Evaluating the activity of salivary enzymes as stress biomarkers under psychological stress and their relationship with rumination and personality traits.

BACKGROUND: Salivary enzymes are used as non-invasive biomarkers to assess the activity of the sympathetic-adrenal-medullary system. The aim of this study was to evaluated levels of acid phosphatase, beta-glucuronidase and cathepsin salivary enzymes under psychological tension and their connection with rumination and personality traits. METHODS: A total of 60 medical students, who wanted to participate in the final exam, two months before the exam, the inventory emotional control questionnaire and the neo-short form were completed. Saliva samples were taken in both the basal conditions and under exam stress. RESULTS: A significant difference was found between the mean of level salivary enzymes in rest and under exam stress. Also, we found a positive and significant correlation between the activity of salivary enzymes and personality traits such as neuroticism, extraversion, agreeableness and rumination (p < .01, p < .05) level. Neuroticism, agreeableness and rumination predicted 45% of the variance of salivary acid phosphatase, neuroticism and rumination predicted 49% of the variance of salivary beta-glucuronidase and neuroticism, extraversion and rumination predicted 38% of the variance of salivary cathepsin under stress exam. CONCLUSION: The results of this study show, levels of salivary enzymes may increase in individuals with traits of neuroticism, extraversion, agreeableness and rumination through response to psychological stressors.

Metformin synergistically increases the anticancer effects of lapatinib through induction of apoptosis and modulation of Akt/AMPK pathway in SK-BR3 breast cancer cell line.

Objectives: Combination chemotherapy is a beneficial intervention for breast cancer, versus single therapy. We investigated the effect of Metformin (Met) on Lapatinib (Lap)-induced apoptosis in SK-BR3 cells. Materials and Methods: Toxic effect of Met and Lap on SK-BR3 cells was measured using MTT assay. Flow cytometry was used to measure the co-treatment effect of Met on lapatinib-induced apoptosis. The relative expression of Bax, Bcl2, and P21 was measured using a real-time PCR. The activity of caspase 3 and 9 was measured using an ELISA kit. The protein level of AMPK and Akt was determined using Western blot analysis. Results: Metformin and lapatinib alone and combined form showed significant time- and dose-dependent toxic effects on SK-BR3 cell viability. The greatest synergistic inhibitory effect on the cell viability [combination index (CI) = 0.51] was remarkable at Met 100 mM combined with Lap 100 nM. The combination has a stronger apoptotic death (46%) versus lapatinib alone. The combination considerably increased the mRNA expression of Bax and P21, and caspase 3 and 9 activity, while, decreasing the mRNA expression of Bcl2. Additionally, the combination significantly up-regulated and down-regulated the protein levels of AMPK and Akt, respectively. Conclusion: The metformin-lapatinib combination can induce more potent apoptotic death versus each compound individually. The combination may be suggested as a valuable therapeutic intervention in patients with breast cancer. However, additional in vivo studies are necessary to evaluate the clinical use of the combination for induction of apoptosis and its antitumor effects.

Synergistic anti-cancer effects of silibinin-etoposide combination against human breast carcinoma MCF-7 and MDA-MB-231 cell lines.

OBJECTIVES: Recently, there is a significant focus on combination chemotherapy for cancer using a cytotoxic drug and a phytochemical compound. We investigated the effect of silibinin on etoposide-induced apoptosis in MCF-7 and MDA-MB-231 breast carcinoma cell lines. MATERIALS AND METHODS: The cytotoxic effects of silibinin and etoposide were determined using MTT assay after 24 and 48 hr incubation with these drugs individually and combined. The mRNA expression of Bax and Bcl2, and protein levels of P53, phosphorylated p53 (P-P53), and P21 were determined using real-time PCR and western blot analysis, respectively. The caspase 9 activity was measured using an ELISA kit. RESULTS: Silibinin and etoposide alone and combined significantly inhibit cell growth in a dose and time-dependent manner in both cell lines. The strongest synergistic effects in terms of MCF-7 cell growth inhibition [combination index (CI) = 0.066] were evident. The silibinin-etoposide combinations cause a much powerful apoptotic death (47% and 40%) compared with each compound individually in MCF-7 and MDA-MB 231 cells, respectively. Additionally, the silibinin-etoposide combinations significantly increased the expression of P53, P-P53, and P21 in MCF-7 cells. Neither silibinin nor etoposide individually increased the level of P53 and P-P53 in MDA-MB-231 cells, but both of them individually and combined increased the level of P21. CONCLUSION: Since the silibinin-etoposide combination induces apoptosis in both cell lines with and without expression of p53, thus, it is suggested that this combination may be a successful therapeutic strategy for breast cancer regardless of P53 status.

Effects of the Hydroalcoholic Extract of Zingiber officinale on Arginase I Activity and Expression in the Retina of Streptozotocin-Induced Diabetic Rats.

BACKGROUND: Emerging 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. OBJECTIVES: This 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. METHODS: In 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. RESULTS: Our 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). CONCLUSIONS: Our 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.

Salivary Testosterone Levels Under Psychological Stress and Its Relationship with Rumination and Five Personality Traits in Medical Students.

OBJECTIVE: The 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. METHODS: A 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. RESULTS: Salivary 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. CONCLUSION: Salivary 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.

Levels of salivary immunoglobulin A under psychological stress and its relationship with rumination and five personality traits in medical students

Background and Objectives: The measurement of salivary immunoglobulin A is a useful and non-invasive method for measuring stress. Personality traits and rumination act as possible mediators in the relationship between psychological stressors and the immune system. This study was aimed to evaluate the levels of salivary IgA under psychological stress and its relationship with rumination and five personality traits in medical students. Methods: In this cross- sectional study, 45 medical students who intended to participate in the final exam were selected by simple random sampling. Two months before the exam, in the peribasal conditions, the NEO Personality Inventory-Short Form and Emotional Control Questionnaire(ECQ) were completed. Saliva samples were taken from students in both the basal conditions and exam stress conditions. Salivary IgA was measured by an ELISA test. Data was analyzed using paired samples T-test, Pearson correlation analysis, and stepwise regression. Results: A significant reduction of salivary IgA levels was found in exam stress conditions. Also, a significant negative correlation was found between traits of neuroticism and rumination with salivary IgA, as well as a significant positive correlation between of openness to experience and emotional inhibition with salivary IgA. Openness to experience and emotional inhibition may predict a substantial variance (34%) of salivary IgA under exam stress. Conclusions: Salivary IgA is reduced in response to exam stress. In addition, the rumination and personality traits may reduce or increase stress effects on the immune system, particularly the salivary IgA (AU)

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Investigation of respirable particulate matter pollutants on air-breathing zone workers in the Beam Rolling Mills Factory (Iran National Steel Industrial Group), Ahvaz, Iran.

Workers of iron and steel factories are exposed to a wide range of pollutants depending on the particular process, the materials involved, the effectiveness of monitoring and the control measures. Adverse effects are determined by the physical state and propensities of the pollutant involved, the intensity and duration of the exposure, the extent of pollutant accumulation in the body and the sensitivity of the individual to its effects. The main aim of this study is to assess the levels of the indoor respirable particulate matter (RPM) and to compare the health condition of exposed workers, with nonexposed employees group. Line 630 has only one furnace of 40 tons and line 650 has two furnaces of 20 and 40 tons capacity due to which the mean of the RPM concentrations in the breathing zone was significantly different (P < 0.05) in line 650 but not in line 630 as compared with National Institute for Occupational Safety and Hygiene's (3 mg/m(3)). The average of the RPM concentrations in production line 650 is higher than that of production line 630, with the 95% confidence interval in saw cabin station number 1 of production line 650.