stopping the exposure to CS, were significantly reduced compared
to the positive control (C1) group (Table 1).
For experiment II, these two parameters of the group exposed
to CS for four weeks (C2) were significantly increased
compared to the negative control group. The two parameters
in the group treated with high doses of antioxidants during
exposure to CS were significantly lower than those of the positive
control (C2) group (Table 1).
3.2. Effect of antioxidants on heart weight
Regarding experiment I, it was noticed that the weight of the
heart and the heart index (the percent of its weight in relation
to the body weight of the animal) of the group exposed to CS
were significantly higher compared to the negative control (C0)
group. Heart weight continued to increase even after treatment
with a low dose of antioxidants, while a high dose could
slightly reduce this increase (Table 1).
In experiment II, there was a significant increase in the
heart weight as well as the percentage of its weight in relation
to body weight in the group exposed to CS for four weeks
compared to the negative control (C0). Administration of high
doses of antioxidants succeeded in reducing both parameters,
while low doses failed to do that (Table 1).
3.3. Effect on the lipid profile
Regarding experiment I, the cholesterol level was increased in
the group exposed to CS for three weeks compared to the negative
control (C0) group. Cholesterol level, as well as the percent
of its decrease, was significantly decreased in C2, in which
the rats were exposed to CS for three weeks, and then the
exposure was stopped for the next four weeks without treatment.
The percentage of decrease in the cholesterol level was
significant in the groups treated with either low or high doses
of antioxidants after stopping the exposure to CS. The highest
significant decrease was noticed in the group treated with high
doses of antioxidant (22.24%) (Table 2). The same changes
were noticed in the levels of LDL; the highest percentage of decrease
in the LDL level was recorded in the group treated with
a high dose of antioxidants (39.11%) (Table 2).
For experiment II, the level of cholesterol was increased in
the group exposed to smoking for four weeks compared to the
negative control (C0). The cholesterol level was significantly
decreased in the groups treated with either low or high doses
of antioxidants during the exposure to CS below the cholesterol
level of the negative control group. The same changes
were noticed in the level of LDL (Table 3).
Regarding experiment I, there was an insignificant decrease
in the levels of triglycerides in the groups treated with low
doses of antioxidants after stopping exposure to CS; the high
doses of antioxidants resulted in a significant decrease, and
the percentage of decrease was 25.29% (Table 2). Experiment
II revealed that there was a significant decrease in the level of
triglycerides in the groups treated with low or high doses of
antioxidants during their exposure to CS compared to the negative
control; the percent of decrease were 33.96% and 35.1%,
respectively (Table 3).
The level of HDL decreased by 14.2% in the group exposed
to CS for three weeks compared to the negative control. By the
end of experiment I, the level of HDL increased even without
treatment. There was a significant increase in HDL level in the
groups treated with low or high doses of antioxidants after
stopping exposure to CS compared to the negative control;
the percentages of increase were 28.88% and 29.19%, respectively
(Table 2). For experiment II, the level of HDL decreased
by 16.7% in the group exposed to CS for four weeks compared
to the negative control. HDL level increased in the groups
treated with low and high doses of antioxidants during exposure
to CS compared to the negative control (Table 3).
3.4. Effect on the histological structure of carotid artery
The carotid arteries of rats from the negative control group
(C0) that received a standard diet had relatively wide lumens
and thin walls. The arteries had intact structures (Fig. 2A