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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. 126 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 127 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 100 128 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 129 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, 130 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 131 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 132 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 |