(Austin, Texas, September 9, 2015) The nonprofit American
Botanical Council (ABC) says that the New York Attorney General’s (NY AG’s)
investigation on the herb devil’s claw has reached an incorrect conclusion
based on its too-narrow interpretation of botanical classifications.
Today the NY AG sent cease-and-desist letters to 13
companies that sell devil’s claw herbal dietary supplements informing them that
their products containing devil’s claw material were tested at the New York
Botanical Garden using DNA technology. The results showed that the devil’s claw
was a different botanical species than what was labeled, and what the NY AG
termed a “less desirable” species of the herb.
In botanical classification and nomenclature, devil’s claw
is usually known scientifically by its Latin name, Harpagophytum procumbens, where Harpagophytum
is the genus of the plant and procumbens
refers to the species of the plant. The DNA-barcoding tests commissioned by the
NY AG showed that some herbal supplements actually contain Harpagophytum zeyheri, a slightly different form of devil’s claw,
i.e., a different, but very closely related species. In effect, they are like
two siblings.
“Both species of devil’s claw have a similar chemical
profile,” said Thomas Brendler, a medicinal plant expert and editor of the African Herbal Pharmacopeia, a
compilation of technical information of various African medicinal plants,
including their botany, growing conditions, range of habitat, chemistry, and
traditional and modern medicinal activities and uses.
“While both species differ marginally in shape and chemical composition, both are considered equally
effective,” he added.
According to various government-recognized medicine
evaluation bodies and pharmacopeias, the two species of devil’s claw are
considered interchangeable for the purpose of their use for their medicinal
actions. These organizations include the European Medicines Agency, the European Pharmacopoeia, and the
unofficial ESCOP (European
Scientific Cooperative for Phytotherapy), a pan-European consortium of
medicinal plant experts. Also listing both species as interchangeable is the
proposed monograph “Harpagophytum species root” in the United States
Pharmacopeia’s Herbal Medicines
Compendium.
Brendler added that many, possibly most, devil’s claw extracts in the world market are based on
mixtures of the two species, as are devil’s claw herbal teas and dried powdered
root materials used in supplements and other products. Both species of devil’s
claw have been in the market in the United States since the 1980s, he noted.
“We sincerely
appreciate Attorney General Schneiderman’s interest in the quality of herbal
materials sold in dietary supplements and his apparent desire to help consumers
maintain access to high-quality, safe, and effective herbal products,” said
Mark Blumenthal, founder and executive director of ABC.
“We here at ABC
have a similar mission, as evidenced by our long-time efforts in the
ABC-AHP-NCNPR Botanical Adulterants Program in which we have been working on
educating industry and all relevant stakeholders about quality issues in the
global herbal market,” he continued. “However, splitting the devil’s
claw genus in the very narrow way that they have done in this investigation is
akin to splitting hairs — it has no real meaning or value to anyone,
particularly the herb consumer.”
“This may be a hair-splitting botanical distinction,”
noted Blumenthal, “but it certainly is not a legal or regulatory one,
especially since authoritative sources recognize both species as being ‘devil’s
claw.’”
Blumenthal added that, according to data ABC used for its
annual herb market report, devil’s claw is a relatively low-selling herb in the
United States. In 2014, devil’s claw ranked 162nd in sales in the US mainstream retail market and 150th in the
natural and health foods channel. Total estimated sales of devil’s claw dietary
supplements in the United States range from approximately $250,000 to up to
$500,000.
About Devil’s Claw
Devil’s claw,
the vernacular name for the two species Harpagophytum
procumbens and H. zeyheri, occurs
in the desert regions of southern Africa (Namibia, Botswana, and South Africa).
Its bitter root has historically been used to treat a wide range of ailments
and, prominently, as an anti-inflammatory and digestive. Major clinical uses in
modern phytotherapy (herbal medicine) focus on its anti-inflammatory effects in
the treatment of joint diseases and back pain. The suggested mechanism of
action is through COX-2 inhibition. Some 20 human clinical trials conducted
over the last 30 years have confirmed its safety and efficacy in the treatment
and alleviation of degenerative joint disease, osteoarthritis, and lower back
pain.