Phenolic profiles and antioxidant activity of defatted camelina and sophia seeds

The effect of post-harvest technologies on selected metabolites in persimmon (Diospyros kaki Thunb.) fruit

BACKGROUND

Tannins are frequently a main focus in the investigation of de-astringency treatments of persimmon, and the effect of a controlled atmosphere on other phytochemicals is often overlooked. In the present study, changes in the content of total soluble and insoluble phenolics, soluble tannins, saponins, and carotenoids, as well as changes in primary metabolites, were monitored.

RESULTS

Generally, treatment with ethylene induced a decrease in total phenolic content, whereas, when treated with CO₂ , the content of total phenolics remained unchanged compared to the level of total phenolics before treatment. Treatment with apple-sourced ethylene did not significantly affect the level of total phenolics. Additionally, for both varieties, 'Kaki Tipo' and 'Rojo Brillante', the share of insoluble phenolics strongly increased when treated with CO₂ , whereas, when treated with ethylene, the same change applied for the ratio of soluble phenolics. The content of carotenoids varied markedly among treatments and varieties, whereas the content of total saponins remained unchanged, regardless of the treatment and variety.

CONCLUSION

The results obtained in the present study show that the content of metabolites in persimmon was affected markedly and variedly using post-harvest technology. Apart from the treatment used, changes in the content of metabolites are also affected markedly by the persimmon variety. © 2018 Society of Chemical Industry.

Opinion on the Hurdles and Potential Health Benefits in Value-Added Use of Plant Food Processing By-Products as Sources of Phenolic Compounds

Plant foods, their products and processing by-products are well recognized as important sources of phenolic compounds. Recent studies in this field have demonstrated that food processing by-products are often richer sources of bioactive compounds as compared with their original feedstock. However, their final application as a source of nutraceuticals and bioactives requires addressing certain hurdles and challenges. This review discusses recent knowledge advances in the use of plant food processing by-products as sources of phenolic compounds with special attention to the role of genetics on the distribution and biosynthesis of plant phenolics, as well as their profiling and screening, potential health benefits, and safety issues. The potentialities in health improvement from food phenolics in animal models and in humans is well substantiated, however, considering the emerging market of plant food by-products as potential sources of phenolic bioactives, more research in humans is deemed necessary.

Identification of Epigenetic Mechanisms Involved in the Anti-Asthmatic Effects of Descurainia sophia Seed Extract Based on a Multi-Omics Approach

Asthma, a heterogeneous disease of the airways, is common around the world, but little is known about the molecular mechanisms underlying the interactions between DNA methylation and gene expression in relation to this disease. The seeds of Descurainia sophia are traditionally used to treat coughs, asthma and edema, but their effects on asthma have not been investigated by multi-omics analysis. We undertook this study to assess the epigenetic effects of ethanol extract of D. sophia seeds (DSE) in an ovalbumin (OVA)-induced mouse model of asthma. We profiled genome-wide DNA methylation by Methyl-seq and characterized the transcriptome by RNA-seq in mouse lung tissue under three conditions: saline control, OVA-induced, and DSE-treated. In total, 1995 differentially methylated regions (DMRs) were identified in association with anti-asthmatic effects, most in promoter and coding regions. Among them, 25 DMRs were negatively correlated with the expression of the corresponding 18 genes. These genes were related to development of the lung, respiratory tube and respiratory system. Our findings provide insights into the anti-asthmatic effects of D. sophia seeds and reveal the epigenetic targets of anti-inflammatory processes in mice.

Antidepressant activity of an aqueous extract from okra seeds

Faced with the increasing incidence of major depression disorder (MDD) and the unsatisfactory effect of current drugs, there has been growing attention on the relation between dietary supplements and MDD prevention. In this research, the antidepressant activity of okra seed extract (OSE) was evaluated with behavioral tests including an open field test, tail suspension test (TST), forced-swimming test (FST) and novelty suppressed feeding test (NSFT) for sub-chronic treatment and chronic sleep-interruption (CSI) animal models. The chemical constituents of OSE were identified by using UPLC-DAD/Q-TOF MS. To investigate the mechanism, the prefrontal cortex and hippocampus were collected to determine neurotransmitters, total antioxidant capacity (T-AOC), superoxide dismutase (SOD) and malondialdehyde (MDA). Blood serum was prepared for the determination of corticosterone (CORT) and adrenocorticotropic hormone (ACTH). Results demonstrated that OSE possessed an antidepressant effect in both sub-chronic treatment and CSI animal models through suppressing the hyperactivation of the hypothalamic-pituitary-adrenal (HPA) axis, alleviating oxidative stress and regulating neurotransmitter levels in the hippocampus and frontal cortex. Besides, chemical analysis based on the UPLC-DAD/ESI-Q-TOF MS approach showed that OSE mainly contained catechin and quercetin derivatives. The present study provided a scientific basis for developing okra seeds to be a dietary supplement for MDD prevention.

Antioxidant Activity and In Vitro Antiglycation of the Fruit of Spondias purpurea

Hyperglycemia in diabetes mellitus causes irreversible life-threatening micro- and macrovascular complications. There is evidence that the glycation reaction leads to a chemical modification of the proteins contributing to the complications of diabetes. It is known that advanced glycation end products (AGEs) are formed by glycation and oxidation reactions called glycoxidation. CML, a nonfluorescent AGE, has become a biomarker of glycoxidative damage; other AGEs appear to induce oxidative stress, which results in cytotoxicity. To determine antioxidant activity, the FRAP, DPPH, and TEAC tests were used, as well as the polyphenols content using Folin-Ciocalteu's method. To evaluate the antiglycation activity, the BSA/glucose system was used, and the fructosamine concentration, protein carbonyl content, thiol, and CML groups were determined. The results obtained show that the hexane extract of the fruit of Spondias purpurea (CFH) effectively inhibits the glycation reaction, in addition to increasing the thiol groups and decreasing levels of fructosamine, protein carbonyl, and CML. In addition, CFH presented significant antioxidant activity. CFH inhibits the glycation reaction; therefore, it can help prevent complications related to AGEs in diabetes mellitus; it also reduces oxidative stress and is effective in protecting proteins from oxidative damage.

Antioxidants in flour of the oilseed crop Camelina sativa (L.) Crantz

Forty-seven accessions of Camelina sativa (L.) Crants (41 spring and 6 winter forms) were analyzed for antioxidant activity, total phenolic content (TPC), flavonoids and proanthocyanidins. The antioxidant activity (AA%) was high in camelina accessions and with a significant variability among accessions and between spring and winter forms. The highest antioxidant activities have been observed in some spring accessions (CAM35, CAM173 and CAM268). TPC was high in camelina and significantly different among accessions. Antioxidant activity resulted highly correlated with TPC, while no correlation was observed with flavonoid and proanthocyanidin contents. Significant variability was observed among accessions but not between groups (winter and spring) for flavonoid and proanthocyanidin contents. These two classes of compounds showed a significant inverse correlation between them suggesting that their synthesis is in competition. The camelina cake can enrich the animal diet of antioxidant compounds (phenolics) and some spring accessions are more promising for future breeding programs.

UPLC-ESI-QTOF-MS²-Based Identification and Antioxidant Activity Assessment of Phenolic Compounds from Red Corn Cob (Zea mays L.)

In this study, the extraction of phenolic antioxidants from red corn cob was carried out using ultrasound-assisted extraction (UAE). The solid:liquid ratio and extraction time were evaluated when obtaining these bioactive compounds. The total phenolic contents were evaluated using the Folin Ciocalteu method, while the antioxidant activity was measured by ABTS^•+ and DPPH^• assays. The amount of phenolic compounds ranged from 215.17 ± 33.49 to 527.33 ± 103.79 GAE mg/100 g and, overall, high solid:liquid ratios and time periods release more phenolic compounds. Moreover, the red corn cob extracts showed higher radical scavenging capacity according to the results obtained using the ABTS^•+ technique compared to the DPPH^• test. The coupling of liquid chromatography and mass spectrometry assay allowed the determination of 11 phenolic compounds, including phenolic acids and flavonoids. Thus, our results demonstrated for the first time the potential of red corn cob as a source of bioactive compounds, which might be included in food and pharmacological preparations.

Antioxidant Activity and Spectroscopic Characteristics of Extractable and Non-Extractable Phenolics from Terminalia sericea Burch. ex DC

The aim of this study was to determine the antioxidant activity of the extractable and non-extractable phenolics of Terminalia. Sericea Burch. Ex DC. Free, ester bound, ether or glycoside bound and insoluble phenolics were extracted from the fruit, leaves, stem, and root samples. Follin Ciocalteu was used to estimate the phenolic content while DPPH (2,2-diphenyl-1-picrylhydrazyl) assay was used to determine the antioxidant activity. The data obtained were subjected to multivariate analysis for relationships. The result indicated that the highest average total phenolic contents and antioxidant activities were found in the free (14.8 mgGAE/g; IC50 6.8 μg/mL) and ester bound (15.1 mgGAE/g; IC50 6.4 μg/mL) extractable phenolics. There was a strong negative correlation between TPC and DPPH (r = -0.828). Agglomerative hierarchical clustering revealed three clusters. Cluster one contained the insoluble and glycoside phenolics while cluster 2 contained only free phenolic acid of the root. The third cluster was predominantly free and ester bound phenolic extracts. The principal component analysis score plot indicated two major clusters with factor 1 (F1) explaining 61% of the variation. The nuclear magnetic resonance spectroscopy spectra indicated that gallic acid and resveratrol are the major phenolic compounds present in the root. This study has demonstrated that extractable phenolics contributed more to the antioxidant activities compared to the non-extractables.

Biological Activities of Camelina and Sophia Seeds Phenolics: Inhibition of LDL Oxidation, DNA Damage, and Pancreatic Lipase and α-Glucosidase Activities

The free, esterified and insoluble-bound phenolics of defatted meals of camelina and sophia seeds were extracted using an ultrasonic-assisted procedure and alkaline hydrolysis. The antioxidant activities of the extracts were evaluated using DPPH and hydroxyl radical scavenging assays as well as inhibition of bleaching of β-carotene in an oil-in-water system. Moreover, inhibition activity against pancreatic lipase, α-glucosidase, low density lipoprotein (LDL) oxidation and DNA damage induced by peroxyl and hydroxyl radicals were examined for all seed extracts using in vitro systems. The seed extracts of camelina and sophia not only showed significant antioxidant activity but also inhibited pancreatic lipase and α-glucosidase activities effectively. These enzymes in the digestive tract are associated with lipid and carbohydrate digestion, respectively, and control obesity and blood glucose level in the human body. The findings of this work may provide supporting information that camelina and sophia meals may inhibit human LDL oxidation and DNA nicking caused by free radicals and upon consumption may also exert anti-obesity and antidiabetic effects. However, further research is required to confirm these biological activities in vivo.

PRACTICAL APPLICATION

The seed phenolic extracts of camelina and sophia not only showed significant antioxidant activity but also effectively inhibited the activities of pancreatic lipase and α-glucosidase. Thus, camelina and sophia seed meals may serve as nutritional ingredients with bioactive phenolics that show in vitro antioxidant and biological effects. However, further research is required to confirm these health effects in vivo.