[MPWG] Star anise & Tamiflu story

[rrr at montana.com]

So sorry! I thought this had been sent! Here it is again.
Robyn


You can learn more about Tamiflu from various websites, including
www.wikipedia.org, from which some of this information is here repeated.

“Four drugs are available to treat and/or prevent influenza. They are
amantadine and rimantadine, zanamivir, and oseltamivir. Rimantadine and
amantadine are effective only against type A influenza. Zanamivir and
oseltamivir inhibit both influenza A and B viruses.

Relenza (zanamivir) and Tamiflu (oseltamivir), are the first of a new
class of antiviral drugs called neuraminidase inhibitors. The surfaces of
influenza viruses are dotted with neuraminidase proteins. Neuraminidase,
an enzyme, breaks the bonds that hold new virus particles to the outside
of an infected cell. Once the enzyme breaks these bonds, this sets free
new viruses that can infect other cells and spread infection.
Neuraminidase inhibitors block the enzyme's activity and prevent new virus
particles from being released, thereby limiting the spread of infection.”

Most herbalists know something about plant chemical compounds, but few
have studied plant metabolism/biochemistry, which explains how plants make
chemical compounds. Plants use three main biochemical pathways to make
both primary and secondary compounds: the shikimate or shikimic pathway,
the mevalonate/deoxyxylulose pathway and the acetate or polyketide
pathway.

Shikimic acid is one of the metabolites in the beginning of the shikimate
pathway. This pathway only occurs in plants and microorganisms, which is
why it provides an attractive strategy to develop herbicide,
antiparasitic, and antimicrobial chemicals and drugs.

Shikimic pathway compounds such as isoflavones and lignans can be
bioactive in humans too as phytoestrogens (think soy or red clover
isoflavones) or adaptogens (think Schizandra chinensis).

However, herbicides and antimicrobials are usually crafted with the
intention of inhibiting an enzyme that only occurs in fungal and/or
bacterial pathogens, thus keeping the organism from producing something it
needs to infect or maintain life.

Thus, the neuraminidase inhibitor strategy.

Every plant makes shikimic acid, because important primary and secondary
metabolites must be made via this pathway: flavonoids, coumarins, and even
lignin (wood). Industry has found many ways to synthesize shikimic acid,
including from quinic acid from cinchona bark, from E. coli, and from
carbohydrates (e.g., D-arabinose and D-ribose). But synthetic shikimic
acid is very expensive. Which may be why drug companies focus on raw plant
material. They may get a better profit margin.

With a little phytosleuthing on the web, I found some scientific papers.
Shende Jiang (see his website on shikimic acid), found a way to make
shikimic acid in large quantities from Illicium verum (Chinese star anise)
seed (Tetrahedron 54 (1998) 4697-4753 and Chem Res Chinese U (2002)
18(2):146-152).

Industry has found many ways to synthesize shikimic acid, including from
quinic acid from cinchona bark, from E. coli, and from carbohydrates
(e.g., D-arabinose and D-ribose). Apparently, one can get a fair amount of
shikimic acid out of Ginkgo as well. In any case, synthesizing shikimic
acid is said to be very expensive.

A shortage of star anise is said to be the reason for a worldwide shortage
of Tamiflu. This sounds a little simplistic. The shortage of star anise
material is not necessarily agreed upon by all. Also, Roche Laboratories
employs another way to make shikimic acid, by fermentation of E. coli.
Still, it is a very laborious process and takes many months, apparently.

Drinking Illicium tea or just about any plant tea, likely contains some
shikimic acid, but in teeny weeny amounts, along with teeny weeny amounts
of hundreds of other chemical compounds. (Note that a close look-a-like,
Japanese star anise, I. anisatum, has shown neurological and
gastrointestinal toxicity, and is a whole OTHER story! See the AHPA and
ABC websites.)

This whole star anise story could easily turn into another wild yam scam
scenario, where people think that ingesting the plant is the same as
taking a drug.

Our bodies cannot make progesterone out of wild yam, nor can our bodies
make Tamiflu out of star anise.

I'll bet the plot gets thicker. Just watch. Someone will show an antiviral
activity in this plant and then we'll all get really confused!

Robyn Klein, AHG Herbalist, M.S., Medical Botany
Department of Plant Sciences and Plant Pathology
Montana State University