الفهرس 
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Abstract
In the present study we determined and measured the
biochemical activities of the honey bee antioxidant enzymes such as
as superoxide dismutase (SOD), catalase (CAT), glutathione
peroxidase (GPx), glutathione-s-transeferase (GST), ascorbate
peroxidase (APOX), reduced glutathione (GSH) and total peroxide
concentrations.
The biochemical activities of the antioxidant enzymes were
carried out simultaneously with the apiary activities, bee population,
sealed brood, stored pollns, honey areas and recording the
simultaneously with the meteorological records in the active season
(June to Sep.) and the moderatly-avctive season (Oct. to Dec.).
Superoxide dismutases (SODs) are the first line of defense
against oxygen free radicals, especially the O2•−,
and from other
products of oxidative stress. O2•− is dismutated by SOD to hydrogen
peroxide, 2O2•− +2H+ → H2O2 + O2•−. In the current study, the SOD
activity in honey bee Apis mellifera was determined, the results
pointed out that in both races of honey bee, hybrid and carniolan, the
activity was similar.
Even so, the activity was evidently increased all over the whole
months in both two races in the active season, this may be attributed
to the overproduction of SOD to overcome O2•− generation. The
results also demonstrated that, the SOD elevation was analogous with
honey bee activities. On the contrary, the recorded SOD activities in
the moderately active season were reduced, this might be due to the
lesser production and generation of O2•−. In addition, the SOD activity was affected by the temperature
and relative humidity, the elevation was in the active season where
the degrees of both temperature and relative humidity were high
while the opposite has been observed in the moderately active season.
The results of the present work indicated that there was a highly
significant positive correlation between the SOD activity and both the
temperature and relative humidity indicating the influence of the
temperature on the activity of SOD in both carniolan and hybrid
honey bees.
Significant amounts of H2O2 can diffuse out from mitochondria
CAT is recognized to serve as the defenses against H2O2 . Our
findings showed greatly dissimilarity against the months; the CAT
activity was declined allover the months, through the active and
moderately active seasons. It was proposed that CAT is inefficient at
reducing hydrogen peroxide to low levels because of its high Km.
The ability of GPx to reduce various hyDROPeroxides, as well as
H2O2, has led to the proposal of an important role of this enzyme in
the protection of tissues against oxidative damage. In the present
study the GPx activity was recorded, in point of a comprehensive
conception, our observations all over the whole experiment
demonstrated that GPx activity was reduced generally, GPx activity
was similar in both races however; the GPx activity was highly
affected by months.
On the other hand, in the moderately active season it was
observed that, the GPx values and activity were particularly higher
than those measured in the active season; this may support our
hypothesis about the presence of action of other enzyme that compete and scavenge the peroxides, and we think that it is the GST, where its
values were lower than those noticed in the active season.
Ascorbate peroxidase (APOX) catalyzes the oxidation of
ascorbic acid with concurrent H2O2 reduction:
AA + H2O2 DHA + 2H2O
The APOX activities of honey bees were measured, the results
showed that APOX activity wasn’t affected neither by race (hybrid
and carniolan) nor type (foraging and nursing) nevertheless, but in the
active season; the APOX activity generally increased. We think that
APOX could compete with the overproduction of H2O2 and
compensate the defect of CAT levels, in contrast, when the oxidative
stress reduced, the APOX activity declined allover the moderately
active season; where the H2O2 concentrations decreased consequently.
This might be explained the raise and decline of APOX activity.
Glutathione S-transferases (GSTs) have been recognized to play
an important role in the detoxification of endogenous and exogenous
xenobiotics, in both vertebrates and invertebrates, GSTs are important
in phase I metabolism of organophosphorus and organochlorine
compounds and play a significant role in resistance to these
insecticides in insects. GST activities has been determined in the
present study, the results demonstrated that GST activity was
significantly influenced during the whole period of the study.
Generally, the activity varied between increase and decrease in both
seasons and races. We could attribute this fluctuation in such manner
of GST activity to the GPx action because it was observed allover the
trial, especially in the active season, that when the GPx values decreased the GST activities were increased. This could be returned
to interchangeable action between them whereas; the GPx is isoform
the GST and they are in opposite relationship with each other, we
belief that this conflicting relation in activity is for the benefit of the
insects in order to render the oxidants and ROS to the minimum
levels, and protect them from the damage.
Reduced glutathione (GSH) is a tripeptide that is important in
maintaining the cellular redox status of the cell. The GSH activity
was studied and the results of the present work pointed out that, the
GSH content was highly elevated in the active season; Also the
results of the current study, showed that the elevation of GSH content
was in parallel with the elevation of total peroxides concentration, we
figure that this raise must be for compensating the defect in activity
of other enzymes in addition, the GSH it self might be acted as nonenzymatic
antioxidant scavenger, moreover, GSH acts as a cofactor
or co-substrate for many other enzymes. In view of the previous
observations and suggestions this might be interpreted why GSH was
elevating, we could speculate that this might be due to its ability to
act as a radical scavenger.
Moreover, there was positive significant correlation between the
apiary activities, also the temperature and the relative humidity
affected the GSH activity, where increased during the active season
as these two factors have increased, the correlation between them and
the content of the GSH was highly significant positive. In the
moderately active season; the GSH content in both of the two races
was conspicuously reduced throughout the whole months this of
course might be due to the reduction oh the total peroxide concentrations, so there no need for more generation and synthesis of
GSH to meet the oxidative stress.
The rapid dismutation of O2•− to H2O2 can result in increased
concentrations of hydrogen peroxide and hydroxyl radical which
results in oxidative damage to lipids, proteins and nucleic acids. The
results in the current work, showed that total peroxide concentrations
were markedly increasing during the active season, this might be due
to the increase in activity of honey bees and flight to collect more
nectar and pollen, the allelochemicals are present in pollen and nectar
and the oxidation of phenols produces reactive oxygen species ROS
including H2O2 . The increasing of activity in apiary result in raising
the metabolic pathways in which to detoxify the peroxides,
allelochemicals by cytochrom (P-450, b, c) and increasing loads of
oxidative stress.Increasing the honey bees activities in apiary met by
increasing the bee population and sealed brood areas where they
showed the peaks in for both races, so the ingestion of
alellochemicales increased and the production and generation of
peroxides raised also. Subsequently, increasing the dismutation
process by SOD followed by the action of the rest of detoxifing
enzymes on hydrogen peroxide. This was reinforced by the highly
positive correlation for the SOD, GSH and total peroxide. The
significant positive correlation between the apiary activities,
temperature and the total peroxide concentration supported this
observation. While the contradictory during have been observed in
the moderately active season. The data obtained during the present
study showed that, the apiary records were in line with biochemical
experiment. The results of correlation analysis between the antioxidant
enzymes activities, the total peroxide concentration in active and
moderately active seasons could indicate the presence of significant
coordinated antioxidant actions. The increase or decreases of the
antioxidants are according to the contents and levels of peroxides
indicating that there must be a strategy and specific manner strategy
for managing peroxides at safe levels. The most endogenous
defensive and protective strategy is the antioxidant systems, changes
in the activities of antioxidant enzymes have been shown to correlate
with the physiological and metabolic activities. The increased
oxidative stress leads to an up-regulation of antioxidant enzymes.