الفهرس 
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Abstract
In the present study, three synthetic sweeteners were purchased from the local market, these namely aspartame, sucralose and stevia in addition to sucrose as natural sugar for comparison. The synthetic sweeteners were dissolved in distilled water and stored at 4ºC till use.
The design of the experiment lasted for 8 weeks. The control group oral dosing injected with distilled water. The second group (sucrose-feeding) was oral dosing injected with 2ml/kg from 10%sucrose solution for 8 weeks. The third group received 2 ml from aspartame solution. The fourth group sucralose-feeding group was oral dosing injected daily with ml of sucralose solution for 8 weeks. The fifth group oral dosing injected with stevia solution. All sugars and synthetic sweetener solutions and water were carefully supplied.
The results could be summarized as follows:-
In the present work, effects of two synthetic sweeteners (SS) beside sucrose and stevia on whole body weight, organ weights and some biochemical parameters of albino rats (males and females) were studied. Results generally showed that average body weights (n=5) of female always increase with different extents. Sucralose-feeding animals revealed the highest increases followed by aspartame-feeding. Use sucralose in rats feeding led to double in average weight from 95 g as initial weight to 206 g as final weight (116%). Stevia-feeding rats recorded increases in body weight in the first month higher than those determined in the second one.
Effects of synthetic sweetener on the weights of liver, kidney, pancreas and spleen of animals studied here indicate that increases in all organs with different extents after 4 and 8 weeks. Effects of SSs on liver weight indicate that feeding with aspartame and sucralose led to the highest levels in liver weights.
The results showed the kidney weights increased in all groups and the increment is more apparent in females of sucralose-feeding animal group. The results showed the pancreas weights increased in all groups and the increment is highest in aspartame-feeding animals. Effects of SSs on pancreas weights are more apparent after 8 weeks than those reported after 4 weeks. Spleen weights of animals treated with aspartame revel the highest increases. The results also, showed that treatment with sucralose and stevia don’t led increases in spleen weights.
Results show glucose blood levels (GBLs) after feeding of male and female of albino rats for one and two months. Our results indicate that the GBLs raise when non-caloric synthetic sweeteners i.e. aspartame, sucralose and stevia were used for feeding of male and female.
Alanine amino transferase (ALT) and AST activities increased with different extents and the treatment with sucralose led to the highest activity (45 U). The calculated values for AST/ALT ratios ranged from 0.84 to 1.58 and don’t exceeded 1.58. The AST/ALT ratio increases in liver functional impairment.
The concentration of total protein after experiment period for 4 and 8 weeks in males and females of albino rats ranged from 5.2 to 10.1 and the lowest one was recorded when stevia was used in feeding. The total protein levels in the first 4 weeks are always lower than those reported in the second period (after 8 weeks).
The administration of sucralose and aspartame decreased the total protein. Furthermore, the results of the study showed that the lowest mean in total protein was in the control group, and its highest mean was in sugar group,
The globulin concentrations ranged from 2.95 to 5.55 mg/dl. The globulin levels in the first period (after 4 weeks) are always lower than those reported in the second period one (after 8 weeks). The results indicate that A/G ratios in the second period (after 8 weeks) are lower than 1.0 that mean globulin fraction is higher than albumin one.
The kidney functions were determined through three different parameters; these are uric acid, urea and creatinine. Uric acid concentrations ranged from 3.2 to 5.5 and from 3 to 5.4 mg/dl after one month and two months feeding respectively. Our results also indicate that feeding with aspartame; sucralose and stevia recorded higher levels of uric acid in compared with control. All recorded values of creatinine are higher than those reported for control. Creatinine concentrations ranged from 0.80 to 2.0 mg/dl and the highest value was recoded for albino rat females feeding with aspartame for two months and lowest one was recorded for stevia animal group.
Results concerning body weight of albino rat males are also determined and it is clear that the final weight of all groups increased with different extents. The initial weights ranged from 520 g for aspartame-feeding group to 639 g for sucrose-feeding group and the final weights reach to be 923 g to 1295 g for sucrose-feeding group and sucralose-feeding group respectively.
The average weight gain in the control group in 30 days was 56.67 gm and that of the experimental group was 60.67 gm who attributed this to the fact that sucralose was given by gavage and hence not tasted. Thus, quantity of food intake remains unaltered. Hence, in the present study, oral gavage was used to administer sucralose rather than mixing it with the food
Effect of synthetic sweetener on lipid profile:-
The effect of aspartame, sucralose and stevia on four different parameter of lipid profile namely total cholesterol, triglyceride (TG) LDL-cholesterol (LDL) and HDL-cholesterol (HDL) in comparison with untreated sample (control) and sucrose were assayed
Effect of synthetic sweetener on HDL-cholesterol
Levels of HDL-cholesterol ranged from 18 to 52 mg/dl and the highest levels were recorded for control animals and the lowest ones were found in the blood serum of sucralose group. The results showed that oral dosing of aspartame, sucralose and stevia led to decreases of HDL-cholesterol with different extents.
Effect of synthetic sweetener on LDL-cholesterol
Concentrations of LDL-cholesterol took the opposite course of HDL-cholesterol (good cholesterol), where the process of feeding synthetic sweeteners led to an increase in LDL-cholesterol. Our results also, showed that recorded increases in the 8 weeks are always higher than those reported after 4 weeks.
Effect of synthetic sweeteners on total cholesterol (TC):-
The total cholesterol after 4 and 8 weeks feeding of albino male and female rats which received oral dosing from three different synthetic sweeteners beside sucrose for comparison were assayed. Our results showed that TC increased with different extents and ranged from 81 to 222 mg/dl. The lowest level was recorded for male rats received sucrose and the highest one was in stevia group.
Effect of synthetic sweetener on triglyceride (TG):-
Results of triglyceride concentrations in the serum of rats (males and females) received aspartame, sucralose and stevia by oral dosing. These results showed that stevia caused clear increases in TG after 4 weeks and 8 weeks.
The desirable borders of TG is <150 mg/dl, borderline ranged from 150 to 199 mg/dl but the high risk of TG is recorded when the concentrations ranged from 200 to 400 mg/dl. The reasons for TG assays are to know the possibility of hypertriglyceridemia and/or hyperlipidemia. Though the scientists are not yet sure how the elevated triglyceride levels can cause atherosclerosis (which lead to heart attacks, strokes and even death); they are certain that hypertriglyceridemia always accompany other diseases which raise the risk to coronary heat diseases (CHD).
Effect of synthetic sweetener on VLDL-Cholesterol
Very low density lipoprotein (VLDL) concentrations were calculated from triglycerides contents through 5 and the values. The results showed that VLDL-cholesterol levels ranged from 12 to 37 mg/dL during whole experimental.
Our results also showed that stevia-feeding animals revealed higher concentrations. Lipid profile such as total cholesterol, triglyceride level, LDL and VLDL levels increased in all phases of feeding treatments of all synthetic sweetener treated groups compared to control group.
Histological examination of tested organs
More than 90 section from liver, kidney, spleen, and pancreas were prepared, fixed and examined and the results were summarized as follows:-
(I)-LIVER
Histological sections of liver of albino rat females after 4 weeks:-
a) On control
Sections examined showed liver with mild congestion in central veins in the center of hepatic lobule and mild inflammation in portal tracts.
b) On aspartame-treated
Sections examined showed hepatic tissue with normal architecture and mild congestion in central veins in the center of hepatic lobule.
c) On sucralose-treated
Sections examined showed hepatic tissue with normal architecture and dilatation in central veins in the center of hepatic lobule and hepatic veins in portal tracts without congestion.
d) On stevia-treated
Sections examined showed hepatic tissue with normal architecture and mild congestion in central veins in the center of hepatic lobule and mild inflammation in portal tracts.
e) On sucrose-treated
Sections examined showed liver with moderate congestion in central veins in the center of hepatic lobule and mild inflammation in portal tracts.
Histological sections of liver of albino rat males after 4 weeks:-
a) On-sucrose
Sections examined showed liver with mild congestion in central veins in the center of hepatic lobule and mild inflammation in portal tracts.
b) On aspartame-treated
Sections examined showed hepatic tissue with focal swelling of hepatocytes and moderate congestion in central veins in the center of hepatic lobule.
c) On sucralose-treated
Sections examined showed liver with moderate congestion in central veins in the center of hepatic lobule and mild inflammation in portal tracts
d) On stevia-treated
Sections examined showed liver with mild congestion in central veins in the center of hepatic lobule and mild inflammation in portal tracts.
Histological sections of liver of albino rat females after 8 weeks:-
A. On aspartame-treated
Sections examined showed liver with mild congestion in central veins in the center of hepatic lobule and moderate inflammation in portal tracts.
B. On sucrose-treated
Sections examined showed liver with mild congestion in central veins in the center of hepatic lobule and mild inflammation in portal tracts.
C. On sucralose-treated
Sections examined showed liver with moderate congestion in central veins in the center of hepatic lobule and mild inflammation in portal tracts.
D. On stevia-treated
Sections examined showed liver with moderate congestion in central veins in the center of hepatic lobule and mild inflammation in portal tracts.
Histological sections of liver of albino rat males after 8 weeks:-
a) On control
Sections examined showed liver with mild hydropic degeneration in hepatocytes
b) On sucrose-treated
Sections examined showed liver with mild congestion in central veins in the center of hepatic lobules.
c) On aspartame-treated
Sections examined showed liver with moderate congestion in central veins in the center of hepatic lobule and mild inflammation in portal tracts.
d) On stevia-treated
Sections examined showed liver with moderate congestion in central veins in the center of hepatic lobules and mild inflammation in portal tracts.
(II)-KIDNEY
Histological section of kidney of albino rat female after 4 weeks.
a) On aspartame-treated
Sections examined showed normal glomeruli with mild cloudy swelling in proximal and distal convoluted tubules and moderate chronic inflammation in renal pelvis.
b) On sucralose-treated
Sections examined showed mild glomerulonephritis with mild cloudy swelling in renal tubules and moderate chronic inflammation in renal pelvis.
c) On sucrose-treated
Kidney tissue with mild cloudy swelling in proximal convoluted tubules.
d) On stevia-treated
Sections examined showed normal glomeruli with mild cloudy swelling in proximal and distal convoluted tubules.
Histological section of kidney of albino rat male after 4 weeks.
A. On control
Sections examined showed focal small glomeruli with moderate cloudy swelling in proximal and distal convoluted tubules.
B. On aspartame-treated
Sections examined showed focal small glomeruli with moderate cloudy swelling in renal tubules and moderate chronic inflammation in renal pelvis.
C. On sucrose-treated
Sections examined showed mild cloudy swelling in renal tubules and mild chronic inflammation in renal pelvis.
D. On sucralose-treated
Sections examined showed mild cloudy swelling in renal tubules and mild chronic inflammation in renal pelvis.
E. On stevia-treated
Sections examined showed moderate cloudy swelling in renal tubules and mild chronic inflammation in renal pelvis.
Histological section of kidney of albino rat female after 8 weeks.
a) On Untreated-kidney
Sections examined showed renal tissue with normal glomeruli with moderate cloudy swelling in proximal convoluted tubules
b) On aspartame-treated
Sections examined showed moderate cloudy swelling in renal tubules and mild chronic inflammation in renal pelvis.
c) On sucralose-treated
Kidney tissue with atrophic glomeruli and mild cloudy swelling in renal tubules.
d) On sucrose-treated
Sections examined showed mild cloudy swelling in renal tubules and mild chronic inflammation in renal pelvis.
e) On stevia-treated
Sections examined showed moderate cloudy swelling in renal tubules and mild chronic inflammation in renal pelvis.
Histological section of kidney of albino rat male after 8 weeks.
a) On untreated kidney (control)
Sections examined showed mild cloudy swelling in renal tubules and mild chronic inflammation in renal pelvis.
b) On aspartame-treated
Sections examined showed moderate cloudy swelling in renal tubules and moderate chronic inflammation in renal pelvis.
c) On sucralose-treated
Sections examined showed moderate cloudy swelling in renal tubules.
d) On sucrose-treated
Sections examined showed moderate cloudy swelling in renal tubules and moderate chronic inflammation in renal pelvis.
e) On stevia-treated
Sections examined showed mild cloudy swelling in renal tubules
(III)-PANCREAS
Effects of synthetic sweeteners on female pancreas after 8 weeks
Pancreas sections of female albino rats from control group were examined and results showed pancreatic tissue with mild swelling in pancreatic acini. The results also, showed pancreatic tissue with mild congestion in blood vessels. Aspartame consumption led to mild congestion in blood vessels and decrease in number of islets of Langerhans in pancreatic tissue. Stevia consumption revealed decrease in number of islets of Langerhans and sections examined showed pancreatic tissue with moderate congestion in blood vessels. Sucralose sections examined showed normal secretory acini of exocrine pancreas. Sucrose sections examined showed pancreatic tissue with decrease in number of islets of Langerhans.
Effect of synthetic sweeteners on some hematological parameters.
The effects of synthetic sweeteners on 11 parameters of the blood feature of albino rats (males and females) after oral dosing for 4 and 8 weeks were determined. These parameters are Red Blood cells RBC, (2)- Haemoglobin HGB, (3)- Hematocrit HCT, (4)- Red cell Distribution Width RDW-SD (5)- Red cell Distribution width RDW-CV, (6)- Mean platelet volume MPV, (7)- Platelet Distribution Width PDW.
These data revealed a reduction in total red blood cells (RBCs), including hemoglobin content of the blood.
Present study revealed that the synthetic sweeteners cause clear increase in glucose blood levels and lipid profile. The aspartame group after 4 weeks showed lesser increase compared to other two synthetic sweeteners.