No you’re not, wake up! You haven’t even started reading yet!
I suffered a nasty shock recently when I discovered that the audaciously sunny California poppy is called “Eschscholzia californica.” Eschscholzia? Bleh. Such a slushy mouthful to hang on a cute little flower. But despite the disservice done to it by Linnaeus, the California poppy has held up bravely, bringing sunshine and some surprising biochemical utility to our coast.
Doped up on poppy seeds
Ever since I watched the Mythbusters episode where Adam and Jaime were able to make themselves test positive for morphine and codeine by gobbling poppy seed cake and bagels, I’ve been curious about how widespread the expression of narcotics in related flowers actually is. The first surprise was that the poppy seeds we eat are straight from Papaver somniferum, the same opium poppy used to make, well, opium. Can someone with FDA expertise please explain how possession of poppy seeds is no problem, and growing opium poppies in your yard is totally cool (really, some of my neighbors have them right out front), but you could never do that for cannabis or coca plants?
Meanwhile, both California poppies (genus Eschscholzia) and opium poppies (genus Papaver) are members of the Papaveraceae family, which has been around for 70 million years or so, and these two genera are roughly 30-50 million years distant from each other in evolutionary time. So what is the likelihood that the biosynthetic machinery for morphine and codeine and the like is shared between them? Surprise #2: quite high!
Morphine and codeine are both alkaloids made via several steps from the amino acid tyrosine. California poppies have all the enzymes involved in this pathway, but because of the bias in the way those enzymes are used, very little of these narcotics are made in California poppies, with several other alkaloids being favored instead. (Everybody got that? So don’t go off and start smoking CA poppies now, ok?) One of the benzophenanthridine alkaloids made by California poppies, sanguinarine (named for the bloodroot where it was first found), is worth a little more discussion.
Do I have any poppy seeds stuck in my teeth?
In the 1990s, sanguinarine was found to be a potent antimicrobial, and so effective against plaque bacteria that the company Viadent added it to their toothpaste and mouthwash for several years…until it was found that it also killed off human cells, leading to precancerous mouth lesions. Yuck.
But wait! That actually was handy for sanguinarine, because in the course of characterizing its toxicity to human cells, it was found to preferentially target dividing cells, and where are dividing cells a problem? In cancer of course! Consequently, sanguinarine and a related E. californica alkaloid, chelerythrine, are under investigation for their antiproliferative and pro-apoptotic effects in prostate cancer.
Extra nity-gritty: Poppies in the lab
At the same time, the actual yield of any of these compounds from living poppy plants is pretty low, so a fairly rigorous side discipline has sprung up around trying to get E. californica to make more of sanguinarine and other useful alkaloids. One approach has been to find the rate-limiting enzymes of benzophenanthridine alkaloids and force the plant to express more of them. Another has taken advantage of the fact that all these alkaloids are made as a stress response in plants, and has involved stressing the plant with everything from aspirin to yeast extract in order to drive up their production. Both approaches use a cell culture system based on small chunks of E. californica tissue, and I derive a small amount of joy from imagining racks of agar petri dishes filled with poppy plantlets.
Want more detail? Here are references!
Adhami VM, Aziz MH, Reagan-Shaw SR, Nihal M, Mukhtar H, & Ahmad N (2004). Sanguinarine causes cell cycle blockade and apoptosis of human prostate carcinoma cells via modulation of cyclin kinase inhibitor-cyclin-cyclin-dependent kinase machinery. Molecular cancer therapeutics, 3 (8), 933-40 PMID: 15299076
Cho, H., Son, S., Rhee, H., Yoon, S., Lee-Parsons, C., & Park, J. (2008). Synergistic effects of sequential treatment with methyl jasmonate, salicylic acid and yeast extract on benzophenanthridine alkaloid accumulation and protein expression in Eschscholtzia californica suspension cultures Journal of Biotechnology, 135 (1), 117-122 DOI: 10.1016/j.jbiotec.2008.02.020
Takemura T,, Chow YL,, Todokoro T,, Okamoto T,, & Sato F (2010). Over-expression of rate-limiting enzymes to improve alkaloid productivity Methods Mol Biol, 643, 95-109 DOI: 10.1007/978-1-60761-723-5_7