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Home > Health Conditions > Bladder & Urinary Tract Formulas >
Benfotiamine (S-benzyolthiamine-O-monophosphate) is a
synthetic derivative of thiamin, belonging to the family of compounds
known as "allithiamines." Benfotiamine is fat-soluble and thus more
bioavailable and physiologically active than thiamin.* Characteristic of
the allithiamines is an open thiazole ring within the chemical structure
of these thiamine-related compounds, making them fat (lipid) soluble. In
contrast, thiamine, which is water soluble, has a closed thiazole ring.
The lipid solubility of benfotiamine, conferred by this open ring,
increases its bioavailablity. Benfotiamine is readily absorbed at higher
doses, in contrast to absorption of water-soluble thiamin salts, which
decreases at higher doses, due to saturation of absorption sites in the
intestines.1 In a double-blind, cross-over trial,
comparing bioavailability of benfotiamine to that of thiamine in 12
subjects, benfotiamine caused an average 5-fold greater increase in
blood thiamine levels than thiamin mononitrate, with a concomitant
greater thiamine concentration in erythrocytes (red blood cells).2
Benfotiamine readily passes through intestinal mucosal cells, where it
is converted into physiologically active thiamine. Benfotiamine inceases
blood levels of thiamine pyrophosphate (TPP), the primary thiamin
co-enzyme.3
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Benfotiamine raises the blood level of thiamine pyrophosphate (TPP), the
biologically active co-enzyme of thiamine.4
Thiamine and its Co-enzyme, TPP
Thiamine (vitamin B1) plays an essential part in the metabolism of
glucose, through actions of it co-enzyme TPP (thiamine pyrophosphate).
TPP is formed by the enzymatically-catalyzed addition of two phosphate
groups donated by ATP to thiamine. TPP also goes by the name "thiamine
diphosphate." In the cytoplasm of the cell, glucose, a 6-carbon sugar,
is metabolized to pyruvic acid, which is converted into acetyl-CoA,
otherwise known as "active acetate." Acetyl CoA enters the
mitochondrion, where it serves as the starting substrate in the Kreb’s
cycle (citric acid cycle). The Krebs cycle is the primary source of
cellular metabolic energy. TPP, along with other co-enzymes, is
essential for the removal of CO2 from pyruvic acid, which in turn is a
key step in the conversion of pyruvic acid to acetyl CoA. CO2 removal
from pyruvic acid is called "oxidative decarboxylation," and for this
reason, TPP was originally referred to as "cocarboxylase." TPP is thus
vital to the cell’s energy supply.
Benfotiamine helps maintain healthy cells in the presence of blood
glucose. Acting as a biochemical "super-thiamin," it does this through
several different cellular mechanisms, as discussed below.
Benfotiamine and Glucose Metabolism
Benfotiamine normalizes cellular processes fueled by glucose
metabolites.
As long as glucose remains at normal levels, excess glucose metabolites
do not accumulate within the cell. The bulk of the cell’s glucose supply
is converted to pyruvic acid, which serves as substrate for production
of acetyl CoA, the primary fuel for the Krebs cycle. Of the total amount
of metabolic energy (in the form of ATP) released from food, the Krebs cycle generates about 90
percent.5 In the presence of elevated glucose
levels, the electron transport chain, the final ATP-generating system in
the mitochondrion, produces larger than normal amounts of the oxygen
free radical "superoxide." This excess superoxide inhibits
glyceraldehyde phosphate dehydrogenase (GAPDH), as key enzyme in the
conversion of glucose to pyruvic acid, resulting in an excess of
intermediate metabolites known as "triosephosphates." Increase
triosephophate levels trigger several cellular mechanisms that result in
potential damage to vascular tissue. Cells particularly vulnerable to
this biochemical dysfunction are found in the retina, kidneys and
nerves.
Benfotiamine has been shown to block three of these mechanisms: the
hexosamine pathway, the diaglycerol-protein kinease C pathway and the
formation of Advanced Glycation End-poducts. As discussed below,
benfotiamine does this by activating transketolase, a key
thiamin-dependent enzyme.6
Benfotiamine stimulates tranketolase, a cellular enzyme essential for
maintenance of normal glucose metabolic pathways.*
Transketolase diverts the excess fructose-6-phosphate and
glyceraldehydes-3-phosphate, (formed by the inhibition of GAPDH, as
mentioned above), into production of pentose-5-phosphates and
erythrose-4-phosphate and away from the damaging pathways. Benfotiamine
activates transketolase activity in bovine aortic endothelial cells
incubated in glucose.6 To test benfotiamine’s
ability to counteract these metabolic abnormalities caused by elevated
blood glucose, studies have been done in diabetic rats. Benfotiamine
increases transketolase activity in the retinas of diabetic rats, while
concomitantly decreasing hexosamine pathway activity, protein kinase C
activity and AGE formation.6
Benfotiamine and Protein glycation
Benfotiamine controls formation of Advanced Glycation End-products (AGEs).
AGEs have an affinity for proteins such as collagen, the major
structural protein in connective tissue. AGEs are formed through
abnormal linkages between proteins and glucose. This occurs via a
non-enzymatic glycosylation reaction similar to the "browning reaction"
that takes place in stored food.7 At high glucose
concentrations, glucose attaches to lysine, forming a Schiff base, which
in turn forms "early glycosylation products." Once blood glucose levels
return to normal levels, the amount of these early glycosylation
products decreases, and they are not particularly harmful to most tissue
proteins. On long-lived proteins such as collagen, however, early
glycosylation products are chemically rearranged into the damaging
Advanced Glycation End-products.
AGE formation on the collagen in coronary arteries causes increased
vascular permeability. This vessel "leakiness" allows for abnormal
cross-linking between plasma proteins and other proteins in the vessel
wall, comprising vascular function and potentially occluding the vessel
lumen. A number of other potentially harmful events may also occur,
including production of cytokines that further increase vascular
permeability. Endothelin-1, a strong vasoconstrictor, is over produced,
increasing the possibility of thrombosis and generation of oxygen free
radicals is stimulated.8
It is vitally important to support normal glucose metabolic pathways so
that formation of AGEs is minimized. Benfotiamine, in the test tube (in
vitro) prevents AGE formation in endothelial cells cultured in high
glucose by decreasing the glucose metabolites that produce AGEs.9
Endothelial cells make up the membranes that line the inner walls of
organs and blood vessels. In a rat study comparing the effects of
Benfotiamine with water-soluble thiamin, Benfotiamine inhibited AGE
formation in diabetic rats while completely preventing formation of "glycooxidation
products," which are toxic by products of chronic elevated blood
glucose. AGE levels were not significantly altered by thiamin.10 Benfotiamine also normalized nerve function in the animals. After
three months of administration, "nerve conduction velocity (NCV)," a
measure of nerve function, was increased by both benfotiamine and
thiamin; at six months, NCV was normalized by benfotiamine, whereas
thiamin produced no further increases in this parameter.
Dysfunctional glucose metabolic pathways leading to AGE formation occurs
in endothelial cells of the kidneys. In a recent animal study,
benfotiamine was administered to rats with elevated glucose levels.
Benfotiamine increased transketolase activity in the kidney filtration
system of these rats, while at the same time shifting triosephophates
into the pentose pathway and preventing protein leakage.11
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Suggested Adult Use: Take two capsules daily.
Benfotiamine has an excellent tolerability profile and can be taken
for long periods without adverse effects.3,12
The statements in this fact sheet have not been evaluated by the Food
and Drug Administration. This product is not intended to diagnose,
treat, cure or prevent any disease.
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1. Bitsch R, Wolf M, Möller J. Bioavailability assessment of the
lipophilic benfotiamine as compared to a water-soluble thiamin
derivative. Ann Nutr Metab 1991;35(2):292-6.
2. Schreeb KH, Freudenthaler S, Vormfelde SV, et al. Comparative
bioavailability of two vitamin B1 preparations: benfotiamine and
thiamine mononitrate. Eur J Clin Pharmacol 1997; 52(4):319-20.
3. Loew D. Pharmacokinetics of thiamine derivatives especially of
benfotiamine. Int J Clin Pharmacol Ther 1996;34(2):47-50.
4. Frank T, Bitsch R, Maiwald J, Stein G. High thiamine diphosphate
concentrations in erythrocytes can be achieved in dialysis patients by
oral administration of benfontiamine. Eur J Clin Pharmacol.
2000;56(3):251-7.
5. Pike RL, Brown ML. Nutrition, An Integrated Approach, 3rd Ed. New
York:MacMillan; 1986:467.
6. Hammes H-P, Du X, Edlestein D, et al. Benfotiamine blocks three major
pathways of hyperglycemic damage and prevents experimental diabetic
neuropathy. Nat Med 2003;9(3):294-99.
7. Monnier VM, Kohn RR, Cerami A. Accelerated age-related browning of
human collagen in diabetes mellitus. Proc Natl Acad Sci
1984;81(2):583-7.
8. Brownlee M. The pathological implications of protein glycation. Clin
Invest Med 1995;18(4):275-81.
9. Pomero F, Molinar Min A, La Selva M, et al. Benfotiamine is similar
to thiamine in correcting endothelial cell defects induced by high
glucose. Acta Diabetol 2001;38(3):135-8.
10. Stracke H, Hammes HP, Werkman D, et al. Efficacy of benfotiamine
versus thiamine on function and glycation products of peripheral nerves
in diabetic rats. Exp Clin Endocrinol Diabetes 2001;109(6):300-6.
11. Babaei-Jadidi R, Karachalias N, Ahmed N, et al. Prevention of
incipient diabetic nephropathy by high-dose thiamine and benfotiamine.
Diabetes 2003;52(8):2110-20.
12. Bergfeld R, MatsumaraT, Du X, Brownlee M. Benfotiamin prevents the
consequences of hyperglycemia induced mitochondrial overproduction of
reactive oxygen specifies and experimental diabetic neuropathy
(Abstract) Diabetologia 2001; 44(Suppl1):A39. |
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