الفهرس 
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Abstract
Diabetes mellitus was considered as becoming a global epidemic
health problem. Therefore, the aim of the current work was carried out
to determine the biological effects of different levels of dried
Jerusalem artichoke (10, 15 and 20%) for eight weeks on diabetic rats
on blood glucose, lipid profile, liver and kidney functions and
antioxidant effect in diabetic rats. Also, studying the characteristics of
fortified products (cake and bread) with different percentages of dried
Jerusalem artichoke Flour.
Thirty adult male rats were divided into 2 main groups, group
(1) control negative group (6 rats) fed on basal diet while, group (2)
twenty four rats were injected with Streptozotocin (60 mg/kg b.wt.) to
induce hyperglycemia, then were divided into 4 subgroups,
Subgroup (1) was fed on basal diet only and served as a control
positive group.
Subgroup (2): was fed on basal diet supplemented with 10 % JAP.
Subgroup (3): were fed on basal diet supplemented with 15 % JAP.
Subgroup (4): were fed on basal diet supplemented with 20 % JAP.
After 8 weeks, blood samples were received into clean dry
centrifuge tube and centrifuged to separate serum. Serum was kept
frozen at (-20 °c) till analysis.
Livers, spleens, kidneys, hearts, lung and a small piece of
pancreatic tissue were carefully removed, cleaned, washing in saline
solution, the percent of the organ to body weight was calculated.
Histopathological examination of liver kidneys and pancreases was
carried out.
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The results indicated the following:
1. Chemical composition of Jerusalem artichoke
powder(JAP):
Jerusalem artichoke powder (JAP) contains high percentage of
crude protein (9.1%) and fiber reach to (3.44%). JAP had low content
of total fats (0.74%), while ash content gave high percentage (6.01%).
Total carbohydrate content of JAP was (72.81%), the types of
carbohydrates was inulin (75.81 %) which is adding more advantage to
JAP. Moreover, our results detected that, JAP had higher content of
thiamin (0.115%). JAP had high contents of Fe, Se, K and Mg (22.07,
2.094, 2518 and 112.7 mg/100 dray matter respectively) and it has low
content in Na, Ca and P, Increased the level of K comparable to Na
make JAP more advantageous to blood pressure patients. JAP had
higher content in total antioxidant activity (2108 mg Ascorbic Acid
equivalent).
2. Results from the biological study:
1- Effect of different levels of Jerusalem artichoke powder on
body weight, FI and FER of diabetic rats:
The induction of diabetes with STZ caused a significant
(P<0.05) lowered of final body weight and body weight gain % for
diabetic control group as compared to negative control group and the
initial body weight of the same group. The addition of JAP at different
levels significantly (P<0.05) increased the final body weight and body
weight gain % as compared to the corresponding weights of control
positive group. However, the diabetic rats fed on diets supplemented
with JAP at 10% had significant (P<0.05) decrease in final body
weight comparing with control positive group. There were slight
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changes in final body weight and body weight gain % of rats fed on
JAP at 15 and 20%.
With regarding to FER, the treated diabetic rats fed on different
levels of JAP had a significant (P<0.05) increased in the value of FER
as compared to positive control group. There were significantly
(P<0.05) differences in the mean values of FER among all groups fed
on JAP. Increasing supplementation of JAP level exhibited higher
mean values of FER and final body weight, but lower value of feed
intake.
2- Relative organs weight of diabetic rats :
The addition of JAP at the three levels 10, 15 and 20 % caused a
significant (P<0.05) decrease in the relative organs weight of (liver,
heart, spleen, kidney and lung), as compared to control positive group.
The mean relative organs weight of the groups fed on JAP at 15 and
20% were in the normal range with the control negative group expect
for the liver’s weight. Also, it could be observed that there were
insignificant changes in the relative organs weight (liver, heart, spleen,
kidney and lung) among the groups fed on the different levels of JAP.
3- Water supply of diabetic rats:
The addition of JAP with 10% showed difference in amount of
consumed water during the experiment, it started with 133.3 ml/day/rat
then gradually decreased after four weeks to reached to 100 ml/day/rat,
then the amount of water consumed was decreased in a large amount
(58.3 – 41.7 ml/day/rat) during the second four week of the
experiment. The addition of JAP at 15% showed differences in water
consumption during the experimental period, after first week the
amount of water consumption was 125 ml/day/rat then gradually
lowered after second week of the experiment it reached to 100
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ml/day/rat. After that, water consumption was decreased in high large
amount started with (66.7 ml/day/rat) and finished with
(33.3ml/day/rat). On the other hand, the recorded amount of water
supply in rats fed on JAP at 20 % started with 125 ml/day/rat and
gradually lowered during the experimental periods, it ranged from 75
ml at the second week to 25 ml/day/rat at the end of experiment.
4- Serum glucose of diabetic rats:
The addition with JAP at different levels of 10, 15 and 20 %
caused a continuous reduction (P<0.05) for the mean value of glucose
during the different times of experiment as compared to baseline.
Pronounced decrease occurred in serum glucose levels in the
hyperglycemic rats during feeding on different levels of JAP
comparing to the positive control. Increasing the level of addition
showed an associated highly lower serum glucose.
5- Insulin concentration of diabetic rats:
The addition of JAP at different levels illustrated significantly
(P<0.05) higher values of insulin as compared to control positive
group. There were significant (P<0.05) differences in the mean value
of serum insulin among the three different levels of JAP. It was noticed
that, the mean insulin secretion was increased with the increasing level
of JAP. It should be noted that, the level of JAP at 20% gave the
highest insulin secretion as compared to control group and other
treated groups.
6- Lipid profile of diabetic rats:
Rats fed on diets supplemented with JAP at the three different
levels demonstrated a significant (P<0.05) increase the values of HDLc
as compared to positive control group. On the other hand, the mean
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values of serum TC, TG, VLDL-c and LDL-c were significantly
(P<0.05) decreased in the group fed on diets supplemented with JAP
at 10, 15 and 20%, as compared to control positive group. It was clear
that, the mean value of serum HDL-c, TG, TC, VLDL-c and LDL-c for
the group fed on JAP 20 % were in the normal range as compared to
control negative group.
7- Kidney functions of diabetic rats:
Supplementation with 10, 15 and 20% of JAP significantly
(P<0.05) decrease the mean values of serum urea and uric acid as
compared to control positive group. There were no changes in the
mean value of serum urea and uric acid among the rats fed on JAP
with concentration 10 and 15% and also no changes were observed
between the rats fed on JA 15 and 20%. Addition of JAP at the level
of 20% improved the kidney function as there was no significant
difference were observed for serum uric acid and urea among the rats
fed on 20% of JAP and control normal group.
8- Liver functions of diabetic rats:
The mean values of serum AST and ALT concentration were
significantly (P<0.05) decreased in diabetic rats that fed on basal diets
supplemented with JAP 15 and 20 % as compared to control positive
group. Slight differences in the mean value of both ALT and AST were
observed in group fed on diet supplemented with JAP 10% as
compared to positive control group. On the other hand, the mean
values of serum ALT and AST in the group fed on diet supplemented
with JAP 20% were in the normal range with the control negative
group. No changes were seen in the serum AST between the group fed
on JAP 15 and 20%, however, there were a significant (P<0.05)
differences in serum ALT between those two groups. It is obvious that,
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the addition of JAP at the level of 20% demonstrated positive effect on
liver function in diabetic rats.
9- Antioxidant enzymes of diabetic rats:
Feeding rats with JAP at different levels significantly decreased
the mean value of MDA but significantly (P<0.05) increased the mean
value of SOD and GR comparing to control positive group. There were
insignificant differences in the mean value of MDA and GR between
the groups fed on JAP at 15 and 20%, however there were a significant
(P<0.05) different in the mean value of SOD between the same group.
It was observed that the mean value of GR of the groups fed on
JAP at 15 and 20% was in the normal range with the control negative
group. Also, there were no significant differences among the different
levels of JAP on the mean value of GR. With regarding to SOD, there
were no significant differences between the groups fed 10 and 15 %
JAP. With increasing the addition of JAP, the concentration of both
SOD and GR were increased but MDA was decreased.
10- Histopathological results:
Pancreas, livers and kidneys of rat from control negative group
showing no histopathological changes. On the other hand, positive
control group showed apoptosis of cells of islets of Langerhan‘s and
necrosis of cells of islets of Langerhan‘s and hyperplasia of pancreatic
duct, vacuolations of epithelial lining renal tubules and cystic
dilatation of renal tubules and congestion of central vein and hepatic
sinusoids.
In regarding to the third diabetic rats that fed on basal diet and
supplemented with JAP at 10 %, some rats had congestion of
pancreatic blood vessels, slight congestion of glomerular tuft and
Kupffer cells activation while the other rats showing no
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histopathological changes in the tested organs. In addition, the fourth
and fifth group that fed on basal diet and supplemented with JAP at 15
and 20 % had no histopathological changes in the tested organs.
3- Organoleptic study:
A. Cakes:
Cakes fortified with different levels of JAP (10, 15 and 20%)
had significantly lower scores for exterior color at p<0.05 in
comparison with the control. It was observed that, there were no
changes in external color for all samples. The same results were
noticed for internal color. It was noticed that, scores given to taste of
cakes fortified with 20% JAP was significantly (P<0.05) higher than
that of the control sample, while this cake was numerically higher than
that of other treatments.
Scores of flavor for cakes fortified with 10 and 15 % of JAP were
not change significantly as compared to that of control sample.
Fortified cake with 20% JAP had significantly higher scores of flavor
as compared to other treatments and control. There were no significant
changes in texture and cell uniformity for all fortified cakes as
compared to control samples. In relation to general acceptability, all
fortified samples with different levels of JAP were organoleptically
accepted with comparing to control sample. Overall, there were no
significant changes between the three tested samples. The fortified
cake with JAP (10, 15 and 20 %) among all the fortified samples
maintained better characteristics with regard to taste, flavor, cell
uniformity, texture and general acceptability.
B. Bread:
It was found that bread fortified with different levels of JAP had
higher scores for taste, tenderness and flavor compared to control
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sample with no significant differences. Bread which was fortified with
10% of JAP had significantly higher scores for exterior color at
(P<0.05) in comparison to the control and other treated breads, while ,
there were no significant changes in external color for the bread
fortified with 15 and 20 % as compared to control sample.
Bread fortified with 15 and 20% JAP had significantly lower
scores for interior color in comparison with the control sample. There
were no significant changes in internal color for three fortified bread.
The results showed no significant differences in inner crumb among
the bread fortified with 10% JAP and control sample. Inner crumb
scores were significantly lower with increasing the level of substitution
to 15 and 20% as compared to control sample and other treatments.
It was noticed that, fortification with different levels of JAP
didn‘t affect the outer surface of the bread as compared to control
sample, while there were a significant differences in outer surface
between the bread fortified with JAP at 10 and 20%. No significant
difference was found upon fortification with 10 and 15 % JAP
compared to the control sample in regard to general acceptability, but,
bread fortified with 20% JAP had lower acceptability compared to
control sample and other treatments.
The fortified bread with JAP (10 %) among all the fortified
samples maintained better characteristics with regard to taste, flavor,
cell uniformity, tenderness, inner crumb and general acceptability.
Finally: It could be concluded that the administration of JAP at
the different levels (10, 15 and 20%) to STZ-induced diabetic rats
significantly reduced blood glucose and blood lipids. Therefore, JAP
might be used as a fortification substance for cake and bread to prevent
and reduce diabetes and its complication