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Melatonin is a phytochemical in olive oil
Abstract
Given the numerous observations regarding the positive effects of olive oil consumption and the presence of melatonin in edible plants, we addressed for the first time the question of melatonin determination in virgin olive oil. All the extra virgin olive oil registered designation of origins from Spain and commercial samples of refined olive and sunflower oil were used. Immunoprecipitation and ELISA were combined for melatonin determination. Melatonin is present in olive oil at higher levels in extra virgin olive oil than in refined olive or sunflower oil samples. We concluded that melatonin is part of the phytochemical profile of the olive oil. Particularly, extra virgin olive oil had almost double the melatonin contents of the other refined oils analysed. Thus, melatonin may account for the healthy effects of the Mediterranean diet in which olive oil is the main source of fat.
... From the first detection of melatonin in plant in 1995, numerous studies have shown the presence of melatonin in different plant species and tissues, with concentrations ranging from pg g −1 to μg g −1 of plant material [20,[23][24][25][26][27][28]. Melatonin concentrations in the plants differ not only from species to species but also among varieties within the same species. ...
... Different analytical techniques to detect melatonin in plants have been reported, including radioimmunoassay [12], immunoprecipitation [28], HPLC combined with fluorescence detection, elettrochemical detection or mass spectrometry [19,25,26]. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) seems up to now the most reliable technique to determine melatonin in plants [34,35]. ...
... The melatonin content of aerial parts of hemp varieties under study is within the range of plants like Olea europaea L. and Laurus nobilis L. [17,28]. ...
Melatonin (N-acetyl-5-methoxytryptamine), was first isolated in the bovine pineal gland, and then was discovered in bacteria, algae and higher plants. Melatonin concentrations in plants differ from species to species, among varieties within the same species and also within different organs or tissues of a given plant as roots, leaves, fruits, flowers, and seeds. Although the presence of melatonin in plants seems to be a universal trait, there is still lack of information on its occurrence in several plants, in particular in hemp (Cannabis sativa L.). The aim of this study was to develop a method to quantitate melatonin in the aerial parts of the plant, constituted of leaves and flower heads, and in the seeds, of four different hemp varieties using liquid chromatography–tandem mass spectrometry (LC–ESI/MS/MS). A sample preparation procedure with methanol extraction followed by solid-phase clean-up protocol was set up for melatonin extraction and a LC–ESI/MS/MS method in single reaction monitoring (SRM) was used for its determination. Chromatographic separation was achieved on a C18 column using a gradient elution with acetonitrile–buffer ammonium formate/formic acid system. The developed method, validated as per International Conference on Harmonization guidelines, was successfully applied to analyze hemp samples varieties belonging to fiber-type or drug-type chemotypes. The melatonin was found to accumulate highly in seeds in the range 13.43–30.40 ng g⁻¹ while the content in the aerial parts was assessed in the range 1.16–4.85 ng g⁻¹. No correlation was found between the melatonin levels detected in aerial parts and seeds in each hemp variety and the concentration of specific cannabinoids in the same variety.
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... Immunoprecipitation and ELISA were combined for melatonin determination (de la Puerta et al. 2007). A combined method was used for melatonin extraction, based on sequential methanol and chloroform extraction. ...
... EIA has also been applied to melatonin determination. Indeed, the commercial kit based on a competitive enzyme immunoassay (Melatonin ELISA, IBL-Hamburg) was applied to determine melatonin in olive oil for the first time (de la Puerta et al. 2007) and it was also used to determine melatonin in grape skin extracts from different cultivars (Iriti et al. 2006). However, Van Tassel and O'Neill (2001a) reported their concerns when attempting to validate RIA in tomato (Lycopersicum esculentum) and Pharbitis nil extract samples. ...
Nowadays, several groups are devoted to the development of reliable analytical methodologies such as microchip electrophoresis (ME), capillary electrophoresis (CE), liquid chromatography (LC), coupled to different detection strategies, and, particularly, the application of nano-technologies and nanomaterials in the development of sensors for the determination of melatonin (MEL), its isomers, and precursors in different plant tissues and food samples. These approaches provide useful tools and knowledge to demonstrate the great potential of this natural substance for agricultural applications, improving crop production and quality of functional foods. The analysis of MEL in plants and foods represents a highly challenging task due to its low concentration range, the difficulty in the selection of the extraction solvents because of its amphipathic nature, and the fact that it reacts quickly with other matrix components. Chemical complexity of plant extract can also interfere with MEL determinations, giving false positive results if methods from vertebrate MEL research are directly adopted. Indeed, the additional challenges related to the vast variety of matrices as well as the extremely wide concentration range (ppm–ppq levels) should be considered. Therefore, the main objective of this chapter is to take a closer look at the recent trends in analytical tools employed to contribute to the elucidation of the biological role of MEL in plants, and its implications in human health.
... De la Puerta et al. measured the melatonin content of different virgin olive oils and reported values that ranged between 71 and 119 pg/mL, with the highest amount of melatonin being detected in virgin olive oils produced via the cold process. Additionally, the refinement process reduces the melatonin content in olive oil, even though refined olive oil showed a higher content of melatonin than sunflower oil [61]. ...
The Mediterranean diet (MD) has beneficial effects on human health, which is evidenced by the observation of lower incidence rates of chronic diseases in Mediterranean countries. The MD dietary pattern is rich in antioxidants, such as melatonin, which is a hormone produced mainly by the pineal gland and controls several circadian rhythms. Additionally, melatonin is found in foods, such as fruit and vegetables. The purpose of this systematic review was to assess the melatonin content in Mediterranean foods and to evaluate the influence of the MD on melatonin levels in both humans and model organisms. A comprehensive search was conducted in four databases (PubMed, Scopus, Cochrane Library and Web of Science) and data were extracted. A total of 31 records were chosen. MD-related foods, such as tomatoes, olive oil, red wine, beer, nuts, and vegetables, showed high melatonin contents. The consumption of specific MD foods increases melatonin levels and improves the antioxidant status in plasma.
... Common foods and beverages such as olive oil, coffee, wine, and even beer are rich sources of melatonin. 1,7,[22][23][24][25][26] It is also found in many common fruits and vegetables, including tomatoes, grape skins, tart cherries, walnuts, and other fermented food products, with concentrations markedly higher than those found in vertebrate tissues. [27][28][29] Most foods and drinks consumed by humans contain melatonin, and their intake probably increases circulating melatonin levels and the total antioxidant status of human serum. ...
Beer is a drink that is part of the diet of many peoples, it is a fermented beverage with a low alcohol content originating from cereal fermentation (barley or wheat) and contains melatonin. Melatonin (N‐acetyl‐5‐methoxytryptamine) is a molecule with a wide range of antioxidant, oncostatic, immunomodulatory, and cytoprotective properties. The aim of this work was to review the data supporting the idea that moderate consumption of beer, because of its melatonin content, is particularly useful in the diets of healthy subjects and in other physiological situations (pregnancy, menopause, old age, …), through food products as functional tools. Methods: Data source: a) The MEDLINE / PubMed search was conducted from 1975 to April 2022, and b) Our own experience and published studies on melatonin, the immune system, and beer. In this perspective, we provide a background on the mechanisms of melatonin generation in beer, its concentrations, and its possible effects on health. Conclusions: Melatonin contained in beer, as part of the diet of healthy individuals and in some special physiological situations, could act as a protective factor and improve the quality of life of those who drink it in moderation. This article is protected by copyright. All rights reserved.
... Most food groups that contain high melatonin levels and have a positive effect on sleep quality (such as vegetables, fruits, seeds, legumes, vegetable oils, eggs and milk products) are considered a priority in the Mediterranean diet (31). live oil, which appears as a main source of fat in the Mediterranean diet, contains melatonin and plays an important role in improving sleep quality (32). The positive effect of fruits, vegetables, and dairy products on sleep, apart from their melatonin content, is also attributed to other types of compounds. ...
Background: Previous studies has shown that low quality diet is correlated with chronic sleep disorders. Mediterranean dietary pattern is considered as a high quality diet which has been shown to have beneficial effects on overall health. Thus, the aim of our study was to investigate the correlation between adherence to Mediterranean dietary pattern and insomnia score in a population of adolescent girls.
Methods: Total Data of 734 adolescent girls between 12-18 years old has been considered in this cross-sectional study. To assess dietary intake, a food frequency questionnaire was used. To assess the inherence to Mediterranean dietary style, a modified model of Mediterranean diet was applied and the scores were ranged from 0-9. A valideated version of Insomnia Severity Index questionnaire wss used to assess insomnia. To explore the associations between MED-style diet and insomnia, logistic regression was conducted in crude and adjusted models.
Results: The participants with higher adherence to MED-style diet had higher intake of fruits, vegetables, nuts, fish, total energy intake, carbohydrate, dietary fiber, potassium, Beta-carotene, vitamin C, iron and folate. A significant inverse association between adherence to the MED-style diet score and insomnia score was obtained in crude model (β= -0.125; P-value = 0.019) and also after adjustment for confounding variables (β= -0.120; P=0.048).
Conclusion: There is an inverse relationship between adherence to the Mediterranean dietary style and the prevalence of insomnia among Iranian adolescent girls. Prospective studies are necessary to confirm these results and clarify whether a causal relationship exists.
... Of them, production of melatonin (N-acetyl-5-methoxytryptamine) is well established among the majority of monocotyledons and dicotyledons families [28,29]. Despite its production in the mitochondria and chloroplast of roots and leaves, its translocation to meristems, flowers and fruits promotes growth of aerial parts of the plant [30][31][32]. It is found in higher amounts in reproductive tissues that are young and decline in senescence tissues. ...
Abiotic stress adversely affects plant growth and metabolism and as such reduces plant productivity. Recognized as a major contributor in the production of reactive oxygen species (ROS), it hinders the growth of plants through induction of oxidative stress. Biostimulants such as melatonin have a multifunctional role, acting as a defense strategy in minimizing the effects of oxidative stress. Melatonin plays important role in plant processes ranging from seed germination to senescence, besides performing the function of a biostimulant in improving the plant’s productivity. In addition to its important role in the signaling cascade, melatonin acts as an antioxidant that helps in scavenging ROS, generated as part of different stresses among plants. The current study was undertaken to elaborate the synthesis and regulation of melatonin in plants, besides emphasizing its function under various abiotic stress namely, salt, temperature, herbicides, heavy metals, and drought. Additionally, a special consideration was put on the crosstalk of melatonin with phytohormones to overcome plant abiotic stress.
... In a study examining the amount of melatonin in extra virgin olive oil, sunflower oil, and refined olive oil, it was observed that the amount of melatonin in extra virgin olive oil samples was higher than in sunflower and refined olive oil samples (de la Puerta et al., 2007). A group of researchers has reported the amount of melatonin that there was no significant difference in melatonin between the samples, but a remarkable difference between the amounts of trans-resveratrol (Mercolini et al., 2008). ...
Vegetables and fruits are found in the most popular diets. And they are considered as rich sources of vitamins and minerals. Vitamin and mineral deficiency are one of the major causes of various diseases that are common nowadays. Especially vitamins which are known to affect directly on various hormones in our body. Melatonin (N-acetyl-5-methoxytryptamine), one of these hormones, is synthesized in various peripheral organs and tissues, especially the pineal gland and retina. Endogenous melatonin secretion rhythm is regulated by the suprachiasmatic nucleus and maintained with a bright dark cycle. Melatonin hormone is responsible for many activities in the human body. In addition to, especially is found in various foods (milk and milk product, nuts, olive oil, and various fruits). In this review, the recent studies that focused on the biosynthesis and metabolism of melatonin in addition to those investigated food content of melatonin and their effects on physiological and biological human health.
... Çalışmada melatonin düzeyi sızma zeytinyağında (Toscano orijinli) 108 ±17.3 pg/ml, rafine zeytin yağında 53 ±5.6 pg/ml ve ayçiçek yağında 50±12.2 pg/ml olarak tespit edilmiştir [49]. ...
... Oleic acid is the main constituent of olive oil, which is produced by dehydrogenation from stearic acid by stearoyl-ACP desaturase (SACPD) and then desaturated into linoleic acid by FAD2 (Estruch et al., 2018). Melatonin has been found present in olive oil, specifically in the extra virgin types (Fernández-Montesinos et al., 2010;De la Puerta et al., 2007). ...
Olive oil possesses medicinal properties which include antimicrobial, antioxidant and anti-inflammatory, anti-diabetes, and anti-cardiovascular diseases. Oleic acid is the most abundant (95%) constituent of olive oil and others include linoleic acid, oleuropein, oleanolic acid, maslinic acid, melatonin, and others. The objective of this study is to predict the molecular targets and properties of key bioactive components of olive oil in human. Bioinformatics methods, which involved pharmacokinetics prediction, target prediction and gene network analyses, were used. The results showed that oleic acid has similar targets with linoleic acid, and showed significant probability of binding to several targets such as fatty acid-binding proteins in the adipose, epidermal, liver and muscle as well as alpha, delta and gamma peroxisome proliferator-activated receptors (PPARs). Carbonic anhydrase showed to be the only significant target of tyrosol, while protein-tyrosine phosphatase 1B, and CD81 antigen were targeted by maslinic acid and oleanolic acid. This study has applauded oleic acid, linoleic acid and tyrosol as olive oil bioactive constituents that have several potential pharmacological effects in humans that modulate several enzymes, receptors and transcription factors. The future work will be to investigate the effects of oleic acid on fatty acid-binding proteins and telomerase reverse transcriptase; melatonin on quinone reductase 2; tyrosol on carbonic anhydrase II; maslinic acid and oleanolic acid on protein-tyrosine phosphatase 1B.
... Of these sources, the determination method is the focus of attention herein. The measurement methods of melatonin in plants are diverse and include radioimmunoassay, 4 ELISA, 7,[47][48][49][50] HPLC-UV, 51 HPLC-FD, HPLC-EC, 33 HPLC-MS, 31,34,52 HPLC-ECD, 53,54 HPLC-F, 55 HPLC-ESI-MS/ MS, 56 CEC (CE-HPLC), 57 MEPS-HPLC-F, 36 UPLC-MS/MS, 40,44 UPLC-HR-MS, 58 LC-MS-ESI, 59 LC-DAD-ESI-MS, 60 and GC-MS. 61 These methods differ in many regards including differences in sensitivity, accuracy, and specificity. ...
In recent years, people have become increasingly interested in bioactive ingredients from plants, especially antioxidant molecules such as melatonin, which are beneficial to human health. The purpose of this article is to provide new information on plant-derived foods with a high content of melatonin. We comprehensively summarize the content of melatonin in plant-derived foods and discuss the factors that influence melatonin levels to provide new ideas on enhancement. Additionally, we describe the biosynthetic pathway of melatonin and identify its major functions. Medicinal herbs are often rich in melatonin while many vegetables and fruits exhibit somewhat lower levels with wide variations among species. The genetic traits of plants, the phenological stage of the cultivar, the photoperiod, the level of stress to which the plants are exposed at the time of harvest, exposure to agrochemicals and determination methods are the main factors affecting the melatonin content. To date, standardization of uniform sampling times and the use of suitable pretreatments as well as determination methods have not been achieved. The results of the studies reviewed highlight the potentially important role of plant melatonin in influencing the progression of human diseases. Based on the health promotional aspects of melatonin, consuming foods containing higher concentrations of tryptophan and melatonin is suggested.
... The presence of indoleamines in roasted beans, which pass into coffee brew, might be useful for consumers. Various refined and extra-virgin Spanish olive oils were found to contain between 650 and 119 pg mL −1 MEL (de la Puerta et al. 2007). MEL was also determined in virgin argan oils (Venegas et al. 2011). ...
In food and biological systems, the main function of tocochromanols is antioxidant action – they deactivate free radicals and protect lipids from peroxidation (autoxidation). In addition to the antioxidant role of vitamin E and protection against oxidative stress, the “non-antioxidant” functions of vitamin E, including cell signaling and antiproliferation, is also described. Tocopherols and tocotrienols are not the only compounds classified as tocol derivatives. This chapter also includes an overview of the properties and occurrence of other forms of tocols (including: tocomonoenols, tocodienols, and plastochromanol-8). Content of tocochromanols in food may be determined using a wide range of analytical techniques. Capillary gas chromatography and high performance liquid chromatography coupled with various detection systems and mass spectrometers enable identification of individual compounds. In the analysis of these compounds, spectroscopic methods are also being developed. The principles of these techniques are discussed in the chapter and examples of their applications are also provided.
... In fact, it is present in some fruits [3]. The presence of MEL has also been described in olive oil, especially in extra virgin olive oil, and in sunflower oil [4]. In addition, the presence of MEL in grapes and wines has been recently described. ...
Melatonin is a hormone secreted in the pineal gland with several functions, especially regulation of circadian sleep cycle and the biological processes related to it. This review evaluates the bioavailability of melatonin and resulting metabolites, the presence of melatonin in wine and beer and factors that influence it, and finally the different benefits related to treatment with melatonin. When administered orally, melatonin is mainly absorbed in the rectum and the ileum; it has a half-life of about 0.45–1 h and is extensively inactivated in the liver by phase 2 enzymes. Melatonin (MEL) concentration varies from picograms to ng/mL in fermented beverages such as wine and beer, depending on the fermentation process. These low quantities, within a dietary intake, are enough to reach significant plasma concentrations of melatonin, and are thus able to exert beneficial effects. Melatonin has demonstrated antioxidant, anticarcinogenic, immunomodulatory and neuroprotective actions. These benefits are related to its free radical scavenging properties as well and the direct interaction with melatonin receptors, which are involved in complex intracellular signaling pathways, including inhibition of angiogenesis and cell proliferation, among others. In the present review, the current evidence on the effects of melatonin on different pathophysiological conditions is also discussed.
... It is of great interest that herbs used to treat free radical-associated diseases (e.g., neurological disorders) and retard aging exhibited the highest melatonin concentration. Extra virgin olive oil, which is beneficial for human health, was also noted to be with melatonin (De la Puerta et al., 2007). Colored grains from purple wheat crops were also found enriched in melatonin and SDG (Secoisolariciresinol DiGlucoside), besides having anthocyanins (Hosseinian et al., 2008). ...
Recently, melatonin has gained significant importance in plant research. The presence of melatonin in the plant kingdom has been known since 1995. It is a molecule that is conserved in a wide array of evolutionary distant organisms. Its functions and characteristics have been found to be similar in both plants and animals. The review focuses on the role of melatonin pertaining to physiological functions in higher plants. Melatonin regulates physiological functions regarding auxin activity, root, shoot, and explant growth, activates germination of seeds, promotes rhizogenesis (growth of adventitious and lateral roots), and holds up impelled leaf senescence. Melatonin is a natural bio‐stimulant that creates resistance in field crops against various abiotic stress, including heat, chemical pollutants, cold, drought, salinity, and harmful ultra‐violet radiation. The full potential of melatonin in regulating physiological functions in higher plants still needs to be explored by further research.
... Melatonin is also present in different parts of plants including the flowers, roots, leaves, fruits, and seeds. Typical ranges of melatonin concentration in plants vary from picograms to micrograms per gram (Burkhardt et al., 2001;de la Puerta et al., 2007;Paredes et al., 2009;Reiter et al., 2005). Consequently, natural sources of melatonin in plants have attracted increased research interest in the context of human diets (Huang and Mazza, 2011; bib_citation_to_be_resolvedKol a r and Mach a ckov a, 2005; Paredes et al., 2009;Posmyk and Janas, 2009;Reiter et al., 2007;Tan et al., 2012). ...
The ability to predict melatonin stability during food processing or storage is important. Therefore, the degradation of melatonin in both aqueous solutions and fruit juice samples was investigated. The pH values of aqueous solutions were set over a pH range from 1 to 13 and at four different temperatures (60, 70, 80 and 90 °C). The highest remaining melatonin (CR) was observed in the lowest pH solution (pH = 1, CR > 65%). Melatonin concentrations decreased with rising pH levels from pH 4 to 13 during storage time. The thermal degradation rate constant of melatonin (k) values obtained followed the order: k90°C (0.175) >k80°C (0.123) >k70°C (0.082) >k60°C (0.027). Thermal degradation kinetics followed the first-order reaction model with a high range of coefficients of determination (0.9744 < R² < 0.995). The temperature also affected on melatonin degradation in fruit juices which the degradation rate was increased with the presence of light and high temperature. Our results can be used as guidelines to develop a processing method that predicts melatonin degradation during thermal processing of food products.
... Our research group has also recently demonstrated that melatonin, present in an extensive array of foods, such as vegetables and their fruits and seeds, medicinal herbs, and fermented products (tomatoes, pistachio, strawberry, cherry, bread, olive oil, wine, beer, etc.), as well as other bioactive indolic compounds (e.g., serotonin, 3-indolacetic acid), also present in fermented food (wine and beer) [23][24][25][26][27][28][29][30], and one of the serotonin human metabolites (5-hydroxytryptophol) [31,32] possess potential anti-VEGF signalling effects [19]. This research has demonstrated that these indolic compounds present a different anti-VEGF molecular signalling mechanism to that of phenolic compounds; serotonin, 3-indolacetic acid, melatonin and 5-hydroxytryptophol appear to interact with the cell surface components of the endothelial membrane, such as VEGFR-2, among others, preventing VEGF from activating the receptor. ...
Angiogenesis drives evolution and destabilisation of atherosclerotic plaques and the growth and expansion of tumour cells. Vascular endothelial growth factor (VEGF) is the main endogenous pro-angiogenic factor in humans. The aim was to provide insight into the anti-VEGF activity of bioactive compounds derived from aromatic amino acids (serotonin, melatonin, 3-indoleacetic acid, 5-hydroxytryptophol and hydroxytyrosol). Experiments involved endothelial cell migration (wound-healing assay), the molecular mechanisms (ELISA assay) and the downstream effects (phospholipase C gamma 1 (PLCγ1), protein kinase B (Akt) and endothelial nitric oxide synthase (eNOS) by Western blot) on human umbilical vein endothelial cells (HUVECs). The data suggest for the first time that hydroxytyrosol interacts with surface components of the endothelial cell membrane (, preventing VEGF from activating its receptor. Serotonin and 5-hydroxytryptophol significantly inhibited HUVEC migration (98% and 50%, respectively) following the same mechanism. Conversely to other bioactive compounds, the anti-angiogenic effect of melatonin, serotonin, 3-indoleacetic acid and 5-hydroxytryptophol is not mediated via PLCγ1. However, hydroxytyrosol inhibits PLCγ1 phosphorylation. Additionally, melatonin and serotonin maintained eNOS phosphorylation and hydroxytyrosol significantly activated eNOS—all via Akt. These data provide new evidence supporting the interest in melatonin, serotonin, 3-indoleacetic acid, 5-hydroxytryptophol and hydroxytyrosol for their further exploitation as anti-VEGF ingredients in food.
... Low concentrations of this compound is also present in a number of vegetables, fruits, seeds, medicinal herbs, or fermented products (Chen et al., 2003;Dubbels et al., 1995;Hattori et al., 1995;Manchester et al., 2000;Murch et al., 1997;Reiter, 1991;Reiter et al., 2015). Hence, nuts, tomatoes, beetroots, cucumber, banana, strawberry, cherry, apple, olive oil, wine, beer among others have been reported as foods containing MEL at concentrations varying between 5 pg/g or mL to 230 μg/g or mL (de la Puerta et al., 2007;Di Bella and Gualano, 2006;Hornedo-Ortega et al., 2016a,b;Iriti and Varoni, 2016;Lei et al., 2013;Maldonado et al., 2009;Oladi et al., 2014;Reiter et al., 2005;Rodriguez-Naranjo et al., 2011;Stürtz et al., 2011;Zhao et al., 2013). In fact, circulating MEL in humans due to its intake from certain food has been estimated between 15 and 700 fold higher (0.15 and 21 ng/mL respectively) than endogenous MEL (Cerezo et al., 2017). ...
... Melatonin is a natural body hormone which can also be found in several herbal agents such as rice grains and olive (mainly in extra virgin) (11)(12)(13). It has potent antioxidant effects through direct neutralization of free radicals, as well as stimulation of antioxidant defense enzymes (14). ...
Background
Jejunum is the most radiosensitive part of the gastrointestinal system. This is a main issue, leading to several side effects to patients with abdominal cancers, in addition to affecting their quality of life. Epithelial layer and clonogenic cells in the jejunum are the most sensitive parts of intestine, while damage to vascular may lead to chronic inflammation and bleeding. Both melatonin and metformin have shown abilities to attenuate radiation toxicity through modulation of DNA damage responses, neutralization of free radicals and alleviation of inflammation. In this study, we aimed to evaluate the possible radioprotective effects of melatonin and metformin when administered either alone or as a combination, in rat’s jejunum against a high dose of radiation.
Materials and Methods
40 male rats were divided into 8 groups as G1: control; G2: metformin; G3: melatonin; G4: melatonin + metformin; G5: radiation; G6: radiation + melatonin; G7: radiation + metformin; G8: metformin + melatonin + radiation. Rats were irradiated with 10 Gy gamma rays while treatments was administered at 100 mg/kg. 3.5 days after irradiation, all rats were sacrificed for histopathological evaluation of the jejunum.
Results
This study showed that whole body irradiation of rats led to severe injuries to the epithelial and vascular of jejunum. Single administration of either melatonin or metformin, was unable to mitigate radiation toxicity. However, administering the combination of melatonin and metformin could mildly mitigate radiation-induced jejunum injury.
Conclusion
From the results of this study, we suggest that the combination of melatonin and metformin has superior radioprotective effect for jejunum compared with the single administration of these drugs.
... Additionally, this compound is present at low concentrations in a number of vegetables, fruits, seeds, medicinal herbs, or fermented products [18][19][20][21][22][23][24]. Hence, nuts, tomatoes, beetroots, cucumber, banana, strawberry, cherry, apple, walnut, pistachio, bread, cocoa powder, green coffee, mustard seeds, feverfew, olive oil, wine and beer have been reported as foods containing MEL at concentrations varying between 5pg/g or mL to 230 µg/g or mL [25][26][27][28][29][30][31][32][33][34][35]. Considering melatonin bioavailability (up to 56%, with a mean value of 19%) [35][36][37][38] and plasma volume (5 L), the circulating melatonin would be between 0.15 and 21 ng/mL (for mean melatonin bioavailability = 19%) [39]. ...
The abnormal assembly of α-synuclein (α-Syn) is an initial step in the formation of Lewy bodies in the brain, which finally causes the neuronal death, being considered as a pathological hallmark in Parkinson’s disease (PD). Certain food bioactives or their metabolites at very low concentrations can trespass the blood brain barrier (BBB) that might, thereafter, act simultaneously. The aim of this work was to evaluate the inhibitory and destabilising capacities on α-Syn kinetics and the neuroprotective effects of three well-known bioactive compounds able to cross the BBB and present in foods; melatonin (MEL), protocatechuic acid (PCA) and hydroxytyrosol (HT), and their combinations. For this purpose, different in vitro techniques (Thioflavin T (ThT), Transmission Electronic Microscopy (TEM), electrophoresis and MTT assay) were used. All tested compounds and their combinations were able to abolish the toxicity induced by α-Syn. In addition, the combination of PCA (100 µM) +HT (100 µM) showed the highest inhibitory effect against α-Syn fibril formation and destabilises α-Syn fibrils (88 and 62%, respectively). This is the first time that MEL, PCA and HT prove a joint effect against α-Syn aggregation and toxicity when they are tested together.
... In fact, melatonin has been reported in strawberries, kiwis, pineapples, bananas and apples [24]. The presence of melatonin has also been described in olive oil, extra virgin olive oil, and in sunlower oil at concentrations between 71 and 113 pg mL −1 [53]. Other foods from Mediterranean diet that have sown high concentration of melatonin are salmon (3.7 ng g −1 ), chicken and lamb (2.3 ng g −1 and 1.6 ng g −1 respectively), bread's crumb and crust (341 and 138 pg g −1 respectively) and yogurt (126 pg g −1 ) [54,55]. ...
... Dietary sources of melatonin include edible seeds, such as rice and sweet corn ( Hattori et al., 1995;Manchester et al., 2000), roots, leaves and fruits (especially, strawberries, kiwis, pineapples, bananas and apples) of a considerable variety of plants (Paredes, Korkmaz, Manchester, Tan, & Reiter, 2009;Stürtz, Cerezo, Cantos, & GarcíaParrilla, 2011). Melatonin is also found in olive oil at higher levels in extra virgin olive oil than in refined olive or sunflower oil samples (De la Puerta et al., 2007). In addition, melatonin has been reported in grapes (skins), wines and beer ( Iriti et al., 2006;Fernández-Mar et al., 2012). ...
An understanding of the biochemical composition of edible organisms is extremely important to determine their nutritional value. Some species can be recommended for human consumption only after assessing their nutritive value. Eating the right foods can help prevent, or more successfully manage, an illness. Seafoods have been recognized as nutraceuticals, or functional foods, with beneficial effects on one or more targeted functions. They contain important biochemical components, such as total protein, carbohydrates, and lipids, and in particular fatty acids, which are essential for human health. The aim of this study was to profile the chemical characteristics and nutritive value of certain species, caught in the Ionian Sea, that are of high commercial interest in Mediterranean countries and are found in fish markets.
... Various ELISAs for MLT have been developed, one even allowing the direct use of human serum (Chegini et al. 1995). A commercial kit based on a competitive enzyme immunoassay (Melatonin ELISA, IBL-Hamburg) was applied to determine MLT in olive oil for the first time (de la Puerta et al. 2007). This same kit was used to determine MLT in grape skin extracts from different cultivars (Iriti, Rossoni, and Faoro 2006), wine (Guerrero, Martínez-Cruz, and Elorza 2008) and cow milk (Kollmann et al. 2008;Garcia-Parrilla, Cantos, and Troncoso 2009). ...
Melatonin has been found in many species of animals, and it was most extensively studied in vertebrates – mammals, birds, reptiles, amphibians, bony and cartilaginous fish, and cyclostomes.This endogenous neurohormone has also been identified in bacteria, algae, fungi, insects, and plants. Nowadays, melatonin is widely used in countries as a food supplement, however alternative or natural sources of melatonin have been a matter of interest.
Concentrations of melatonin in the different alternative sources may vary, ranging from picograms to micrograms, and have been subjected to evaluation by many authors who constantly update the levels found. Efficient analytical methods for the determination of melatonin, together with optimized extraction protocols, help confirming its presence and determine melatonin in the most diverse sources.
Melatonin can be detected by several methods, such as immunological techniques, radioimmunoassay and enzyme-immunoassay. However, in recent years, chromatographic methods have been the most widely used separation techniques in this field. Liquid chromatography techniques are more beneficial economically, and also more time-efficient when sample derivatization is not required prior to analysis; several detectors have been coupled to liquid chromatography, such as mass spectrometry, fluorescence and electrochemical detection. However, gas chromatographic applications have also been described, the most common being gas chromatography-mass spectrometry.
Sample pre-treatment represent the critical step before chromatographic measurement for the determination of melatonin. This becomes even more relevant when there are so many different sample sources which require a wide adaptation of the extraction procedures to solid samples (e.g., fruits, plants, mammal pineal gland, drug tablets) or liquid samples (e.g., urine, plasma, oral fluid, oils). Several procedures for the extraction of melatonin have been reported, and these include ultrasound-assisted extraction, liquid–liquid extraction, and solid phase extraction.
This chapter will review pre-analytical procedures, as well as analytical conditions, to determine melatonin in both biological and non-biological samples.
... Other fruits and vegetables, like tomatoes (UDENFRIEND; LOVENBERG; SJOERDSMA, 1959; VAN TASSEL et al., 2001), red plum, avocado (UDENFRIEND; LOVENBERG; SJOERDSM, 1959), olive oil (DE LA PUERTA et al., 2007) and grapes (MURCH et al., 2010;BOCCALANDRO et al., 2011) have also been pointed out like melatonin rich foods, but more researches are necessary to confirm if their melatonin content is also noted in individuals serum. The literature also indicates that carbohydrates-rich meals, especially with high GI, may increase the secretion of melatonin and consequently improve the quality of sleep (AFAGHI; O'CONNOR; CHOW, 2007). ...
The complexity of sleep function and its association with other physiological processes are still not clear in the literature and there is an increased interest in understanding it. Considering the negative consequences caused by the disruption in sleep pattern, strategies which aim to empower sleep quality, such as diet, should be studied and promoted. Until this moment, there is much discussion about the effects caused by a reduction in sleep time on metabolism and food intake, however, there is a lack of studies that have attempted to review the information about the influence of food intake on sleep. Therefore, this review aims to summarize some of the findings relating nutrition strategies and sleep. Results regarding macronutrients suggest that fat-rich diets may reduce sleep time, high-protein meals seem to improve alertness, while carbohydrate intake is associated with improvement in sleepiness. More studies evaluating the types of carbohydrate are necessary, but the literature suggests that the ingestion of high-GI carbohydrate foods is associated with a lower sleep latency. Regarding micronutrients, folate, vitamin B12, B6, D, C, A and E have been associated with sleep parameters. Other foods like banana, walnuts, tart cherry juice, cow’s milk, rich-tryptophan and high-carbohydrate foods seem to positively affect melatonin levels, which may enhance sleep quality. The relationship between diet and sleep is very complex, and further investigations are necessary for its understanding.
... In Spain, researchers found melatonin concentrations in virgin olive oil (71 § 15.1 and 119 § 2.93 pg/mL), refined olive oil (53 § 5.6 and 75 § 6.92 pg/mL) and sunflower oil (50 § 12.2 pg/mL) (de la Puerta et al. 2007). ...
Melatonin is an indolamine with a recognized chronobiotic role. In turn, the supplementation of melatonin through capsules has been shown to be efficient in the modulation of inflammatory markers, oxidative stress, as well as in the control of hypertension and metabolic syndrome. However, the science of nutrition is interested in the study of the food sources of this hormone and its possible therapeutic effects. Thus, this review aimed to identify and present scientific papers that quantified melatonin in foods and evaluated its application in intervention studies. In total, 278 studies were found, of which 17 were included in this review. The results show that meats, fish, eggs, cereals, tubers, oilseeds, mushrooms, fruits, vegetables, alcoholic and non-alcoholic beverages and dairy products had some items analyzed for their melatonin concentrations. The concentrations reported presented considerable amplitude among different foods and even within the same species, possibly due to differences in cultivation and different hormonal dosing techniques. Also, different concentrations of melatonin can be presented for the same food when submitted to processes such as cooking, roasting or fermentation. The intervention studies presented positive results regarding the consumption of foods rich in melatonin and clinical-metabolic indicators. However, in order to guide nutritional behavior, it is necessary to consult a composition table that makes melatonin concentrations available and considers the processes involved in the preparation of the food. With this table, it will be possible to analyze the real effect of habitual consumption of melatonin from food on health.
... Melatonin is a pleiotropic hormone synthesized by the pineal gland, secreted into the blood stream, and involved in the entrainment of the circadian rhythm such as sleep and wake timing, blood pressure controlling, energy balance favoring and inhibiting brown adipose tissue formation, and seasonal reproduction, etc. [32,33]. It is also a phytochemical compound present in various foods from fungi to animals and plants [34]. Melatonin (and its metabolites) also plays multiple roles as a potent antioxidant and a free radical scavenger in cellular homeostasis (i.e., cell survival, apoptosis, thermogenesis, inflammation, etc.) by binding specific melatonin receptors (i.e., MT1, MT2) [35][36][37][38][39][40][41][42][43][44], and also improves the nuclear or mitochondria dysfunction in diabetic and obese animal model through its antioxidant capacity [45][46][47][48]. ...
Insulin resistance (IR) is an important stress factor in the central nervous system, thereby aggravating neuropathogenesis and triggering cognitive decline. Melatonin, which is an antioxidant phytochemical and synthesized by the pineal gland, has multiple functions in cellular responses such as apoptosis and survival against stress. This study investigated whether melatonin modulates the signaling of neuronal cell death induced by endoplasmic reticulum (ER) stress under IR condition using SH-SY5Y neuroblastoma cells. Apoptosis cell death signaling markers (cleaved Poly [ADP-ribose] polymerase 1 (PARP), p53, and Bax) and ER stress markers (phosphorylated eIF2α (p-eIF2α), ATF4, CHOP, p-IRE1, and spliced XBP1 (sXBP1)) were measured using reverse transcription-PCR, quantitative PCR, and western blottings. Immunofluorescence staining was also performed for p-ASK1 and p-IRE1. The mRNA or protein expressions of cell death signaling markers and ER stress markers were increased under IR condition, but significantly attenuated by melatonin treatment. Insulin-induced activation of ASK1 (p-ASK1) was also dose dependently attenuated by melatonin treatment. The regulatory effect of melatonin on neuronal cells under IR condition was associated with ASK1 signaling. In conclusion, the result suggested that melatonin may alleviate ER stress under IR condition, thereby regulating neuronal cell death signaling.
... Melatonin ranged 0.03-0.29 ng/g in the tested edible oils, among which refined linseed presented 0.29 ng/g and virgin soybean 0.19 ng/g [63,64]. De la Puerta et al. also demonstrated that generally the melatonin levels in the refined olive and sunflower oil were about half of those in the extra virgin olive oil [63]. ...
Insomnia is a serious worldwide health threat, affecting nearly one third of the general population. Melatonin has been reported to improve sleep efficiency and it was found that eating melatonin-rich foods could assist sleep. During the last decades, melatonin has been widely identified and qualified in various foods from fungi to animals and plants. Eggs and fish are higher melatonin-containing food groups in animal foods, whereas in plant foods, nuts are with the highest content of melatonin. Some kinds of mushrooms, cereals and germinated legumes or seeds are also good dietary sources of melatonin. It has been proved that the melatonin concentration in human serum could significantly increase after the consumption of melatonin containing food. Furthermore, studies show that melatonin exhibits many bioactivities, such as antioxidant activity, anti-inflammatory characteristics, boosting immunity, anticancer activity, cardiovascular protection, anti-diabetic, anti-obese, neuroprotective and anti-aging activity. This review summaries the dietary sources and bioactivities of melatonin, with special attention paid to the mechanisms of action.
... Indeed, VEGF and VEGFR-2 are molecular targets for drug therapies that aim for the inhibition of VEGF signaling[7]. Melatonin is an ubiquitous molecule, which has been found not only in the human pineal gland but also in vegetables and their fruits and seeds, medicinal herbs, and fermented products such as nuts, tomatoes, beetroots, cucumber, banana, strawberry, cherry, apple, walnut, pistachio, bread, cocoa powder, green coffee, mustard seeds, feverfew, St John's Wort, olive oil, wine, beer, etc., at concentrations varying between 5 pg/g or mL to 230 µg/g or mL[13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29]. According to the 2011 EFSA Comprehensive European Food Consumption Database (France, Germany, United Kingdom, Spain and Italy)[30], the mean intake of melatonin from the consumption of just twelve food items (tomato, beetroot, banana, strawberry, cherry, apple, walnut, pistachio, bread, olive oil, wine, and beer) ranges between 4 and 550 µg/day, with the United Kingdom and Spain being the countries with the lowest and highest intake of melatonin, respectively. ...
Excessive concentrations of vascular endothelial growth factor (VEGF) trigger angiogenesis, which causes complications such as the destabilization of atherosclerotic plaques and increased growth of tumors. This work focuses on the determination of the inhibitory activity of melatonin and other indolic related compounds on VEGF-induced VEGF receptor-2 (VEGFR-2) activation and an approximation to the molecular mechanism underlying the inhibition. Quantification of phosphorylated VEGFR-2 was measured by ELISA. Migration wound-healing assay was used to determine cell migration of human umbilical vein endothelial cells (HUVECs). This is the first time that melatonin, 3-indolacetic acid, 5-hydroxytryptophol, and serotonin are proved to significantly inhibit VEGF-induced VEGFR-2 activation in human umbilical vein endothelial cells and subsequent angiogenesis. 3-Indolacetic acid showed the highest inhibitory effect (IC50 value of 0.9704 mM), followed by 5-hydroxytryptophol (35% of inhibition at 0.1 mM), melatonin (30% of inhibition at 1 mM), and serotonin (24% of inhibition at 1 mM). An approximation to the molecular mechanism of the inhibition has been proposed, suggesting that indolic compounds might interact with the cell surface components of the endothelial membrane in a way that prevents VEGF from activating the receptor. Additionally, wound-healing assay revealed that exposure of HUVECs to melatonin and 3-indolacetic acid in the presence of VEGF significantly inhibited cell migration by 87% and 99%, respectively, after 24 h. These data demonstrate that melatonin, 3-indolacetic acid, 5-hydroxytryptophol, and serotonin would be good molecules for future exploitation as anti-VEGF signaling agents.
... Until a decade ago, melatonin was thought to be only produced only in the animal kingdom. Later it has been identified in the edible plants, such as bananas, cherries, white sprouts, cucumbers 4 , walnuts 5 and in olive oil 6 . Melatonin is an almost ubiquitous molecule in the animal and plant kingdom. ...
In recent years, people have become increasingly interested in bioactive molecules in plants that are beneficial to human health, and melatonin (N-acetyl-5-methoxytryptamine) has attracted research attention due to its excellent performance. In this study, the content of melatonin in oilseeds was investigated. From the results, it was found that sesame is an important natural food source of melatonin intake. Furthermore, the variation in melatonin content was explored in a natural sesame population, and its contents varied from 0.04 to 298.62 ng g−1. Through a genome-wide association study (GWAS), a candidate gene SiWRKY67 was screened that regulates melatonin content in sesame. The sesame hairy root transformation system was developed and used to verify this gene, and it was found that the overexpression of SiWRKY67 could positively promote the melatonin content in the hairy roots. Our results provide not only a foundation for understanding the genetic structure of melatonin content in sesame seeds but also a reference for the marker-assisted breeding of sesame varieties with high melatonin content.
Melatonin is a neurohormone produced and released by the pineal gland. Neurons placed in the eye surface send a signal when the person is exposed to darkness to the suprachiasmatic nuclei and that prompts melatonin release. This biomolecule is in charge of synchronizing body circadian rhythms such as sleep or hunger. Intense light exposure can avoid its release or healthy rhythm. Apart from that, the scientific literature has suggested that melatonin influences immune system, antioxidant capacity, or cell preservation. Moreover, melatonin can be supplied by dietary food such as grapes, dairy or fermented products. Interestingly, some foods contain a significant amount of melatonin and can be considered as good sources of that bioactive molecule. The information in this chapter will cover melatonin dietary sources, biological capacity, related metabolites, and proven benefits in the human body.
This review paper highlights the role of melatonin in many diseases, coronavirus (SARS-CoV-2) disease (covid-19) and multi-physiological functions in plants. Based on its ubiquitous distribution (animal, human, plant, fungi, bacteria, algae), and multi-directional activity, melatonin is recommended as one of the most versatile biological signal of nature. Melatonin, so called a Hormone of darkness, has a high safety profile and potential to be used as COVID-19 therapy. Melatonin is a light sensitive molecule used in the therapy of sleeping disorders-insomnia, glaucoma, stroke, cancers, puberty, Alzheimers disease, Parkinson disease, ultraviolet light skin damage protection, thrombocytopenia, in smoking cessation, headache protection, migrane, and as an antioxidant. Melotonin is present in different parts of all the plant species studied, including leaves, stems, roots, fruits and seeds. Melatonin plays an important aspect to regulate the several physiological role of plants viz. circadian regulator, cytoprotector, growth promoter, antioxidant and free radical scavenger. In plants, melatonin also promotes rhizogenesis, cellular expansion and provide defense against environmental stress condition. Melatonin aids plants in terms of root growth, leaf morphology, chlorophyll preservation and fruit development.
Over the last few years, an increasing interest in the scientific research of natural antioxidant molecules from plants capable to attenuate, or even prevent, stress oxidative-related disorders, such as diabetes, inflammatory, and neurological pathologies has been observed. Serotonin and melatonin are two of these molecules, being widely found in Mediterranean foodstuffs, fruits, vegetables, and medicinal herbs. The consumption of foods containing both antioxidants can raise their physiologic concentrations in blood and, consequently, enhance antioxidant defenses, improve mood, and treat sleep disorders, depression, and anxiety. Currently, there exist several analytical methods suitable for the determination of melatonin and serotonin in fruits and edible plants. Among them, the most used include chromatographic techniques and immunological assays. This work aims to present a comprehensive overview of the biosynthesis of these indolamines in nature, the most common techniques used to detect and quantify both compounds in fruits, vegetables, medicinal herbs, and other food sources, as well as to address their health benefits, particularly their antioxidant, neuroprotective, and sleep-promoting effects.
Indoleamines such as melatonin and serotonin have been found not only in mammalians but also in diverse living organisms, microorganisms, and plants. In the last decade of investigations, these molecules have been found in various edible plants and processed foods. Melatonin has been reported in edible fruits (grape, banana, strawberries, apple, pineapple, Kiwi fruit, tart cherries, etc.), vegetables (tomato, pepper, mushroom, cabbage, cauliflower, cucumber, carrot, beetroot, etc.), nuts and raw seeds (walnuts, sunflower, green cardamom, fenugreek, white and black mustard, etc.), juices and beverages (wines, green and roasted coffee beans, decoction brew). Also, the intake of these indoleamines-containing foods could significantly increase the melatonin/serotonin concentration in human serum, indicating these indoleamines could provide beneficial health effects. Studies have shown that melatonin has many bioactivities, such as antioxidant, anti-inflammatory, enhancing immunity, anticancer, improving circadian cycle, cardiovascular protecting, antidiabetic, anti-obese, antiaging, and neuroprotection. The nutritional implications of indoleamines as bioactive molecules are well documented and hence, it becomes one of the thrust areas of interest to explore their levels in various edible plants and food products. This chapter describes the occurrence of melatonin and serotonin in selected edible plants, fruit, vegetables, and processed foods and their bioavailability along with possible human health effects.
The recently established relation between the metabolism of aromatic amino acids of yeast and the production of different bioactive molecules during fermentation opens up new and interesting research topics. Among these molecules, melatonin has drawn researchers’ attention in the last decade given its potential benefits for human health. This review summarizes melatonin production in fermented beverages, and conventional and current methods for detecting melatonin in yeast-derived samples. In addition, the role of melatonin in yeast is discussed and the biosynthetic pathway of melatonin is presented in Saccharomyces cerevisiae.
Melatonin (N-acetyl-5-methoxytryptamine) is a multifunctional nontoxic signaling molecule, universally distributed in different plant organs and accountable for invigorating numerous physiological mechanisms against various adverse environmental factors. In the current review, we revealed that the biosynthesis of melatonin occurred in plants by themselves and accumulation of melatonin vacillated distinctly by regulating its biosynthesis and metabolic pathways under stress conditions. its concentration varied from plant to plant and even organ to organ of plants. Endogenous or exogenously applied melatonin boosted the tolerance against several environmental stresses, such as cold, heavy metals, drought, salt, chilling injury and temperature through a direct scavenging of reactive oxygen species (ROS) and reactive nitrogen species (RNS) production by enhancing antioxidant enzymes activity, non-enzymatic antioxidants, and enzymes related to oxidized protein repair. In addition, melatonin acts as an important signaling molecule to induce protective mechanisms via up-regulating the expression of defense genes by activating the SA, GA and ABA dependent pathways. There are also several studies that melatonin promotes seed germination, seedling growth, root regeneration, root growth and photosynthesis rate of horticultural crops under the influence of several environmental stresses. However, our review emphasized the multiple roles of melatonin against environmental stresses in horticultural crops along with future research directions, which could be useful for improving the eco-friendly crop production and ensure food safety.
Melatonin is a neurohormone that regulates circadian rhythms in the human body. It can also be taken to alleviate insomnia and sleep disorders. Pasteurized milk is a good source of nutrients and some bioactive compounds. Recently, the growing trend of healthy foods has resulted in higher competition with regard to milk products. Functional milk has been developed with higher bioactive compounds to respond to consumer demand. High melatonin pasteurized milk was developed using selected edible grains and mulberry leaves to fortify melatonin in pasteurized milk. Melatonin and free tryptophan of fourteen edible grains and mulberry leaves were determined using HPLC-FD. Highest melatonin concentrations were observed in white sesame, sunflower and soybean (75.24, 67.45 and 56.49 ng/g dry weight (dw), with highest concentrations of free tryptophan in soybean, red bean and mung bean (2617.83, 1527.23 and 845.27 ng/g dw, respectively), while melatonin and free tryptophan contents in fresh mulberry leaves were 51.57 ng/g and 210.53 ng/g dw, respectively. Soymilk powder and mulberry leaf tea were supplemented to prepare high melatonin pasteurized milk. Results showed that chemical compositions, melatonin and free tryptophan contents significantly increased (P < 0.05) with increasing amounts of soymilk powder and mulberry leaf tea. Sensory evaluation gave highest overall liking score for the treatment consisting of mulberry leaf tea (4.00%), soymilk powder (4.00%) and milk (89.80%). Findings indicated that mulberry leaves and soybean are both good sources of melatonin and free tryptophan and can be applied to prepare high melatonin pasteurized milk.
The Mediterranean diet is defined as the way of eating based on the traditional foods and drinks of the countries surrounding the Mediterranean Sea. The beneficial health effect of the Mediterranean diet is generally attributed to the rich phytochemical content, high amount of dietary fiber and fermented foods of this diet. In addition to all these bio actives, the Mediterranean diet is also prominent with the presence of melatonin. An essential amino acid, tryptophan, is the precursor of melatonin. Melatonin has a positive effect on health due to its antioxidant, anti-inflammatory, anticancer properties as well as the healing effect on cardiovascular diseases and responsibility for the circadian rhythm in the body. Consumption of foods containing melatonin significantly increases the serum melatonin concentration. Therefore, maximum health benefits are expected with the consumption of foods in the Mediterranean diet, not only their polyphenols and bioactive compounds but also synergistic effects among the polyphenols, bio actives and melatonin. This article will review foods in the Mediterranean diet, their melatonin contents and their expected health benefits.
N-acetyl-5-methoxy-tryptamine (melatonin) is a natural substance produced both by plants, as a secondary metabolite, and animals, by the pineal gland and other tissues. In humans, melatonin participates in numerous functions including the regulation of mood, sleep, reproduction, promotion of immunomodulation, antioxidant defense and as an anti-inflammatory agent. The anti-inflammatory activity of melatonin could yield beneficial effects on intake, particularly against the chronic inflammation which underlies many chronic diseases. This review aims to provide an assessment of the literature data on the anti-inflammatory activity of melatonin, with a particular focus on the mechanisms responsible for this behavior. We can conclude that many in vitro studies and in vivo studies in experimental animal model systems show that melatonin exerts anti-inflammatory activity in a number of chronic diseases which affect different organs in different circumstances. Clinical trials, however, often fail to reach positive results and are thus far inconclusive. Thus, in the future, long-term well-designed investigations on melatonin-rich foods or melatonin food supplements could provide valuable information towards public health recommendations on melatonin, taking into account both the nature of the compound and the optimal dose, for protection from long-term inflammation linked to chronic diseases.
The role of the diet as well as the impact of the dietary habits on human health and disease is well established. Apart from its sleep regulatory effect, the indoleamine melatonin is a well-established antioxidant molecule with multiple health benefits. Convincing evidence supports the presence of melatonin in plants and foods with the intake of such foods affecting circulating melatonin levels in humans. While numerous actions of both endogenous melatonin and melatonin supplementation are well described, little is known about the influence of the dietary melatonin intake on human health. In the present review, evidence for the cardiovascular health benefits of melatonin supplementation and the dietary melatonin is discussed. Current knowledge on the biological significance as well as the underlying physiological mechanism of action of the dietary melatonin is also summarized. Whether dietary melatonin constitutes an alternative preventive treatment for cardiovascular disease is addressed.
The main objective of this chapter is to provide information on a substance that has revolutionized studies in various scientific fields and is expected to have a great impact on the study of natural substances with nutraceutical properties. Phyto-melatonin (plant melatonin) is chemically related to amino acids but with very diverse properties. The interest in phyto-melatonin is due to its outstanding action at cellular and physiological level, while its plant origin offers many opportunities because it is a natural compound. An overview on its origin, its action in plants in general and in particular plant species with high levels of phytomelatonin, and its use as a nutraceutical, is present. The beneficial effects that it may have on human health are also analyzed. The differences between synthetic melatonin and phyto-melatonin, according to their origin and purity, will be presented. Finally, a brief discussion on the current market for phyto-melatonin and its limits and possibilities is presented.
Nowadays, depending on the progress of science and technology, our eating habits have changed. The shape and quality of nutrition is important for human health. Especially, some food components have various effect on central nervous system such as depression, anxiety, sleep, appetite. Food constituents are transported into the central nervous system via the neutral amino acids such as phenylalanine, leucine, isoleucine, tyrosine and valine. Amino acids have an important role in human nutrition. It cannot be synthesized in the body and one of the essential amino acids that must be taken outside, trytophan, is indispensable in human nutrition because of it has the many functions. In recent years, scientific community concentrated on the various functions of L-Trytophan (L-Trp) as pioneer in the secretion of the hormones serotonin and melatoninin in the human body. The hormones serotonin and melatonin is responsible for activities such as psychology, sleep, body temperature, blood pressure balance, antioxidant effect, cancer inhibitor, sexuality, autism and circadian rhythms in human body that they are available in various foods such as milk, kefir, yogurt, orange, strawberry, grape, olive oil, walnut, prune, nut, pomegranate, coffee, kiwi and banana. In this study, L-Trp, serotonin and melatonin biosynthesis and metabolism, food profiles and in terms of their physiological and biological effects on human health has been compiled.
Melatonin, known as a powerful wide-spectrum antioxidant, is consumed as a food supplement in some countries, but its applicability as an antioxidant additive was not yet studied. Therefore, we evaluated the antioxidant activity of melatonin by DPPH, ABTS, FRAP and ORAC assays as well as its ability to inhibit perilla oil oxidation. The activities of four other related indoles were also compared. Melatonin showed the highest antioxidant activity (mmol trolox equivalent per mol indole, mmol TE) in ORAC (2,159) assay, but a low antioxidant activity in DPPH (0.63), ABTS (91), and FRAP (764) assays, whereas serotonin showed an opposite result. Addition of 1% (w/w) melatonin to perilla oil extended the induction period of oxidation up to about 2 times (2.93?0.47h) compared to that of control (1.43?0.26h) in the Rancimat assay, corresponding to almost 50% of the ability of butylated hydroxyl toluene (BHT). Tryptamine was the most effective indole that inhibited perilla oil oxidation ().
Melatonin (MEL) is a natural powerful antioxidant that may provide beneficial human health effects. Given that MEL is absorbed when melatonin-containing foods are eaten, the intake of these foods could maintain plasma melatonin concentration, which diminishes with age. Fermentation increases the MEL levels in foods and is considered a promising technological process by different sectors (consumers, industry, etc.). The formation of MEL and its isomers (IMs) occurs during controlled alcoholic fermentation of different foods. This is due to the action of microorganisms (yeasts and bacteria) and environmental stressors as elevated alcohol levels or lactic-acid production may naturally increase in these bioactive compounds. The possible enhancement of MEL and IMs in the fermented foods could improve their health benefits by increasing their blood levels in humans, thereby improving antioxidative defense mechanisms.
Once thought to be exclusively a molecule of the animal kingdom, melatonin has now been found to exist in plants as well. Among a number of actions, melatonin is a direct free radical scavenger and an indirect antioxidant. Melatonin directly detoxifies the hydroxyl radical (*OH), hydrogen peroxide, nitric oxide, peroxynitrite anion, peroxynitrous acid, and hypochlorous acid. The products from each of these reactions have been identified in pure chemical systems and in at least one case in vivo; the interaction product of melatonin with the OH, i.e., cyclic 3-hydroxymelatonin, is found in the urine of humans and rats. Some of the products that are produced when melatonin detoxifies reactive species are also highly efficient scavengers. As a result, a cascade of scavenging reactions may enhance the antioxidant capacity of melatonin. Additionally, melatonin increases the activity of several antioxidative enzymes, thereby improving its ability to protect macromolecules from oxidative stress. Melatonin is endogenously produced and is also consumed in edible plants. In animal experiments, feeding melatonin-containing foods raised blood levels of the indole. Because physiologic concentrations of melatonin in the blood are known to correlate with the total antioxidant capacity of the serum, consuming foodstuffs containing melatonin may be helpful in lowering oxidative stress.
Twenty-four edible plants were investigated for the presence of melatonin, heretofore considered to be a molecule found only in the animal kingdom. The amount of melatonin in different plants varied greatly with highest melatonin being present in plants of the rice family. Melatonin was identified by radioimmunoassay and verified by high performance liquid chromatography with fluorescence detection. Feeding a diet containing plant products rich in melatonin to chicks increased radioimmunoassayable levels of melatonin in their blood. Likewise, melatonin extracted from plants inhibited binding of [125I]iodomelatonin to rabbit brain. Thus, melatonin ingested in foodstuffs enters the blood and is capable of binding to melatonin binding sites in the brain of mammals.
Interest in the health-promoting effects of virgin olive oil, an important part of the "Mediterranean diet", prompted us to determine the antiinflammatory effects of erythrodiol, beta-sitosterol and squalene, identified as major components of the so-called "unsaponifiable fraction" of virgin olive oil, as well as of the phenolic compounds from the "polar fraction": oleuropein, tyrosol, hydroxytyrosol and caffeic acid. Their activities were compared to those of both, total unsaponifiable and polar fractions. This study was designed to analyse the antiinflammatory effect of these specific compounds from virgin olive oil on edema in mice induced by either arachidonic acid (AA) or 12-O-tetradecanoylphorbol acetate (TPA). The inhibition of the myeloperoxidase (MPO), marker enzyme of the accumulation of neutrophils in the inflamed tissue, was also investigated by the TPA model. The topical application of the olive oil compounds (0.5 mg/ear) produced a variable degree of antiinflammatory effect with both assays. In the auricular edema induced by TPA, beta-sitosterol and erythrodiol from the unsaponifiable fraction of the oil showed a potent antiedematous effect with a 61.4% and 82.1% of inhibition respectively, values not very different to that of the reference indomethacin (85.6%) at 0.5 mg/ear. The four phenolics exerted a similar range of inhibition (33-45%). All compounds strongly inhibited the enzyme myeloperoxidase, indicating a reduction of the neutrophil influx in the inflamed tissues. The strongest inhibitor of AA edema was the total unsaponifiable fraction which inhibition was 34%, similar to that obtained by the reference drug dexamethasone at 0.05 mg/ear. Among the phenolics, oleuropein also produced an inhibition of about 30% with the same dose, but all the other components were found less active in this assay. The anti-inflammatory effects exerted by both unsaponifiable and polar compounds might contribute to the potential biological properties reported for virgin olive oil against different pathological processes.
A Mediterranean diet quality index (MDQI) was devised to give an overall assessment of dietary habits and to identify groups at risk.
The MDQI was based on scores given for selected levels of consumption of selected nutrients and foods.
Mediterranean southern France.
The sample included 473 men and 491 women in three age classes recruited at random.
Only 9.5% of men, 9.0% of women, 4.7% of 20-34 year old subjects, 6.6% of 35-54 year old subjects and 14.0% of 55-76 year old subjects were shown to have a healthy diet. However, 10.1% of men, 8.6% of women, 19.4% of 20-34 year old subjects, 10.2% of 35-54 year old subjects and 4.6% of 55-76 year old subjects were shown to have a poor diet. There were significantly fewer smokers among subjects with a good diet but the distribution of moderate wine drinkers was comparable between those with a good diet and those with a poor diet. Correspondence analysis associated a healthy diet with 55-76 year old men and women living in rural areas, who had received primary schooling only and who were manual workers. Both men and women with a poor MDQI score tended to be young and smokers. In addition, women with a poor MDQI tended to be heavy drinkers and obese.
This study showed that the Mediterranean model, which is generally recognized as a healthy diet, appears restricted to older people and to rural areas, whereas urbanized young people depart from it. A nutritional prevention policy targeted at young adults is required to encourage them to adhere to the Mediterranean model. Smoking and drinking showed different distribution patterns in the sample under study.
The term "Mediterranean diet," implying that all Mediterranean people have the same diet, is a misnomer. The countries around the Mediterranean basin have different diets, religions and cultures. Their diets differ in the amount of total fat, olive oil, type of meat and wine intake; milk vs. cheese; fruits and vegetables; and the rates of coronary heart disease and cancer, with the lower death rates and longer life expectancy occurring in Greece. Extensive studies on the traditional diet of Greece (the diet before 1960) indicate that the dietary pattern of Greeks consists of a high intake of fruits, vegetables (particularly wild plants), nuts and cereals mostly in the form of sourdough bread rather than pasta; more olive oil and olives; less milk but more cheese; more fish; less meat; and moderate amounts of wine, more so than other Mediterranean countries. Analyses of the dietary pattern of the diet of Crete shows a number of protective substances, such as selenium, glutathione, a balanced ratio of (n-6):(n-3) essential fatty acids (EFA), high amounts of fiber, antioxidants (especially resveratrol from wine and polyphenols from olive oil), vitamins E and C, some of which have been shown to be associated with lower risk of cancer, including cancer of the breast. These findings should serve as a strong incentive for the initiation of intervention trials that will test the effect of specific dietary patterns in the prevention and management of patients with cancer.
The work presented here examines the possible effects of nutritional deficiencies on the characteristics of the plasma transport protein for vitamin D and its metabolites (vitamin D binding protein, DBP) in the growing rat. Deficiencies in both dietary protein intake and dietary energy intake may decrease the concentration of DBP in the circulation, although plasma DBP was not affected by dietary Ca deficiency. None of the dietary factors examined appears to influence the affinity of DBP for its major ligand, 25-hydroxycholecalciferol (25(OH)D(3)). Protein-deficient rats seemed to have difficulty in maintaining adequate concentrations of 1,25-dihydroxycholecalciferol (1,25(OH)(2)D(3)) in the circulation. The sensitivity of DBP to dietary protein and energy intake may constitute a novel mechanism that may help to explain the observed associations between malnutrition and the development of metabolic bone disease, through alterations to the cellular availability of vitamin D ligands to DBP.
Melatonin (N-acetyl-5-methoxi-tryptamine), a well-known animal hormone synthetised by the pineal gland, plays a key role in the circadian rhythm of vertebrates. An exhaustive bibliographical revision of studies on melatonin in plants published since 1990 points to very few studies (around 20), of which only 8 have a clear plant physiological focus. The data presented in this study demonstrate that melatonin plays a physiological role in plant tissues. Melatonin is seen to be a molecule that promotes vegetative growth in etiolated Lupinus albus L. hypocotyls, in a similar way to IAA. The measurements of melatonin and IAA in lupin hypocotyls by high-performance liquid chromatography with electrochemical detection, and their identification by tandem mass spectrometry, point to a different distribution of these molecules in etiolated hypocotyls.
Epidemiological studies show that populations consuming a predominantly plant-based Mediterranean-style diet exhibit lower incidences of chronic diseases than those eating a northern European or North American diet. This observation has been attributed to the greater consumption of fruits and vegetables and the lower consumption of animal products, particularly fat. Although total fat intake in Mediterranean populations can be higher than in other regions (ca. 40% of calories), the greater proportion is derived from olive oil and not animals. Increased olive oil consumption is implicated in a reduction in cardiovascular disease, rheumatoid arthritis, and, to a lesser extent, a variety of cancers. Olive oil intake also has been shown to modulate immune function, particularly the inflammatory processes associated with the immune system. Olive oil is a nonoxidative dietary component, and the attenuation of the inflammatory process it elicits could explain its beneficial effects on disease risk since oxidative and inflammatory stresses appear to be underlying factors in the etiology of these diseases in man. The antioxidant effects of olive oil are probably due to a combination of its high oleic acid content (low oxidation potential compared with linoleic acid) and its content of a variety of plant antioxidants, particularly oleuropein, hydroxytyrosol, and tyrosol. It is also possible that the high oleic acid content and a proportionate reduction in linoleic acid intake would allow a greater conversion of alpha-linolenic acid (18:3n-3) to longer-chain n-3 PUFA, which have characteristic health benefits. Adoption of a Mediterranean diet could confer health benefits in high-risk populations.
The endothelium is involved in many of the processes related to the development of atherosclerosis, which is considered an inflammatory disease. Actually, traditional risk factors for atherosclerosis predispose to endothelial dysfunction, which is manifested as an increase in the expression of specific cytokines and adhesion molecules. There are firm evidence supporting the beneficial effects of olive oil, the most genuine component of the Mediterranean diet. Although the effects of olive oil and other oleic acid-rich dietary oils on atherosclerosis and plasma lipids are well known, the roles of minor components have been less investigated. Minor components constitute only 1-2% of virgin olive oil (VOO) and are composed of hydrocarbons, polyphenols, tocopherols, sterols, triterpenoids and other components usually found in traces. Despite their low concentration, non-fatty acid constituents may be of importance because studies comparing monounsaturated dietary oils have reported different effects on cardiovascular disease. Most of these compounds have demonstrated antioxidant, anti-inflammatory and hypolipidemic properties. In this review, we summarize current knowledge on the effects of these compounds contained in VOO on vascular dysfunction and the mechanisms by which they modulate endothelial activity. Such mechanisms involve the release of nitric oxide, eicosanoids (prostaglandins and leukotrienes) and adhesion molecules, in most cases by activation of nuclear factor kappaB by reactive oxygen species.
To fulfil a comprehensive approach to consumption, which is necessary to characterise food habits and their relationship to diseases, using a diet quality index (DQI) developed for a Mediterranean region (Med-DQI).
A cross-sectional nutritional survey provided the data for the construction of the DQI.Subjects: A representative sample made up of 964 subjects from a French Mediterranean area, Hérault département.
Foods such as olive oil, fish and cereals were used instead of nutrients to build up scores which constructed the Med-DQI. Biochemical analysis identified biomarkers used to validate the Med-DQI. Correspondence factorial analysis illustrated the characteristics of subjects with different scores given by the Med-DQI.
The subjects could be satisfactorily classified by the Med-DQI. The oldest age, less educated, overweight, manual workers, living in a rural area and male classes showed a better Med-DQI. For women, they were also from the oldest age class, but some of them were from the upper social class, with an ideal BMI and lived by the Mediterranean shore. A composite biomarker index, based on plasma carotene and vitamin E levels and the percentage of EPA and DHA in erythrocytes membranes, can identify subjects with good and poor Med-DQI.
Med-DQI G is a good instrument to identify groups at risk with regard to nutritional quality. Subjects with alpha + beta-carotene levels >1 mg/l, vitamin E > 30 mg/l, EPA > 0.65% and DHA > 4% of fatty acids in erythrocytes are likely to have a good diet.
To put the debate on the Mediterranean diet in context by highlighting historical and prospective changes in the level and composition of food consumption in the world and key Mediterranean countries.
Data from FAO's food balance sheets are used to illustrate historical evolution. Projections to 2030 are presented from FAO's recent and ongoing work on exploring world food and agriculture futures.
International.
Many developing countries are undergoing diet transitions bringing them closer to the diets prevalent in the richer countries, i.e. with more energy-dense foods. There follows an increase in the incidence of diet-related non-communicable diseases, which are superimposed on the health problems related to undernutrition that still afflict them. In parallel, many low-income countries are making little progress towards raising food consumption levels necessary for good nutrition and food security. Wider adoption of food consumption patterns akin to those of the Mediterranean diet hold promise of contributing to mitigate adverse effects of such diet transitions. However, the evolution of food consumption in the Mediterranean countries themselves is not encouraging, as these countries have also followed the trend towards higher shares of energy-dense foods. Possible policy responses to these problems include measures to raise awareness of the benefits of healthier diets and/or to change relative food prices in favour of such diets (by taxing fattening foods) or, at the extreme, making individuals who follow 'bad' diets, and thus are prone to associated diseases, bear a higher part of the consequent costs borne by the public health systems (tax fat people).
Afterhe successful discovery of the melatonin molecule by Aaron B Lerner et al at Yale University in 1958, melatonin and the pineal gland, a tiny endocrine gland situated at the center of the human brain, have primarily been considered in terms of their effects on the endocrine and reproductive systems. During the last decade, a substantial body of research has defined melatonin as a remarkable molecule with pleiotropic effects on the immune system. Moreover, its synthesis cannot be considered as exclusively endocrine; key immunocompetent cells have the functional enzymatic machinery for melatonin synthesis, paving the wayfo r complex intracrine, autocrine and paracrine regulatory loops. The immunomodulatory role of melatonin, with regard to infection, inflammation and autoimmunity, is outlined here, and the evidence discussed in this review strengthens the notion that the nature of an immune response may be modified, and therefore therapeutically manipulated, by circadian effector signals.
Melatonin is a ubiquitous molecule and widely distributed in nature, with functional activity occurring in unicellular organisms, plants, fungi and animals. In most vertebrates, including humans, melatonin is synthesized primarily in the pineal gland and is regulated by the environmental light/dark cycle via the suprachiasmatic nucleus. Pinealocytes function as 'neuroendocrine transducers' to secrete melatonin during the dark phase of the light/dark cycle and, consequently, melatonin is often called the 'hormone of darkness'. Melatonin is principally secreted at night and is centrally involved in sleep regulation, as well as in a number of other cyclical bodily activities. Melatonin is exclusively involved in signaling the 'time of day' and 'time of year' (hence considered to help both clock and calendar functions) to all tissues and is thus considered to be the body's chronological pacemaker or 'Zeitgeber'. Synthesis of melatonin also occurs in other areas of the body, including the retina, the gastrointestinal tract, skin, bone marrow and in lymphocytes, from which it may influence other physiological functions through paracrine signaling. Melatonin has also been extracted from the seeds and leaves of a number of plants and its concentration in some of this material is several orders of magnitude higher than its night-time plasma value in humans. Melatonin participates in diverse physiological functions. In addition to its timekeeping functions, melatonin is an effective antioxidant which scavenges free radicals and up-regulates several antioxidant enzymes. It also has a strong antiapoptotic signaling function, an effect which it exerts even during ischemia. Melatonin's cytoprotective properties have practical implications in the treatment of neurodegenerative diseases. Melatonin also has immune-enhancing and oncostatic properties. Its 'chronobiotic' properties have been shown to have value in treating various circadian rhythm sleep disorders, such as jet lag or shift-work sleep disorder. Melatonin acting as an 'internal sleep facilitator' promotes sleep, and melatonin's sleep-facilitating properties have been found to be useful for treating insomnia symptoms in elderly and depressive patients. A recently introduced melatonin analog, agomelatine, is also efficient for the treatment of major depressive disorder and bipolar affective disorder. Melatonin's role as a 'photoperiodic molecule' in seasonal reproduction has been established in photoperiodic species, although its regulatory influence in humans remains under investigation. Taken together, this evidence implicates melatonin in a broad range of effects with a significant regulatory influence over many of the body's physiological functions.
Epidemiological studies have consistently shown that regular consumption of fruits and vegetables is strongly associated with reduced risk of developing chronic diseases, such as cancer and cardiovascular disease. It is now widely believed that the actions of the antioxidant nutrients alone do not explain the observed health benefits of diets rich in fruits and vegetables, because taken alone, the individual antioxidants studied in clinical trials do not appear to have consistent preventive effects. Work performed by our group and others has shown that fruits and vegetable phytochemical extracts exhibit strong antioxidant and anti proliferative activities and that the major part of total antioxidant activity is from the combination of phytochemicals. We proposed that the additive and synergistic effects of phytochemicals in fruits and vegetables are responsible for these potent antioxidant and anticancer activities and that the benefit of a diet rich in fruits and vegetables is attributed to the complex mixture of phytochemicals present in whole foods. This explains why no single antioxidant can replace the combination of natural phytochemicals in fruits and vegetables to achieve the health benefits. The evidence suggests that antioxidants or bioactive compounds are best acquired through whole-food consumption, not from expensive dietary supplements. We believe that a recommendation that consumers eat 5 to 10 servings of a wide variety of fruits and vegetables daily is an appropriate strategy for significantly reducing the risk of chronic diseases and to meet their nutrient requirements for optimum health.
Objective
The olive oil-rich Mediterranean diet protects against cardiovascular disease, which involves inflammatory processes. This study investigated the effects of phenolic compounds found in extra virgin olive oil on inflammatory mediator production by human mononuclear cells.
Methods
Diluted human blood cultures were stimulated with lipopolysaccharide in the presence of phenolics (vanillic, p-coumaric, syringic, homovanillic and caffeic acids, kaempferol, oleuropein glycoside, and tyrosol) at concentrations of 10−7 to 10−4 M. Concentrations of the inflammatory cytokines tumor necrosis factor-α, interleukin-1β, and interleukin-6 and of the inflammatory eicosanoid prostaglandin E2 were measured by enzyme-linked immunosorbent assay.
Results
Oleuropein glycoside and caffeic acid decreased the concentration of interleukin-1β. At a concentration of 10−4 M, oleuropein glycoside inhibited interleukin-1β production by 80%, whereas caffeic acid inhibited production by 40%. Kaempferol decreased the concentration of prostaglandin E2. At a concentration of 10−4 M, kaempferol inhibited prostaglandin E2 production by 95%. No effects were seen on concentrations of interleukin-6 or tumor necrosis factor-α and there were no effects of the other phenolic compounds.
Conclusions
Some, but not all, phenolic compounds derived from extra virgin olive oil decrease inflammatory mediator production by human whole blood cultures. This may contribute to the antiatherogenic properties ascribed to extra virgin olive oil.
Melatonin, a molecule with antioxidant properties that is widely distributed in the animal kingdom, has now been shown to exist in the plant kingdom, including edible plants. Our findings show that melatonin is not only an endogenously produced antioxidant, but that it is also consumed in the diet. Since melatonin concentrations in the blood correlate with the total antioxidant status of this fluid, it is likely that dietary melatonin could be important in protecting against oxidative damage.
The seeds of plants represent the anlage of the next generation and are vital to their existence. Melatonin has been identified in the leaves and flowers of plants but not in seeds. In this study, we examined the seeds of 15 edible plants for the presence of melatonin which was extracted using cold ethanol. Melatonin was initially identified by radioimmunoassay and subsequently quantified and confirmed using high performance liquid chromatography. The physiological concentrations of melatonin in the 15 seeds studied ranged from 2 to 200 ng/g dry weight. The highest concentrations of melatonin were observed in white and black mustard seeds. This level of melatonin is much higher than the known physiological concentrations in the blood of many vertebrates. Since the seed, particularly its germ tissue, is highly vulnerable to oxidative stress and damage, we surmise that melatonin, a free radical scavenger, might be present as an important component of its antioxidant defense system. Thus, melatonin in seeds may be essential in protecting germ and reproductive tissues of plants from oxidative damage due to ultraviolet light, drought, extremes in temperature, and environmental chemical pollutants.
Melatonin, a molecule with antioxidant properties that is widely distributed in the animal kingdom, has now been shown to exist in the plant kingdom, including edible plants. Our findings show that melatonin is not only an endogenously produced antioxidant, but that it is also consumed in the diet. Since melatonin concentrations in the blood correlate with the total antioxidant status of this fluid, it is likely that dietary melatonin could be important in protecting against oxidative damage.
Olive oil is an integral ingredient of the Mediterranean diet and accumulating evidence suggests that it may have health benefits that include reduction of risk factors of coronary heart disease, prevention of several varieties of cancers, and modification of immune and inflammatory responses. Olive oil appears to be an example of a functional food, with varied components that may contribute to its overall therapeutic characteristics. Olive oil is known for its high levels of monounsaturated fatty acids and is also a good source of phytochemicals including polyphenolic compounds, squalene, and alpha-tocopherol.
In the context of this presentation, European means the European scientific community, which, over the last decade, has been working on the concepts for functional foods, producing a number of documents including a consensus paper, guidelines and scientific publications. The Functional Food Science in Europe (FUFOSE) project has been quite a unique attempt to establish a strong scientific framework to justify the functional food concept, to discover and develop new functional foods that are primarily function-driven, and to substantiate claims scientifically. Being clearly positioned as part of nutrition, the functional food concept is, however, quite distinct from other approaches like food supplementation or food fortification, and functional foods are different from nutraceuticals, pharmafoods, vitafoods and ‘alicaments’, all terms that are not defined conceptually. Functional foods are food products to be taken as part of the usual diet in order to have beneficial effects that go beyond what are known as traditional nutritional effects. Moreover, these beneficial effects have to be demonstrated scientifically to justify two specific types of claim: the enhanced function claim or the reduction of disease risk claim.
Functional food is a key concept for the future of nutrition as a science because it results from the implementation in nutrition of all the basic scientific knowledge that has accumulated over the past two or three decades. To the benefit of public health this progress cannot be ignored, it needs to be recognized fully and used. But, today, functional food is still mainly a scientific concept that serves to stimulate research and the development of new products.
Melatonin is a highly conserved molecule that not only exists in animals, but also is present in bacteria, unicellular organisms and in plants. Since melatonin is an antioxidant, in plants melatonin was speculated to protect them from intrinsic and environmental oxidative stress. More importantly, melatonin in edible plants inevitably enters animals and human through feed and food. In this study, more than 100 Chinese medicinal herbs were analyzed using the methods of solid phase extraction and HPLC-FD on-line with MS to determine whether melatonin is present in these commonly used herbs. Melatonin was detected in majority of these plants. Sixty-four of them contain melatonin in excess of 10 ng per gram dry mass. Melatonin levels in several herbs are in excess of 1000 ng/g. It is well known that normal average physiological plasma levels of melatonin are only 10-60 pg/mL. These high level-melatonin containing plants are traditionally used to treat diseases which presumably involve free radical damage. The current study provides new information concerning one potentially effective constituent present in a large number of medicinal herbs. The results suggest that these herbs should be reevaluated in reference to their nutritional and medicinal value.
This chapter reviews the neural connections between the retinas and the pineal gland and summarizes the role of the light:dark cycle and the biological clock, i.e. the suprachiasmatic nuclei, in regulating pineal melatonin synthesis and secretion. The cellular mechanisms governing the nocturnal production of melatonin are described together with the way in which the misuse of light interferes with the circadian melatonin cycle and the total quantity of the indole generated. The chapter describes the nature of the membrane melatonin receptors and their signal transduction mechanisms in peripheral organs. The clinical implications and potential uses of melatonin in terms of influencing the biological clock (e.g. sleep and jet lag), immune function, and cancer initiation and growth are noted. Additionally, the chapter includes a description of the newly discovered free radical scavenging and antioxidant activities of melatonin; it also includes a list of clinical situations in which melatonin has been used with beneficial effects.
Evidence is synthesized that foods and food patterns act synergistically to influence the risk of several chronic diseases. Whole-grain consumption and risk of disease are presented as a model of food synergy. Food synergy is defined as additive or more than additive influences of foods and food constituents on health. Risk appears to be lower with consumption of whole grain than of refined grain; that is, benefit accrues when all edible parts of the grain are included (bran, germ, and endosperm). It appears that phytochemicals that are located in the fiber matrix, in addition to or instead of the fiber itself, are responsible for the reduced risk. Risk is further reduced if whole-grain foods are consumed in a diet otherwise high in plant foods. To gain full understanding of the pathways by which food synergies work, it is desirable to use several "top down" approaches, starting with the larger units, namely foods or food patterns, and working down to smaller units that provide protection from disease. Study of foods, food patterns, and individual nutrients or food components in reducing disease risk is seen as complementary. Epidemiologic, clinical trial, and in vitro approaches to such research are needed.
Epidemiological studies have consistently shown that regular consumption of fruits and vegetables is strongly associated with reduced risk of developing chronic diseases, such as cancer and cardiovascular disease. It is now widely believed that the actions of the antioxidant nutrients alone do not explain the observed health benefits of diets rich in fruits and vegetables, because taken alone, the individual antioxidants studied in clinical trials do not appear to have consistent preventive effects. Work performed by our group and others has shown that fruits and vegetable phytochemical extracts exhibit strong antioxidant and antiproliferative activities and that the major part of total antioxidant activity is from the combination of phytochemicals. We proposed that the additive and synergistic effects of phytochemicals in fruits and vegetables are responsible for these potent antioxidant and anticancer activities and that the benefit of a diet rich in fruits and vegetables is attributed to the complex mixture of phytochemicals present in whole foods. This explains why no single antioxidant can replace the combination of natural phytochemicals in fruits and vegetables to achieve the health benefits. The evidence suggests that antioxidants or bioactive compounds are best acquired through whole-food consumption, not from expensive dietary supplements. We believe that a recommendation that consumers eat 5 to 10 servings of a wide variety of fruits and vegetables daily is an appropriate strategy for significantly reducing the risk of chronic diseases and to meet their nutrient requirements for optimum health.
The olive oil-rich Mediterranean diet protects against cardiovascular disease, which involves inflammatory processes. This study investigated the effects of phenolic compounds found in extra virgin olive oil on inflammatory mediator production by human mononuclear cells.
Diluted human blood cultures were stimulated with lipopolysaccharide in the presence of phenolics (vanillic, p-coumaric, syringic, homovanillic and caffeic acids, kaempferol, oleuropein glycoside, and tyrosol) at concentrations of 10(-7) to 10(-4) M. Concentrations of the inflammatory cytokines tumor necrosis factor-alpha, interleukin-1beta, and interleukin-6 and of the inflammatory eicosanoid prostaglandin E2 were measured by enzyme-linked immunosorbent assay.
Oleuropein glycoside and caffeic acid decreased the concentration of interleukin-1beta. At a concentration of 10(-4) M, oleuropein glycoside inhibited interleukin-1beta production by 80%, whereas caffeic acid inhibited production by 40%. Kaempferol decreased the concentration of prostaglandin E2. At a concentration of 10(-4) M, kaempferol inhibited prostaglandin E2 production by 95%. No effects were seen on concentrations of interleukin-6 or tumor necrosis factor-alpha and there were no effects of the other phenolic compounds.
Some, but not all, phenolic compounds derived from extra virgin olive oil decrease inflammatory mediator production by human whole blood cultures. This may contribute to the antiatherogenic properties ascribed to extra virgin olive oil.
Melatonin is present in plants consumed as vegetables; however, only a limited number of vegetables have been tested for melatonin. The antiproliferative, antioxidative, and immunostimulatory effects of melatonin have been reported from laboratory studies. The potential protective effects of vegetable against cancer and cardiovascular disease may be partially attributable to an increased melatonin intake from vegetables. As a first step to test this hypothesis, we evaluated whether vegetable intake is associated with an increased urinary melatonin in 289 community-dwelling Japanese women. Diet, including vegetable consumption, was assessed with a validated 169-item semiquantitative food-frequency questionnaire. Urinary 6-sulfatoxymelatonin (aMT6-s) was measured in the first-void morning urines. There was a significant positive association between vegetable intake and urinary aMT6-s levels. The mean urinary aMT6-s was 16% higher in women with the highest quartile of vegetable intake than it was in those with the lowest quartile of intake. This association may be explained by the melatonin contained in vegetables. However, data should be regarded as preliminary because it is impossible to estimate dietary melatonin intake from vegetables and or from the entire diet because of incomplete data for melatonin in plants.
We investigated whether melatonin is present in walnuts (Juglans regia L.) and, if so, tested whether eating walnuts influences melatonin levels and the total antioxidant status of the blood.
Melatonin was extracted from walnuts and quantified by high-performance liquid chromatography. After feeding walnuts to rats, serum melatonin concentrations were measured using a radioimmunoassay and the "total antioxidant power" of the serum was estimated by using the trolox equivalent antioxidant capacity and ferric-reducing ability of serum methods.
Mean +/- standard error melatonin concentrations were 3.5 +/- 1.0 ng/g of walnut. After food restriction of rats and then feeding them regular chow or walnuts, blood melatonin concentrations in the animals that ate walnuts were increased over those in the rats fed the control diet. Increases in blood melatonin were also accompanied by increases in trolox equivalent antioxidant capacity and ferric-reducing ability of serum values.
Melatonin is present in walnuts and, when eaten, increase blood melatonin concentrations. The increase in blood melatonin levels correlates with an increased antioxidative capacity of this fluid as reflected by augmentation of trolox equivalent antioxidant capacity and ferric-reducing ability of serum values.
1. Ageing represents a great concern in developed countries because the number of people involved and the pathologies related with it, like atherosclerosis, morbus Parkinson, Alzheimer's disease, vascular dementia, cognitive decline, diabetes and cancer. 2. Epidemiological studies suggest that a Mediterranean diet (which is rich in virgin olive oil) decreases the risk of cardiovascular disease. 3. The Mediterranean diet, rich in virgin olive oil, improves the major risk factors for cardiovascular disease, such as the lipoprotein profile, blood pressure, glucose metabolism and antithrombotic profile. Endothelial function, inflammation and oxidative stress are also positively modulated. Some of these effects are attributed to minor components of virgin olive oil. Therefore, the definition of the Mediterranean diet should include virgin olive oil. 4. Different observational studies conducted in humans have shown that the intake of monounsaturated fat may be protective against age-related cognitive decline and Alzheimer's disease. 5. Microconstituents from virgin olive oil are bioavailable in humans and have shown antioxidant properties and capacity to improve endothelial function. Furthermore they are also able to modify the haemostasis, showing antithrombotic properties. 6. In countries where the populations fulfilled a typical Mediterranean diet, such as Spain, Greece and Italy, where virgin olive oil is the principal source of fat, cancer incidence rates are lower than in northern European countries. 7. The protective effect of virgin olive oil can be most important in the first decades of life, which suggests that the dietetic benefit of virgin olive oil intake should be initiated before puberty, and maintained through life. 8. The more recent studies consistently support that the Mediterranean diet, based in virgin olive oil, is compatible with a healthier ageing and increased longevity. However, despite the significant advances of the recent years, the final proof about the specific mechanisms and contributing role of the different components of virgin olive oil to its beneficial effects requires further investigations.
In a recent study melatonin (N-acetyl-5-methoxytryptamine), a well-investigated animal molecule but minimally studied in plants, was seen to have a physiological role as growth-promoting molecule in lupin hypocotyls. In the present study, the role of melatonin as a growth promoter is extended to coleoptiles of canary grass, wheat, barley and oat, in which it shows a relative auxinic activity [with respect to indole-3-acetic acid (IAA), the main auxin in plants] of between 10 and 55%. In addition, melatonin is seen to have an important inhibitory growth effect on roots similar to that played by auxin. The quantitation by liquid chromatography with electrochemical detection and identification by tandem mass spectrometry of melatonin and IAA in etiolated coleoptiles of the monocots assayed showed that both compounds are present in similar levels in these tissues. These results point to the co-existence of auxin and melatonin in tissues and raises the possibility of their co-participation in some physiological actions as auxinic hormones in plants.
Diets that are high in fruits, vegetables, legumes, and whole grains and include fish, nuts, and low-fat dairy products have protective health effects. The traditional Mediterranean diet encompasses these dietary characteristics. Other compounds of the Mediterranean diet, the antioxidants, which exist in abundance in vegetables, fruit, beverages, and also virgin olive oil, may contribute to the prevention of coronary heart disease and possibly several forms of cancer and other diseases, thus providing a plausible explanation for its apparent benefits. It may be misleading to focus on a single element of the diet; this may explain, at least in part, the disappointing and frustrating results obtained in trials with vitamin supplementation, prematurely thought to be "the magic bullet" for preventing a myriad of chronic diseases. The results of intervention studies aimed at evaluating whether Mediterranean-type diets are superior to classic diets in the secondary prevention of coronary heart disease have all been encouraging. The biologic mechanisms by which these compounds might exert their effects include, among others, antioxidant functions and induction of detoxification enzymes. However, from a public health perspective it is not essential to wait for elucidation of every mechanism underlying health promotion activities and interventions; given the simplicity of the diet quality score, increasing the intake of recommended foods represents a practical recommendation for improving health.
High postprandial serum lipid concentrations are associated with increased oxidative stress which, in turn, increases the risk of atherosclerosis. Epidemiological studies correlate lower incidence of cardiovascular disease with adherence to the Mediterranean diet. The aim of this study was to evaluate changes in inflammatory (TXB(2) and LTB(4)) and oxidative stress markers (urinary hydrogen peroxide levels and serum antioxidant capacity), in addition to classic lipid parameters, after a fat-rich meal administered to 12 normolipemic, healthy subjects. Following a Latin square design, subjects were divided into three groups, each one receiving a different kind of oil (extra virgin olive oil; EVOO, olive oil; OO or corn oil; CO, together with 150g of potatoes), with 2-week washout periods between treatments. Blood samples were drawn at baseline and after 1, 2, and 6h after the meal. A significant decrease in inflammatory markers, namely TXB(2) and LTB(4), after 2 and 6h after EVOO (but not OO or CO) consumption and a concomitant increase of serum antioxidant capacity were recorded. These data reinforce the notion that the Mediterranean diet reduces the incidence of coronary heart disease partially due to the protective role of its phenolic components, including those of extra virgin olive oil.
The Mediterranean Diet has been associated with greater longevity and quality of life in epidemiological studies, the majority being observational. The application of evidence-based medicine to the area of public health nutrition involves the necessity of developing clinical trials and systematic reviews to develop sound recommendations. The purpose of this study was to analyze and review the experimental studies on Mediterranean diet and disease prevention. A systematic review was made and a total of 43 articles corresponding to 35 different experimental studies were selected. Results were analyzed for the effects of the Mediterranean diet on lipoproteins, endothelial resistance, diabetes and antioxidative capacity, cardiovascular diseases, arthritis, cancer, body composition, and psychological function. The Mediterranean diet showed favorable effects on lipoprotein levels, endothelium vasodilatation, insulin resistance, metabolic syndrome, antioxidant capacity, myocardial and cardiovascular mortality, and cancer incidence in obese patients and in those with previous myocardial infarction. Results disclose the mechanisms of the Mediterranean diet in disease prevention, particularly in cardiovascular disease secondary prevention, but also emphasize the need to undertake experimental research and systematic reviews in the areas of primary prevention of cardiovascular disease, hypertension, diabetes, obesity, infectious diseases, age-related cognitive impairment, and cancer, among others. Interventions should use food scores or patterns to ascertain adherence to the Mediterranean diet. Further experimental research is needed to corroborate the benefits of the Mediterranean diet and the underlying mechanisms, and in this sense the methodology of the ongoing PREDIMED study is explained.
Olive oil as a functional food: epidemiology and nutritional approaches Olive oil and modulation of cell signaling in disease prevention
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Purslane: a terrestrial source of omega-3 fatty acids
- A P Simopoulos
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Postprandial anti-inflammatory and antioxidant effects of extra virgin olive oil
- Bogani
The role of virgin olive oil components in the modulation of endothelial function
- Perona
Purslane: a terrestrial source of omega-3 fatty acids
- Simopoulos