g fw, which corresponds to 0.71 mg/g fw of active isothiocyanates. In our study, total content of SADs in 6-day-sprouts was 4.85 mg/g dw. Recalculating to fresh weight gives 0.37 mg/g fw, which suggests that SADs might well influence biological effects of glucosinolates.”

The current study measured eight glucosinolates but no isothiocyanates. Don’t think this 2005 study provided bases for close comparisons, since it had unknown broccoli cultivar, unknown sprout age, and unanalyzed isothiocyanates.

Comparisons to a two-decimal-point precision should use the same cultivar and contexts, to include growing conditions. For example:

  • The 3-day study showed wide variation in sulforaphane weights among six broccoli cultivars’ seeds, from 2.43 mg to 12.07 mg per gram of seeds. And:

    “Knowledge concerning the bioavailability of plant ITCs is essential to predict the potential level of exposure as GL determination alone may not accurately reflect how much of the final active ITC can be formed from sprouts.”

  • The three cultivars studied in Lab analyses of broccoli sprout compounds had broccoli sprout sulforaphane amounts vary from 0.3 to 1.2 μmol / g fw in one growing season, then from 0.2 to 0.6 μmol / g fw the next year.

But these researchers knew that:

“In a study, diminishing amounts of total phenolic acids in sprouts of three broccoli cultivars was observed only between 3rd and 7th day of germination under photoperiod conditions and only when expressed on fresh weight basis. After recalculating results to dry weight, amounts were increasing during the whole 14-day observation period.

Trends cannot be treated as universal, but are dependent on growth conditions and variety of the plant.”

“0.37 mg/g fw” of Day 6 sinapic acid derivatives would be lower than Day 7 of four 3-day study cultivars’ total phenolics, and between Days 5 and 7 of the other two. I’d guess that the current study’s cultivar, Cezar, would be neither the lowest nor the highest cultivar if comparably measured for total phenolics.

3. These researchers compared other studies to an extent that isn’t usually seen. The result was good information such as:

“The most significant difference is sinapine that was not detected in either of the two above mentioned works, but is a major component of extracts investigated in the present work.

In one study, 7-day-sprouts were germinated under photoperiod conditions and without monitoring the phenolic profile in preceding growing days. Dominating constituents identified were trisinapoyl-gentiobiose, that was also present in relevant quantities in 6-day-sprouts, and sinapoyl-malate, that was not detected in our study.

Taking into account the significant role of these compounds (especially sinapoyl-malate) in UV-protection, light availability might have caused much quicker sinapine degradation and synthesis of SADs more suitable for those conditions. The same study also demonstrated that additional UVA and UVB irradiation before harvest further induced production of some of the constituents.

4. Flavonoids and hydroxycinnamic acids are subgroups of phenolic compounds. Sinapic acid derivatives are a category of hydroxycinnamic acids.

Would microwaving sinapic acid derivatives have similar effects to what was described in Microwave broccoli to increase flavonoid levels? That’s the subject of Microwaving broccoli sprouts may not affect phenolic levels.

Eat broccoli sprouts for pain?

This 2018 study investigated pain-relieving effects of two broccoli sprout compounds, sulforaphane and chlorogenic acid:

“Pharmacological evidence of the antinociceptive properties of broccoli aqueous extracts and bioactive metabolites were investigated in an experimental model of pain.

It was found that sprouts produced better antinociceptive response than seeds and inflorescence of broccoli, where SFN [sulforaphane] and CA [chlorogenic acid] were partial responsible. Opioid receptors were implicated in the antinociceptive effect of SFN, whereas calcium channels were involved in the concentration-dependent spasmolytic activity.

Our results give evidence of a dose-dependent antinociceptive effect of CA that might act in a synergic interaction with SFN and other metabolites to produce antinociceptive activity.”

https://www.sciencedirect.com/science/article/abs/pii/S0753332218333286 “Broccoli sprouts produce abdominal antinociception but not spasmolytic effects like its bioactive metabolite sulforaphane” (not freely available)

8-day-old broccoli sprouts were treated Days 5-8 with methyl jasmonate to increase glucosinolates as Our model clinical trial for Changing to a youthful phenotype with broccoli sprouts did.

I hadn’t previously noticed papers on “Chlorogenic and Sinapic acid derivatives” that are part of my daily intake, but there’s much recent research. Consider these October 2020 chlorogenic acid papers for example:

I found If it stinks, it’s good for you as a result of it citing this study. See Broccoli sprout compounds include sinapic acid derivatives to follow on that subject.

I rated this study as Required further work. This is my 31st week of eating a clinically relevant amount of broccoli sprouts every day, and I still take acetaminophen.

If it stinks, it’s good for you

This 2019 review subject was hydrogen sulfide and broccoli sprout compounds:

“Release of H2S was identified as a hidden mechanism responsible for effects of natural compounds that were used for a long time for pharmacological, therapeutic or nutraceutical purposes. For instance, the release of H2S was recognized as the main mechanism accounting for the biological effects of garlic.

There is evidence of a close overlap between numerous physiological / biological effects attributed to natural ITCs [isothiocyanates] and H2S. They both behave as antioxidant and anti-inflammatory agents, are activators of potassium channels modulating a vasodilatory effect, and are chemopreventive agents. Moreover, an impressive overlap can be observed in the molecular mechanisms of action.

Vascular inflammation results from the persistence of oxidative and/or inflammatory stimuli on the endothelium and vascular smooth muscle. These types of stimuli can be a consequence of prolonged status of mild inflammation and are typical in certain metabolic / cardiovascular diseases, spreading to all organs and tissues.

Advanced glycation end products (AGEs) are responsible for an increase in LDL. Binding of AGEs to their receptors RAGE results in an increase in intracellular ROS generation and in activation of NF-kB. Oral consumption of SFN [sulforaphane] precursor-rich broccoli sprouts decreases the serum levels of AGEs in humans.

Inflammatory response plays a pivotal role in initiation and maintenance of chronic neuropathic pain. Inhaling low concentrations of H2S protects motor neurons from degeneration and delayed paraplegia in a mouse model of sciatic constriction injury. This effect has been ascribed to the activation of the Nrf2 pathway.

Dose-dependent rise of the pain threshold mediated by SFN was fully prevented by simultaneous administration of hemoglobin, confirming that H2S is likely to be the real player in ITC-induced analgesia. Kv7 channel activation can be considered one of the main mechanisms in the antinociceptive activity of H2S-releasing drugs.”

https://www.liebertpub.com/doi/10.1089/ars.2019.7888 “Organic Isothiocyanates as Hydrogen Sulfide Donors” (not freely available)

These reviewers were long on equivalencies and short on proofs. Unlike study researchers, reviewers aren’t bound to demonstrate evidence from tested hypotheses. Reviewers are free to:

  • Express their beliefs as facts;
  • Over/under emphasize study limitations; and
  • Disregard and misrepresent evidence as they see fit.

Study researchers are obligated to provide detailed analyses of why observed effects couldn’t have been produced from unobserved causes. That didn’t happen here.

Anti-tumor effects of β-glucan

This comprehensive 2020 rodent study investigated dozens of scenarios for β-glucan in the context of anti-tumor immunity:

“Neutrophils and granulopoietic progenitors are major cellular effectors of β-glucan-induced trained immunity. The anti-tumor effect of β-glucan-induced trained immunity was mediated by qualitative changes in neutrophils.

A tumor-suppressive phenotype in neutrophils was associated with training of granulopoiesis mediated by type I IFN [interferon] signaling. Our analysis provided additional evidence for trained immunity-induced epigenetic rewiring of granulopoiesis toward an anti-tumor phenotype and corroborated the experimentally demonstrated IFN- and ROS-related mechanisms.

We observed inhibition of tumor growth by systemic transfer of trained neutrophils into already tumor-bearing mice. As granulocyte transfusion is currently considered as a therapy in humans with neutropenia, it is conceivable that cancer patients could receive as an adjuvant immunotherapy granulocytes from normal donors after induction of trained immunity in the latter.

Our study is the first to link the anti-tumor actions of β-glucan to trained immunity. We show here that the innate immune training and rewiring of granulopoiesis underlies the anti-tumor effect of β-glucan.”

https://www.cell.com/cell/fulltext/S0092-8674(20)31299-X “Innate Immune Training of Granulopoiesis Promotes Anti-tumor Activity”

Which do you prefer? The study’s graphical abstract:

or one of its volcano plots?

Here’s an overview of one investigated direction:

“To determine whether adaptive immunity is involved in the anti-tumor effect induced by β-glucan, mice that lack B and T cells were treated with β-glucan [1 mg] prior to the secondary tumor challenge. Pre-treatment with β-glucan decreased both B16-F10 [melanoma] and LLC [Lewis lung carcinoma] tumor burden also in [these] mice, showing that the anti-tumor effect of β-glucan-induced trained immunity does not require adaptive immunity.”

This study provided another example of what they called rewiring (but I term reprogramming) of the body’s environmental signaling pathways to achieve a desired phenotype, trained innate immunity. Whatever the terminology, almost every day over the past fifteen years I’ve eaten β-glucan in an oats breakfast and a 1/3, 1/6 yeast supplement at dinner as part of individually evolving.

Reprogramming other signaling pathways are in blog posts such as:

Take responsibility for your one precious life.

Flying over waves

Nano-sulforaphane vs. barbecue chemicals

This 2020 chicken study investigated the capability of nano-sulforaphane to protect embryonic survival and neurogenesis from a barbecued meat chemical:

“Common teratogenic [of, relating to, or causing malformations of an embryo or a fetus] factors related to the development of the nervous system, such as alcohol consumption and smoking, have attracted wide attention. Teratogenic factors such as PhIP, the most abundant amine produced in common cooking procedures, can affect early embryonic development, leading to abnormal development of the nervous system.

Nano-sized medicine, in comparison with conventional medicine, leads to increased active concentrations and bioavailability. Both PhIP and nanoparticles can cross the placental barrier and enter the fetus from the external environment.

Chick embryos (100 per group) were incubated with 0.1% DMSO (Control); 20μM, 100μM, 200μM, or 300μM PhIP; or 200μM PhIP + 5μM Nano-SFN [sulforaphane] for 36 h:

  • Mortality rates were 0% for the Control, 8% with 20μM PhIP, 20% with 100μM PhIP, 53% with 200μM PhIP, 85% with 300μM PhIP, and 7% with 200μM PhIP + 5μM Nano-SFN.
  • Neural tube malformation rates [for the remaining live embryos] were 0% for the Control, 5% with 20μM PhIP, 14% with 100μM PhIP, 36% with 200μM PhIP, 14% with 300μM PhIP, and 6% with 200μM PhIP + 5μM Nano-SFN.

Women at the early stage of pregnancy should avoid barbecue. Instead, increase intake amount of cruciferous vegetables, which benefits fetal neural development.”

https://www.sciencedirect.com/science/article/abs/pii/S0940960220301618 “Nano-sulforaphane attenuates PhIP-induced early abnormal embryonic neuro-development” (not freely available)


Dietary contexts matter

Two papers illustrated how actions of food compounds are affected by their contexts. The first was a 2020 UCLA rodent study:

“Long-chain polyunsaturated fatty acids (PUFAs), particularly omega-3 (n-3) PUFAs, have been indicated to play important roles in various aspects of human health. Controversies are observed in epidemiological and experimental studies regarding the benefits or lack of benefits of n-3 PUFAs.

Dietary docosahexaenoic acid (DHA; 22:6 n-3) supplementation improved select metabolic traits and brain function, and induced transcriptomic and epigenetic alterations in hypothalamic and hippocampal tissues in both context-independent and context-specific manners:

  • In terms of serum triglyceride, glycemic phenotypes, insulin resistance index, and memory retention, DHA did not affect these phenotypes significantly when examined on the chow diet background, but significantly improved these phenotypes in fructose-treated animals.
  • Genes and pathways related with tissue structure were affected by DHA regardless of the dietary context, although the direction of changes are not necessarily the same between contexts. These pathways may represent the core functions of DHA in maintaining cell membrane function and cell signaling.
  • DHA affected the mTOR signaling pathway in hippocampus. In the hypothalamus, altered pathways were more related to innate immunity, such as cytokine-cytokine receptors, NF-κB signaling pathway, and Toll-like receptor signaling pathway.

DHA exhibits differential influence on epigenetic loci, genes, pathways, and metabolic and cognitive phenotypes under different dietary contexts.”

https://onlinelibrary.wiley.com/doi/10.1002/mnfr.202000788 “Multi‐tissue Multi‐omics Nutrigenomics Indicates Context‐specific Effects of DHA on Rat Brain” (not freely available)

A human equivalent age period of the subjects was 12 to 20 years old. If these researchers want to make their study outstanding, they’ll contact their UCLA colleague Dr. Steven Horvath, and apply his new human-rat relative biological age epigenetic clock per A rejuvenation therapy and sulforaphane.

The second paper was a 2016 review Interactions between phytochemicals from fruits and vegetables: Effects on bioactivities and bioavailability (not freely available):

“The biological activities of food phytochemicals depend upon their bioaccessibility and bioavailability which can be affected by the presence of other food components including other bioactive constituents. For instance, α-tocopherol mixed with a flavonol (kaempferol or myricetin) is more effective in inhibiting lipid oxidation induced by free radicals than each component alone.

Interactions of phytochemicals may enhance or reduce the bioavailability of a given compound, depending on the facilitation/competition for cellular uptake and transportation. For example, β-carotene increases the bioavailability of lycopene in human plasma, and quercetin-3-glucoside reduces the absorption of anthocyanins.

Combinations of food extracts containing hydrophilic antioxidants and lipophilic antioxidants showed very high synergistic effects on free radical scavenging activities. A number of phytochemical mixtures and food combinations provide synergistic effects on inhibiting inflammation.

More research should be conducted to understand mechanisms of bioavailability interference considering physiological concentrations, food matrices, and food processing.”

Each of us can set appropriate contexts for our food consumption. Broccoli sprout synergies covered how I take supplements and broccoli sprouts together an hour or two before meals to keep meal contents from lowering sulforaphane bioavailability.

Combinations of my 19 supplements and broccoli sprouts are too many (616,645) for complete analyses. Just pairwise comparisons like the second paper’s example below would be 190 combinations.

binary isobologram

Contexts for each combination’s synergistic, antagonistic, or additive activities may also be influenced by other combinations’ results.

My consumption of flax oil (alpha linolenic acid C18:3) probably has effects similar to DHA since it’s an omega-3 PUFA and I take it with food. The first study’s human equivalent DHA dose was 100mg/kg, with its citation for clinical trials stating “1–9 g/day (0.45–4% of calories) n-3 PUFA.”

A 2020 review Functional Ingredients From Brassicaceae Species: Overview and Perspectives had perspectives such as:

“In many circumstances, the isolated bioactive is not as bioavailable or metabolically active as in the natural food matrix.”

It discussed categories but not combinations of phenolics, carotenoids, phytoalexins, terpenes, phytosteroids, and tocopherols, along with more well-known broccoli compounds.

Diving for breakfast