تاثير الثايموكوينون الخافض للسكر والمجدد الانسجة بنكرياس الجرذان المستحث فيها داء السكري باستخدام الستربتوزوتوسين == Antihyperglycemic And Pancreatic Regenerative Effect of Thymoquinone In Streptozotocin Induced Diabetic Male Rats
Author name:
وجدان ثامر مهدي التميمي
Supervisor name:
جبار عباس احمد الساعدي | هاشم محمد عبد الكريم
General topic:
Biology
Specific topic:
Zoology - Histology
Degree:
Doctorate
University:
University of Al-Qadisiyah - Faculty Of Education - Department Of Biology
Language:
English
University location:
Qadisiyah
First pages:
24T2674 - p.pdf
Abstract:
To evaluate the anti - hyperglycaemic potent of thymoquinone from Nigella sativa seed in streptozotocin - induced diabetic male rats, the present study has been carried out at the College of Education, Al - Qadisiya University during the period extended from April, 15, 2012 to December, 15, 2012. mRNA expression level of Reg3a, InsI, InsII, PDX1, Pax6, NeuroD1, and MafA genes have been evaluated in pancreatic tissues as well. Sixty five adult male rats (aged 56 days and weighted 138±8.8g) have been used in the present study. Diabetes has been inducted in 52 male rats by injection of single dose of streptozotocin (60 mg/ kg, b.w., i.p.). Diabetes mellitus has been confirmed by blood glucose concentration (to be more than 200 mg/ dl). Intact and streptozotocin - induced diabetic male rats have been assigned to five equal groups (13 per each); Intact (C) and non treated diabetic (DM) rats have been injected with normal saline (100?l, sc) anddrenched with drinking water daily for 42 days. Thymoquinone treated diabetic rats (TQ50 and TQ100) have been injected with normal saline (100?l, sc) and drenched with thymoquinone suspention (50 and 100 mg/ kg, b.w., respectively) daily for 42 days. Insulin treated diabetic rats were injected with insulin (4 IU, sc) and drenched with drinking water daily for 42 days. Body weights were registered daily during the experiment. All overnight fasted animals were sacrificed after general anesthesia by combination of xylazine and ketamine (10 mg and 90 mg/kg, ip, respectively). Blood samples was collected from abdominal vein for determination of serum glucose and insulin concentrations. Samples from pancreatic tissues in all groups have been quickly removed, dipped in liquid nitrogen for RNA extraction and molecular study. Other pancreatic tissues were fixed in formalin forhistopathological and immunohistochemical study. The results demonstrated significant decrease in body weight gain of untreated diabetic (DM) and insulin treated diabetic (DMI) groups as compared with that of intact control (C) and thymoquinone treated diabetic (TQ50 and TQ100) groups, started from the fourth day of experiment, which showed insignificant differences when compared with each other. While the lowest body weight gain has been registered in DM group.Results of serum glucose concentrations referred to significant elevation in diabetic groups compared with intact control. In comparison between the diabetic groups, glucose concentration revealed significant decrease in thymoquinone and insulin treated rats (TQ50, TQ100, and DMI) compared with untreated diabetic rats (DMI). on the other hand, insulin treated males (DMI) and thymoquinone treated males (TQ50 and TQ100) recorded no significant difference in serum insulin concentration when compared witheach other but they were significantly lower than that of intact control male rats (C), but the average means of these four groups were significantly higher than that of non - treated diabetic male rats (DM).Quantification analysis results of gene expression, performed by real - time RT - PCR, revealed that treatment with thymoquinone caused significant increase of mRNA expression levels of Reg3a, InsI, InsII, PDX1, Pax6, NeuroD1 and MafA genes during the studied period. Histological findings of thymoquinone treated pancreases revealed normal cellularity of islets of Langerhans and normal exocrine tissue except few congestion in it, whereas those obtained from non treated diabetic rats showed complet impairment of some islands and highly destructed of others. Normal hepatic architecture with the appearance of radiating shape around the central vein, has been shown in the section obtained from thymoquinone treated diabetic rats except few congestion, obvious regeneration and mitotic division in the nuclei of hepatocytes. Sections obtained from non treated diabetic male rats showed sever congestion, large thrombi in the hepatic tissue, and loss of hepatic architecture with sever hemorrhage, degeneration in hepatocytes, and dilation of sinusoids. Section obtained from kidneys of thymoquinone treated diabetic rats reveales normal renal convoluted tubules with normal epithelium of the tubules and high cellularity of glomeruli. Whearas those obtained non treated diabetic rat revealed dilation of renal convoluted tubules with necrosis in the epithelium of the tubules and sever hemorrhage in the renal tissue. Immunohistochemical results revealed that male rats drenched with thymoquinone registered higher scores of positive cells and intensity of staining compared with other diabetic (DM and I) groups. Hisological sections obtained from pancreases of control male rats showed actively stained islets of Langerhan's by immunohistochemistry with actively stained populations of beta, alpha, and delta cells, whereas those obtained from pancreases of non treated diabetic male rats showed damage of most cell populations and negatively stained for the few remaining beta cells. on the other hand, section obtained from pancreases of diabetic male rats treated with thymoquinone showed actively stained islets of Langerhan's by immunohistochemistry with actively stained populations of beta, alpha, and delta cells. While those obtained from pancreases of diabetic male rats treated with insulin, in the same stages of experiment, showed negatively stained beta cells and other cells of islets of Langerhan's. Histopathological findingsrevealed moderate improvement of pancreatic changes shown in both exocrine and endocrine (Islands of Langerhan's) parts. It can be concluded that drenching of 50 or 100 mg/ kg, bw, of thymoquinone from Nigella sativa seed has potent hypoglycemic effect in experimentally - induced diabetic mature male rats. As well as its positive role in elevating the expression level of Reg3a, InsI, InsII, PDX1, Pax6, NeuroD1
