Dietary resveratrol administration increases MnSOD expression and activity in mouse brain.
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Dietary resveratrol administration increases MnSOD expression and
activity in mouse brain.
Robb EL, Winkelmolen L, Visanji N, Brotchie J, Stuart JA.
Department of Biological Sciences, Brock University, 500 Glenridge
Road, St. Catharines, Ont., Canada.
trans-Resveratrol (3,4',5-trihydroxystilbene; RES) is of interest for
its reported protective effects in a variety of pathologies, including
neurodegeneration. Many of these protective properties have been
attributed to the ability of RES to reduce oxidative stress. In vitro
studies have shown an increase in antioxidant enzyme activities
following exposure to RES, including upregulation of mitochondrial
superoxide dismutase, an enzyme that is capable of reducing both
oxidative stress and cell death. We sought to determine if a similar
increase in endogenous antioxidant enzymes is observed with RES
treatment in vivo. Three separate modes of RES delivery were utilized;
in a standard diet, a high fat diet and through a subcutaneous osmotic
minipump. RES given in a high fat diet proved to be effective in
elevating antioxidant capacity in brain resulting in an increase in
both MnSOD protein level (140%) and activity (75%). The increase in
MnSOD was not due to a substantial proliferation of mitochondria, as
RES treatment induced a 10% increase in mitochondrial abundance
(Citrate Synthase activity). The potential neuroprotective properties
of MnSOD have been well established, and we demonstrate that a dietary
delivery of RES is able to increase the expression and activity of
this enzyme in vivo.
PMID: 18486604 [PubMed - as supplied by publisher]
Ted
So Resveretrol should be taken with some fatty food?
Paul Antonik Wakfer
Some pertinent quotes from the full text:
"Here, we report that both dietary and subcutaneous RES delivery
methods are capable of altering the activities of key antioxidant
enzymes GPx, CAT, and MnSOD, and increasing mitochondrial content in
heart, brain and liver."
"CuZnSOD protein levels were unchanged by RES in all tissues and
experimental groups (data not shown). In contrast, the mitochondrial
isoform, MnSOD, protein level was found to vary in response to RES
administration and delivery method. Administration of RES in a
standard diet was ineffective in modulating MnSOD protein levels in
all examined tissues (Fig. 1). In liver of the minipump delivery
group, MnSOD was elevated with RES treatment when compared to the DMSO
vehicle control (Fig. 1A). A substantial increase in MnSOD protein
level in brain was observed when RES was given in a high fat diet.
Interestingly, administration of RES through an osmotic minipump,
which was hypothesized to provide the highest circulating levels of
RES, was ineffective in raising MnSOD protein levels above control
values in brain (Fig. 1B). In contrast to observations made in brain
tissue, MnSOD levels decreased in heart tissue of mice fed RES in a
high fat diet (Fig. 1C). To ascertain whether changes in protein level
were reflective of enzyme activity, SOD activity was measured. Changes
in MnSOD protein levels in the high fat treatment method corresponded
to a parallel increase, or decrease, in enzyme activity (Fig. 1D)."
"to determine if any observed changes in MnSOD, a mitochondria
specific antioxidant, were a result of a change in the number of
mitochondria, citrate synthase (CS) activity was measured. CS is a
citric acid cycle enzyme whose activity is commonly measured as a
proxy of mitochondrial number. CS activity was unchanged in liver of
RES-treated mice in all three delivery methods (Fig. 2A). CS activity
was increased in brain tissue of mice given RES in high fat diet and
through an osmotic minipump (Fig. 2B). An increase in CS activity was
also observed in heart tissue of mice given RES in high fat diet,
while a decrease in mitochondrial number was observed in the minipump
treatment group (Fig. 2C). MnSOD protein levels were normalized to CS
activity to account for any changes in protein level due to increased
mitochondrial number. With mitochondrial number accounted for, changes
in MnSOD protein level continued to follow the same trends (data not
shown)."
"The effect of RES on cellular antioxidant enzyme capacity was further
analyzed by measuring the activities of catalase and glutathione
peroxidase, two enzymes that participate in the removal of hydrogen
peroxide. RES delivery though a standard laboratory diet failed to
change the activity of catalase in any of the examined tissues. An
induction of catalase activity in heart tissue of mice administered
RES through a high fat diet or osmotic minipump was observed (Fig.
3B), while this effect was absent in liver (data not shown) and brain
tissue (Fig. 3A)."
"A subtle decrease in glutathione peroxidase activity was observed in
brain tissue of mice treated with RES through high fat diet or osmotic
minipump (Fig. 4A). In contrast, GPx activity was increased in heart
cells of mice given RES through a high fat diet. A trend toward
increasing GPx activity in the heart tissue of the RES minipump
treatment group was also observed, although the effect did not reach
statistical significance (Fig. 4B)."
" Discussion
"Recently, RES has been reported to improve mitochondrial function of
mice on a high calorie diet [6] and [11]. We hypothesized that an
improved ability to metabolize mitochondrial ROS may play an important
role in this observation, based on our previous finding that chronic
RES treatment dramatically upregulates MnSOD in human cells in vitro
[13]. MnSOD is the only SOD present in the mitochondrial matrix, and
is capable of reducing intracellular oxidative stress. Overexpression
of MnSOD increases resistance to mitochondrial dysfunction,
permeability transition, and apoptotic death invoked by oxidative
stress in various disease contexts [16], [17], [18], [19] and [20].
"It is therefore interesting that RES administered in a high fat diet
induced a significant increase in MnSOD protein level (140%) and
activity (75%) in brain tissue that could not be explained simply by
proliferation of mitochondria (10%). This is an important observation
given that MnSOD overexpression alone is neuroprotective, ameliorating
oxidative damage in response to ischemic events and chemical stressors
such as MPTP [19], [20], [21] and [22]. RES has also been shown to
protect against neuronal death [23], [24] and [25] and is therefore of
interest for its potential ability to protect against
neurodegeneration [26]. We thus suggest that MnSOD is a downstream
target of RES that plays a role in the neuroprotective effects of this
polyphenol. From the present study, it is clear that the mode of
delivery is important in determining RES’s effects. Improved delivery
methods, or longer term treatments may allow for further elevation of
MnSOD expression in the brain. In any event, it appears that RES could
represent a safe dietary means by which increased MnSOD expression can
be achieved in brain, and neuroprotective benefit realized.
"MnSOD protein level has been shown to vary between different regions
of the brain [27], however, whether this reflects differences in MnSOD
per mitochondrion, or simply differences in the mitochondrial content
of neurons within different brain regions is unclear. While evidence
of MnSOD induction with RES may support its use to prevent oxidative
stress associated with neurodegenerative disease, this experiment was
conducted with whole tissue homogenates, and it is therefore not
possible to determine whether specific areas of the brain are
influenced more than others. It will be interesting to examine
specific brain regions, such as the substantia nigra, to determine
whether the effects of RES are highly localized.
"RES has many cardio-protective properties [5] and interacts with a
number of antioxidants in the heart, such as thioredoxin [28].
Previous studies have reported increased levels of SOD in cultured
cardiomyocytes (H9C2 cells) treated with micromolar concentrations of
RES, as well as in the myocardium of diabetic hearts [29] Y. Li, Z.
Cao and H. Zhu, Upregulation of endogenous antioxidants and phase 2
enzymes by the red wine polyphenol, resveratrol in cultured and aortic
smooth muscle cells leads to cytoprotection against oxidative and
electrophilic stress, Pharmacol. Res. 53 (2006), pp. 6–15. Article |
PDF (444 K) | View Record in Scopus | Cited By in Scopus (13)[29] and
[30]. Nonetheless, under the conditions used in this study a decrease
in MnSOD protein level and activity was observed. RES did, however,
induce subtle increases in the activities of glutathione peroxidase
and catalase in heart tissue of both the high calorie and minipump
groups. This agrees with previous observations made in vascular tissue
treated with RES. In these experiments, GPx and CAT were found to be
critical in RES’s protective effects against oxidative stressors in
cultured aortic preparations [31]. It is therefore interesting that
changes in these enzymes were also observed in vivo. The net result of
reduced MnSOD activity concomitant with increased capacity to remove
H2O2 should be a reduction in [H2O2], which could also be protective
in cardiomyocytes.
"In addition to altering MnSOD levels, RES has been reported to
interact directly with mitochondrial oxidative phosphorylation [32],
[33] and [34] and biogenesis [6], [11] and [35]. One observation that
has been made is that RES treatment in a high fat diet increases
mitochondrial abundance in liver, brown adipose tissue and skeletal
muscle of mice [6] and [11]. Interestingly, we did not observe an
increase in CS activity (a proxy of mitochondrial number) in liver,
despite using a comparable dose of RES in the same strain of mice.
This may be due to differences in the length of treatment time and the
age of the mice at the onset of RES treatment. However, significant
increases in CS activity were observed in brain and heart tissue of
the high fat RES group. Therefore, it seems that oral administration
of RES is capable of inducing mitochondrial proliferation in a variety
of highly oxidative tissues. The mechanism and significance of this
potentially important observation remain to be determined. It may
represent a general shift toward a more oxidative metabolism, as is
observed in caloric restriction [6]. However, genetic manipulations
that increase MnSOD have also been shown to increase mitochondrial
oxidative capacity [16]. Therefore, the improved mitochondrial and
physiological function observed in rodents treated with RES
administered in high fat diets may be directly linked to the induction
MnSOD or other antioxidant enzymes in addition to mitochondrial
proliferation.
"While we do not know the circulating levels of RES in each treatment
group, it is interesting that the extent to which RES was able to
induce changes in antioxidant enzymes and mitochondrial number was
dependent on its route of administration. This perhaps suggests that
the delivery modes were able to augment RES’s transport and
accumulation in the body. RES undergoes extensive chemical
modifications in the small intestine following its ingestion, and is
quickly metabolized [9]. Despite its apparent low bioavailability, 4
weeks of chronic exposure to RES was sufficient to induce a number of
changes in the observed enzymes. RES is a hydrophobic molecule, and it
may be that interactions with serum proteins and lipids are able to
increase localized concentrations, while circulating plasma levels
remain low. In any case, administering RES in a high fat diet was
highly effective in modifying antioxidant enzyme activities, and
mitochondrial number. This property may be exploited to further
increase the bioavailability of this polyphenol following ingestion.
"In conclusion, RES in a high fat vehicle may represent a dietary
means of achieving the protective effects of increased MnSOD levels in
the brain."
--Paul Wakfer
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Paul Antonik Wakfer
I do not think that the study clearly shows that to be the case. The
better effects on MnSOD from the high fat diet may simply be because
MnSOD was upregulated more in order to deal with the negative effects
of the high fat diet. Even with the normal diet resveratrol would have
a reasonable amount of fat accompanying it during digestion.
Still, it may be valuable, and certainly will not hurt, to take one's
resveratrol with the fattiest portions of one's daily food intake.
Olafur Pall Olafsson
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Hi Paul,
Thanks for the good report. I did not see any mention of the dose
though in your quotes and it is not given in the abstract. It is worth
mentioning that the comparison between the dietary and subcutaneous
administrations was not entirely fair because the dose in the former
case was twice as high as in the latter case. Here is the relevant
part of the full text for those interested:
"RES was incorporated into mouse chow of both standard and high fat
diets at a concentration of 0.1% (w/w), such that mice obtained a RES
intake of approximately 200 mg/kg/day. Alzet 2004 mini-pumps were
preloaded with 50% degassed DMSO or 1.825M RES prepared in 50%
degassed DMSO. The minipumps were implanted subcutaneously under
isoflorane anesthesia and released vehicle or RES at a flow rate of
0.25 lL/h to give a dosage of 100" mg/kg/day.
Paul Antonik Wakfer
Yes, I should have reported the dose, but I was more interested in
commenting about the fat related situation.
OTOH, I am not sure which way you are relating the different dosages
(dietary versus subcutaneous) with respect to "fairness" (not a very
scientific word to describe the situation).
IMO, since subcutaneous dosing eliminates the initial pass through the
liver of dietary administration, only using half the dose is likely
"unfair" in the direction of enhancing the subcutaneous dosing
effects, rather than the other way around that I think you meant. To
say it more scientifically, I think that in order for the dosages to
be experimentally equivalent in any reasonable manner the subcutaneous
dosage should have been much less than 1/2 the dietary dose.
However, since no one is likely going to take resveratrol
subcutaneously, I think that the more important part of the result is
the relationship of the effects of resveratrol to fat in the diet. I
think that this result shows that it is quite important now to have
some other investigations determine whether or not resveratrol has
major benefits *only* for those taking a high fat diet, and/or whether
or not resveratrol is more effective for all kinds of users when taken
with a fatty meal. For myself, as a result of this study I have
decided to cease taking resveratrol at non-mealtimes and thus to take
my entire daily intake with my one long daily meal.I am not certain
about this strategy, it is simply my best guess for now.
Olafur Pall Olafsson
I was lacking a better word. Now that I think of it the word accurate
is probably better to describe what I mean. My thought was that in
order to get an accurate comparison between different routes of
administration of resveratrol the route of administration would have
to be the only thing different between the groups, everything else,
including the dose, would have to be constant in order for it to be an
accurate comparison between the different routes of administration.
> IMO, since subcutaneous dosing eliminates the initial pass through the
> liver of dietary administration, only using half the dose is likely
> "unfair" in the direction of enhancing the subcutaneous dosing
> effects, rather than the other way around that I think you meant. To
> say it more scientifically, I think that in order for the dosages to
> be experimentally equivalent in any reasonable manner the subcutaneous
> dosage should have been much less than 1/2 the dietary dose.
If you mean experimentally equivalent in terms of the dose of
resveratrol that reaches the blood then I agree that the subcutaneous
dose should have been much lower. Thus in terms of resveratrol
concentration in the blood the dose was "unfair" in the direction of
enhancing the subcutaneous dosing effects. On the other hand since
some of the effects of resveratrol in vivo are caused by it's
metabolites, in terms of resveratrol metabolites (created during it's
passing through the liver) the dose was "unfair" in the direction of
enhancing the oral dosing effects, even more so because of the higher
dose used. It is not clear to me from reading the full text what
exactly the authors were trying to compare. If they were trying to
reach a similar concentration of resveratrol in the blood by the two
different routes then why did they only have the oral dose twice the
subcutaneous dose? I am no expert on resveratrol but AFAIK because of
the rapid metabolism of resveratrol in the liver the oral dose would
have to have been a good bit higher to reach concentration of
resveratrol in the blood similar to that reached with the subcutaneous
dose. Unfortunately the authors didn't measure the blood concentration
of resveratrol in the study. In any case I don't think this was an
accurate comparison. Depending on what they were trying to compare I
think they should have either given the same dose of resveratrol or
adjusted the doses so both routes would led to similar concentrations
of resveratrol in the blood.
> However, since no one is likely going to take resveratrol
> subcutaneously, I think that the more important part of the result is
> the relationship of the effects of resveratrol to fat in the diet. I
> think that this result shows that it is quite important now to have
> some other investigations determine whether or not resveratrol has
> major benefits *only* for those taking a high fat diet, and/or whether
> or not resveratrol is more effective for all kinds of users when taken
> with a fatty meal.
I agree.
> For myself, as a result of this study I have
> decided to cease taking resveratrol at non-mealtimes and thus to take
> my entire daily intake with my one long daily meal.I am not certain
> about this strategy, it is simply my best guess for now.
Given the information that is available that would be my best guess
also. Thus I will continue to take resveratrol with meals as I have
been doing.