الفهرس 
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Abstract
Organophosphorus poisoning is still an important health attention
in Egypt where agriculture is the main livelihood of people. With the
advance of times, pesticides are, nowadays routinely used for modern
cultivation method. These are readily available as over the counter
preparations in village shops and act as a common agent for suicidal
purpose after trivial family problems.
The high rate of organophosphate compound poisoning can be
attributed to the uncontrolled trade of this material, its inappropriate
conservation, and its widespread use by the public and consequent
availability.
The biochemical evaluation demonstrated that the enzymatic
activity of cholinesterase was strongly inhibited by exposure to OP,
whereas that of catalase increased significantly. This increase can be
explained by the stimulation of antioxidant defense system.
A healthy cell has a mortal enemy called free radical which is
unstable and reacts quickly with the nearest stable molecule abstracting
its electron to attain stability. When the attacked molecule loses its
electron, it becomes a free-radical itself, these formations of free-radicals
continue on and on if antioxidants are not available. Free radical
production becomes excessive and causes molecular damage.
Propagation and initiation of free radicals chain reaction can be
minimized by the donation of hydrogen from the antioxidants. The
destructive effects of free radicals can be prevented with the addition of
anti-oxidants in the diet or by anti-oxidant supplements. A good antioxidant
complex supplement actually has advantages over diet sources in
that the complex has many different specific types of anti-oxidants which
seek out and destroy free radicals at many various cellular sites.
Catalase is one of the cellular defense mechanisms against
cytotoxic oxygen species (H2O2). Catalase is present in cells of aerobic
organism. Catalase converts two molecules of the strong oxidant,
hydrogen peroxide, to molecular oxygen and two molecules of water.
The present findings indicate that cells continually suffer from
oxidative stress in spite of over-activity of antioxidant defense
mechanism as indicated by increase in CAT activity.
The higher levels of antioxidant enzymes may be necessary to
detoxify increased concentration of ROS that are generated from
oxidative stress because of OP toxicity. The body could not compensate
in a short period. Therefore, the antioxidants at suitable doses should be
given in order to reduce oxidative damage, which could be effective in
speedy recovery of acute OP poisoning cases.
Clinical Part
During the study period, out of 2558 cases of poisoning admitted to
MPCC, 468 cases were due to organophosphorus insecticides poisoning.
Incidence was more common in females (58.1%). Sex ratio (M: F) was
1:1.39 and 21-30 years was the age group which commonly affected.
Unmarried persons were more involved. Most of the cases (71.8%)
belonged to rural area.
The most common mode was suicidal (88.5%) due to financial and
domestic problems, while 6.4% of cases were accidental and 5.1% were
occupational.
The common route of exposure was ingestion of poison (94.7%).
The most common manifestations were miosis 83.3%, followed by
vomiting 82.7% and abdominal pain 78.6%. Nearly two thirds of the
patients had bradycardia and more than half of the studied cases
manifested with sweating representing 57.7%. Disturbed consciousness
level was found in 24.3% of cases and only 17.3% had diarrhea.
Most patients were mildly affected (60.5%), 31.4% were moderate and
lastly 8.1% were severe. Mortality was significantly higher in severe
toxicity group. Hypokalemia was the most common electrolyte
imbalance.
Most cases (86.1%) arrived to hospital in less than 4 hours, followed by
11.5% arrived 4 to 8 hours after consumption of poison. Only 2.4 % of
cases came after 8 hours. Late hospital arrival increased the severity of
poisoning.
Female suicide (62.6%) exceeded that of the male (37.4%), while males
outnumbered females in accidental and occupational poisoning.
There was highly significant relation between plasma cholinesterase level
on admission and severity grades of poisoning, which can be helpful for
predicting the outcome in OP poisoning cases.
Mild cases were hospitalized for 2.7 ± 1.4 days, while moderate cases
were hospitalized for 4.8 ± 2.5 days. Severe cases stayed for longer
periods in hospital with a mean value of 11.6 ± 5.9 days.
Plasma cholinesterase levels were significantly decreased as compared to
controls and increased up to normal level after treatment with atropine
and toxogonin.
Catalase activity was highly significantly increased in OP patients as
compared to controls. Activity of CAT was inhibited but not altered
significantly after treatment with atropine and oxime.
Experimental part
The toxic effect of profenofos on male adult albino rats was studied
with estimation of two biomarkers cholinesterase and catalase activities at
different time intervals 1 hour, 6, 24 hours and 7 days after single oral
dose (1/10 LD50).
The animals were divided equally into four main groups as
follows:
•group (I):Control group
•group (II):Organophosphorus toxicity group
Profenofos was administered as a single sub-lethal oral dose 20
mg/Kg (1/10 LD50).
•group (III): Organophosphorus + antidotes treated group
Profenofos was administered as a single oral dose 20 mg/Kg. Then the
rats were treated with 17 mg/kg atropine and 30 mg/kg toxogonin IP.
•group (IV): Organophosphorus + antidotes + antioxidants treated
group
Profenofos was administered as well as atropine and toxogonin as
mentioned above. The animals were treated concomitantly with vitamin C
200 mg/kg and vitamin E 150 mg/kg once daily for 7 days orally.
Toxicity manifestations
Rats administered profenofos showed signs of toxicity related to
cholinesterase inhibition (miosis, lacrimation, salivation, muscle tremors,
muscle weakness, diarrhea) which decreased both in intensity and
frequency with passage of time. Observed improvement occurred with
atropine and oxime treatment. However, this improvement was more
prominent in vitamin C and E given group.
Body weight changes of rats
There was body weight gain of all studied groups after 7 days; the
lowest body weight gain was recorded in group II (7.2%) and higher
weight gain (8.1%) in group III, while the highest weight gain among the
toxicity groups was found in group IV treated with antidotes and
antioxidants (14.4%).
Cholinesterase activity
Serum cholinesterase activity of rats after 1 hour
The activity of serum cholinesterase of rats orally received
profenofos was suppressed and the difference was statistically highly
significant in relation to controls. The activity was 41.14% of the control
in group II. The application of treatment in group III and IV caused an
increase in cholinesterase activity compared to the poisoned animals of
group II but the difference was statistically non-significant.
Cholinesterase activities were 46.01% of the control in group III and
47.65% in group IV.
Serum cholinesterase activity of rats after 6 hours
An increase was observed in the values of serum cholinesterase
after 6 hours. It was 51.29% of the control in OP group. Again an
increase in the enzyme level was observed in antidotes treated group
(57.22%) with the highest increase (61.75%) in rats treated with antidotes
and antioxidants. A greater efficiency in the restoration of cholinesterase
activity in group IV caused a significant difference in relation to group II.
Serum cholinesterase activity of rats after 24 hours
Further increase was observed in serum cholinesterase after 24
hours. Rats of group II had 68.32% of the control activity. Higher values
were recorded in animals receiving treatment; 83.64% in group III and
88.23% in group IV. The difference between group IV and the controls
was attenuated.
Serum cholinesterase activity of rats after 7 days
After 7 days with regaining of cholinesterase activity, much
improvement was recorded in serum cholinesterase of rats of all groups.
Serum cholinesterase of group II (OP) was 92.05% of the control activity,
while that of group III and IV was 94.77% and 98.72% respectively. The
difference between the groups became non-significant.
As regards brain cholinesterase, it was inhibited by profenofos.
Antidotes caused increase cholinesterase activity in brain tissues with
further increase in rats treated with additional vitamin C and E.
Brain cholinesterase activity of rats after 1 hour
As regards brain cholinesterase, it was inhibited by profenofos to
50.28% of the control activity in group II. The difference was statistically
highly significant compared to control rats with non-significant elevation
after treatment as compared to OP exposed rats. As compared to control
group, the levels were 55.05% and 56.56% in group III and IV
respectively.
Brain cholinesterase activity of rats after 6 hours
Higher level of brain cholinesterase activity was recorded after 6
hours related to control. It was 60.94% of the control activity in OP
exposed group. More elevation was recorded in group III (77.84%) and in
group IV (86.6%).
Brain cholinesterase activity of rats after 24 hours
After 24 hours, more increase was recorded of brain CHE (72.07%,
83.99% and 89.51% of the control) in groups II, III and IV respectively.
Brain cholinesterase activity of rats after 7 days
After a week in this experimental condition, brain cholinesterase
activity did not show statistical differences between the groups. The
percentages of activity were 90.56% in group II, 91.58% in group III and
98.15% in group IV of the control activity.
Catalase activity
High CAT activities were detected in rats poisoned with
profenofos. Less elevation was reported in rats receiving antidotal
treatment. Treatment with vitamin C and E exerts an antioxidative effect
by decreasing lipid peroxidation and CAT activity in blood and brain.
Serum catalase activity of rats after 1 hour
The present study resulted in highly significant increased CAT
activities in treated rats in relation to control. Activities of groups II, III
and IV were 157.95%, 151.6% and 148.54% of the control respectively.
Serum catalase activity of rats after 6 hours
High CAT activities were detected in rats poisoned with profenofos
in group II (139.18% of the control). Less elevation was reported in rats
receiving treatment (129.9% for group III and 123.45% for group IV).
Serum catalase activity of rats after 24 hours
Comparing enzyme activities of animals after 24 hours, it was
noticed persistent elevation of CAT activity (130.86%) in OP exposed
rats with less value in group III and IV (122.78% and 111.23% of the
control respectively). The values of group IV became non-significant in
relation to the control.
Serum catalase activity of rats after 7 days
The values of activity in rats determined after 7 days showed
downward tendency towards control values. The activities in group II
were 121.75% and 110.05% group III with nearly normalization in
animals of group IV (103.57%). The addition of vitamin C and E to
routine treatment caused significant decrease in serum catalase activity in
relation to group II.
Brain catalase activity of rats after 1 hour
High brain CAT activities were observed in rats poisoned with
profenofos. The activity increased significantly to144.15% of the control
in group II. Less elevation was recorded in group III and in group IV
(133.34% and129.15% of the control respectively).
Brain catalase activity of rats after 6 hours
Persistent increased CAT activity was detected in profenofos
treated rats in relation to control (142.36%). Less elevation was recorded
in group III (133.05%) and (116.78%) in group IV.
Brain catalase activity of rats after 24 hours
Brain catalase activity of rats in groups II, III and IV were 136.37%,
129.55 % and 115.64% of the control respectively after 24 hours.
Brain catalase activity of rats after 7 days
After 7 days, CAT activities in profenofos treated rats were
123.66% of the control. The activities were 122.74 % in antidotal treated
group and 104.17 % after treatment with antioxidants. The differences
between groups were non-significant.
Histological examination of brain (Hx& E)
Exposure to profenofos causes important degenerative changes in
brain tissue in the form of congestion of cerebral blood vessels, edema
and pyknotic nuclei.
Rats treated with antidotes showed milder histopathological
features. Marked improvement was observed in animals treated with a
combination of vitamins C and E.
Seven days after the intoxication, it was observed that structural
changes were regressed. Mild vascular congestion and persistent
vaculation were noted in group II. Section from group III showed mild
vascular congestion and little perivascular edema. In group IV, nearly
normal morphological appearance of the nerve cells was observed with
residual fine vacuolations.
PAS reaction for detection of mucopolysaccharides
Cerebral cortex of control group showed very strong PAS reaction,
while section of rats treated with OP (group II) and dissected after 24
hours showed weak PAS reaction. Animals of group III showed weak to
moderate PAS reaction after 24 hours. Cerebral cortex of rats of group IV
stained moderately.
After 7 days, higher staining was noted in different groups. The
cells moderately stained in group II. While, some of the cells strongly
stained in group III with much improvement was seen in group IV.
Toluidine blue stain for detection of Nissl’s granules
Control animals showed very strong blue staining of Nissl’s
granules. Cells of rat cerebral cortex treated with OP were seen with
faintly stained cytoplasm without clear Nissl’s granules in the degenerated
cells.
Sections of albino rat cerebral cortex treated with OP and antidotal
therapy showing nerve cells containing Nissl’s granules moderately blue
stained and others weakly stained after 24 hours, while weak reaction was
detected in few degenerated cells in group IV.
After 7 days, OP treated group showed moderate staining.
Antidotal therapy showed restoration of most of cells to nearly their
darkly stained cytoplasm containing Nissl’s granules, while sections of
animals treated with additional antioxidants showed strongly stained
cytoplasm.
Immunohistochemical stain for Glial Fibrillar Acidic
Protein (GFAP)
Astrocytes did not express GFAP at immunohistochemically
detectable levels, or express only very low levels in control group, while
they showed positive immunoreaction for GFAP in profenofos toxicity
group after 24 hours.
Animals treated with antidotal therapy showed less prominent
GFAP immunohistochemical staining compared to OP group. Vitamins C
and E given to rats in group IV caused weak GFAP marking after 24
hours.
After 7 days, sections of rat cerebral cortex treated with OP
showed strong positive immunoreactivity with extensive overlapping and
interdigitations of processes of astrocytes. Antidotal therapy caused less
astrocytic density compared to OP group with moderately reactive
astrocyte processes which do not overlap. Addition of antioxidants
showed GFAP marking nearly similar to control group.
The study concluded that oxidative stress plays an essential role in
profenofos mediated injury and the combination of vitamins C and E
ameliorated profenofos biochemical and histological deficits through
their free radical scavenging effect. The addition of vitamin C and E in
repeated doses to routine treatment of OP poisoning can play
supplementary role and enhance the effectiveness of therapy.