Phenethyl Isothiocyanate

I wrote a post on broccoli back in April, but only recently came across some more info that I thought I would discuss briefly today. It’s about a substance contained in cruciferous vegetables (in addition to broccoli, also: cauliflower, kale, cabbage, watercress, radishes, and arugula or rucola, which by the way is also rich in vitamin C and iron, etc.) called phenethyl isothiocyanate, more familiarly known as PEITC, which has chemopreventive properties. According to a 2005 University of Pittsburgh study (http://tinyurl.com/2p52nh), Evidence is accumulating to indicate that PEITC can suppress proliferation of cancer cells in culture by causing apoptosis and/or cell cycle arrest [ ]. Growth inhibition, apoptosis induction, and/or cell cycle arrest by PEITC has been noted in human leukemia, prostate, myeloma, hepatoma, and colon cancer cells. Please note that myeloma is mentioned in the same breath as the following words: cell arrest, apoptosis and growth inhibition! PEITC inhibits NF-kappa B and activates the tumor suppressor p53, among other things. This is all very good news. I will attempt to get my hands on the specific study citing MM cells affected by PEITC this fall.

A study published in the 2000 issue of Biochemical Pharmacology (http://tinyurl.com/2hmeu5) states that The dietary isothiocyanates and cancer chemopreventive agents phenethyl isothiocyanate and allyl isothiocyanate and their cysteine conjugates inhibited the growth and induced apoptosis of human leukaemia HL60 (p53 ˆ’) and human myeloblastic leukaemia-1 cells (p53+) in vitro. And a study published in Cancer Research in 2007 (http://tinyurl.com/ywk4yw) shows that PEITC has an effect on angiogenesis: the present study suggests that inhibition of angiogenesis may be an important mechanism in cancer chemoprevention by PEITC.

I also found a couple of studies on the combined synergistic effect of curcumin and PEITC on prostate cancer. A 2005 study (http://tinyurl.com/32gz8b) published in Carcinogenesis showed that this dynamic duo exerted a more potent effect on prostate cancer cells when administered together rather than apart. They also had apoptotic effects on these cells. A 2006 Cancer Research study confirmed that this combination significantly slowed the growth of tumours, but this time in vivo (mice), whereas the effect was minimal when both substances were administered separately. Another study on PEITC and prostate cancer cells (http://tinyurl.com/29zljl), published in 2004, is interesting because it mentions that PITC, a PEITC analogue, didn’t have any anti-cancer effects: These results indicated that even a subtle change in isothiocyanate (ITC) structure could have a significant impact on its biological activity. This particular sentence inspired me to write about a doubt that I have had concerning curcumin analogues. I think I mentioned this in a previous post, probably when I was discussing the issue of nanocurcumin, but at any rate, here it is: by fiddling around with these molecules, don’t we risk altering them too much for them to provide any anti-cancer benefits? Is it possible that the more we stray from the original extract, the more we may diminish its effectiveness? Am I way off base here? My non-scientific brain cannot provide any answers, of course.

Peekaboo, July 21 2007There are many other studies on PEITC and different cancers, but this post was beginning to look like a laundry list, so I cut most of it. However, those interested in seeing my rather large PEITC file can drop me a note and I will gladly forward it.

I would like to end by saying that I have been asked to give more information on my day-to-day life. So I will be doing that from time to time. Bits and pieces from what I consider to be my rather boring life. Oh, wait, how can life be boring with a new kitten in the house??? 🙂

3 Comments

  1. Must broccoli family vegetables be eaten RAW to get PEITC? I have read much abou the benefits of those foods.. but never any indication about whether they can be lightly steamed. Light steaming kills whatever it is that tends to inhibit thyroid function.. does it also kill whatever it is in broccoli, etc that inhibits cancer?
    What are your hunches? Have you seen any information?
    Love that little Kitty.

  2. I hope Peekaboo is feeling better! By the way, does the word “peekaboo” have meaning in Italian? Or is it sort of like “O.K.” which seems to have seeped into all languages?

  3. See this study regarding what I think is one of the two natural curcumin analogs:

    Metabolism and Anticancer Activity of the Curcumin Analogue, Dimethoxycurcumin

    From the abstract:

    Dimethoxycurcumin is significantly more potent than curcumin in inhibiting proliferation and inducing apoptosis in HCT116 cells treated for 48 h. Nearly 100% of curcumin but <30% of dimethoxycurcumin was degraded in cells treated for 48 h, and incubation with liver microsomes confirmed the limited metabolism of dimethoxycurcumin. Both compounds were rapidly degraded in vivo but dimethoxycurcumin was more stable.

    Or, Margaret, is your concern with *synthetic* analogs?

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