[tt] Are "stem cell enhancers" safe?

Fri May 18 12:40:24 UTC 2007

http://www.the-scientist.com/news/home/53194/

For sale: Stem cell enhancers

Dietary supplement claims to boost circulating stem cells, but is it
safe?

[Published 15th May 2007 02:49 PM GMT]

A California company is marketing the latest in dietary supplements, an
extract from algae they claim will boost the number of circulating stem
cells, easing disease and discomfort. Consumers have already spent
millions on the "stem cell enhancer," but some stem cell researchers
remain unconvinced the product even works -- and warn that the
"enhancer" may trigger other problems, including cancer.

"I would look at this with great, great, great skepticism," said William
Frishman at the New York Medical College in Valhalla.

"I strongly advise anybody not to take this drug" until more studies are
done, said Thomas Eschenhagen, a professor at the University Medical
Center Hamburg-Eppendorf. Eschenhagen told The Scientist the effect of
the product does not appear drastic, based on information from the
company. But whether it's safe, "we simply don't know."

According to STEMTech HealthSciences, the product, StemEnhance, made
from the blue-green algae Aphanizomenon flos-aquae, promises to "support
your stem cells in maintaining proper organ and tissue functioning in
your body." The product is marketed online and at least one distributor
advertises with leaflets door-to-door, asking "What have your STEM CELLS
done for you lately?"

Online testimonials of StemEnhance claim a range of benefits, including
reducing hot flashes and heartburn, easing withdrawal from
methamphetamine addiction, and curing chronic back pain. In response to
a The Scientist Blog about the product, one customer and distributor
wrote the product cured knee and back pain, and discomfort from kidney
cysts. "Since starting this product-I no longer have kidney or back
pain, I personally can go hours without urinating which before I swear
was at least once an hour and my knees don't hurt when I get up off the
toilet."

Others are less enthusiastic. The "skeptical guide to multilevel
marketing" Web site MLM Watch calls StemTech's claims "dubious." On the
Web site Wellness Clubs of America, dedicated to promoting healthy
lifestyle, founder Dale Peterson questions the safety of ingesting
potentially toxic algae, stating "People love magic pills, gimmicks &
slick web sites, even when they may be hazardous to their health. I have
to give Stem Enhance's creators credit -- not everyone could turn a
potentially deadly pond scum into the cure-for-all-diseases."

Anecdotally, there has been overwhelming evidence the product -- sold
for approximately $1 per pill -- does wonders, Christian Drapeau,
StemTech's Chief Science Officer, told The Scientist. In some cases,
diabetics have ceased taking insulin, wheelchair-bound people with
multiple sclerosis have walked, and Alzheimer's and Parkinson's patients
experienced improved cognitive function, he said. "It's pretty clear it
is a natural process of healing."

Drapeau estimated the company has sold 425,000 bottles -- approximately
$60 each -- since November 2005, and is now selling roughly 50,000
bottles per month.

The extract elevates circulating stem cells by the actions of two
uncharacterized compounds, one that acts to stimulate release of cells
from the bone marrow, and another that facilitates migration of the
cells to tissues all over the body, said Drapeau.

Drapeau said he has tested one of the compounds in humans, and it acts
as a blocker of L-selectin, a cell adhesion molecule. Drapeau said the
compounds are as yet unnamed. An article due for publication in
Cardiovascular Revascularization Medicine suggests an extract from A.
flos-aquae mobilizes CD34+ stem cells from the bone marrow, he added.
The managing editor of the journal confirmed the paper is expected to
publish this summer.

This is a somewhat plausible mechanism, according to Wojtek Wojakowski
at the Silesian School of Medicine in Katowice, Poland. An extract that
acts as an L-selectin blocker could elevate circulating stem cells,
which may "help with [cells] leaving the bone marrow," Wojakowski told
The Scientist. "But this approach was not tested in clinical studies."

The company Web site presents results from 15 volunteers, showing that
cells in the blood labeled with CD34 antibody increased by about 25%
within an hour after taking StemEnhance.

But many stem cell researchers remain unconvinced. "At this point
there's no clear-cut evidence that an increase of these stem cells is
something good," Eschenhagen said. Scientists debate the role of
circulating progenitor cells in healing injury, particularly regarding
cardiovascular damage, he said, and have reached no consensus as to
whether supplementing progenitor numbers improves tissue repair.

"Basically I think that it's true that higher levels of endothelial
progenitor cells have been associated with better long-term [health]
outcomes," said Kreton Mavromatis at Emory University. But there is no
causative study showing those cells are responsible for improved health,
Mavromatis told The Scientist.

And if the product does what it says, it may not be safe, according to
Frishman. One of the risks of taking a stem cell enhancer is that it
could activate dormant cancer cells, he told The Scientist. There are
other stem cell enhancing drugs that target particular cell types, such
as granulocyte colony-stimulating factor, which elevates white blood
cells after chemotherapy. "Here [with StemEnhance] you're giving a
general stem cell booster," Frishman said. "Some people might have
occult malignancies and all of a sudden you're giving them a stem cell
booster."

Drapeau said he has not seen any evidence the product causes harm, and
is hesitant to produce too much data saying it works, out of fear the US
Food and Drug Administration will revoke its status as a dietary
supplement -- where it's available to everyone sick and well -- and
consider it a drug that requires a prescription. "We have not yet
documented in a rigorous manner the health benefits [of StemEnhance]
essentially because they are so obvious, and I am concerned if we get
data showing the product is effective...we will be in a difficult
position with the FDA," Drapeau said.

Kerry Grens
mail at the-scientist.com

Links within this article:

William Frishman
'http://complab.nymc.edu/Medicine/Faculty.htm

Thomas Eschenhagen
http://www.akdae.de/05/10Mitglieder/Eschenhagen.html

STEMTech HealthSciences
http://www.stemtechbiz.com

A. McCook, "Selling stem cells door-to-door," The Scientist, May 8,
2007.
http://www.the-scientist.com/blog/display/53186

SM Barrett, "StemTech's dubious claims," MLM Watch, November 26, 2005.
'http://www.mlmwatch.org/04C/Stemtech/stemtech.html

Wellness Clubs of America
http://www.wellnessclubsofamerica.com/Stemenhance

Kneuer C et al., "Selectins--potential pharmacological targets?" Drug
Discovery Today, 11:1034-40, 2006.
http://www.the-scientist.com/pubmed/17055414

Cardiovascular Revascularization Medicine
http://www.elsevier.com/wps/find/

Wojakowski W et al., "Mobilization of CD34/CXCR4+, CD34/CD117+, c-met+
stem cells, and mononuclear cells expressing early cardiac, muscle, and
endothelial markers into peripheral blood in patients with acute
myocardial infarction," Circulation, 16:3213-20, 2004.
http://www.the-scientist.com/pubmed/15533859

Bellucci R et al., Modulation of VLA-4 and L-selectin expression on
normal CD34+ cells during mobilization with G-CSF," Bone Marrow
Transplantation, 23:1-8, 1999.
http://www.the-scientist.com/pubmed/10037043

Zimmermann WH and Eschenhagen T, "Questioning the relevance of
circulating cardiac progenitor cells in cardiac regeneration,"
Cardiovascular Research, 68:344-6, 2005
http://www.the-scientist.com/pubmed/16253213

Laflamme MA and Murry CE, "Regenerating the heart," Nature
Biotechnology, 23:845-56, 2005.
http://www.the-scientist.com/pubmed/16003373

K Chien, "Making a play at regrowing hearts," The Scientist, August
2006.
http://www.the-scientist.com/article/display/24104/

Werner N et al., "Circulating endothelial progenitor cells and
cardiovascular outcomes," New England Journal of Medicine, 353:999-1007,
2005.
http://www.the-scientist.com/pubmed/16148285

I. Oransky, "Trial of the heart," The Scientist, October 2006.
http://www.the-scientist.com/article/display/24908

Kreton Mavromatis
http://med.emory.edu/faculty/profile_cv.cfm?id=7406