The effect of tropisetron on peripheral diabetic neuropathy: possible protective actions against inflammation and apoptosis.

Diabetic peripheral neuropathy (DPN) is a common nerve disorder of diabetes. The aim of this study was to explore the protective effects of tropisetron in DPN. Type 1 diabetes was created by a single injection of streptozotocin (50 mg/kg, ip). Tropisetron (3 mg/kg, ip) was administered daily for 2 weeks. Our analysis showed that nerve fibers and their myelin sheaths were thinned with decreased myelinated fiber number in diabetic animals. The intensity of Bcl-2 staining decreased and the intensity of Bax staining increased in the sciatic nerves of diabetic rats by using immunohistochemical staining. Furthermore, diabetes significantly increased tumor necrosis factor-alpha, interleukin 1-ß (TNFα and IL-1ß) and Bax/Bcl-2 ratio in sciatic nerves of rats. However, intraperitoneal injection of tropisetron significantly reversed these alterations induced by diabetes. These findings suggest that tropisetron attenuates diabetes-induced peripheral nerve injury through its anti-inflammatory and anti-apoptotic effects, and may provide a novel therapeutic strategy to ameliorate the process of peripheral neuropathy in diabetes.

Cyclosporine A induces testicular injury via mitochondrial apoptotic pathway by regulation of mir-34a and sirt-1 in male rats: The rescue effect of curcumin.

Testicular damage contributes to cyclosporine A (CsA) induced male infertility. However, the exact underlying molecular mediators involved in CsA-induced testis disorder remains unclear. The present study aimed to characterize the role of mir-34a/sirt-1 in CsA induced testicular injury alone or in combination with curcumin. A total of twenty-eight male Wistar rats were subdivided into four groups: control (Con), sham, cyclosporine A (CsA), cyclosporineA + curcumin (CsA + cur). The animals received cyclosporine A (30 mg/kg) and curcumin (40 mg/kg) for 28 days by oral gavage. At the end of the experiment, CsA administration significantly resulted in a decrease in testis weight and testis coefficient. The molecular analysis demonstrated that CsA exposure increased 8-OHdg and Nox4 protein contents in the testis tissue. TUNEL staining indicated that CsA caused the number of apoptotic cells to increase in the testes of male rats. In addition, exposure to CsA resulted in an increased expression of Bax, and a decreased expresion in that of Bcl-2, with a concomitant up-regulation of the Bax/Bcl-2, c-Caspase-3/p-Caspase-3 ratio and cytochrome c level. Meanwhile, exposure to CsA increased the expression of mir-34a and decreased sirt-1 protein level in the testis tissue samples compared to the control group. Taken together, our findings suggested that CsA can cause damage to testicular germ cells via oxidative stress and mitochondrial apoptotic pathway, and probably mir-34a/sirt-1 play a crucial role in this process. It also demonstrates that these negative effects of CsA can be reduced by using curcumin as an antioxidant and anti-inflammatory agent.