RESUMEN
A comparison of crude curcuminoid extract and purified curcumin was made to evaluate the immunoprotective effect of Curcuma longa (turmeric) Zingiberaceae. Carbon tetrachloride (CCl4) induced selective cytolytic effects among immature (PNA(+)) thymocytes and peripheral helper (CD4(+)) T lymphocytes in the spleen were paralleled by a significant reduction in CD25, CD71, and Con A receptor expression. Treatment with curcumanoid crude extract, at two different doses, showed a significant restoration of lymphocyte viability and CD25, CD71, and Con A receptor expression in both immature (PNA+) thymocytes and splenic helper (CD4(+)) T lymphocytes. Turmeric crude extract, at both low and high dose, was found to be more efficient as compared to purified curcumin, suggesting synergistic effect of curcumin with other components of the crude extract.
Asunto(s)
Tetracloruro de Carbono/toxicidad , Curcuma/química , Estrés Oxidativo/efectos de los fármacos , Extractos Vegetales/farmacología , Subgrupos de Linfocitos T/patología , Animales , Antígenos CD/metabolismo , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Curcumina/química , Curcumina/farmacología , Subunidad alfa del Receptor de Interleucina-2/metabolismo , Masculino , Ratas Wistar , Receptores de Superficie Celular/metabolismo , Receptores de Transferrina/metabolismo , Subgrupos de Linfocitos T/efectos de los fármacos , Subgrupos de Linfocitos T/metabolismo , Timocitos/citología , Timocitos/efectos de los fármacosRESUMEN
The up-regulation of angiotensin II AT1 receptors has been implicated as a major mediator in the development of hypertension and progressive nephropathy in experimental diabetes. In spite of the documented potential of garlic treatments in ameliorating diabetic complications, the possible involvement of the angiotensin II AT1 receptor, as a central target for the anti-diabetic potential of garlic, has not been explored. Three groups of rats were studied after 8 weeks following diabetes induction: normal, streptozotocin-induced diabetic (control diabetic), and garlic-treated diabetic rats. A polyclonal antibody of proven specificity to the AT1 receptor, as verified by western blotting, indicated in immunohistochemical assays that AT1 receptor labeling was significantly increased in adrenal and renal tissues of control diabetic rats compared to the normal group. The increased AT1 receptor labeling involved all cortical zones and medullary chromaffin cells of the adrenal gland. Except for glomerulii, increased AT1 receptor labeling was also evident in proximal convoluted tubules in the renal cortex, and all tubular segments and interstitial cells outlining the vasa recta bundles in the inner stripe of the outer renal medulla. Compared with control diabetic rats, the labeling of the AT1 receptor in the garlic-treated diabetic group was significantly reduced throughout adrenal and renal regions to levels comparable to those observed in normal rats. The capacity of garlic to modulate diabetes-induced AT1 receptor up-regulation may be implicated in reversing the detrimental consequences of excessive Ang II signaling, manifested by the development of hypertension and nephropathy.
Asunto(s)
Glándulas Suprarrenales/efectos de los fármacos , Diabetes Mellitus Experimental/tratamiento farmacológico , Diabetes Mellitus Experimental/metabolismo , Ajo , Médula Renal/efectos de los fármacos , Túbulos Renales Proximales/efectos de los fármacos , Receptor de Angiotensina Tipo 1/biosíntesis , Glándulas Suprarrenales/metabolismo , Animales , Glucemia/efectos de los fármacos , Glucemia/genética , Glucemia/metabolismo , Células Cromafines/efectos de los fármacos , Células Cromafines/metabolismo , Diabetes Mellitus Experimental/genética , Regulación hacia Abajo/efectos de los fármacos , Médula Renal/metabolismo , Túbulos Renales Proximales/metabolismo , Masculino , Ratas , Ratas Sprague-Dawley , Receptor de Angiotensina Tipo 1/genética , Receptor de Angiotensina Tipo 1/metabolismo , Regulación hacia Arriba/efectos de los fármacosRESUMEN
This study investigates the potential of green tea to modulate oxidative stress and angiotensin II AT(1) receptor expression in renal and hepatic tissues of diabetic rats. Three groups of rats were studied after 8 weeks following diabetes induction: normal, streptozotocin-induced diabetic (diabetic control), and green-tea-treated diabetic rats. Total antioxidant, catalase, and malondialdehyde levels were assayed by standard procedures. Levels of AT(1) receptor labeling, in renal and hepatic tissues of the three rat groups, were immunohistochemically investigated using an anti-AT(1) receptor antibody. Levels of total antioxidant and catalase were significantly reduced, whereas malondialdehyde levels and AT(1) receptor labeling were significantly increased in renal and hepatic tissues of diabetic control rats compared to normal rats. Compared to diabetic control rats, total antioxidant and catalase levels were significantly increased, whereas malondialdehyde levels and AT(1) receptor labeling in the green-tea-treated diabetic group were significantly reduced throughout hepatic lobules and renal cortical and medullary vascular and tubular segments to levels comparable to those observed in normal rats. The capacity of green tea to modulate diabetes-induced oxidative stress and AT(1) receptor upregulation may be beneficial in opposing the deleterious effects of excessive angiotensin II signaling, manifested by progressive renal and hepatic tissue damage.