1,096 research outputs found

    Release of Mast Cell Tryptase into Saliva: A Tool to Diagnose Food Allergy by a Mucosal Challenge Test?

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    Background: Our aim was to examine whether measurement of the saliva mast cell tryptase (MCT) concentrations before and after a mucosal challenge test with the offending food would be helpful in diagnosing food allergy. Methods: We performed a retrospective analysis of 44 food challenge tests performed in 38 patients between 2006 and 2009. Patients with a suspected history of food allergy chewed the food until they developed symptoms or until the amount of time known from the patients' history to usually be required for the provocation of symptoms had passed. In 5 patients, saliva samples for the measurement of MCT were collected at minutes 0, 1, 4, 8, 11, and 16 after the first onset of symptoms. The remainder of the patients only had samples taken before chewing and 4 min after the end of the test period. Results: During repeated measurements, MCT peaked about 4 min after the onset of symptoms (p = 0.028). During 33 of the 44 tests (75.0%), we observed oral symptoms during testing; after 25 of the 33 (75.8%) tests evoking symptoms, the saliva MCT concentration increased. The MCT increase was negative in all other tests where no oral symptoms could be provoked. Conclusions: The measurement of saliva MCT 4 min after the onset of symptoms may be helpful to diagnose food allergy. Because of numerous confounding variables, however, a negative saliva MCT increase does not exclude food allergy. Copyright (C) 2011 S. Karger AG, Base

    LC-MS/MS Characterization of Phenolic Metabolites and Their Antioxidant Activities from Australian Native Plants

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    Polyphenols are considered vital bioactive compounds beneficial for human health. The Australian flora is enriched with polyphenols which are not fully characterized yet. Thus, the main objective of this study was to identify and characterize the Australian native sandalwood nuts, wattle seeds, lemongrass, and old man saltbush for phenolic compounds and their antioxidant activities. In this study, we tentatively identified a total of 155 phenolic compounds including 25 phenolic acids, 55 flavonoids, 22 isoflavonoids, 22 tannins, 22 lignans, 33 stilbenes, 33 coumarins and derivatives, 12 tyrosols and derivatives, and 6 phenolic terpenes. The highest total phenolic content (TPC) (15.09 ± 0.88 mg GAE/g) was quantified in lemongrass, while the lowest TPC (4.17 ± 0.33 mg GAE/g) was measured in wattle seeds. The highest total flavonoid content (TFC) and total condensed tannins (TCT) were measured in lemongrass and wattle seeds, respectively. A total of 18 phenolic metabolites were quantified/semi-quantified in this experiment. Lemongrass contains a vast number of phenolic metabolites

    Characterization, Antioxidant Potential, and Pharmacokinetics Properties of Phenolic Compounds from Native Australian Herbs and Fruits

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    In recent decades, plant bioactive phenolic compounds gained much attention due to their various health benefits. Therefore, this study aimed to analyze native Australian river mint (Mentha australis), bush mint (Mentha satureioides), sea parsley (Apium prostratum), and bush tomatoes (Solanum centrale) for their bioactive metabolites, antioxidant potential, and pharmacokinetics properties. LC-ESI-QTOF-MS/MS was applied to elucidate these plants’ composition, identification, and quantification of phenolic metabolites. This study tentatively identified 123 phenolic compounds (thirty-five phenolic acids, sixty-seven flavonoids, seven lignans, three stilbenes, and eleven other compounds). Bush mint was identified with the highest total phenolic content (TPC—57.70 ± 4.57 mg GAE/g), while sea parsley contained the lowest total phenolic content (13.44 ± 0.39 mg GAE/g). Moreover, bush mint was also identified with the highest antioxidant potential compared to other herbs. Thirty-seven phenolic metabolites were semi-quantified, including rosmarinic acid, chlorogenic acid, sagerinic acid, quinic acid, and caffeic acid, which were abundant in these selected plants. The most abundant compounds’ pharmacokinetics properties were also predicted. This study will develop further research to identify these plants’ nutraceutical and phytopharmaceutical potential

    Identification and characterization of anthocyanins and non-anthocyanin phenolics from Australian native fruits and their antioxidant, antidiabetic, and anti-Alzheimer potential

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    Polyphenols are vital bioactive constituents that have beneficial effects on human health. The aim of this study was to characterize the biologically active phenolic metabolites in Australian native commercial fruits (Kakadu plum, Davidson’s plum, quandong peach, and muntries) and their antioxidant, α-glucosidase, and acetylcholinesterase inhibition activities. Polyphenols were measured through total phenolic content (TPC), total flavonoid content (TFC), total condensed tannin (TCT), and total monomeric anthocyanin content (TMAC). Moreover, different in-vitro biological assays (DPPH, ABTS, FICA, OH-RSA, α-glucosidase, and acetylcholinesterase inhibition activities) were conducted to measure the antioxidant, anti-diabetic, and anti-Alzheimer’s potential of these selected fruits. LC-ESI-QTOF-MS/MS was implied for identification and quantification purposes. In this study, a total of 307 bioactive metabolites (51 phenolic acids, 194 flavonoids, 15 tannins, 23 other polyphenols, 5 stilbenes, 12 lignans, and 7 terpenoids) were putatively identified. A total of 41 phenolic compounds were quantified/semi-quantified. Kakadu plum was identified with a higher concentration of polyphenols and biological activities compared to Davidson plum, quandong peach, and muntries. Molecular docking was also conducted to discover the actual role of the most abundant phenolic metabolites in the α-glucosidase and acetylcholinesterase inhibition activities

    Prevalence of Self-Medication of Psychoactive Stimulants and Antidepressants among Undergraduate Pharmacy Students in Twelve Pakistani Cities

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    Purpose: To evaluate the prevalence of self-medication of psychoactive stimulants and antidepressants among pharmacy students of Pakistan.Methods: A cross-sectional survey on self-medication of psychoactive stimulants and antidepressants among pharmacy students was conducted with a structured and validated questionnaire distributed to a total of 2981 final year undergraduate pharmacy students in 12 major Pakistani cities (Karachi, Lahore, Islamabad, Rawalpindi, Sargodha, Dera Ismail Khan, Abbottabad, Bahawalpur, Hyderabad, Faisalabad, Multan and Peshawar) of Pakistan. Out of this, 2516 (718 male and 1798 female) students completed and returned the questionnaire.Results: Prevalence of self-medication of psychoactive stimulants was 1.31 (1.13 – 1.75 for 95% CI) and antidepressants was 8.34 (8.03 – 8.85 for 95% CI). A majority of the students (63 %) identified academic competition as a driving force for indulging in self-medication of psychoactive stimulants while nearly all the students (96 %)admitted using antidepressants to obtain relief from the pressure of studies (p < 0.05).Conclusion: Pakistani pharmacy students, despite being aware of the hazards of psychoactive stimulants, indulge in self-medication. Prevalence of self-medication with antidepressants is very high among the students due to the pressure of studies. Primarily, academic competition is the major driving force for the use of psychoactive stimulants.Keywords: Self-medication, Psychoactive stimulants, Antidepressants, Pharmacy students, Academicpressur

    A Comparative Study for Nutritional and Phytochemical Profiling of Coffea arabica (C. arabica) from Different Origins and Their Antioxidant Potential and Molecular Docking

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    Coffee is the most widely used beverage globally and contains many bioactive compounds, including phenolic compounds, alkaloids, triterpenes, organic acids, amino acids, hormones, and fatty acids. The main objective of this study was the comparative profiling of Australian, Colombian, Ethiopian, and Peruvian C. arabica using LC-ESI-QTOF-MS/MS. In this study, we tentatively identified 136 bioactive metabolites, including five (05) organic acids, six (06) alkaloids, three (03) amino acids (l-phenylalanine, l-tyrosine, and l-pyroglutamic acid), two (02) hormones (melatonin and serotonin), two fatty acids, one (01) furopyrans (goniothalenol), one (01) carotenoid (crocetin), three (03) terpenoids, thirty-eight (38) phenolic acids, forty-one (41) flavonoids, five (05) stilbenes, three (03) lignans and twenty-three (23) other polyphenols in C. arabica. The highest TPC value (17.74 ± 0.32 mg GAE/g) was measured in Colombian coffee while the lowest TPC value (10.24 ± 0.73 mg GAE/g) was in Peruvian coffee. Colombian coffee has a higher antioxidant potential than other studied coffee samples. A total of nineteen phenolic metabolites were mapped through LC-MS/MS. Quinic acid derivatives were quantified in higher concentrations than other metabolites. Furthermore, molecular docking predicted that chlorogenic acid is a main bioactive compound that contributes to anti-Alzheimer and anti-diabetic activities of C. arabica. The obtained results indicate that C. arabica contains a vast number of bioactive compounds which have potential health benefits. Furthermore, research could be conducted to validate the effect of these metabolites on the flavor profile of coffee beverages

    Screening and Characterization of Phenolic Compounds from Australian Grown Bananas and Their Antioxidant Capacity

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    Bananas are an essential source of staple food and fruit worldwide and are widely regarded as the world’s largest fruit crop, with more than 100 million tons total annual production. Banana peel, a by-product that represents about 40% of the entire banana’s weight, and pulp are rich in bioactive compounds and have a high antioxidant capacity. As the production of polyphenols in fruit and vegetables is highly dependent on environmental conditions, genetic factors, and the level of maturity, this study aims to characterize six Australian banana cultivars in various stages of ripening for their phenolic compounds using the liquid chromatography-electrospray ionization quadrupole time of flight mass spectrometry (LC-ESI-QTOF-MS/MS), polyphenols quantification with the high-performance liquid chromatography coupled with photodiode array detector (HPLC-PDA), and their antioxidant capacity. All bananas were analysed for total polyphenols content (TPC), total flavonoids content (TFC), and total tannin content (TTC) and their antioxidant activities. Ripe Ducasse peel and pulp contained the highest amounts of total polyphenols content (1.32 and 1.28 mg gallic acid equivalent (GAE) per gram of sample), total tannin contents (3.34 mg catechin equivalent (CE) per gram of sample), and free radical scavenging capacity (106.67 mg ascorbic acid equivalent (AAE) per g of sample). In contrast, ripe Plantain peel had the greatest total flavonoids (0.03 mg quercetin equivalent (QE) per g of sample). On the other hand, unripe Ladyfinger pulp possessed the highest total antioxidant activity (1.03 mg AAE/g of sample). There was a positive correlation between flavonoids and antioxidant activities. By using LC-ESI-QTOF-MS/MS, a total of 24 phenolic compounds were tentatively characterized in this research, including six phenolic acids, 13 flavonoids, and five other polyphenols. Quantification of phenolic compounds by the high-performance liquid chromatography coupled with photodiode array detector (HPLC-PDA) revealed a higher content of phenolic acids. These findings confirmed that banana peel and pulp have considerable antioxidant activity and can be employed in human food and animal feed for variant health enhancement uses

    LC-MS/MS-QTOF Screening and Identification of Phenolic Compounds from Australian Grown Herbs and Their Antioxidant Potential

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    Culinary spices and herbs have been used to impart a characteristic flavour and aroma in food due to their appealing fragrance. Recently, bioactive compounds from herbs, especially phenolics, have gained much attention due to their potential health outcomes. The aim of this study was to characterize and quantify the phenolic compounds from 10 widely used Australian-grown herbs (oregano, rosemary, bay, basil, sage, fenugreek, dill, parsley, mint and thyme). For this purpose, liquid chromatography mass spectrometry (LC-MS) was used for the complete profiling of polyphenolic compounds and quantification of abundant phenolic compounds was completed with high-performance liquid chromatography—photodiode array detection (HPLC-PDA). Polyphenols from Australian-grown herbs were estimated through total phenolic content (TP), total flavonoids (TF) and total tannins (TT) along with their in-vitro antioxidant activities. Oregano and mint were estimated with the highest value of TP (140.59 ± 9.52 and 103.28 ± 8.08 mg GAE/g, milligram gallic acid equivalent/gram) while rosemary and mint had the highest TF (8.19 ± 0.74 and 7.05 ± 0.43 mg QE (quercetin equivalent)/g). In this study, eighty-four (84) phenolic compounds were screened and confirmed through LC-MS/MS by comparing their masses and fragmentation pattern with published libraries. The results of this study validate the use of these herbs as bioactives and their positive impact on human health

    A Random Matrix Approach to Echo-State Neural Networks

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    Abstract Recurrent neural networks, especially in their linear version, have provided many qualitative insights on their performance under different configurations. This article provides, through a novel random matrix framework, the quantitative counterpart of these performance results, specifically in the case of echo-state networks. Beyond mere insights, our approach conveys a deeper understanding on the core mechanism under play for both training and testing
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