ObjectiveThe purpose of this study was to evaluate the salivary testosterone levels under psychological stress and its relationship with rumination and five personality traits in medical students.MethodsA total of 58 medical students, who wanted to participate in the final exam, were selected by simple random sampling. Two months before the exam, in the basal conditions, the NEO Inventory short form, and the Emotional Control Questionnaire (ECQ) were completed. Saliva samples were taken from students in both the basal conditions and under exam stress. Salivary testosterone was measured by ELISA. Data was analyzed using multivariate analysis of variance with repeated measures, paired samples t-test, Pearson correlation and stepwise regression analysis.ResultsSalivary testosterone level of men showed a significant increase under exam stress (p<0.05). However, a non-significant although substantial reduction observed in women. A significant correlation was found between extroversion (r=-0.33) and openness to experience (r=0.30) with salivary testosterone (p<0.05). Extraversion, aggression control and emotional inhibition predicted 28% of variance of salivary testosterone under stress.ConclusionSalivary testosterone reactivity to stress can be determined by sexual differences, personality traits, and emotional control variables which may decrease or increase stress effects on biological responses, especially the salivary testosterone.

Postprandial hyperglycemia plays an important role in the development of type 2 diabetes. Inhibition of alpha-amylase was led to a delay in breaks down of starch and glycogen and prevented a rapid rise in blood sugar. Alpha-amylase was isolated by gel filtration chromatography Sephadex G-75 from bovine pancreas. Then, total methanolic extracts of plants were prepared and IC50values of extracts on alpha-amylase were obtained and compared with acarbose IC50. The polyphenolic content of extracts and antioxidant capacity were determined by Folin-Ciocalteu test and DPPH test, respectively. The specific activity of alpha-amylase was 48.2 U/mg. For inhibition of alpha-amylase, IC50values ofH. persicum,Z. jujuba, and acarbose were 307, 827, and 113 μg/ml, respectively. For inhibition of DPPH radical, IC50values of extracts were 235 and 701 μg/ml. Total phenolic contents of methanol extracts were73.8±3.2and44.2±1.8 μg tannic acid equivalent/mg extract. Acarbose causes gastrointestinal symptoms and liver toxicity, butH. persicumandZ. jujubadecrease these side effects and prevent gastrointestinal disorders. Due to the high polyphenolic content and antioxidant capacity of these plants and significant inhibitory effect of the plants on alpha-amylase, these plants can be proposed for treatment of diabetic patients.

Reproductive toxicity of carboxyl-functionalised carbon nanotubes (CNT-COOH), as the most commonly used form of water-soluble CNTs, is not clearly studied. The aim of this study was to investigate in vitro toxicity of carboxylated single-walled and multi-walled CNTs (SWCNT-COOH and MWCNT-COOH) against human spermatozoa. Sperm cells from healthy donors were incubated with 0.1-100 μg/ml of SWCNT-COOH or MWCNT-COOH at 37°C for up to 5 hr. Viability of sperm cells was assessed using MTT test, and sperm motility was evaluated following World Health Organization guideline. Production of reactive oxygen species (ROS) and nitric oxide (NO) in sperm was also assessed. We showed that both MWCNT-COOH and SWCNT-COOH following incubation in vitro with human spermatozoa did not exert negative effect on viability while motility was significantly (p < .05) dropped in a dose-dependent manner. Moreover, there was no significant effect of the type, dose and exposure time of the CNT-COOH on NO production. Exposure of sperm cells to both examined types of CNTs at concentrations as low as 0.1 μg/ml caused a significant increase in ROS levels. In conclusion, carboxylated forms of CNTs seem to be harmful for human spermatozoa. Further studies, especially using in vivo models, are needed to decide about reprotoxicity of carboxylated forms of CNTs.

BackgroundEmerging evidence suggests that an increased arginase activity is involved in vascular dysfunction in experimental animals. Zingiber officinale Roscoe, commonly known as ginger, has been widely used in the traditional medicine for treatment of diabetes.ObjectivesThis study aimed at investigating the effects of the hydroalcoholic extract of Z. officinale on arginase I activity and expression in the retina of streptozotocin (STZ)-induced diabetic rats.MethodsIn this experimental study, 16 male Wistar rats weighing 200 – 250 g were assessed. Diabetes was induced via a single intraperitoneal injection of STZ (60 mg/kg body weight). The rats were randomly allocated into four experimental groups. Untreated healthy and diabetic controls received 1.5 mL/kg distilled water. Treated diabetic rats received 200, and 400 mg/kg of the Z. officinale extract dissolved in distilled water (1.5 mL/kg). Body weight, blood glucose and insulin concentration were measured by standard methods. The arginase I activity and expression were determined by spectrophotometric and western blot analysis, respectively.ResultsOur results showed that blood glucose concentration was significantly decreased in diabetic rats treated with the extract compared to untreated diabetic controls (P < 0.01). Treatment with 400 mg/kg of the extract reduced arginase I activity and expression (P < 0.05). A significant elevation in body weight was observed in diabetic rats treated with the extract. Serum insulin was significantly increased in diabetic rats treated with 400 mg/kg of the extract compared to diabetic controls (P < 0.05).ConclusionsOur results suggest that the Z. officinale hydroalcoholic extract may potentially be a promising therapeutic option for treating diabetes-induced vascular disorders, possibly through reducing arginase I activity and expression in the retina.

Background: Diabetes mellitus is the most common leading cause of cardiovascular-related mortality and morbidity worldwide. Citrullus colocynthis (C. colocynthis) belongs to the Cucurbitaceae family and has been used as an anti-diabetic treatment in traditional medicine. Objectives: The aim of this study was to assess the effects of hydro-alcoholic leaf extract of C. colocynthis on the serum biochemical factors and histopathological changes in streptozotocin-induced diabetic rats. Methods: The current experimental study was performed on 24 male rats, which became diabetic with 60 mg/kg body weight intraperitoneal injection of streptozotocin (STZ). The animals were divided into four groups: untreated healthy controls, healthy controls treated with the extract, untreated diabetic and diabetic treated with extract, respectively. The animals were treated with 75 mg/kg body weight orally hydro-alcoholic leaf extract of C. colocynthis for 3 weeks. Results: The results indicated that fasting blood sugar (FBS), triglycerides (TG), low-density lipoprotein (LDL), total cholesterol, aspartate aminotransferase, alanine aminotransferase, creatinine, urea, and bilirubin (total and conjugated) in diabetic rats treated with the extract significantly decreased compared to the other groups. Conversely, high-density lipoprotein (HDL) and serum albumin were significantly increased in diabetic rats treated with extract. Histopathological findings showed STZ-induced diabetic complications in the pancreas, kidney and liver were improved following treatment with hydro-alcoholic leaf extract of C. colocynthis. Conclusions:The administration of hydro-alcoholic leaf extract of C. colocynthis had a significant anti-hyperglycemic and anti hyperlipidemic effect and improved diabetic complications. In addition, Citrullus C. leaf extract may have a protective effect on the liver, kidneys, and pancreas.