Different values obtained by the FRAP method for the determination of slowly and rapidly reacting phenols

A number of methods have been applied to measure total antioxidant capacity (TAC), including FRAP, which is based on reducing the amount of iron ions in a complex compound. Researchers often use measurement of absorbance 10 min after mixing a sample with the FRAP reaction solution to calculate TAC. The FRAP solution has been shown to alter absorbance over time by ca 0.0010–0.0020 per hour, under storage conditions. This article intends to show that some substances do not fully or sufficiently react within the common analysis period. It is evident from the results that some substances react more quickly and others very slowly. Absorbance in relation to various phenols was measured. Compared to the levels of absorbance at 10 min, mean absorbance at 48 h was higher by 5,395% for vanillin, 426% for caffeic acid, 170% for sinapinic acid, 67% for gallic acid, 19% for syringic acid, and only by 4% for Trolox. Results for vanillin and caffeic acid indicate potential auto-catalysis.

Analysis of phenolic profile, total phenolic content and antioxidant activity in Anacardium occidentale leaves

Anacardium occidentale young leaves are consumed traditionally as part of a Southeast Asian diet. The regular consumption is believed to have beneficial effects on health in general and potentially against type 2 Diabetes mellitus due to its high content of polyphenols. This study was aimed to investigate the polyphenol content of the plant using two methanol extracts; Free Phenolic Extract (FPE) and Bound Phenolic Extract (BPE) as well as highlight the presence of six phenolic acids and flavonoids namely; gallic acid, sinapinic acid, caffeic acid, ferulic acid, quercetin and kaempferol using High performance liquid chromatography-photodiode array (HPLC-UV-Vis). The results for polyphenols and flavonoids content showed high amounts of total polyphenols in BPE with 8.5±0.57 mg GAE/g as well as high amounts of total flavonoids in both extracts FPE and BPE with 0.58±0.06 and 0.86±0.05 mg QE/g respectively (p<0.05). The presence of these polyphenols was further confirmed by measuring the antioxidant activity through the scavenging of the free radical DPPH which showed an IC50 value for FPE (5.17±0.64 µg/ mL, BPE (4.96±0.12 µg/mL) compared to the positive control ascorbic acid (4.91±0.43 µg/mL). The high-performance liquid chromatography-photodiode array confirmed the presence of all four targeted phenolic acids with the highest amount showing in gallic acid and sinapinic acid in BPE with 148.12±6.44 µg gallic acid/g dry weight and 47.02±1.94 µg sinapinic acid/g dry weight respectively. As for flavonoids, quercetin was present in both extracts with 20.38±1.22 µg/g dry weight in BPE and 5.21±0.1 µg/g dry weight in FPE while Kaempferol was not detectable in either extract. These findings confirmed the importance of A. occidentale as a rich source of polyphenols which can be further investigated to determine its effects in-vitro and in-vivo on non-communicable diseases such as type 2 diabetes.

The use of gamma irradiation to stimulate bioactive compound synthesis in Inonotus obliquus submerged cultures

Inonotus obliquus is a parasite on the birch and other trees and is also a well-known medicinal mushroom. Its sterile conk is highly sought for its bioactive compounds such as phenols, polysaccharides, triterpenoids, and steroids. It was traditionally used to treat various gastrointestinal diseases, viral and parasitic infections, to counteract the progression of cancers, and to stimulate the immune system. We used acute gamma irradiation, followed by short-term submerged cultivation, as an oxidative stress inducer to enhance the synthesis of mycelial metabolites. The 300 Gy and 400 Gy doses showed the best results across the whole experimental design. Each assayed criterion had a different corresponding optimal stimulation dose. In one experiment, sublethal doses of irradiation triggered the dry weight of the cultured mycelium to increase by 19.764%. The free radical scavenging potential of the mycelium extracts increased by 79.83%. The total phenolic content of mycelium extracts and culture broth increased by 55.7% and 62.987%, respectively. The total flavonoid and sinapinic acid content of the broth increased by 934.678% and 590.395%, respectively. As such, gamma irradiation pre-treatment of the mycelial inoculum proved an interesting, economically and environmentally effective tool for stimulating secondary metabolite synthesis in submerged mycelium cultures.

Large-Scale Analysis of Apolipoprotein CIII Glycosylation by Ultrahigh Resolution Mass Spectrometry

Apolipoprotein-CIII (apo-CIII) is a glycoprotein involved in lipid metabolism and its levels are associated with cardiovascular disease risk. Apo-CIII sialylation is associated with improved plasma triglyceride levels and its glycosylation may have an effect on the clearance of triglyceride-rich lipoproteins by directing these particles to different metabolic pathways. Large-scale sample cohort studies are required to fully elucidate the role of apo-CIII glycosylation in lipid metabolism and associated cardiovascular disease. In this study, we revisited a high-throughput workflow for the analysis of intact apo-CIII by ultrahigh-resolution MALDI FT-ICR MS. The workflow includes a chemical oxidation step to reduce methionine oxidation heterogeneity and spectrum complexity. Sinapinic acid matrix was used to minimize the loss of sialic acids upon MALDI. MassyTools software was used to standardize and automate MS data processing and quality control. This method was applied on 771 plasma samples from individuals without diabetes allowing for an evaluation of the expression levels of apo-CIII glycoforms against a panel of lipid biomarkers demonstrating the validity of the method. Our study supports the hypothesis that triglyceride clearance may be regulated, or at least strongly influenced by apo-CIII sialylation. Interestingly, the association of apo-CIII glycoforms with triglyceride levels was found to be largely independent of body mass index. Due to its precision and throughput, the new workflow will allow studying the role of apo-CIII in the regulation of lipid metabolism in various disease settings.

Optimization of Chinese Chive Juice as a Functional Feed Additive

Allium tuberosum, commonly known as the Chinese chive (CC) is often used as a traditional medicine in East Asia for its health benefits. To explore the potential of CC as a functional feed additive, antibacterial and antioxidant assays, untargeted metabolomics, and a 2 × 3 × 3 fractional factorial design (FFD) were conducted. In the present study, CC displayed stable DPPH radical scavenging activity with constant total phenolic content, however, the total flavonoid contents and the antibacterial activities were attenuated following heat treatment. The FFD results identified the solid content (SBM) as the main determinant of the antibacterial activity and moisture content of the CC products along with two other factors: drying time and temperature. Two CC products manufactured with 30% (w/v) SBM with 3 h drying at 80 °C and 20% (w/v) SBM with 8 h drying at 60 °C obtained the maximum antibacterial activity and least moisture content (<5%). Liquid chromatography-tandem mass spectrometry based multivariate analysis revealed 14 changed compounds in the non-heated and heated CC including flavonols, sinapinic acid, and lysophospholipids, which might affect the functionality. In conclusion, we propose an empirical approach to the pre-processing of CC juice that is suitable for blending in feed and simultaneously retaining its bioactivities.

Chemical Composition and Concentration of Bioactive Compounds in Garlic Cultivated from Air Bulbils

This study was designed to determine the chemical composition, antioxidant activity, and selected bioactive compound content and occurrence in whole immature and mature garlic plants grown from air bulbils. Two winter garlic cultivars, Harnaś and Ornak, of Polish origin, were cultivated from air bulbils at the Experimental Station of the Agricultural University in Kraków, Poland. Harvest bunching of garlic of both cultivars was carried out in May and in June. Mature plants were harvested in July. In whole plant proximate analysis, the concentration of vitamin C, total polyphenols, antioxidant activity, carotenoids, chlorophyll a and b, as well as glutathione level were determined. P-coumaric acid was found in Harnaś and Ornak samples collected in May. Sinapinic acid was identified in Ornak samples collected in June and July. Identification of sulphur compounds depended on the term of harvesting. Significantly higher content of total phenolic compounds, antioxidant activity, as well as other bioactive compounds, was measured in the Harnaś and Ornak cultivars harvested in May. A significantly lower level of bioactive compounds was determined in mature plants harvested in July. The organosulfur compound profile and polyphenolic profile depended on the time of harvesting. Immature garlic cultivated from air bulbils is recognized as a potential source of bioactive compounds in human nutrition, however, more research, in particular in vivo studies, is required to confirm its functional properties.

Cytotoxicity of Palladium Nanoparticles Against Aspergillus Niger

Background: Investigating the bioactivity of nanoscale materials against microorganisms give a comprehensive, proactive understanding of nanomaterial toxicity and explore their potential for applications. Methods: The aim of this study is to assess the changes in the mycelium growth and proteomics for filamentous fungi Aspergillus niger (A. niger) caused by palladium nanoparticles (Pd NPs). In this study, quantitative analysis of the mycelium growth and protein content of A. niger upon incubation with different concentrations of Pd NPs (0-1350 ng/mL) were reported. Matrix Assisted Laser Desorption/ Ionization Mass Spectrometry (MALDI-MS) was also used to analyze the changes of the proteins content of A. niger in different medium using two different matrices; α-cyano-4-hydroxycinnamic acid (CHCA), and sinapinic acid (SA). We found that Pd NPs decrease the mycelium growth of A. niger. Results: The protein contents are increased at low concentrations of Pd NPs, while it decreases with high concentration. MALDI-MS results show change of the protein contents for A. niger upon incubation with Pd NPs. Mycelia biomass decreases at high concentration of Pd NPs. Conclusion: The biological activity of Pd NPs depends on their concentration and cell culture medium. These new findings may add valuable information about the cytotoxicity of Pd NPs.

An In Vitro Study Determining the anti-inflammatory activities of sinapinic acid-containing extracts generated from Irish rapeseed meal

Sinapinic acid (SA) has been shown to possess various bioactive properties including anti-diabetic, anti-inflammatory and histone deacetylase inhibitory activities. However, the amount obtained from our diet is insufficient to produce beneficial effects on health. Therefore, isolating this bioactive phenolic from a natural source, such as rapeseed meal, could generate extracts containing concentrated amounts of SA which could be consumed as a functional food ingredient to prevent health-related disease, particularly inflammation. Inflammation is a multi-faceted pathology, which plays a role in numerous diseases including cardiovascular disease, diabetes, arthritis and cancer. Current therapies such as non-steroidal anti-inflammatories (NSAIDs) are associated with various adverse side effects, with the result being an increase in research aiming to identify natural compounds which possess anti-inflammatory activity. In this work, an in vitro study assessed the anti-inflammatory activities of two sinapinic acid-containing extracts on human-derived peripheral blood mononuclear cells (PBMCs). Both extracts were found to significantly reduce the levels of key pro-inflammatory cytokines including TNF-alpha, IL-12 and IL-6. Importantly, these extracts were found to be more potent than commercial SA in terms of their anti-inflammatory activities. Results demonstrate the potential of these extracts as anti-inflammatory agents.

Polyphenols from Lycium barbarum (Goji) Fruit European Cultivars at Different Maturation Steps: Extraction, HPLC-DAD Analyses, and Biological Evaluation

Goji berries are undoubtedly a source of potentially bioactive compounds but their phytochemical profile can vary depending on their geographical origin, cultivar, and/or industrial processing. A rapid and cheap extraction of the polyphenolic fraction from Lycium barbarum cultivars, applied after homogenization treatments, was combined with high-performance liquid chromatography (HPLC) analyses based on two different methods. The obtained hydroalcoholic extracts, containing interesting secondary metabolites (gallic acid, chlorogenic acid, catechin, sinapinic acid, rutin, and carvacrol), were also submitted to a wide biological screening. The total phenolic and flavonoid contents, the antioxidant capacity using three antioxidant assays, tyrosinase inhibition, and anti-Candida activity were evaluated in order to correlate the impact of the homogenization treatment, geographical origin, and cultivar type on the polyphenolic and flavonoid amount, and consequently the bioactivity. The rutin amount, considered as a quality marker for goji berries according to European Pharmacopeia, varied from ≈200 to ≈400 µg/g among the tested samples, showing important differences observed in relation to the influence of the evaluated parameters.

Mechanism of Action and Interactions between Thyroid Peroxidase and Lipoxygenase Inhibitors Derived from Plant Sources

This study focused on the effect of kaempferol, catechin, apigenin, sinapinic acid, and extracts from plants (i.e., parsley, cumin, mustard, green tea, and green coffee) on thyroid peroxidase (TPO) and lipoxygenase (LOX) activity, antiradical potential, as well as the result of interactions among them. Catechin, sinapinic acid, and kaempferol acted as a competitive TPO inhibitors, while apigenin demonstrated an uncompetitive mode of inhibitory action. Ethanol extracts from all plants acted as competitive TPO inhibitors, while, after in vitro digestion, TPO activation was found especially in the case of mustard (24%) and cumin (19.85%). Most importantly, TPO activators acted synergistically. The TPO effectors acted as LOX inhibitors. The most effective were potentially bioaccessible compounds from green tea and green coffee (IC50 = 29.73 mg DW/mL and 30.43 mg DW/mL, respectively). The highest free radical scavenging ability was determined for catechin and sinapinic acid (IC50 = 78.37 µg/mL and 84.33 µg/mL, respectively) and potentially bioaccessible compounds from mustard (0.42 mg DW/mL) and green coffee (0.87 mg DW/mL). Green coffee, green tea, cumin, and mustard contain potentially bioaccessible TPO activators that also act as effective LOX inhibitors, which indicate their potentially health-promoting effects for people suffering from Hashimoto’s disease.