Nutjaree Pratheepawanit Johns

Serum melatonin levels and antioxidant capacities after consumption of pineapple, orange, or banana by healthy male volunteers

Melatonin is a naturally occurring molecule biosynthesized by the pineal gland of vertebrates; it also has been identified in many plants. It is considered an important antioxidant and may retard the development of some neurodegenerative diseases and cancer. Previous studies in humans have measured melatonin metabolites in urine and have indicated that melatonin‐containing foods may provide dietary melatonin. This study tested whether the consumption of fruits or fruit juice containing melatonin would influence the serum melatonin concentration and antioxidant status. In this crossover study, 12 healthy male volunteers took either juice extracted from one kilogram of orange or pineapple or two whole bananas, with a 1‐wk washout period between the fruit or fruit juices. An enzyme‐linked immunosorbent (ELISA) assay was used to determine the serum melatonin concentration. Serum antioxidant capacity was determined by ferric reducing antioxidant power (FRAP) assay and oxygen radical antioxidant capacity (ORAC) assay. The highest serum melatonin concentration was observed at 120 min after fruit consumption, and compared with before consumption levels, their values were significantly increased for pineapple (146 versus 48 pg/mL P = 0.002), orange (151 versus 40 pg/mL, P = 0.005), and banana (140 versus 32 pg/mL, P = 0.008), respectively. Serum antioxidant capacity following fruit consumption also significantly increased in both the FRAP (7–14% increase, P ≤ 0.004) and ORAC (6–9% increase, P = 0.002) assays. Both the serum FRAP and ORAC values strongly correlated with serum melatonin concentration for all three fruits. These findings suggest that tropical fruit consumption increases the serum melatonin concentrations and also raises the antioxidant capacity in the serum of healthy volunteers in proportion to serum melatonin levels.

Dietary intake of melatonin from tropical fruit altered urinary excretion of 6-sulfatoxymelatonin in healthy volunteers.

This study assessed the melatonin content of six tropical fruits and examined whether human consumption could contribute to dietary melatonin as measured by 6-sulfatoxymelatonin (aMT6-s, a marker of circulating melatonin in the body). Melatonin was extracted using methanol and analyzed by high-performance liquid chromatography. In a clinical crossover study, 30 healthy volunteers consumed selected fruits one at a time, with a 1week wash-out period between fruits, until completing all six fruits. Most fruits had moderate melatonin content. Significant increases in urine aMT6-s concentrations were seen after the consumption of pineapple (266%, p = 0.004), banana (180%, p = 0.001), and orange (47%, p = 0.007). The need to analyze melatonin both in fruit and as in vivo uptake was demonstrated. Further study is warranted regarding the clinical effect of fruit consumption in people with age-related melatonin reduction problems such as sleeplessness and illnesses involving oxidative damage.

Pineal Calcification Is Associated with Symptomatic Cerebral Infarction

BACKGROUND Pineal calcification and low melatonin have been shown to be risk factors for stroke in animal studies; however, there are limited clinical data on the association of pineal calcification and stroke in humans. METHODS All computed tomographic (CT) scans of the brains of patients >15 years of age during the year 2011 at a university teaching hospital were retrospectively reviewed. Patient medical charts were used to obtain the risk factors for stroke, including diabetes, hypertension, dyslipidemia, age, and sex. Cerebral infarction was identified by having clinical syndromes of stroke and a positive CT scan. Patients with embolic or hemorrhagic stroke were excluded. Pineal calcification was evidenced by the CT scans. The association of various stroke risk factors and cerebral infarction were calculated using logistic regression analysis. RESULTS A total of 1614 patients were included, and symptomatic cerebral infarction was identified in 620 patients (38.4%). Regarding stroke risk factors in symptomatic cerebral infarction patients, the majority of patients were male (356 [57.4%]), >50 years of age (525 [84.7%]), and had hypertension (361 [58.2%]); some had diabetes (199 [32.1%]) and dyslipidemia (174 [28.1%]). Pineal calcification was found in 1081 patients (67.0%), with a male:female ratio of 1.5:1. Significant factors related to cerebral infarction by univariate logistic regression were age >50 years, hypertension, diabetes, dyslipidemia, and pineal calcification. Pineal calcification as a risk factor for cerebral infarction had an adjusted odds ratio of 1.35 (95% confidence interval 1.05-1.72). CONCLUSIONS Pineal calcification may be a potential new contributor to cerebral infarction.

Melatonin inhibits cholangiocarcinoma and reduces liver injury in Opisthorchis viverrini-infected and N-nitrosodimethylamine-treated hamsters.

The human liver fluke Opisthorchis viverrini infection and N‐nitrosodimethylamine (NDMA) administration induce cholangiocarcinoma (CCA) and liver injury in hamsters. Melatonin protects against liver injury and reduces the alteration of mitochondrial structure, mitochondrial membrane potential, and mitochondrial pro‐ and anti‐apoptotic pathways in various cancer types. To investigate the chemopreventive effect of melatonin on CCA genesis and liver injury, hamsters were treated with a combination of O. viverrini infection and NDMA concurrently administered with melatonin (10 mg/kg and 50 mg/kg) for 120 days. Melatonin treatment at 50 mg/kg caused a significant reduction in liver/body weight ratios and decreased tumor volumes leading to an increase in the survival of animals. In the tumorous tissues, the high‐dose melatonin reduced DNA fragmentation and mitochondrial apoptosis by inducing anti‐apoptotic protein (Bcl‐2) in the mitochondrial fraction and down‐regulating cytochrome c, pro‐apoptotic protein (Bax), and caspase‐3 in tumor cytosol. Moreover, a high‐dose melatonin treatment significantly increased mitochondrial antioxidant enzymes and prevented mitochondrial ultrastructure changes in the tumor. Overall, melatonin has potent chemopreventive effects in inhibiting CCA genesis and also reduces liver injury in hamster CCA, which, in part, might involve in the suppression of CCA by reducing tumor mitochondria alteration.

Assessment of 8-isoprostane (8-isoPGF2α) in urine of non- small cell lung cancer (NSCLC) patients undergoing chemotherapy.

8-Isoprostane (8-isoPGF2α) is a reliable marker and considered a gold standard for lipid peroxidation. There are very few reports of 8-isoprostane levels in cancer patients, and in patients undergoing chemotherapy. Oxidative stress is however expected and has been observed in patients with cancer. This study measured 8-isoprostane levels in urine by ELISA of 25 patients undergoing chemotherapy for advanced non-small cell lung cancer, at cycles 1, 2, and 3 of treatment. It considers the creatinine clearance of the patients, and correction of 8-isoprostane levels by creatinine clearance, and overnight urine volume methods. The average 8-isoprostane levels in urine increased more than 6 to 12 fold on chemotherapy treatment, from 532±587 pg/mL at cycle 1, 6181±4334 at cycle 2, and 5511±2055 at cycle 3. Similar results were obtained if 8-isoprostane levels were corrected for overnight urine volume, giving averages of 285±244 μg at cycle 1, 4122±3349 at cycle 2, and 3266±1200 at cycle 3. No significant difference was seen in average total overnight urine volume or number of urinations between chemotherapy cycles except for a large variation in urine volume between cycle 2 and 3. Creatinine levels were significantly different only between cycles 1 and 2 (p=0.016). In conclusion, cisplatin therapy has been shown to induce high levels of lipid peroxidation in lung cancer patients and can be assessed from the 8-isoprostane marker in overnight urine, with or without urine volume correction.

Validation of the Thai Version of a Work-related Quality of Life Scale in the Nursing Profession

Background Currently available questionnaires for evaluating the quality of worklife do not fully examine every factor related to worklife in all cultures. A tool in Thai is therefore needed for the direct evaluation of the quality of worklife. Our aim was to translate the Work-related Quality of Life Scale-2 (WRQLS-2) into Thai, to assess the validity and reliability of the Thai-translated version, and to examine the tools accuracy vis-à-vis nursing in Thailand. Methods This was a descriptive correlation study. Forward and backward translations were performed to develop a Thai version of the WRQLS. Six nursing experts participated in assessing content validity and 374 registered nurses (RNs) participated in its testing. After a 2-week interval, 67 RNs were retested. Structural validity was examined using principal components analysis. The Cronbachs alpha values were calculated. The respective independent sample t test and intraclass correlation coefficient were used to analyze known-group validity and test–retest reliability. Multistate sampling was used to select 374 RNs from the In- and Outpatient Department of Srinagarind Hospital of the Khon Kaen University (Khon Kaen, Thailand). Results The content validity index of the scale was 0.97. Principal components analysis resulted in a seven-factor model, which explains 59% of the total variance. The overall Cronbachs alpha value was 0.925, whereas the subscales ranged between 0.67 and 0.82. In the assessment results, the known-group validity was established for the difference between civil servants and university employees [F (7.982, 0.005) and t (3.351; p < 0.05)]. Civil servants apparently had a better quality worklife, compared to university employees. Good test–retest reliability was observed (r = 0.892, p < 0.05). Conclusion The Thai version of a WRQLS appears to be well validated and practicable for determining the quality of the work-life among nurses in Thailand.

Pineal calcification is a novel risk factor for symptomatic intracerebral hemorrhage

BACKGROUND Pineal calcification is associated with symptomatic cerebral infarction in humans. However, there are limited data on the association of pineal calcification and intracerebral hemorrhage. We evaluated this association of symptomatic intracerebral hemorrhage and pineal calcification by computed tomography of the brain. METHODS We reviewed all computed tomographic (CT) scans of the brains of patients over 15 years of age during the year 2011 at a university teaching hospital. Symptomatic intracerebral hemorrhage was identified by having clinical syndrome of stroke and acute intracerebral hemorrhage from brain CT scans. Pineal calcification was also evidenced by brain CT scans. Other stroke risk factors were recorded. The association of various risk factors including pineal calcification and intracerebral hemorrhage was calculated using logistic regression analysis. RESULTS There were 2140 CT scans of the brains during the study period. Of those, 1071 scans (50.05%) met the study criteria. Intracerebral hemorrhage and pineal calcification were found in 77 (7.2%) and 689 (64.3%) patients, respectively. Pineal calcification was a significant risk factor for intracerebral hemorrhage with an adjusted odds ratio of 2.36 (95% confidence interval of 1.22-4.54). Other significant factors were age>50 years, hypertension, and diabetes. CONCLUSION Pineal calcification is associated with symptomatic intracerebral hemorrhage.

Preliminary Psychometric Properties of the Chinese Version of the Work-Related Quality of Life Scale-2 in the Nursing Profession

Objectives As quality of work-life (QWL) among nurses affects both patient care and institutional standards, assessment regarding QWL for the profession is important. Work-related Quality of Life Scale (WRQOLS) is a reliable QWL assessment tool for the nursing profession. To develop a Chinese version of the WRQOLS-2 and to examine its psychometric properties as an instrument to assess QWL for the nursing profession in China. Methods Forward and back translating procedures were used to develop the Chinese version of WRQOLS-2. Six nursing experts participated in content validity evaluation and 352 registered nurses (RNs) participated in the tests. After a two-week interval, 70 of the RNs were retested. Structural validity was examined by principal components analysis and the Cronbachs alphas calculated. The respective independent sample t-test and intra-class correlation coefficient were used to analyze known-group validity and test-retest reliability. Results One item was rephrased for adaptation to Chinese organizational cultures. The content validity index of the scale was 0.98. Principal components analysis resulted in a seven-factor model, accounting for 62% of total variance, with Cronbachs alphas for subscales ranging from 0.71 to 0.88. Known-group validity was established in the assessment results of the participants in permanent employment vs. contract employment (t = 2.895, p < 0.01). Good test-retest reliability was observed (r = 0.88, p < 0.01). Conclusion The translated Chinese version of the WRQOLS-2 has sufficient validity and reliability so that it can be used to evaluate the QWL among nurses in mainland China.

Pineal calcification is associated with pediatric primary brain tumor.

Melatonin has been associated with various tumors, including brain tumor, and shown to inhibit growth of neuroblastoma cells and gliomas in animal models. Likewise, patients with glioblastoma receiving melatonin reported better survival than controls. Pineal calcification may lead to a decreased production of melatonin by calcified glands. This study assessed association between pineal calcification and primary brain tumor in pediatric/adolescent patients.

The anti-oxidant effects of melatonin derivatives on human gingival fibroblasts

OBJECTIVES Aim of this in vitro study was to evaluate the anti-oxidant activity of indole ring modified melatonin derivatives as compared with melatonin in primary human gingival fibroblast (HGF) cells. METHODS Anti-oxidant activity of melatonin (MLT), acetyl-melatonin (AMLT) and benzoyl-melatonin (BMLT) was evaluated by5 standard methods as follows: 2, 2-diphenyl-1-picrylhydrazyl (DPPH); ferric ion reducing antioxidant power (FRAP); superoxide anion scavenging; nitric oxide (NO) scavenging; and thiobarbituric acid reactive substances (TBARs).Evaluation of cellular antioxidant activity (CAA) and protectivity against H2O2 induced cellular damage was performed via MTT assay in HGF cells. RESULTS According to the standard anti-oxidant assays, the antioxidant power of AMLT and BMLT were slightly less than MLT in FRAP and superoxide scavenging assays. In the NO scavenging and TBARs assays, BMLT and AMLT were more potent than MLT, whereas DPPH assays demonstrated that MLT was more potent than others. BMLT and AMLT had more potent anti-oxidant and protective activities against H2O2in HGF cells as compared with MLT. CONCLUSIONS MLT derivatives demonstrated different anti-oxidant activities as compared with MLT, depending upon assays. These findings imply that N-indole substitution of MLT may help to improve hydrogen atom transfer to free radicals but electron transfer property is slightly decreased. Anti-oxidant and protective effects of melatonin derivatives (AMLT and BMLT) on human gingival fibroblasts imply the potential use of these molecules as alternative therapeutics for chronic inflammatory oral diseases.