What Are Some Non-Kavalactone Compounds in Kava?

Dear Kava Guru,

What are some compounds in kava root besides kavalactones?

George,

Reno, NV

By now, you’ve probably heard me gush enough about kavalactones to know that these relaxing, anxiolytic compounds are a big part of what makes kava such a joy to consume. Yet as it turns out, there is actually quite a diverse range of chemical constituents in kava root: beside the six main kavalactones—kavain, dihydrokavain, yangonin, desmethyoxyyangonin, methysticin, and dihydromethysticin—there are many subsidiary kavalactones that occur in much smaller amounts, as well as a totally different class of compounds called chalconoids [1]. Chalconoids are probably the most interesting compounds in kava, besides kavalactones of course. Otherwise known as flavokavains or flavokawains, scientists are starting to realize that the chalconoid compounds in kava have biological actions in the body, and have started to study their effects. There’s even a possibility that the kava market could see a resurgence in demand specifically for flavokavain A, which has been demonstrated to target some types of cancerous cells [2]!

Fresh kava root is about 80% water. Once dried, kava root contains a hefty amount of starch (43%), along with 20% dietary fiber, 12% water, 3.2% sugars, and 3.6% protein [3]. Kavalactones contribute about 15% of the weight of the root. As you can tell from the name, kavalactones are a kind of lactone, a compound widely found in edible food plants, including leafy green vegetables. Without getting too deep into organic chemistry, a lactone compound is classified as an ester formed from the condensation of an alcohol group (-OH) and a carboxylic acid group (-COOH) on the same molecule [4]. The letters in the abbreviations above stand for oxygen, hydrogen and carbon. Don’t worry too much about these terms; I’ve just included them to give you an idea of what chemical class kavalactones belong to.

Some lactones, especially the sesquiterpene lactones found in lettuce and other edible plants in the daisy family Asteraceae, have recognized health benefits. Sesquiterpene lactones are antioxidants and anti-inflammatories that may help protect cells from oxidant damage [5]. In other words, your mother was right when she told you to eat your vegetables—a diet rich in dark pigmented veggies is key to a healthier life!

Kavalactones are not sesquiterpene lactones; they are their own unique class of lactones found almost exclusively in kava kava (Piper methysticum) root. Kava kava’s benefits to health come from kavalactones’ sedative, anticonvulsant, muscle relaxant, nootropic, and anxiolytic effects on the central nervous system [6]. Although pretty much everyone knowledgeable about the kava world knows about the six major kavalactones responsible for these effects, it turns out kava kava may have as many as 14 kavalactone compounds, as well as the chalconoids I mentioned above and other trace compounds. Alexander Shulgin’s 1973 paper lays out a very detailed breakdown of the compounds in kava according to level of concentration, which I’ve reproduced below:

Compounds detectable in kava root at 1% concentration or more: kavain, dihydrokavain, methysticin.

Compounds detectable in kava root at 0.1-1% concentration: yangonin, dihydromethysticin, desmethoxyyangonin, flavokavain A, pinostrobinchalcone, dihydrotectochrysin, alpinetinchalcone, alpinetin, amd dihydrooroxylin A.

Compounds detectable in kava root at 0.01 – 0.1% concentration: methoxy-nor-yangonin, flavokavain B, and methoxyyangonin [7].

The takeaway from this is that while kava contains a range of interesting compounds, most of them are not present in any amount significant enough to suggest that they have biological activity in the body…

…except the chalconoid flavokavains A, B, and C. These compounds are an interesting exception I’ve been wanting to examine in more detail. Chalconoids are intermediary compounds in the biosynthesis of flavonoids—the compounds in plants responsible for pigments [1]. I find this interesting because flavonoids have been found to have a few notable health benefits: researcher are already thinking the flavokavains in kava kava may have antibacterial, antifungal, anti-inflammatory, and anti-tumor properties [1]. All this despite the fact that in 1973 when Shulgin wrote his paper, flavokavains were not considered biologically active compounds [7]!

However, there may be a downside to the flavokavains’ activity. In 2013, flavokavain B started causing some controversy in the kava world as evidence came to light that it might be harmful to liver cells [8]. Now, before you start to worry about your own kava use, let me make it clear that a) these results were based on lab tests of liver cells in vitro, not in human subjects; and b) flavokavain B only occurs in significant degree in so-called ignoble or tudei kava strains such as Isa and Palisi. I personally think the jury’s still out as to whether consumption of tudei kava prepared the traditional way poses a threat to health—but even if it does, it seems more like a reason to avoid tudei kava strains specifically. Kava researcher Vincent Lebot, who first brought the concerns about tudei kava to public light, has stated that noble kava strains are still unequivocally safe [1].

More encouragingly, flavokavain A may actually be beneficial to health: research by Dr Xiaolin Zhi at the University of California Irvine found that flavokavain A destroyed precancerous bladder cells in mice given the compound as a supplement to their diets [2]. Dr Zhi speculated that the flavokavain A specifically targets and destroys these cancer cells [2]. What’s even better about Zhi’s study is that the mice seemed to tolerate the flavokavain A well and did not experience any liver damage or other adverse effects [2]. Furthermore, a recent University of Minnesota study suggested flavokavain A might have similar preventive effects on lung cancers caused by tobacco smoking [9]. It’s clear we have a lot more to learn about the healing potential not only of kavalactones but of the full range of compounds in kava kava!

Mahalo,

Kava Guru

REFERENCES

1. “Simple Test for Checking If Your Kava Is Tudei”. Kava Forums: Connecting Kava Lovers Around the World. Accessed July 30th, 2014. http://www.kavaforums.com/forum/threads/simple-test-for-checking-if-your-kava-is-tudei-please-read-if-youre-new-to-kava.2451/.

2. Vasich, Tom. “Can Kava Cure Cancer?” UC Irvine News, Accessed April 9th, 2014. http://news.uci.edu/features/can-kava-cure-cancer/.

3. “Kava | Composition”. Wikipedia. Last modified July 27th, 2014. http://en.wikipedia.org/wiki/Kava#Composition.

4. “Lactone”. Wikipedia. Last modified June 11th, 2014. http://en.wikipedia.org/wiki/Lactone.

5. Chadwick, Martin, Harriet Trewin, Frances Gawthrop, and Carol Wagstaff. June 2013. “Sesquiterpenoid Lactones: Benefits to plants and people”. International Journal of Molecular Science 14 (6): 12780-12805.

6. “Kavalactone”. Wikipedia. Last modified June 30th, 2014. http://en.wikipedia.org/wiki/Kavalactone.

7. Shulgin, Alexander T. 1973. “The narcotic pepper- the chemistry and pharmacology of Piper methysticum and related species”. United Nations Office on Drugs and Crime Bulletin on Narcotics 2: 59-74.

8. Ping Zhou, Shimon Gross, Ji-Hua Liu, Bo-Yang Yu, Ling-Ling Feng, Jan Nolta, Vijay Sharma, David Piwnica-Worms, and Samuel X. Qiu. December 2010. “Flavokawain B, the hepatotoxic constituent from kava root, induces GSH-sensitive oxidative stress through modulation of IKK/NF-kB and MAPK signaling pathways”. Federation of American Societies for Experimental Biology Journal 24 (12): 4722-4732.

9. “Preliminary study in mice suggests possible lung cancer preventative effect of South Pacific herb.” January 8th, 2014. PR Newswire. http://www.prnewswire.com/news-releases/kava-may-help-prevent-lung-cancer-in-smokers-say-university-researchers-239200161.html.

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