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Frontiers in Nutrition 2020Interactions are occurring in the course of liberation, absorption, distribution, metabolism, and excretion of active ingredients, or at the target receptors. They are...
Interactions are occurring in the course of liberation, absorption, distribution, metabolism, and excretion of active ingredients, or at the target receptors. They are causing therapy failures and undesirable events. Forty-seven of fifty-seven human hepatic isoenzymes are specific and relevant in hormone and vitamin metabolism and biosynthesis. Aromatase (syn. CYP19A1) is one of the specific CYP450 isoenzymes so far not elucidated in detail. As aromatase-inhibiting phytochemicals are currently recommended for breast cancer prevention and as add-on accompanying aromatase-inhibitor pharmacotherapy, it was the aim of this literature review to assess whether a common interpretation on genetic and -omics basis could be found. Articles retrieved showed that traditional antioxidation diet is one of the most approved explanations of inhibition of aromatase by phytonutrients of flavonoid derivatives. Flavonoids compete for the oxygen provided by the heme moiety of aromatase in the course of aromatase-catalyzed conversion of steroid precursors to estrogens. Flavonoids are therefore promoted for breast cancer prevention. A further explanation of flavonoids' mechanism of action proposed was related to enzymatic histone deacetylation. By keeping DNA-structure wide through a high acetylation degree, acetylated histones favor transcription and replication. This mechanism corresponds to a procedure of switching genes on. Inhibiting acetylation and therefore switching genes off might be an important regulation of repressing cancer genes. Aromatase expression depends on the genotype and phenotype of a person. Aromatase itself depends on the expression of the heme moiety encoded in the genotype. Biosynthesis of porphyrins in turn depends on the substrates succinate and glycine, as well as on a series of further enzymes, with ALA synthetase as the rate-limiting step. The effect of the heme moiety as prosthetic group of aromatase further depends on the absorption of iron as a function of pH and redox state. To assess the function of aromatase precisely, multiple underlying biochemical pathways need to be evaluated. As a conclusion, the genetic regulation of metabolism is a complex procedure affecting multiple pathways. To understand a metabolic step, multiple underlying individually performing reactions need to be considered if personalized (nutritional) medicine should bring an advantage for a patient. Nutrition sciences need to consider the genome of an individual to truly find answers to nutrition-derived non-communicable diseases. With current GWAS (genome-wide association study) approaches, inherited errors of metabolism are identified and ideally treated effectively. It is much more difficult to get a precise genetic profile for non-communicable diseases stemming from multifactorial causes. Polygenic risks evaluation is feasible but diagnostic tools are not yet available in a desired extent. Neither flavonoid researchers nor providers of genetic testing kits are going into the details needed for a truly personalized nutritional medicine. The next step with profiling the exome and then the whole genome is on the threshold of becoming routine diagnosis and of bringing the desired details.
PubMed: 32328497
DOI: 10.3389/fnut.2020.00037 -
Phytomedicine : International Journal... Jul 2019Photoactivity, though known for centuries, is only recently shifting back into focus as a treatment option against cancer and microbial infections. The external factor...
BACKGROUND
Photoactivity, though known for centuries, is only recently shifting back into focus as a treatment option against cancer and microbial infections. The external factor light is the ingenious key-component of this therapy: Since light activates the drug locally, a high level of selectivity is reached and side effects are avoided. The first reported photoactive medicines were plant extracts. Synthetic entities (so-called photosensitizers PSs), however, paved the route towards the clinical approval of the so-called photodynamic therapy (PDT), and thus natural PSs took a backseat in the past.
HYPOTHESIS
Many isolated bioactive phytochemicals hold a hidden photoactive potential, which is overlooked due to the reduced common awareness of photoactivity.
METHODS
A systematic review of reported natural PSs and their supposed medicinal application was conducted by employing PubMed, Scifinder, and Web of Science. The identified photoactive natural products were compiled including information about their natural sources, their photoyield, and their pharmacological application. Furthermore, the common chemical scaffolds of natural PS are shown to enable the reader to recognize potentially overlooked natural PSs.
RESULTS
The literature review revealed over 100 natural PS, excluding porphyrins. The PSs were classified according to their scaffold. Thereby it was shown that some PS-scaffolds were analyzed in a detailed way, while other classes were only scarcely investigated, which leaves space for future discoveries. In addition, the literature revealed that many PSs are phytoalexins, thus the selection of the starting material significantly matters in order to find new PSs.
CONCLUSION
Photoactive principles are ubiquitous and can be found in various plant extracts. With the increasing availability of light-irradiation setups for the identification of photoactive natural products, we anticipate the discovery of many new natural PSs in the near future. With the accumulation of chemically diverse PSs, PDT itself might finally reach its clinical breakthrough as a promising alternative treatment against multi-resistant microbes and cancer types.
Topics: Biological Products; Humans; Neoplasms; Photochemotherapy; Photosensitizing Agents; Phytochemicals; Sesquiterpenes; Phytoalexins
PubMed: 31257117
DOI: 10.1016/j.phymed.2019.152985 -
Current Medicinal Chemistry 2019Traditionally, natural medicines have been administered as plant extracts, which are composed of a mixture of molecules. The individual molecular species in this mixture...
Traditionally, natural medicines have been administered as plant extracts, which are composed of a mixture of molecules. The individual molecular species in this mixture may or may not contribute to the overall medicinal effects and some may even oppose the beneficial activity of others. To better control therapeutic effects, studies that characterized specific molecules and describe their individual activity that have been performed over the past decades. These studies appear to underline that natural products are particularly effective as antioxidants and anti-inflammatory agents. In this systematic review we aimed to identify potent anti-inflammatory natural products and relate their efficacy to their chemical structure and physicochemical properties. To identify these compounds, we performed a comprehensive literature search to find those studies, in which a dose-response description and a positive control reference compound was used to benchmark the observed activity. Of the analyzed papers, 7% of initially selected studies met these requirements and were subjected to further analysis. This analysis revealed that most selected natural products indeed appeared to possess anti-inflammatory activities, in particular anti-oxidative properties. In addition, 14% of the natural products outperformed the remaining natural products in all tested assays and are attractive candidates as new anti-inflammatory agents.
Topics: Animals; Anti-Inflammatory Agents; Biological Products; Coumarins; Edema; Plants, Medicinal; Porphyrins; Structure-Activity Relationship
PubMed: 31119997
DOI: 10.2174/0929867325666190523123357 -
Nutrition Research (New York, N.Y.) Nov 2018Several epidemiological studies investigated the relationship between dietary intake of essential trace elements and the risk of esophageal cancer (EC), yielding... (Meta-Analysis)
Meta-Analysis
Several epidemiological studies investigated the relationship between dietary intake of essential trace elements and the risk of esophageal cancer (EC), yielding inconsistent results. We therefore conducted a systematic meta-analysis to investigate and quantify the putative association between the intake of various essential trace elements and the risk of EC. We searched Embase, PubMed, and Web of Science for eligible articles published through April 2018 reporting the odds ratio (OR) with 95% confidence interval (95% CI). Pooled results were then calculated using fixed and random effect models. A total of 20 articles containing 4855 cases from 1 387 482 participants were included in our analysis. We found a significant inverse correlation between total iron intake and the risk of EC (OR = 0.81, 95% CI: 0.70-0.94), particularly in Asian populations. A dose-response analysis revealed that each 5 mg/day increase in total iron intake was associated with a 15% reduction in EC risk (OR = 0.85, 95% CI: 0.79-0.92). In contrast, each 1 mg/day increase in heme iron intake was associated with a 21% increase in EC risk (OR = 1.21, 95% CI: 1.02-1.45). Lastly, a pooled risk estimate revealed that each 5 mg/day increase in zinc intake was associated with a 15% reduction in EC risk (OR = 0.85, 95% CI: 0.77-0.93). Taken together, our analysis indicates that increased dietary intake of total iron and zinc, as well as decreased heme iron intake, may be associated with a lower risk of developing esophageal cancer. These findings have important public health implications with respect to preventing this relatively common form of cancer.
Topics: Diet; Esophageal Neoplasms; Heme; Humans; Iron; Iron, Dietary; Risk Factors; Trace Elements; Zinc
PubMed: 30442229
DOI: 10.1016/j.nutres.2018.07.007 -
Photodermatology, Photoimmunology &... Jan 2020Erythropoietic protoporphyria (EPP) is a semi-dominantly inherited porphyria presenting with photosensitivity during early childhood. Acquired EPP has been reported;...
BACKGROUND
Erythropoietic protoporphyria (EPP) is a semi-dominantly inherited porphyria presenting with photosensitivity during early childhood. Acquired EPP has been reported; however, data regarding this rare disorder are scarce.
PURPOSE
To evaluate the characteristics of acquired EPP.
METHODS
A comprehensive search of PubMed, Google Scholar, ScienceDirect, and clinicaltrials.gov databases was performed by three reviewers. Studies describing patients with acquired EPP were included. Additionally, we present an index case of a 26-year-old patient who acquired clinically and biochemically typical EPP in association with myelodysplastic syndrome (MDS).
RESULTS
We included 20 case reports describing 20 patients. Most (80%) patients were male of mean age 58 ± 13 years. In all patients, acquired EPP was associated with hematological disease, most commonly MDS (85%) followed by myeloproliferative disease (10%). In 86% of cases, hematological disease led to abnormality or somatic mutation in chromosome 18q (the locus of the ferrochelatase gene). The mean erythrocyte protoporphyrin IX concentration was very high (4286 μg/dL). Most (90%) patients presented with photosensitivity, 20% experienced blistering, and 25% presented with hepatic insufficiency, both uncommon in EPP. In 55% of patients, hematological disease was diagnosed after occurrence of cutaneous symptoms. Beta-carotene led to partial control of symptoms in 5 patients and resolution in another patient. Azacitidine treatment of MDS led to resolution of cutaneous symptoms in three patients.
CONCLUSION
We present the distinct features of acquired EPP and highlight that any patient presenting with new-onset photosensitivity, irrespective of age should be evaluated for porphyria.
Topics: Adult; Aged; Azacitidine; Chromosomes, Human, Pair 18; Erythrocytes; Female; Ferrochelatase; Genetic Loci; Humans; Male; Middle Aged; Mutation; Myelodysplastic Syndromes; Photosensitivity Disorders; Protoporphyria, Erythropoietic; Protoporphyrins; beta Carotene
PubMed: 31374130
DOI: 10.1111/phpp.12501