Browsing by Subject "Antioxidant"

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  • Vaario, Lu-Min; Asamizu, Shumpei; Sarjala, Tytti; Matsushita, Norihisa; Onaka, Hiroyasu; Xia, Yan; Kurokochi, Hiroyuki; Morinaga, Shin-Ichi; Huang, Jian; Zhang, Shijie; Lian, Chunlan (2020)
    Tricholoma matsutake is known to be the dominant fungal species in matsutake fruitbody neighboring (shiro) soil. To understand the mechanisms behind matsutake dominance, we studied the bacterial communities in matsutake dominant shiro soil and non-shiro soil, isolated the strains of Streptomyces from matsutake mycorrhizal root tips both from shiro soil and from the Pinus densiflora seedlings cultivated in shiro soil. Further, we investigated three Streptomyces spp. for their ability to inhibit fungal growth and Pinus densiflora seedling root elongation as well as two strains for their antifungal and antioxidative properties. Our results showed that Actinobacteria was the most abundant phylum in shiro soil. However, the differences in the Actinobacterial community composition (phylum or order level) between shiro and non-shiro soils were not significant, as indicated by PERMANOVA analyses. A genus belonging to Actinobacteria, Streptomyces, was present on the matsutake mycorrhizas, although in minority. The two antifungal assays revealed that the broths of three Streptomyces spp. had either inhibitory, neutral or promoting effects on the growth of different forest soil fungi as well as on the root elongation of the seedlings. The extracts of two strains, including one isolated from the P. densiflora seedlings, inhibited the growth of either pathogenic or ectomycorrhizal fungi. The effect depended on the medium used to cultivate the strains, but not the solvent used for the extraction. Two Streptomyces spp. showed antioxidant activity in one out of three assays used, in a ferric reducing antioxidant power assay. The observed properties seem to have several functions in matsutake shiro soil and they may contribute to the protection of the shiro area for T. matsutake dominance.
  • Oksuz, Tugba; Tacer-Caba, Zeynep; Nilufer-Erdil, Dilara; Boyacioglu, Dilek (2019)
    In this study, it is aimed to understand the changes in sour cherry phytochemicals when their co-digestions are simulated in dairy model systems comprising skim milk, non-fat-yoghurt, probiotic yoghurt or cream. These co-digestions were analyzed for their total phenolic and anthocyanin contents, total antioxidant activity (TAA) in addition to phenolic and anthocyanin profiles, individually. Sour cherry phenolics were stable during gastric conditions (120%); 54% lost in pancreatic digestion and being available (59%) in serum available fraction (IN). Anthocyanins were lost both in gastric (30%) and pancreatic digestions (16%), being only little available (0.6%) in IN. Soymilk had inhibitory effects on TAA. Dairy food matrix components evaluated were found to have distinct effects on the measured bioavailability of individual sour cherry phenolics. This study might aid both consumers and industry on selecting the food matrices to aiding increase in bioavailability.
  • Laurel, Markus (Helsingin yliopisto, 2019)
    Chicory (Cichorium intybus) is a biennial or perennial plant belonging to Asteraceae family grown worldwide for its roots, but also for its leaves. Chicory has been utilized as a food crop, but also because of its medicinal properties, for at least two millennia. The aim of the Master's thesis was to produce hair root and cell cultures from chicory, and to evaluate the antimicrobial and antioxidant properties of extracts made from them. Hair root infection is caused by the soil-borne bacterium Agrobacterium rhizogenes, which transfers its own DNA into the genome of the plant and causes the plant to produce opines which the bacteria uses as a nutrient source. Hairy root infection causes the plants to grow excessive amount of lateral roots and at the same time increases the formation of secondary metabolites. Hairy roots can be grown on a solid or liquid medium without added plant hormones, and this phenomenon is utilized in a number of biotechnological applications. The successful initiation of hair roots requires suitable conditions and components, but once these are clear the process itself is quite simple. Wounded explants are infected with either a liquid bacterial suspension or by direct transfer of bacterial growth. After infection bacterial growth is eliminated with the use of antibiotics. Hairy roots are initially identified by morphological traits and verified by detecting rol genes with the use of PRC. Plant cell suspension cultures are produced from explants with the help of auxin and cytokinin in suitable proportions. As with hairy root cultures, plant cell suspension cultures can be harnessed to produce various molecules of economic benefit. Bioactivity of plant extracts can be studied by a variety of different methods. DPPH and antimicrobial assays were used to investigate the bioactivity of hairy root and cell suspension cultures produced for the study. The DPPH assay is used to measure radical scavenging properties of samples, by comparing the results to a reference antioxidant such as for example Trolox, which is a synthetic vitamin-E. Methanol extracts of hairy roots, cell suspension cultures, and natural roots were assayed for their antioxidant properties with the DPPH assay. Hot water extracts of hairy root and cell suspension cultures were tested against VTT-E70045 Staphylococcus aureus strain for antimicrobial properties. The results of the study showed that especially the antioxidant properties of chicory hair roots differ greatly from natural roots and cell suspension cultures. The radical scavenging properties of hairy root extracts were up to 45 times more potent than of extracts made from natural root and cell suspension cultures. The results of the antimicrobial experiment showed that all extracts from hair root and cell suspension cultures had bacteriostatic properties. One hairy root clone 2R5 clearly had antimicrobial effects, and it would be interesting to do a more thorough assessment to find out which compounds are responsible for this.
  • ARIA Grp; Bousquet, Jean; Anto, Josep M.; Iaccarino, Guido; Haahtela, Tari; Zuberbier, Torsten (2020)
    Reported COVID-19 deaths in Germany are relatively low as compared to many European countries. Among the several explanations proposed, an early and large testing of the population was put forward. Most current debates on COVID-19 focus on the differences among countries, but little attention has been given to regional differences and diet. The low-death rate European countries (e.g. Austria, Baltic States, Czech Republic, Finland, Norway, Poland, Slovakia) have used different quarantine and/or confinement times and methods and none have performed as many early tests as Germany. Among other factors that may be significant are the dietary habits. It seems that some foods largely used in these countries may reduce angiotensin-converting enzyme activity or are anti-oxidants. Among the many possible areas of research, it might be important to understand diet and angiotensin-converting enzyme-2 (ACE2) levels in populations with different COVID-19 death rates since dietary interventions may be of great benefit.
  • Bousquet, Jean; Anto, Josep M; Iaccarino, Guido; Czarlewski, Wienczyslawa; Haahtela, Tari; Anto, Aram; Akdis, Cezmi A; Blain, Hubert; Canonica, G. W; Cardona, Victoria; Cruz, Alvaro A; Illario, Maddalena; Ivancevich, Juan C; Jutel, Marek; Klimek, Ludger; Kuna, Piotr; Laune, Daniel; Larenas-Linnemann, Désirée; Mullol, Joaquim; Papadopoulos, Nikos G; Pfaar, Oliver; Samolinski, Boleslaw; Valiulis, Arunas; Yorgancioglu, Arzu; Zuberbier, Torsten (BioMed Central, 2020)
    Abstract Reported COVID-19 deaths in Germany are relatively low as compared to many European countries. Among the several explanations proposed, an early and large testing of the population was put forward. Most current debates on COVID-19 focus on the differences among countries, but little attention has been given to regional differences and diet. The low-death rate European countries (e.g. Austria, Baltic States, Czech Republic, Finland, Norway, Poland, Slovakia) have used different quarantine and/or confinement times and methods and none have performed as many early tests as Germany. Among other factors that may be significant are the dietary habits. It seems that some foods largely used in these countries may reduce angiotensin-converting enzyme activity or are anti-oxidants. Among the many possible areas of research, it might be important to understand diet and angiotensin-converting enzyme-2 (ACE2) levels in populations with different COVID-19 death rates since dietary interventions may be of great benefit.
  • Kasica, Natalia; Podlasz, Piotr; Sundvik, Maria; Tamas, Andrea; Reglodi, Dora; Kaleczyc, Jerzy (2016)
    Pituitary adenylate cyclase-activating polypeptide (PACAP) is a pleiotropic neuropeptide, with known antiapoptotic functions. Our previous in vitro study has demonstrated the ameliorative role of PACAP-38 in chicken hair cells under oxidative stress conditions, but its effects on living hair cells is now yet known. Therefore, the aim of the present study was to investigate in vivo the protective role of PACAP-38 in hair cells found in zebrafish (Danio rerio) sense organs-neuromasts. To induce oxidative stress the 5-day postfertilization (dpf) zebrafish larvae were exposed to 1.5 mM H2O2 for 15 min or 1 h. This resulted in an increase in caspase-3 and p-38 MAPK level in the hair cells as well as in an impairment of the larvae basic behavior. To investigate the ameliorative role of PACAP-38, the larvae were incubated with a mixture of 1.5 mM H2O2 and 100 nM PACAP-38 following 1 h preincubation with 100 nM PACAP-38 only. PACAP-38 abilities to prevent hair cells from apoptosis were investigated. Whole-mount immunohistochemistry and confocal microscopy analyses revealed that PACAP-38 treatment decreased the cleaved caspase-3 level in the hair cells, but had no influence on p-38 MAPK. The analyses of basic locomotor activity supported the protective role of PACAP-38 by demonstrating the improvement of the fish behavior after PACAP-38 treatment. In summary, our in vivo findings demonstrate that PACAP-38 protects zebrafish hair cells from oxidative stress by attenuating oxidative stress-induced apoptosis.
  • Rahaman, Atikur (Helsingin yliopisto, 2018)
    Some flavonoids are thought to have antioxidant functions in plants, but this is still controversial because of a lack of in planta evidence. Methyl viologen (MV) sensitivity was assayed in sterile culture by growing seven day old Arabidopsis seedlings on 0.5x MS media supplemented with and without MV. Seedlings grew for 9 days after that, and then were photographed and root growth measured. We used several flavonoid deficient Arabidopsis transparent testa (tt) mutants and found they were hypersensitive to MV that produces reactive oxygen species (ROS) in chloroplasts and mitochondria. Flavonoids are transported into different compartments of the cell via a specific flavonoid transport system but no chloroplastic or mitochondrial transporters are currently known. To identify potential chloroplastic and mitochondrial transporters, knockout mutants of candidate MATE and ABC transporters have been screened for MV sensitivity. Flavonoids modulate auxin transport, which raises the possibility of passive effects through auxin during ROS sensitivity. To test whether auxin or the inhibitions of auxin transport have a role in protecting against ROS stress, MV sensitivity was assayed under exogenous treatment of artificial auxin (NAA) and an auxin transport inhibitor (NPA) during MV stress. From this study, we obtained data about the role of flavonoids and auxin in ROS signalling. The inhibition of auxin transport modulated MV sensitivity. We found that NAA had no effect or very modest effect. However, a protective effect of NPA was observed that helps against ROS formation, mimicking the effect of flavonoids. NPA induced more protection. One MATE transporter also gave the mimic of (tt) phenotype, however their role in the movement of flavonoids into or out of the chloroplast or mitochondria remains unclear, as they may be transporting some other protective agent that helps against oxidative stress. However, At1g54350 is a candidate for further testing.
  • Figueiredo, Joana; Serrano, João L.; Cavalheiro, Eunice; Keurulainen, Leena; Yli-Kauhaluoma, Jari Tapani; Moreira, Vânia M.; Ferreira, Susana; Domingues, Fernanda C.; Silvestre, Samuel; Almeida, Paulo (2018)
    Barbituric and thiobarbituric acid derivatives have become progressively attractive to medicinal chemists due to their wide range of biological activities. Herein, different series of 1,3,5-trisubstituted barbiturates and thiobarbiturates were prepared in moderate to excellent yields and their activity as xanthine oxidase inhibitors, antioxidants, antibacterial agents and as anti-proliferative compounds was evaluated in vitro. Interesting bioactive barbiturates were found namely, 1,3-dimethyl-5-[1-(2-phenylhydrazinyl)ethylidene]pyrimidine-2,4,6(1H,3H,5H)-trione (6c) and 1,3-dimethyl-5-[1-[2-(4-nitrophenyl)hydrazinyl]ethylidene]pyrimidine-2,4,6(1H,3H,5H)-trione (6e), which showed concomitant xanthine oxidase inhibitory effect (IC50 values of 24.3 and 27.9 mu M, respectively), and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity (IC50 values of 18.8 and 23.8 mu M, respectively). In addition, 5-[1-(2-phenylhydrazinyl)ethylidene]pyrimidine-2,4,6(1H,3H,5H)-trione (6d) also revealed DPPH radical scavenger effect, with an IC50 value of 20.4 mu M. Moreover, relevant cytotoxicity against MCF-7 cells (IC50 = 13.3 mu M) was observed with 5-[[(2-chloro-4-nitrophenyl)amino]methylene]-2-thioxodihydropyrimidine-4,6(1H,5H)-dione (7d). Finally, different 5-hydrazinylethylidenepyrimidines revealed antibacterial activity against Acinetobacter baumannii (MIC values between 12.5 and 25.0 mu M) which paves the way for developing new treatments for infections caused by this Gram-negative coccobacillus bacterium, known to be an opportunistic pathogen in humans with high relevance in multidrug-resistant nosocomial infections. The most promising bioactive barbiturates were studied in silico with emphasis on compliance with the Lipinski's rule of five as well as several pharmacokinetics and toxicity parameters. (C) 2017 Elsevier Masson SAS. All rights reserved.
  • Hemila, Harri; Suonsyrja, Timo (2017)
    Background: Atrial fibrillation (AF), a common arrhythmia contributing substantially to cardiac morbidity, is associated with oxidative stress and, being an antioxidant, vitamin C might influence it. Methods: We searched the Cochrane CENTRAL Register, MEDLINE, and Scopus databases for randomised trials on vitamin C that measured AF as an outcome in high risk patients. The two authors independently assessed the trials for inclusion, assessed the risk of bias, and extracted data. We pooled selected trials using the Mantel-Haenszel method for the risk ratio (RR) and the inverse variance weighting for the effects on continuous outcomes. Results: We identified 15 trials about preventing AF in high-risk patients, with 2050 subjects. Fourteen trials examined post-operative AF (POAF) in cardiac surgery patients and one examined the recurrence of AF in cardioversion patients. Five trials were carried out in the USA, five in Iran, three in Greece, one in Slovenia and one in Russia. There was significant heterogeneity in the effect of vitamin C in preventing AF. In 5 trials carried out in the USA, vitamin C did not prevent POAF with RR = 1.04 (95% CI: 0.86-1.27). In nine POAF trials conducted outside of the USA, vitamin C decreased its incidence with RR = 0.56 (95% CI: 0.47-0.67). In the single cardioversion trial carried out in Greece, vitamin C decreased the risk of AF recurrence by RR = 0.13 (95% CI: 0.02-0.92). In the non-US cardiac surgery trials, vitamin C decreased the length of hospital stay by 12.6% (95% CI 8.4-16.8%) and intensive care unit (ICU) stay by 8.0% (95% CI 3.0-13.0%). The US trials found no effect on hospital stay and ICU stay. No adverse effects from vitamin C were reported in the 15 trials. Conclusions: Our meta-analysis indicates that vitamin C may prevent post-operative atrial fibrillation in some countries outside of the USA, and it may also shorten the duration of hospital stay and ICU stay of cardiac surgery patients. Vitamin C is an essential nutrient that is safe and inexpensive. Further research is needed to determine the optimal dosage protocol and to identify the patient groups that benefit the most.
  • Hemilä, Harri; Suonsyrjä, Timo (BioMed Central, 2017)
    Abstract Background Atrial fibrillation (AF), a common arrhythmia contributing substantially to cardiac morbidity, is associated with oxidative stress and, being an antioxidant, vitamin C might influence it. Methods We searched the Cochrane CENTRAL Register, MEDLINE, and Scopus databases for randomised trials on vitamin C that measured AF as an outcome in high risk patients. The two authors independently assessed the trials for inclusion, assessed the risk of bias, and extracted data. We pooled selected trials using the Mantel-Haenszel method for the risk ratio (RR) and the inverse variance weighting for the effects on continuous outcomes. Results We identified 15 trials about preventing AF in high-risk patients, with 2050 subjects. Fourteen trials examined post-operative AF (POAF) in cardiac surgery patients and one examined the recurrence of AF in cardioversion patients. Five trials were carried out in the USA, five in Iran, three in Greece, one in Slovenia and one in Russia. There was significant heterogeneity in the effect of vitamin C in preventing AF. In 5 trials carried out in the USA, vitamin C did not prevent POAF with RR = 1.04 (95% CI: 0.86–1.27). In nine POAF trials conducted outside of the USA, vitamin C decreased its incidence with RR = 0.56 (95% CI: 0.47–0.67). In the single cardioversion trial carried out in Greece, vitamin C decreased the risk of AF recurrence by RR = 0.13 (95% CI: 0.02–0.92). In the non-US cardiac surgery trials, vitamin C decreased the length of hospital stay by 12.6% (95% CI 8.4–16.8%) and intensive care unit (ICU) stay by 8.0% (95% CI 3.0–13.0%). The US trials found no effect on hospital stay and ICU stay. No adverse effects from vitamin C were reported in the 15 trials. Conclusions Our meta-analysis indicates that vitamin C may prevent post-operative atrial fibrillation in some countries outside of the USA, and it may also shorten the duration of hospital stay and ICU stay of cardiac surgery patients. Vitamin C is an essential nutrient that is safe and inexpensive. Further research is needed to determine the optimal dosage protocol and to identify the patient groups that benefit the most.
  • Hemilä, Harri (2013)
    In their meta-analysis, Bjelakovic et al. (2013) calculated that vitamin E in doses above the RDA (>15 mg) may slightly increase mortality by 3%. This estimate was based on the pooling of the results of 44 studies. However, study-level analyses can lead to different conclusions than do corresponding individual-level analysis, a difference which is called the “ecological fallacy”. ... Given the mainly negative findings in the antioxidant trials, it seems justified to discourage the general population from taking supplements until we have better knowledge of the groups of people who may benefit. However, a single vitamin E effect estimate, such as +3%, does not apply to all people over the globe since, at least, a substantial proportion of Finnish men in the ATBC study are inconsistent with such an effect. The individual-level analysis of the ATBC Study suggests that trials on vitamins E and C for men older than 70 years are warranted.