Saturday, April 2, 2016

Broccoli and Biotransformational Detox

The isothiocyanate called sulforaphane derived from broccoli and other Brassicaseae plants has received a lot of attention as being a wonderful method to activate nuclear factor erythroid 2-related factor 2  (Nrf2) which then activates Phase II of our biotransformation/detox systems.  This is a really good thing. Phase II of our biotransformational/detox system helps us feel better and function better as it is transforming  toxins to be removed from our body. It protects us from cancer which is a biggy in this world of carcinogenic toxins. If you want to know more about this biotransformation system, I wrote an article here. It gives the basics on the system and has some links to more specifics.

Just a little on Nrf2 that is activated by sulforaphane: Nrf2 has been variously described as an: 

1. Activator of cellular defense mechanisms

2.Master redox switch - in other words, protects you from free radicals

Broccoli3. Guardian of long life

Indeed Nrf2  plays a critical role in regulating mRNA of many phase-II drug-metabolizing genes as well as a number of efflux transporters that are important for the hepatic alteration of toxins. It has minimal effect on Phase I CYP450 genes. One of the enzymes Nrf2 can upregulate is quione reductase. This is a Phase II biotransformational/detox enzyme but also does so much more to protect you. It is highly active in the lung tissue, the gut tissue and the cells lining our blood vessels. Here it is thought to be protecting us from toxins we inhale, eat, or those that get past our lungs and gut and get into our blood stream. Quinone reductase (induced by Nrf2 and therefore induced by sulforaphane) is easily and rapidly measured in labs. This makes it a good tool looking for anticarcinogenic phytochemicals by researchers. Sulphoraphane activity can be measured in plants by looking at quinone reductase activation.

Most folks think that sulforaphane is a constituent in the brassica plants. Actually, it is not. These plants are high in a glucosinolate, called glucoraphanin that is turned into sulforaphane when it meets up with an enzyme called myrosinase. All the Brassicaceae family vegetables contain glucoraphanin. These are things such as kale, cauliflower, cabbage, broccoli, brussels' sprout. Some of the Raphanus genus also includes it such as radish. These plants are wonderful places to get phytochemicals as well as nutrients.  It turns out that some cultivars of  broccoli (and especially their  sprouts) are extremely high in glucoraphanin. Research shows the three day old sprouts to contain the most glucoraphanin. The work at Johns Hopkins University found that 3 day old sprouts of all the Brassicaceae family they tested was highest in the glucoraphanin compared to the other young sprouts or the adult vegetables. They found the 3 day old sprouts contained from 10-100 times more glucoraphanin than the mature plants. You can read more about this in the free online 1997 research study. 

Glucoraphanin is contained within the plant cell in a little package called a vacuole. Myrosinase is also contained within the cell but kept compartmentalized away from glucoraphanin. When the plant is chewed or otherwise broken open and cell walls are broken, the glucorpahinin and myrosinase come into contact, and sulforaphane is enzymatically produced. There is also another protein in these plants called epithiospecifier protein which is a noncatalytic inhibitor of myrosinase activity. Epithiospecifier protein produces an inactive sulforaphane nitrile from glucoraphanin when it inhibits myrosinase activity. What this means is that you can not evaluate the activity of sulforaphane by looking at the amount of glucoraphanin alone. For people who purchase supplements that measure glucoraphanin and not epithiospecifer protein, there is no way to know if the epithiospecifer is in the product and will negate some of the glucoraphanin or not. Some products deactivate the epithiospecifer and some ignore its existence. Plus, the product needs to contain myrosinase if the glucoraphanin is going to be changed into sulforaphane.   Additionally, there are other glucosinolates in the broccoli such as erucin and iberin. These are just the ones identified. Erucin and sulforaphane were recently found to be interconvertible. 

Personally, I am a fan of whole foods. Raw broccoli is the way I go. Cooking destroys glucosinolates as well as the enzyme myrosinase. In the lab setting, myrosinase has been destroyed in 3 minutes of steaming. The more you chew on a head of raw broccoli, the tastier it is and the more sulforaphane you make by opening up those cells and mixing glucoraphanin and myrosinase together.  

Things to remember when eating eating broccoli or other Brassicaseae plants:

1. Eat it freshly picked if possible. The glucosinates steadily disappear after harvest. Open air transport and storage in stores can loose 55% of glucosinates after 3 days. Storage in a plastic bag at about 70 degrees farenheight for 7 days will loose about the same amount.

2. Eat it raw. 

3. If you are hypothyroid, you might want to look at the negative side of eating too many  raw Brassicaseaes before entering into a diet high in these plants.

4. When you cut or chew a plant with glucoraphanin and myrosinase, you get synthesis of sulforaphane. However, if you are cutting it or juicing it, the newly created sulforaphane will degrade quite fast. You need to eat it quickly.  

5. The gut bacteria can alter how much sulforaphane you get from your broccoli. The research on this is too sketchy for me to really say anything about it, but we will have better details in the future. The reason I say it is sketchy is I have seen  research on myrosinase being created by gut bacteria which would mean this would help make sulforaphane from glucorophanin. However, I have also seen research on gut bacteria producing the inactive sulforaphane nitrile from glucoraphanin. So, I am left not knowing what to think until I see more data in the future.

Broccoli headThere is much more you could learn about this subject. I suggest reading this new 2016 research article if you want to know more.