Spectrophotometric Determination of Phenolic Antioxidants in the Presence of Thiols and Proteins

Highly sensitive and selective electrochemical sensor for simultaneous determination of gallic acid, theophylline and caffeine using poly(l-proline) decorated carbon nanotubes in biological and food samples

In this work, a novel, simple and reproducible poly(l-proline)/functionalized multi-walled carbon nanotube composite on glassy carbon electrode (poly(PRO)-MWCNTs/GCE) was developed as an electrochemical sensor for the simultaneous determination of gallic acid (GA), theophylline (TP) and caffeine (CAF) by differential pulse voltammetry (DPV). The sensing platform was optimized by experimental design and response surface methodology, using various factors affecting polymerization and detection, such as electropolymerization time and potential, and pH, respectively. As a result, the dispersion conditions were the mixing of 1.78 mg MWCNTs with 1.00 mL l-proline solution to 4.14 mg mL-1 (in SDBS 0.5%), followed by 21 min of sonication with electropolymerization by 16 cyclic scans. In addition, the final analysis was performed at a pH of 3.00 and prior accumulation at 0.350 V for 40 s. The electrochemical behavior of GA, TP and CAF on the optimized sensor was investigated. As a result, the electrode preserves and synergistically combines the properties of each modifier. This new electrochemical sensor showed superior electrocatalytic properties for the oxidation of GA, TP and CAF, which significantly improved the sensitivity of the three compounds. Under the optimized experimental conditions, the detection limits achieved by S/N were 0.03, 0.04 and 0.11 μmol L-1 for GA, TP and CAF, respectively. The analysis of real samples was successfully performed in human breast milk, tea, infusion of yerba mate, coffee, Coca-Cola zero and energy drink, showing good recoveries, ranged between 87 and 108%. The proposed sensor also showed good selectivity, repeatability and reproducibility, indicating feasibility and reliability. This is the first time that the l-proline monomer is used as a dispersant for MWCNTs and as a precursor for the in-situ polymerization of the proline polymer. Previously, the electropolymerizations were carried out with the monomer in solution rather than as an exfoliant of MWCNTs, where the polymer is electrosynthesized between MWCNTs rather than on them. In this way, the large specific surface area and strong adsorption ability of the nanomaterial are enhanced, and the ability to promote electron transfer reaction is increased, which provides enough effective reaction sites.

A novel electrochemical sensor based on an Fe–N–C/AuNP nanohybrid for rapid and sensitive gallic acid detection

An Fe–N–C/AuNP nanohybrid was combined with a glassy carbon electrode to construct a novel electrochemical sensor for rapid detection of gallic acid (GA). The sensor exhibited excellent performance to detect GA with a wide linear response range and low detection limit.

The Anthocyanin Accumulation Related ZmBZ1, Facilitates Seedling Salinity Stress Tolerance via ROS Scavenging

Anthocyanins are a class of antioxidants that scavenge free radicals in cells and play an important role in promoting human health and preventing many diseases. Here, we characterized a maize Bronze gene (BZ1) from the purple colored W22 introgression line, which encodes an anthocyanin 3-O-glucosyltransferase, a key enzyme in the anthocyanin synthesis pathway. Mutation of ZmBZ1 showed bronze-colored seeds and reduced anthocyanins in seeds aleurone layer, seedlings coleoptile, and stem of mature plants by comparison with purple colored W22 (WT). Furthermore, we proved that maize BZ1 is an aleurone layer-specific expressed protein and sub-located in cell nucleus. Real-time tracing of the anthocyanins in developing seeds demonstrated that the pigment was visible from 16 DAP (day after pollination) in field condition, and first deposited in the crown part then spread all over the seed. Additionally, it was transferred along with the embryo cell activity during seed germination, from aleurone layer to cotyledon and coleoptile, as confirmed by microscopy and real-time qRT-PCR. Finally, we demonstrated that the ZmBZ1 contributes to stress tolerance, especially salinity. Further study proved that ZmBZ1 participates in reactive oxygen scavenging (ROS) by accumulating anthocyanins, thereby enhancing the tolerance to abiotic stress.

A New Cryptic Lineage in Parmeliaceae (Ascomycota) with Pharmacological Properties

We used molecular data to address species delimitation in a species complex of the parmelioid genus Canoparmelia and compare the pharmacological properties of the two clades identified. We used HPLC_DAD_MS chromatography to identify and quantify the secondary substances and used a concatenated data set of three ribosomal markers to infer phylogenetic relationships. Some historical herbarium specimens were also examined. We found two groups that showed distinct pharmacological properties. The phylogenetic study supported the separation of these two groups as distinct lineages, which are here accepted as distinct species: Canoparmelia caroliniana occurring in temperate to tropical ecosystems of a variety of worldwide localities, including America, Macaronesia, south-west Europe and potentially East Africa, whereas the Kenyan populations represent the second group, for which we propose the new species C. kakamegaensis Garrido-Huéscar, Divakar & Kirika. This study highlights the importance of recognizing cryptic species using molecular data, since it can result in detecting lineages with pharmacological properties previously overlooked.

Phytochemical Characterization and Pharmacological Properties of Lichen Extracts from Cetrarioid Clade by Multivariate Analysis and Molecular Docking

Introduction

Lichens, due to the presence of own secondary metabolites such as depsidones and depsides, became a promising source of health-promoting organisms with pharmacological activities. However, lichens and their active compounds have been much less studied. Therefore, the present study aims to evaluate for the first time the antioxidant capacity and enzyme inhibitory activities of 14 lichen extracts belonging to cetrarioid clade in order to identify new natural products with potential pharmacological activity.

Materials and Methods

In this study, an integrated strategy was applied combining multivariate statistical analysis (principal component analysis and hierarchical cluster analysis), phytochemical identification, activity evaluation (in vitro battery of antioxidant assays FRAP, DPPH, and ORAC), and enzyme inhibitory activity against acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) and molecular profiling with in silico docking studies of the most promising secondary metabolites. Results. Among fourteen lichen samples, Dactylina arctica stands out for its higher antioxidant capacities, followed by Nephromopsis stracheyi, Tuckermannopsis americana, Vulpicida pinastri, and Asahinea scholanderi. Moreover, Asahinea scholanderi and Cetraria cucullata extracts were the best inhibitors of AChE and BuChE. The major secondary metabolites identified by HPLC were alectoronic acid and α-collatolic acid for Asahinea scholanderi and usnic acid and protolichesterinic acid for Cetraria cucullata. Molecular docking studies revealed that alectoronic acid exhibited the strongest binding affinity with both AChE and BuChE with and without water molecules.

Conclusions

Our results concluded that these species could be effective in the treatment of neurodegenerative diseases, being mandatory further investigation in cell culture and in vivo models.

A 150 kDa Protein Derived from Bull Seminal Plasma Extended the Survival Time of Kacang Goat Sperm Stored at 5°C

Artificial insemination has proven to be an effective method for increasing population size and genetic quality of Kacang goats. However, innovation is required to maintain the quality of Kacang goat semen in storage. This study aimed to examine the effects of supplementing the 150 kDa protein assumed as IGF-I complex derived from bull seminal plasma in skim milk-egg yolk extender on the quality of Kacang goat sperm stored at 5°C. Twelve ejaculates collected from three Kacang goats were divided into three groups. In the control group (T0), the ejaculates were extended with skim milk-egg yolk only. In the treatment groups (T1 and T2), the ejaculates were extended with skim milk-egg yolk supplemented with the IGF-I complex protein at 12 μg and 24 μg/100 mL, respectively. The extended semen was stored at 5°C, and the viability, motility, intactness of the plasma membrane, malondialdehyde concentration, and apoptotic sperm percentage were evaluated daily for five days. The results showed that the T1 was the most effective treatment for maintaining Kacang goat semen at a quality acceptable for artificial insemination over five days of storage at 5°C. However, the T0 and T2 groups retained acceptable qualities for only three days at 5°C. It could be concluded that supplementation of 12 μg of the 150 kDa protein derived from bull seminal plasma per 100 mL extender successfully extended the life span of Kacang goat sperm for five days.

Effect of insulin-like growth factor-1 complex of Simmental bull seminal plasma on post-thawed Kacang buck semen fertility

Background and Aim

Kacang buck sperm is cryosensitive due to the seminal plasma of semen itself. Meanwhile, bull seminal plasma contains the insulin-like growth factor-1 (IGF-1) complex, which is cryoprotective. The addition of the crude protein of Simmental bull seminal plasma increased the quality of post-thawed semen of Kacang buck. The study was conducted to determine the effects of Simmental bull seminal plasma with IGF-1 on the fertility of post-thawed Kacang buck semen.

Materials and Methods

Buck semen was diluted in the following skim milk-egg yolk extender preparations: Without the addition of Simmental bull seminal plasma IGF-1 complex protein (T0); with the addition of 12-μg Simmental bull seminal plasma IGF-1 complex protein (T1); and with the addition of 24-μg Simmental bull seminal plasma IGF-1 complex protein (T2). The extended semen was packed in 0.25-mL straws and frozen. Post-thawed semen fertility was evaluated based on the following variables: Sperm motility, viability, intact plasma membrane (IPM), malondialdehyde (MDA) levels, capacitation status, and acrosome reaction. The difference in each variable among the groups was evaluated using analysis of variance, followed by Tukey's honestly significant difference test, at a 95% level of significance. Meanwhile, principal component analysis (PCA) was used to identify the principal component of semen fertility among the seven parameters.

Results

The T1 group showed the highest sperm motility, viability, IPM, and percentage of incapacitated sperm and the lowest MDA levels, percentage of capacitated sperm, and acrosome reaction. PCA revealed that sperm motility had a moderate to very robust correlation with other variables and is the most crucial parameter, accounting for 80.79% of all variables.

Conclusion

The IGF-1 complex in Simmental bull seminal plasma was useful for increasing the fertility of post-thawed Kacang buck semen, and sperm motility was the principal component of semen fertility.

Nutritional Value of Moringa oleifera Lam. Leaf Powder Extracts and Their Neuroprotective Effects via Antioxidative and Mitochondrial Regulation

Age-related neurodegenerative disorders are an increasing public health problem. Oxidative stress is one of the major causes. Medicinal plant-based functional foods can be effective for these diseases. The aim of this work is to investigate the neuroprotective role of methanol extracts of Moringa oleifera leaf powder on antioxidant/oxidant imbalance and mitochondrial regulation in a H₂O₂-induced oxidative stress model in human neuroblastoma cells. On nutritional analysis, results showed that moringa contained 28.50% carbohydrates, 25.02% proteins, 10.42% fat, 11.83% dietary fiber, 1.108 mg β-carotene, 326.4 µg/100 g vitamin B1 and 15.2 mg/100 g vitamin C. In-vitro assays revealed that moringa methanol extracts had more phenolic content and higher antioxidant activity than acetone extracts. Moreover, pretreatments with methanol extracts showed a protective effect against H₂O₂-induced oxidative damage through increasing cell viability and reducing free radicals. Furthermore, the extract decreased lipid peroxidation and enhanced glutathione levels and antioxidant enzyme activity. Finally, moringa also prevented mitochondrial dysfunction by regulating calcium levels and increasing mitochondrial membrane potential. The most active concentration was 25 µg/mL. In summary, the nutritional and functional properties of Moringa oleifera as a neuroprotective agent could be beneficial to protect against oxidative stress and provide necessary nutrients for a healthy diet.

CUPRAC-Reactive Advanced Glycation End Products as Prognostic Markers of Human Acute Myocardial Infarction

Cardiovascular disorders, especially acute coronary syndromes, are among the leading causes of mortality worldwide, and advanced glycation end products (AGEs) are associated with cardiovascular disease and serve as biomarkers for diagnosis and prediction. In this study, we investigated the utility of AGEs as prognostic biomarkers for acute myocardial infarction (AMI). We measured AGEs in serum samples of AMI patients (N = 27) using the cupric ion reducing antioxidant capacity (CUPRAC) method on days 0, 2, 14, 30, and 90 after AMI, and the correlation of serum AGE concentration and post-AMI duration was determined using Spearman's correlation analysis. Compared to total serum protein, the level of CUPRAC reactive AGEs was increased from 0.9 to 2.1 times between 0-90 days after AMI incident. Furthermore, the glycation pattern and Spearman's correlation analysis revealed four dominant patterns of AGE concentration changes in AMI patients: stable AGE levels (straight line with no peak), continuous increase, single peak pattern, and multimodal pattern (two or more peaks). In conclusion, CUPRAC-reactive AGEs can be developed as a potential prognostic biomarker for AMI through long-term clinical studies.

Lichens of Parmelioid Clade as Promising Multitarget Neuroprotective Agents

Neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease are multifactorial disorders which are increasing in incidence and prevalence over the world without existing effective therapies. The search for new multitarget compounds is the latter therapeutic strategy to address these pathological conditions. Lichens have an important and unknown therapeutic value attributed to their unique secondary metabolites. The aim of this study is to evaluate for the first time the in vitro neuroprotective activities and molecular mechanisms underlying methanol extracts of lichens of the parmelioid clade and to characterize major bioactive secondary metabolites responsible for their pharmacological actions. Of the 15 parmelioid lichen species, our results showed that Parmotrema perlatum and Hypotrachyna formosana methanol extracts exhibited high antioxidant activity as evidenced in ORAC, DPPH, and FRAP assays. Then, SH-SY5Y cells were pretreated with methanol extracts (24 h) followed by Fenton reagent exposure (2 h). Pretreatments with these two more antioxidant methanol lichen extracts increased cell viability, reduced intracellular ROS, prevented oxidative stress biomarkers accumulation, and upregulated antioxidant enzyme (CAT, SOD, GR, and GPx) activity compared to Fenton reagent cells. The neuroprotective activity was much higher for H. formosana than for P. perlatum, even equal to or higher than Trolox (reference compound). Moreover, H. formosana extracts inhibited both AChE and BuChE activities in a concentration dependent manner, and P. perlatum only showed concentration dependent activity against AChE. Finally, chemical composition analysis using TLC and HPLC methods revealed that physodic acid, lividic acid, and lichexanthone are major secondary metabolites in H. formosana and stictic acid and constictic acid are in P. perlatum. These results demonstrated that P. perlatum and, specially, H. formosana are promising multitargeted neuroprotective agents due to their antioxidant and AChE and BuChE inhibition activities.

Heat treatment as postharvest tool for improving quality in extra-early nectarines

BACKGROUND

Extra-early nectarine cultivars such as 'VioWhite 5' could present a lack of organoleptic and nutritional quality. Heat treatments (HT) can be applied to improve their primary characteristics. In this experiment, control (non-treated), HT₁ (3 h; 45 °C) and HT₂ (2 h; 50 °C) were studied. Fruit were stored (10 days; 0 ± 0.5 °C; 90-95% RH) followed by a simulated retail sale period (3 days; 15 °C; 70-75% RH).

RESULTS

HT fruit showed higher weight loss (2.76 ± 0.06% and 3.32 ± 0.01% for HT₁ and HT₂ , respectively; vs. 2.23 ± 0.14% for control) and lower firmness than control samples (28.88% and 21.67% less for HT₁ and HT₂ , respectively). HT treatments induced an increase in soluble solids content and a decrease in total acidity, which led to a better sensory quality. These changes were positively received by consumers. Total antioxidant capacity was enhanced by HT due to an increase in phenolic compound content. A higher enzymatic activity was found in pectin methylesterase and polygaracturonase in HT nectarines when compared to control.

CONCLUSION

The application of HT on extra-early nectarine cv. demonstrated a strong potential to improve consumption quality in the industry. © 2017 Society of Chemical Industry.