Stevia aquatic extract protects the pancreas from streptozocin (STZ) induced damage: A stereological study

In recent years, among antidiabetic medicinal herbs, Stevia received a lot of attention due to its diverse therapeutic applications. Despite extensive reports on the effects of Stevia on the pancreas, its molecular mechanism is not clear yet. In this study, we investigated the protective and preventive effects of oral extracts of Stevia on the pancreas through the stereological methods in streptozocin (STZ) induced diabetic rats. Thus, 66 adult male rats were assigned to six groups (n = 11) viz., healthy control, healthy Stevia (400 mg /kg), diabetic-control, diabetic-metformin (500 mg/kg), diabetic-Stevia and pre-Stevia-diabetic group. Treatment with Stevia significantly reduced fasting blood sugar (FBS) and MDA compared to the diabetic control group (P <0.05). The results indicated that the weight and the volume of the pancreas increased significantly in all our treated groups compared to the diabetic one (P <0.05). The volume density of the pancreatic islands and the number of beta cells increased in healthy and diabetic groups treated with Stevia (P <0.05). However, the pre-treated diabetic rats with Stevia did not show significant preventive effects on the volume and number of beta cells as well as the volume of islets against destructive effects of STZ. More specifically, our results confirmed the protective effects of Stevia through restoring pancreatic cells and repairing the stereological damage induced by STZ.

Curcumin prevents neuronal loss and structural changes in the superior cervical (sympathetic) ganglion induced by chronic sleep deprivation, in the rat model

BACKGROUND: In modern societies, sleep deprivation is a serious health problem. This problem could be induced by a variety of reasons, including lifestyle habits or neurological disorders. Chronic sleep deprivation (CSD) could have complex biological consequences, such as changes in neural autonomic control, increased oxidative stress, and inflammatory responses. The superior cervical ganglion (SCG) is an important sympathetic component of the autonomic nervous system. CSD can lead to a wide range of neurological consequences in SCG, which mainly supply innervations to circadian system and other structures. As the active component of Curcuma longa, curcumin possesses many therapeutic properties; including neuroprotective. This study aimed to evaluate the effect of CSD on the SCG histomorphometrical changes and the protective effect of curcumin in preventing these changes. METHODS: Thirty-six male rats were randomly assigned to the control, curcumin, CSD, CSD + curcumin, grid floor control, and grid floor + curcumin groups. The CSD was induced by a modified multiple platform apparatus for 21 days and animals were sacrificed at the end of CSD or treatment, and their SCGs removed for stereological and TUNEL evaluations and also spatial arrangement of neurons in this structure. RESULTS: Concerning stereological findings, CSD significantly reduced the volume of SCG and its total number of neurons and satellite glial cells in comparison with the control animals ( P < 0.05). Treatment of CSD with curcumin prevented these decreases. Furthermore, TUNEL evaluation showed significant apoptosis in the SCG cells in the CSD group, and treatment with curcumin significantly decreased this apoptosis ( P < 0.01). This decrease in apoptosis was observed in all control groups that received curcumin. CSD also changed the spatial arrangement of ganglionic neurons into a random pattern, whereas treatment with curcumin preserved its regular pattern. CONCLUSIONS: CSD could potentially induce neuronal loss and structural changes including random spatial distribution in the SCG neurons. Deleterious effects of sleep deprivation could be prevented by the oral administration of curcumin. Furthermore, the consumption of curcumin in a healthy person might lead to a reduction of cell death.

Effect of benzene on the cerebellar structure and behavioral characteristics in rats

Objective:To investigate the effects of benzene on rat’s cerebellum structure and behavioral characteristics, including anxiety and motor impairment. Methods:Twenty rats were randomly allocated into two groups orally receiving distilled water and benzene (200 mg/kg/day). A total of 10 rats were used at the beginning of benzene exposure. Two rats died during benzene treatment and 8 rats remained for evaluation of the behavioral test and finally 6 rats underwent histological assessment. At the end of the 4th week, motor function and anxiety were evaluated in rotarod test and elevated plus maze, respectively. Besides, the cerebellum was dissected for structural assessment using stereological methods. Results:Performance of the benzene-treated rats in fixed and accelerating speed rotarod was impaired and their riding time (endurance) was lower compared to the control group (P=0.02). The benzene-treated rats also spent less time in the open arms and had fewer entrances to the open arms in comparison to the control group, indicating anxiety (P=0.01). The total volume of the cerebellar hemisphere, its cortex, intracerebellar nuclei, total number of the Purkinje, Bergmann, Golgi, granule, neurons and glial cells of the molecular layer, and neurons and glial cells of the intracerebellar nuclei were reduced by 34%-76%in the benzene-treated rats in comparison to the distilled water group (P=0.003). The most cell loss was seen in Bergmann glia. Conclusions:The structure of cerebellum altered after benzene treatment. In addition, motor impairment and anxiety could be seen in benzene-treated rats.

Early stereological changes in liver of Sprague-Dawley rats after streptozotocin injection.

BACKGROUND: Diabetes mellitus is associated with biochemical, physiological and pathologic alterations in the liver. We measured changes in structure of rat liver after streptozotocin injection, using stereology. METHODS: Livers of 36 streptozotocin-injected rats were removed after 4, 8 and 12 weeks. Liver volume and weight were measured, and volume-weighted mean volume of hepatocytes and their nuclei were estimated in periportal (Z1), interstitial (Z2) and perivenous (Z3) zones of liver acini. Volume of liver sinusoids was also estimated. RESULTS: Mean volume and weight of the liver were reduced by 15% and 12%, respectively at 4 and 8 weeks after injection. Mean hepatocyte volumes were reduced by approximately 30%, 31% and 24% in Z1, Z2 and Z3 at 4 weeks, 19% and 24% in Z2 and Z3 at 8 weeks, and 14% in Z1 at 12 weeks. Mean volume of hepatocyte nuclei was reduced by approximately 18% and 20% in Z2 and Z3 at 4 weeks, 23% in all three zones at 8 weeks, and 18%, 15% and 13% in Z1, Z2 and Z3, respectively, at 12 weeks. The absolute volume of the sinusoids decreased by 16.5% only at 4 weeks. CONCLUSION: Streptozotocin injection leads to early reduction in volume of hepatocytes, their nuclei and sinusoids in rat liver.