This is a continuation of my November 7 2009 post on *the first report demonstrating that curcumin exerts anti-influenza activity*. Before jumping into the full study, let’s have a quick look at a couple of items mentioned in the abstract (see: http://tinyurl.com/ybug9sl). The first is one that I had never seen (or paid attention to) before: haema-something-or-other, uhm…let’s see…ah yes, haemagglutination, or hemagglutination with the U.S. spelling. The linguist in me tried to figure out the etymology of this term, but that led me nowhere: the gluing of blood? Blood glue? I finally had to look it up. It means: the clumping of red blood cells (voilà!) caused by viruses, antibodies or other substances. And, according to this study, curcumin inhibits the hemawhatever process. My first question was: is that a good thing? Let me see…yes indeedie, it is. See, e.g.: http://tinyurl.com/q2zys9 and http://tinyurl.com/yfdab7j
The second item is amantadine, which is an antiviral drug administered in cases of oseltamivir-resistant H1N1 flu (oseltamivir is better known as Tamiflu). Amantadine was used in this study as a control for the drug resistance test. Two important findings: 1. in contrast to amantadine, viruses did not develop resistance to curcumin; 2. like amantadine, curcumin inhibited influenza virus plaque formation. Okay, now for the full study.
After giving us the usual overview of curcumin’s multifaceted effects, the authors tell us that Recently, several reports demonstrated that NF-kB inhibitors efficiently blocked propagation of influenza, suggesting that modulation of NF-kB signalling may be a target for anti-influenza intervention. Aha! Inhibition of our old archenemy, NF-kappaB…well, that happens to be right up curcumin’s alley. In fact, that is why curcumin was tested in this study in the first place. And, come to think of it, wouldn’t it follow that any old NF-kappa B inhibitor would block the H1N1 virus? If so, then we would be able to choose from a wide array of natural extracts…not just curcumin but also resveratrol and green tea, just to mention a couple…
At any rate, the researchers administered various doses of curcumin (dissolved in DMSO) at three different times: 1. before infection, 2. together with the virus, and 3. after the virus had been added to the cells. They found that the production of virus was significantly reduced upon treatment with curcumin in a dose-dependent manner; in the presence of 30 micromoles of curcumin, the titre of virus was less than 5% of that in mock-treated cells at all time points of infection analysed.
Based on their tests (I will spare you all the details!), the authors postulate that curcumin may directly interfere with a very early stage (possibly directly with the virus particle), to prevent infection. Curcumin was also found to be effective against avian flu (=H6N1).
Let’s go back to the abstract for a second. It ends with a rather puzzling sentence: the methoxyl groups of curcumin do not play a significant role in the haemagglutinin interaction. The full study sheds some light on this issue (skip this paragraph unless you are fascinated by methoxyl groups…): Commercially available curcumin consists of three major components: curcumin, demethoxycurcumin, and bisdemethoxycurcumin. The structure of curcuminoids differs only by the number of methoxyl groups. So one of the study aims was to determine what part these methoxyl groups played in the Flu Virus Battle. Apparently none whatsoever, since all three curcuminoids were effective against the virus, regardless of methoxyl group content. (Yep, I am yawning, too!)
An issue of huge importance is viral resistance. Flu variants resistant to oseltamivir/zanamivir as well as to amantadine and rimantadine have already popped up all over the world. The researchers compared amantadine and curcumin and found that resistant strains developed to amantadine but not to curcumin, indicating treatment of curcumin is not prone to emerging of resistant viruses. Good to know.
Many blog readers have asked me about dosage. Ah, this is where things get a bit muddled (for me, at any rate). Since the abstract is available online, let’s look at this excerpt: treatment with 30 micromoles of curcumin reduced the yield of virus by over 90% in cell culture. Okay, let’s take a deep breath…micromoles. No, these are not teeny tiny moles (right photo) digging teeny tiny holes in our gardens and no, they are not even itsy bitsy beauty marks (left photo). Okay then, if you really must know, in scientific measurements, a micromole is a concentration of one one-millionth of a mole per liter. Ah yes, this is soooo helpful (not!!!).
Well, I have never hidden the fact that math has never been my forte. I looked at conversion charts and molecular weights and filled page after page with divisions and multiplications until I became quite giddy. I gave up.
My blog reader Rebecca has already tried to answer the question for me: her naturopath told her that it would be impossible for us to reach the concentrations used in this cell study. Well, that is certainly, uhm, encouraging…
But hey, all is not lost, in my opinion. As I have mentioned in previous posts (and this is confirmed by private exchanges I have had with Prof. Aggarwal), curcumin works at different levels inside the body. Not just in the bloodstream. And in fact, ever since I began taking curcumin I have been much healthier, as strange as that may sound. It could be a mere question of mind over matter, but I doubt it. Something is definitely happening…
In conclusion, I figure that curcumin, in association with a healthy diet, exercise and a huge dose of caution–avoiding crowded places, washing our hands frequently, etc.–will lend a hand, if only a micromole-sized hand!, in protecting us during this flu-ridden period (I just heard that 1.5 million Italians have contracted the influenza A, or H1N1…yikes!). I have to believe that…otherwise, reading, doing research for, writing and posting about this study has been a complete waste of my/our time…sigh!