|
| | |
|
The role of glucosamine and chondroitin sulfate in treatment for and prevention of osteoarthritis in animals- PDF
June 01 2000, Article # 3097
Researchers
from the University of Maryland’s Department of Pharmaceutical
Sciences, School of Pharmacy, recently published a report that showed
some over-the-counter human products claiming to contain glucosamine
and chondroitin did not have the amounts claimed on the label. In fact,
deviation from label claims ranged from 0% to more than 115%.
The
objective of the re- search, published in the Journal of the American
Nutraceutical Association, was "to evaluate the results of analysis of
actual contents of several products in the marketplace containing
glucosamine and/or chondroitin sulfate and to determine if they
significantly deviate from label claim." The researchers took 14
products containing glucosamine hydrochloride or glucosamine sulfate
and 11 products containing chondroitin sulfate to evaluate using one
method (UV-HPLC). They also took 32 products containing only
chondroitin sulfate to test with another method (titration). This
analysis was "an attempt to evaluate whether different suppliers of
glucosamine or chondroitin sulfate use different grades of material."
What
the researchers found was that some products didn’t contain any of the
labeled materials, and some contained more than was labeled. "Our
results suggest that there is a significant deviation between the
content of the active ingredients (glucosamine or chondroitin sulfate)
and what is stated by the manufacturers on the label." They also
discovered that products with a retail price "of less than or equal to
one dollar per 1,200 mg of chondroitin sulfate were found to be
seriously deficient in meeting label claim (less than 10% of label
claim)."
The study also
examined the intestinal transport (an indirect method to evaluate
intestinal absorption) of several marketed sources of chondroitin
sulfate to determine if these products could be absorbed in the GI
tract. The researchers assessed permeability of various marketed
sources of raw materials of chondroitin sulfate across Caco-2 cell
monolayers.
The
research report noted that the permeability of the different molecular
weight chondroitin sulfates was "found to be significantly different,
with the permeability coefficient increasing with decreasing molecular
weight. This suggests that molecular weight of chondroitin sulfate
could be a possible predictor of permeability." (In other words, low
molecular weight chondroitin sulfate is better than high molecular
weight chondroitin sulfate. For you scientists out there, they reported
"significant" permeability differences with the coefficient increasing
with decreasing molecular weight of 16.9, 8.0, and 4.0 x 103 Daltons.)
Problem is, if a
consumer can’t trust what is in a product by the label claim for human
products, what can a horse owner do? The same as is recommended to
humans by the Arthritis Foundation: 1) consult with your physician
(veterinarian); 2) health care professionals (vets) should become
knowledgeable about these products; 3) consumers should not purchase
through the mail or Internet unless they know the vendor; and
4) consumers should buy from companies that use USP material (neither
chondroitin sulfate nor glucosamine have a monograph yet). (United
States Pharmacopeia, or USP, is the book that contains standards and
regulations for human and vet drugs.)
The group also said
that "the implications of these results are significant and support the
need for regulatory intervention of dietary supplements."
Byron CR, Benson BM, Stewart AA, Pondenis HC.
Department
of Veterinary Clinical Medicine, College of Veterinary Medicine,
University of Illinois, Urbana-Champaign, IL 61801, USA.
OBJECTIVE:
To
evaluate the effects of methylprednisolone acetate (MPA) on
proteoglycan production by equine chondrocytes and to investigate
whether glucosamine hydrochloride modulates these effects at clinically
relevant concentrations. SAMPLE POPULATION:
Articular cartilage
with normal gross appearance from metacarpophalangeal and
metatarsophalangeal joints of 8 horses (1 to 10 years of age).
PROCEDURES:
In vitro chondrocyte pellets were pretreated with glucosamine (0, 1,
10, and 100 microg/mL) for 48 hours and exposed to MPA (0, 0.05, and
0.5 mg/mL) for 24 hours. Pellets and media were assayed for
proteoglycan production (Alcian blue precipitation) and proteoglycan
content (dimethylmethylene blue assay), and pellets were assayed for
DNA content. RESULTS:
Methylprednisolone decreased production of
proteoglycan by equine chondrocytes at both concentrations studied.
Glucosamine protected proteoglycan production at all 3 concentrations
studied. CONCLUSIONS AND CLINICAL RELEVANCE:
Methylprednisolone,
under noninflammatory conditions present in this study, decreased
production of proteoglycan by equine chondrocytes. Glucosamine
had a protective effect against inhibition of proteoglycan production
at all 3 concentrations studied. This suggested that glucosamine may be
useful as an adjunct treatment when an intra-articular injection of a
corticosteroid is indicated and that it may be efficacious at
concentrations relevant to clinical use.
Research Ongoing by: Stacey Oke, DVM, MSc
March 26 2008, Article # 11549
Canadian
researchers recently compared the pharmacologic properties of two
different forms of glucosamine--hydrochloride and sulphate. They
measured significantly higher levels of glucosamine in synovial fluid
samples from horses receiving the oral glucosamine sulphate formulation
as compared to synovial fluid levels in horses receiving oral
glucosamine hydrochloride.
Glucosamine
is a common ingredient in oral joint health supplements that are widely
administered to horses with osteoarthritis. Glucosamine is available in
a number of different forms including hydrochloride, sulphate, and
N-acetyl-D-glucosamine. To date, there is conflicting evidence
surrounding the use of glucosamine for the management of
osteoarthritis, regardless of species.
"It has been
proposed that the type of glucosamine used may impact efficacy,"
explained Sheila Laverty, MVB, Dipl. ACVS, professor and specialist in
equine surgery in the University of Montreal's Veterinary School.
Laverty is also a member of the Canadian Arthritis Network.
A recent review
article suggests that the most favorable clinical trial results of
osteoarthritis in humans were associated with the use of glucosamine
sulphate, which is currently available for human use by prescription
only in European countries.
In the study by
Laverty and colleagues, horses were administered clinically relevant
doses of glucosamine hydrochloride or glucosamine sulphate (20 mg/kg)
via nasogastric intubation. They administered the preparation of
glucosamine sulphate reported to be beneficial in Europe. Both types of
glucosamine were absorbed and were measurable in synovial fluid at one,
six, and 12 hours after administration.
"Following
administration, synovial levels of glucosamine were significantly
higher at one and six hours post-administration of glucosamine sulphate
compared to glucosamine hydrochloride," summarized Laverty. Pure
glucosamine hydrochloride was employed, but the investigators were
unable to obtain commercially available pure glucosamine sulphate for
their study.
Laverty pointed out
that there were substances to improve palatability included with the
glucosamine sulphate preparation they studied. She suggested that these
substances might have enhanced the absorption of the glucosamine
molecule. In addition, it is not clear whether these differences in
synovial fluid levels will have a real, clinical impact on horses with
osteoarthritis. Further research is required.
The study,
"Comparison of pharmacokinetics of glucosamine and synovial fluid
levels following administration of glucosamine sulfate or glucosamine
hydrochloride," will be published in an upcoming edition of the journal
Osteoarthritis and Cartilage.
| |
| | |
|
|