Numerous assays were developed to measure the antioxidant activity, but each has limitations and the results obtained by different methods are not always comparable. Popular examples are the DPPH and ...ABTS assay. Our aim was to study similarities and differences of these two assay regarding the measured antioxidant potentials of 24 phenolic compounds using the same measurement and evaluation methods. This should allow conclusions to be drawn as to whether one of the assays is more suitable for measuring specific subgroups like phenolic acids, flavonols, flavanones, dihydrochalcones or flavanols. The assays showed common trends for the mean values of most of the subgroups. Some dihydrochalcones and flavanones did not react with the DPPH radical in contrast to the ABTS radical, leading to significant differences. Therefore, to determine the antioxidant potential of dihydrochalcone or flavanone-rich extracts, the ABTS assay should be preferred. We found that the results of the flavonoids in the DPPH assay were dependent on the Bors criteria, whereas the structure-activity relationship in the ABTS assay was not clear. For the phenolic acids, the results in the ABTS assay were only high for pyrogallol structures, while the DPPH assay was mainly determined by the number of OH groups.
Due to their antioxidant properties, secondary plant metabolites can scavenge free radicals such as reactive oxygen species and protect foods from oxidation processes. Our aim was to study structural ...influences, like basic structure, number of hydroxyl groups and number of Bors criteria on the outcome of the oxygen radical absorbance capacity (ORAC) assay. Furthermore, similarities and differences to other
antioxidant assays were analyzed by principal component analysis. Our studies confirmed that the antioxidant behavior in the ORAC assay is dominated by the number and types of substituents and not by the Bors criteria, as long as no steric hindrance occurs. For example, morin (MOR) with five hydroxyl groups and two Bors criteria reached an area under the curve of (3.64 ± 0.08) × 10
, which was significantly higher than quercetin-7-D-glucoside (QGU7) (
< 0.001), and thus the highest result. Principal component analysis showed different dependencies regarding structural properties of Folin-Ciocalteu (FC)- and 2,2-diphenyl-1-picrylhydrazyl (DPPH)-assays or 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS)- and ORAC-assays, respectively. Therefore, we conclude that they are based on different reaction mechanisms. The number of hydroxyl groups showed a stronger influence on the antioxidant activity than the Bors criteria. Due to these differences, the correlation of these rapid tests to specific applications should be validated.
Plants produce a diverse array of secondary metabolites that are generally nonessential but facilitate ecological interactions. Fruits, vegetables, seeds and nuts can accumulate bioactive secondary ...metabolites with health-promoting properties, including the potent antioxidant activities of phenolic compounds. Several in vitro assays have been developed to measure the polyphenol content and antioxidant activity of plant extracts, e.g., the simple and highly popular Folin-Ciocalteu (FC) assay. However, the literature contains a number of different descriptions of the assay and it is unclear whether the assay measures the polyphenol content or reducing capacity of the sample. To determine the influence of phenolic structures on the outcome of the FC assay, we tested phenols representing different subgroups (phenolic acids, flavonols, flavanols, dihydrochalcones and flavanones). We observed different results for each reference substance and subgroup. Accordingly, we concluded that the FC assay does not measure the polyphenol content of a sample but determines its reducing capacity instead. Assigning the substances to five structural classes showed that the FC results depend on the number of fulfilled Bors criteria. If a molecule fulfills none of the Bors criteria, the FC results depend on the number of OH groups. We did not find a correlation with other single electron transfer assays (e.g., ABTS and DPPH assays). Furthermore, the FC assay was compatible with all five subgroups and should be preferred over the DPPH assay, which is specific for extracts rich in dihydrochalcones or flavanones.
Plant extracts from natural and renewable resources have the potential to replace conventional antioxidants in many applications and to increase the stability of lubricants. By specific selection of ...raw materials and adaptation of extraction parameters, the properties of the additives can be specifically optimized for the respective application. Easy-to-perform photometric assays enable targeted and rapid process adjustment and pre-selection of extracts. Later, they can be evaluated in application-oriented analytical methods, such as the rancimat test, with regard to their effect in the oil. In our analyses, secondary plant compounds increased the oxidation stability by 300 %, whereas the conventional antioxidants only achieved an increase of 200 %.
Pflanzenextrakte aus natürlichen und nachwachsenden Rohstoffen haben das Potential in vielen Anwendungsbereichen herkömmliche Antioxidantien zu ersetzen und die Oxidationsstabilität von Schmierölen ...zu steigern. Durch spezifische Auswahl der Rohstoffe und Variation der Extraktionsparameter lassen sich die Eigenschaften der Additive spezifisch für den jeweiligen Einsatzzweck anpassen. Einfach durchzuführende photometrische Assays ermöglichen dabei eine gezielte und schnelle Prozessanpassung und Vorauswahl der Extrakte. Diese können später in anwendungsnahen Analysenmethoden, wie dem Rancimat-Test, hinsichtlich ihrer Wirkung im Öl untersucht werden. In unseren Analysen konnten sekundäre Pflanzenstoffe die Oxidationsstabilität um bis zu 300 % erhöhen, wohingegen die konventionellen Vergleichsantioxidantien lediglich eine Erhöhung um 200 % erreichten.
Plant extracts from natural and renewable resources have the potential to replace conventional antioxidants in many applications and to increase the stability of lubricants. By specific selection of ...raw materials and adaptation of extraction parameters, the properties of the additives can be specifically optimized for the respective application. Easy-to-perform photometric assays enable targeted and rapid process adjustment and pre-selection of extracts. Later, they can be evaluated in application-oriented analytical methods, such as the rancimat test, with regard to their effect in the oil. In our analyses, secondary plant compounds increased the oxidation stability by 300 %, whereas the conventional antioxidants only achieved an increase of 200 %. Keywords Plant extracts, phytochemicals, photometric assays, structure-activity relationship, reducing activity, bioadditives Pflanzenextrakte aus naturlichen und nachwachsenden Rohstoffen haben das Potential in vielen Anwendungsbereichen herkommliche Antioxidantien zu ersetzen und die Oxidationsstabilitat von Schmierolen zu steigern. Durch spezifische Auswahl der Rohstoffe und Variation der Extraktionsparameter lassen sich die Eigenschaften der Additive spezifisch fur den jeweiligen Einsatzzweck anpassen. Einfach durchzufuhrende photometrische Assays ermoglichen dabei eine gezielte und schnelle Prozessanpassung und Vorauswahl der Extrakte. Diese konnen spater in anwendungsnahen Analysenmethoden, wie dem RancimatTest, hinsichtlich ihrer Wirkung im Ol untersucht werden. In unseren Analysen konnten sekundare Pflanzenstoffe die Oxidationsstabilitat um bis zu 300 % erhohen, wohingegen die konventionellen Vergleichsantioxidantien lediglich eine Erhohung um 200 % erreichten. Schlusselworter Pflanzenextrakte, sekundare Pflanzenstoffe, photometrische Assays, Struktur-Aktivitats-Beziehung, reduzierende Wirkung, Bioadditive
Biobasierte Schmierstoffe aus pflanzlichen Ressourcen gewinnen als nachhaltige Alternativen zu Mineralölen an Bedeutung. Aktuelle Forschungsarbeiten untersuchen Deodestillate aus der Produktion von ...Speiseölen als vielversprechende Basisöle. Diese Destillate zeigen nach enzymatischer Behandlung einen deutlichen Rückgang freier Fettsäuren, was die Oxidationsbeständigkeit verbessert. Parallel dazu werden pflanzliche Extrakte, reich an Antioxidantien, als potenzielle Bio-Additive eingesetzt, welche die oxidative Stabilität der Schmier Systeme weiter erhöhen. Zusätzlich zeigen Forschungsarbeiten, dass Zellulose-Derivate wie Natriumcarboxymethylzellulose als biologisch hergestellte Verdickungsmittel für wässrige Schmierstoffe dienen können, um die Herausforderungen der geringen Viskosität von Wasser zu adressieren. Diese Erkenntnisse unterstreichen das Potenzial biobasierter Schmierstoffe und Additive, Leistungsfähigkeit mit Umweltverträglichkeit zu vereinen.
Natural antioxidants are known for their ability to scavenge free radicals and protect oils from oxidation. Our aim was to study the structural properties such as the number of hydroxyl groups and ...Bors criteria of phenolic substances leading to high antioxidant activity in oil in order to analyze common trends and differences in widespread in vitro antioxidant assays. Therefore, 20 different phenolic substances were incorporated into rapeseed oil and were measured using pressurized differential scanning calorimetry (P-DSC) and the Rancimat method. The Bors criteria had the highest influence on the antioxidant effect in rapeseed oil, which is why myricetin (MYR), fulfilling all Bors criteria, reached the highest result of the flavonoids. In the Rancimat test and P-DSC, MYR obtained an increase in oxidation induction time (OIT) of 231.1 ± 44.6% and 96.8 ± 1.8%, respectively. Due to differences in the measurement parameters, the results of the Rancimat test and P-DSC were only partially in agreement. Furthermore, we compared the results to in vitro assays (ABTS, DPPH, FC and ORAC) in order to evaluate their applicability as alternative rapid methods. These analysis showed the highest correlation of the oil methods with the results of the DPPH assay, which is, therefore, most suitable to predict the antioxidant behavior of oil.
The ongoing pandemic of coronavirus disease (COVID-19) is a global health crisis that has posed enormous pressure on workers in the health sector (WHS), having a massive impact on their mental ...health. In this study, we aimed to evaluate the sleep quality of WHS during the pandemic and compare frontline WHS to those who are not directly engaged in the care of COVID-19 patients. This cross-sectional, self-reported online survey assessed the sleep quality of WHS in Austria using the Pittsburgh Sleep Quality Index (PSQI). The same questionnaire was sent out two times. Due to the unequal sample and anonymity of the study participants, we analyzed the data of each time point separate from each other. The first study was conducted in April/May 2020, during the first lockdown in Austria (Study1), and the second study was conducted in July/August 2020, when the social restrictions were loosened (Study2). T-test was used to compare the mean values of PSQI scores between frontline vs. non-frontline WHS, while two two-way ANCOVAs were used to analyze differences in the PSQI mean scores (controlled for age) for male vs. female between frontline vs. non-frontline WHS. During the first lockdown in Austria (Study1) we identified a shorter sleep duration of frontline WHS compared to the non-frontline group, however the difference in global PSQI score between these groups was statistically not significant. In the period after loosened restrictions (Study2) the sleep quality, sleep latency, sleep duration, sleep efficiency and global PSQI score was worse in frontline WHS compared to the non-frontline WHS. Furthermore, female WHS scored higher in the PSQI indicating a worse sleep than male WHS. In addition, nurses and nursing assistants had a higher prevalence of poor sleep quality than other occupational groups. Our results indicate that the COVID-19 pandemic negatively impacts the sleep of WHS, affecting particularly frontline WHS. Preventive interventions aiming to promote good sleep quality in WHS during a healthcare crisis like this pandemic are essential to enhance resilience and mitigate the vulnerability of this specific population.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Gut microbiota are suspected to affect brain functions and behavior as well as lowering inflammation status. Therefore, an effect on depression has already been suggested by recent research. The aim ...of this randomized double-blind controlled trial was to evaluate the effect of probiotic treatment in depressed individuals. Within inpatient care, 82 currently depressed individuals were randomly assigned to either receive a multistrain probiotic plus biotin treatment or biotin plus placebo for 28 days. Clinical symptoms as well as gut microbiome were analyzed at the begin of the study, after one and after four weeks. After 16S rRNA analysis, microbiome samples were bioinformatically explored using QIIME, SPSS, R and Piphillin. Both groups improved significantly regarding psychiatric symptoms.
and
were more abundant and β-diversity was higher in the probiotics group after 28 days. KEGG-analysis showed elevated inflammation-regulatory and metabolic pathways in the intervention group. The elevated abundance of potentially beneficial bacteria after probiotic treatment allows speculations on the functionality of probiotic treatment in depressed individuals. Furthermore, the finding of upregulated vitamin B6 and B7 synthesis underlines the connection between the quality of diet, gut microbiota and mental health through the regulation of metabolic functions, anti-inflammatory and anti-apoptotic properties. Concluding, four-week probiotic plus biotin supplementation, in inpatient individuals with a major depressive disorder diagnosis, showed an overall beneficial effect of clinical treatment. However, probiotic intervention compared to placebo only differed in microbial diversity profile, not in clinical outcome measures.
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