|
Title
Effect of antioxidative vitamins on immune function with clinical
applications.
Author
Grimble RF
Address
Institute of Human Nutrition, University of Southampton, U.K.
Source
Int J Vitam Nutr Res, 67(5):312-20 1997
Abstract
Infection and trauma cause inflammatory stress in patients. Tissue
damage, enhanced inflammatory mediator production and suppressed
lymphocyte function may occur as a consequence. The antioxidative
vitamins, ascorbic acid and the tocopherols, are important not
only for
limiting tissue damage but also in preventing increased cytokine
production which is a consequence of excessive activation of
NF kappa
B. Glutathione is a major endogenous antioxidant and is important
for
lymphocyte replication. Two vitamins, vitamin B6 and riboflavin
participate in the maintainance of glutathione status. The former
vitamin acts as a cofactor in the synthesis of cysteine (the
rate
limiting precursor for glutathione biosynthesis) and the latter
vitamin
is a cofactor for glutathione reductase. Deficiencies in tocopherol,
vitamin B6 and riboflavin reduce cell numbers in lymphoid tissues
of
experimental animals and produce functional abnormalities in
the cell
mediated immune response. ascorbic acid and tocopherols exert
anti-inflammatory effects in studies in man and animals. In humans,
dietary supplementation with ascorbic acid, tocopherols and vitamin
B6
enhances a number of aspects of lymphocyte function. The effect
is most
apparent in the elderly.
Title
Essential nutrients and immunologic functions.
Author
Kelley DS; Bendich A
Address
USDA' ARS' PWA' Western Human Nutrition Research Center' Presidio
of
San Francisco' CA 94129' USA.
Source
Am J Clin Nutr, 63(6):994S-996S 1996 Jun
Abstract
Several indexes of immune response' including responses on delayed-type
hypersensitivity skin tests' antibody production' lymphocyte
proliferation' cytokine production' and numbers of the specific
subgroups of white blood cells' are influenced by essential nutrient
intake and may serve as functional tests for evaluating nutritional
status. In certain segments of the population' such as elderly
persons
and smokers' activity of the immune indexes can be increased
through
dietary supplementation with micronutrients' and there may be
a
rationale to increase selected recommended dietary allowances
for the
general population. The activity of the immune system may also
be
enhanced with decreases in total fat intake or lessened with
increases
in total fat intake' particularly of the n-3 type. Research to
date'
therefore' suggests that several dietary components' both essential
and
nonessential' can affect human immune response. The intake of
these
nutrients can be modulated to regulate the activity of the immune
system.
Title
Antioxidants in nutrition and their importance in the anti-/oxidative
balance in the immune system
Author
Biesalski HK; Frank J
Address
Institut f ur Biologische Chemie und Ern ahrungswissenschaft'
Universit
at Hohenheim.
Source
Immun Infekt, 23(5):166-73 1995 Oct
Abstract
Free radicals and reactive oxygen species can damage cells and
tissues
of biological organisms. Due to the fact that these compounds
are
generated continuously in living cells defense mechanisms must
exist.
This so-called antioxidative system ensures that the formation
of free
radicals during different physiological processes does not result
in
cellular damage. Free radicals (oxidants) are produced form the
immune
system. The purpose of this immune cell products is to destroy
invading
organisms and damaged tissue. Oxidants enhance IL-1' IL-8 and
TNF
production in response to inflammatory stimuli. Sophisticated
antioxidant defense systems like enzymes or vitamins protect
directly
and indirectly the host against the damaging influence of oxidants.
While endogenous systems can hardly be influenced' exogenous
antioxidants' delivered by the diet' can be upregulated in the
body. By
this way the pro-/antioxidative capacity can be balanced or even
unbalanced.
Title
Interaction of antioxidative micronutrients with host defense
mechanisms. A critical review.
Author
Schmidt K
Address
Dept. of Surgery, University of T ubingen, Germany.
Source
Int J Vitam Nutr Res, 67(5):307-11 1997
Abstract
An adequate host defense activity critically depends upon the
micronutrient status of an individual among which the cellular
oxidant-antioxidant balance is an important determinant. Oxidative
burst is part of the physiological function of phagocytes connected
to
a massive production and release of reactive oxygen intermediates.
At
the same time, maintenance of the functional capacity of the
host
defense system in fighting against microorganisms and foreign
antigens
is significantly affected by the various reactive oxygen species.
In
order to compensate for this critical condition phagocytes do
show
active uptake and physiologically high intracellular concentrations
of
antioxidants. Thus, optimal function of the host defense system
depends
upon an adequate supply of antioxidative micronutrients and,
on the
other hand, impaired host defense activity can act as a very
early and
sensitive marker of marginal deficiency of antioxidant micronutrients.
Assessment of immune functions can serve as an important preventative
diagnostic tool in the detection of marginal but functionally
relevant
micronutrient deficiencies. Intervention into the functionally
deficient antioxidant micronutrient status can act as the appropriate
preventative or therapeutic treatment with higher efficacy and
less
adverse effects than direct pharmacological modulation of single
immune
functions by specific mediators.
Title
The role of oxidative stress in HIV disease.
Author
Pace GW; Leaf CD
Address
Research Triangle Pharmaceuticals' Durham' NC' USA.
Source
Free Radic Biol Med, 19(4):523-8 1995 Oct
Abstract
Evidence has accumulated suggesting that HIV-infected patients
are
under chronic oxidative stress. Perturbations to the antioxidant
defense system' including changes in levels of ascorbic acid'
tocopherols' carotenoids' selenium' superoxide dismutase' and
glutathione' have been observed in various tissues of these patients.
Elevated serum levels of hydroperoxides and malondialdehyde also
have
been noted and are indicative of oxidative stress during HIV
infection.
Indications of oxidative stress are observed in asymptomatic
HIV-infected patients early in the course of the disease. Oxidative
stress may contribute to several aspects of HIV disease pathogenesis'
including viral replication' inflammatory response' decreased
immune
cell proliferation' loss of immune function' apoptosis' chronic
weight
loss' and increased sensitivity to drug toxicities. Glutathione
may
play a role in these processes' and thus' agents that replete
glutathione may offer a promising treatment for HIV-infected
patients.
Clinical studies are underway to evaluate the efficacy of the
glutathione-repleting agents' L-2-oxothiazolidine-4-carboxylic
acid
(OTC) and N-acetylcysteine (NAC)' in HIV-infected patients.
Title
Immune response to heavy exertion.
Author
Nieman DC
Address
Department of Health and Exercise Science' Appalachian State
University' Boone' North Carolina 28608' USA.
Source
J Appl Physiol, 82(5):1385-94 1997 May
Abstract
Epidemiological data suggest that endurance athletes are at increased
risk for upper respiratory tract infection during periods of
heavy
training and the 1- to 2-wk period following race events. There
is
growing evidence that' for several hours subsequent to heavy
exertion'
several components of both the innate (e.g.' natural killer cell
activity and neutrophil oxidative burst activity) and adaptive
(e.g.' T
and B cell function) immune system exhibit suppressed function.
At the
same time' plasma pro- and anti-inflammatory cytokines are elevated'
in
particular interleukin-6- and interleukin-1-receptor antagonist.
Various mechanisms explaining the altered immunity have been
explored'
including hormone-induced trafficking of immune cells and the
direct
influence of stress hormones' prostaglandin-E2' cytokines' and
other
factors. The immune response to heavy exertion is transient'
and
further research on the mechanisms underlying the immune response
to
prolonged and intensive endurance exercise is necessary before
meaningful clinical applications can be drawn. Some attempts
have been
made through chemical or nutritional means (e.g.' indomethacin'
glutamine' vitamin C' and carbohydrate supplementation) to attenuate
immune changes following intensive exercise.
Title
Differential effect of alpha-tocopherol and ascorbate on oxidative
inJury induced in immune cells by thermal stress.
Author
Franci O; Ranfi F; Scaccini C; Amici A; Merendino N; Tommasi
G;
Piccolella E
Address
Centro Interuniversitario di Immunodiagnostica Sperimentale'
Universit`a della Tuscia' Viterbo' Italy.
Source
J Biol Regul Homeost Agents, 10(2-3):54-9 1996 Apr-Sep
Abstract
As immune cells are often subJected to hyperthermia that can
easily
occur either after intense and/or prolonged exercise or during
defense
against pathogens' in this paper we analysed whether superoxide
anion
production occurred in lymphocytes exposed to high temperature
and'
consequently' if antioxidants could exert any protective function.
The
results demonstrated that an increase of superoxide anion was
induced
in rabbit lymphocytes exposed to 42 degrees C for 1h' although
cell
viability was no affected. However' suppression of either Pokeweed
mitogen (PWM)-driven cell proliferation' or immunoglobulin production
or IL-2 synthesis was observed. To evaluate the capacity of
antioxidants to restore the immune suppressed responses' two
vitamins'
alpha-tocopherol and ascorbic acid' were added to PWM-stimulated
cultures following heat treatment. The data demonstrated that
alpha-tocopherol was able to totally abrogate the inhibitory
effects
mediated by thermal stress' while ascorbic acid did not give
any
protective results.
Title
Effects of B vitamin inJection on bovine herpesvirus-1 infection
and
immunity in feed-restricted beef calves.
Author
Dubeski PL; d`Offay JM; Owens FN; Gill DR
Address
Department of Animal Science' Oklahoma State University' Stillwater
74078-0425' USA.
Source
J Anim Sci, 74(6):1367-74 1996 Jun
Abstract
Because feed and water deprivation during marketing and transport
of
feedlot calves may reduce ruminal B vitamin synthesis at a time
when
calves are most susceptible to infectious agents' we studied
the effect
of B vitamin inJections on infection and immunity in 12 6-mo-old
beef
steer calves (153 +/- 8 kg) that were weaned' limit-fed' and
deprived
of feed. Six calves were inJected with B vitamins and ascorbic
acid
every 48 h for 28 d starting 2 wk before virus inoculation. All
calves
were infected with an attenuated strain of bovine herpesvirus
type 1
(BHV-1) on d 0. From time of arrival (d -20) until the end of
a 3-d
period without food (d -6)' calves lost 13.1% of their initial
weight.
However' they regained weight after re-feeding so that net weight
loss
was 7.7% for the 20-d period prior to infection. The stress/BHV-1
model
resulted in a mild respiratory infection in all calves with no
difference observed between treatment groups. Vitamin inJections
did
not significantly affect virus and interferon titers in nasal
secretions' or lymphocyte blastogenesis. However' the B vitamin
treatment tended to increase serum IgG titers to BHV-1 on both
d 14
(1'120 vs 550' P = .115) and d 28 (2'400 vs 1'830' P = .37) after
infection. Averaged across d 14 and d 28' IgG titers tended to
be
higher (P < .09) for the calves receiving B vitamin inJections'
indicating that the humoral immune response was enhanced by B
vitamin
treatment. B vitamin status in stressed calves at the time of
vaccination or disease challenge may affect the success of the
immune
response.
Title
Micronutrients and immune function: some recent developments.
Author
Thurnham DI
Address
Human Nutrition Research Group, School of Biomedical Sciences,
University of Ulster, Coleraine, UK. di.thurnham@ulst.ac.uk
Source
J Clin Pathol, 50(11):887-91 1997 Nov
Abstract
Micronutrient deficiencies probably have few direct effects on
the
functioning of immune cells. The main effect appears to be a
reduction
in cell mass that may indirectly affect immune cell function,
particularly where T helper cell numbers are reduced. Results
of many
human studies are contradictory. Some of this contradiction may
be
accounted for by the fact that disease may lower concentrations
of
micronutrients in plasma that may be misinterpreted as deficiency.
Low
plasma vitamin A concentrations however appear to impair immune
responsiveness and have deleterious effects on membrane integrity
and
mucosal function. Zinc may have similar effects on gut integrity
and
appears to be particularly useful in the treatment of acute diarrhoea.
Low concentrations of other nutrients such as ascorbate and iron,
may
not necessarily impair immune function. Low plasma ascorbate
may assist
the removal of iron from plasma and low iron concentrations appear
to
increase the cytotoxicity of macrophages.
Title
Vitamins and cancer.
Author
van Poppel G; van den Berg H
Address
TNO Nutrition and Food Research Institute' Zeist' The Netherlands.
Source
Cancer Lett, 114(1-2):195-202 1997 Mar 19
Abstract
The prospect that high intake of certain vitamins may confer
protection
against cancer has drawn substantial attention during the last
decades.
This paper gives a concise update of the role of a number of
promising
vitamins in prevention of cancer. Vitamin A and its analogues
have an
important role in cellular processes related to carcinogenesis.
However' blood vitamin A levels are under strict control and
a high
intake of preformed vitamin A does not seem to be relevant for
cancer
prevention. The antioxidant vitamins C and E and beta-carotene
may also
have other biological activities than free radical trapping that
relate
to their cancer preventive properties. Mechanisms include immune
stimulation' inhibition of nitrosamine formation' enhancement
of cell
communication and an influence on metabolic activation of carcinogens.
Epidemiological data for the antioxidant vitamins are promising'
but
cannot rule out that another factor or combination of factors
in fruits
and vegetables might be responsible for a protective effect.
The B
vitamin folic acid is one of these potential factors that is
currently
thought to have an influence on DNA methylation and thus on
proto-oncogene expression. Folic acid seems to be promising and
deserves further study. Vitamin D might be relevant in colon
cancer
development due to its close links with calcium metabolism that
might
influence cell proliferation. Overall' results are promising'
but the
first human intervention trials on (antioxidant) vitamins and
human
cancer have yielded somewhat disappointing results. At this moment
the
data seem insufficient to make recommendations for vitamin
supplementation to prevent cancer. The results are certainly
in line
with the advice that a diet rich in fruits and vegetables will
help
reduce cancer risk.
Title
Vitamin disturbances in chronic renal insufficiency. I. Water
soluble
vitamins
Author
Pietrzak I
Address
Z Kliniki Nefrologii Instytutu Chor]ob' Wewn,etrznych Akademii
MedyczneJ im. K. Marcinkowskiego w Poznaniu.
Source
Przegl Lek, 52(10):522-5 1995
Abstract
Deficiency and/or altered metabolism of vitamins in CRI is caused
by
uremic toxins' dietary restrictions' catabolic illness' losses
during
dialysis and drug interaction. There are no reports of consistent
studies on vitamin status of water soluble vitamins in CRI. Vitamin
B1
(thiamine) deficiency several authors found most frequently in
CAPD
patients. The cause of this deficiency depends probably on increased
requirement of vitamin B1 due to high glucose intake with peritoneal
dialysis solution. In patients with polyneuropathy high doses
of
thiamine pyrophosphate (Cocarboxylase)' given i.v.' can be helpful
in
this respect. There are conflicting reports concerning plasma
level of
vitamin B2 (riboflavin) in CRI patients. Some authors recommend
its
supplementation. The maJority of patients with CRI exhibit biochemical
and clinical signs of vitamin B6 deficiency. There exists an
univocal
opinion that supplementation of this vitamin effects the cellular
immune system and the amino acid metabolism as well. An adequate
dose
of vitamin B6 is still a matter of dispute. Evidence of vitamin
B12
deficiency has been reported rarely' thus' only few authors recommend
the supplementation of it' mainly in CAPD patients. According
to most
authors the losses of folic acid and ascorbic acid during dialysis
require oral supplementation. Despite the divergences in opinions
concerning the deficiency of water-soluble vitamins in CRI patients'
the supplementation of these vitamins is practised in many
nephrological centers. The amount and the route of vitamins'
administered to CRI patients' should be individualized. |
|
Return to Main Page
