Jeffrey 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.

Determination of melatonin content in traditional Thai herbal remedies used as sleeping aids.

BackgroundMelatonin content was screened in leaves of seven edible herbs used as sleeping aids in Thai traditional medicine. These plants are Piper nigrum L, Sesbania glandiflora (L.) Desv., Sesbania sesban (L.) Merr., Senna tora (L.) Roxb., Moringa oleifera Lam., Momordica charantia L. and Baccaurea ramiflora Lour. Dried leaves were extracted by sonication in methanol for six hours at room temperature, and then melatonin was purified by C18 solid phase extraction (SPE). Melatonin was then quantified by a validated RP-C18 HPLC method with fluorescent detection.FindingsMelatonin contents in extracts of B. ramiflora, S. glandiflora, M. charantia, S. tora and S. sesban were 43.2, 26.3, 21.4, 10.5 and 8.7 ng/g of dry sample weight, respectively. The highest melatonin content was from P. nigrum extract (1092.7 ng/g of dry sample weight). Melatonin was not detected in the extract of M. oleifera. Melatonin identification was confirmed by ELISA.ConclusionsMelatonin was found in six of the seven herbs in the traditional Thai sleeping recipe. One of these, P. nigrum, exhibited an encouragingly high amount of melatonin.

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.

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.