Major Antioxidant Research Articles

Variations of Major Flavonoids, Nutritional Components, and Antioxidant Activities in Mung Beans (Vigna radiate L.) of Different Seed Weights

This study examined the levels of major flavonoids, nutritional components, total secondary metabolite contents, and antioxidant activities in 136 mung bean accessions and statistically analyzed the effect of seed weight difference on each. Vitexin and isovitexin were detected in all the mung bean accessions, with isovitexin being in a higher concentration regardless of seed weight difference. The contents of total protein and total starch were in the ranges of 22.01–28.96 and 32.62–49.03 g/100 g, respectively. Five fatty acids were detected by GC–FID analysis in all mung bean accessions, with linoleic acid being the most dominant (37.96–50.71 g/100 g). Total saponin content (TSC), total phenol content (TPC), DPPH• scavenging activity, ABTS•+ scavenging activity, and ferric reducing antioxidant power (FRAP) showed more than five-fold differences. Analysis of variance supported by multivariate analysis demonstrated that seed weight difference had a significant effect on total starch, all individual fatty acids except for stearic acid and oleic acid, TSC, and all antioxidant activities except for ABTS•+ scavenging activity. On the other hand, vitexin, isovitexin, total protein, total phenol, and total fatty acid contents remained unaffected by seed weight difference. Overall, this study showed the diversity of key flavonoids, nutritional components, total secondary metabolite contents, and antioxidant activities in mung bean genetic materials. Moreover, the study unveiled how seed weight affects the analyzed parameters in mung beans for the first time. These findings could maximize the use of mung beans in food industries and breeding programs as well as lead to more studies in metabolomics and genomics.

Alleviating effect of whey protein supplementation on oxidative stress in hypothyroidism.

Hypothyroidism is one of the most prevalent thyroid pathologies, which causes oxidative stress by disrupting antioxidant mechanisms. In mammals, the thyroid glands regulate metabolism, development, and growth. Dysfunction of the thyroid gland can result in hypothyroidism, hyperthyroidism, thyroiditis, and thyroid cancer. Whey protein is a widely consumed protein supplement containing abundant sulphur-containing amino acids and bioactive peptides. Here, we analysed the effect of whey protein on oxidative stress in hypothyroidism. In vivo studies were conducted in two phases for 30 and 90 days, respectively. Hypothyroidism was induced in Wistar albino rats by administering 0.05% propylthiouracil (PTU) through drinking water. Five hypothyroid groups and the normal control group were maintained in the first 30 day phase of the study. Among these, one group served as the induced control group, three groups received whey protein at different concentrations (100, 300, and 500 mg per kg body weight), and the last group received L-thyroxine (2 μg per 100 g body weight) as a positive medication. The activities of antioxidant enzymes, such as superoxide dismutase, catalase, glutathione peroxidase, and glutathione-S-transferase, were analysed, and the levels of total antioxidants, glutathione, and malondialdehyde were determined. Ca2+ ATPase and Na+/K+ ATPase activities were detected by estimating the inorganic phosphate content. Histopathological analysis was carried out on the thyroid and liver tissues of all groups. Antioxidant activity was notably increased for higher doses of whey protein compared to that in the diseased control group (p < 0.05). From this initial study, the dose that achieved the desired therapeutic effect was 500 mg kg-1, which was considered for the next 90 day phase of the study. The 90 day phase of the study was conducted with five groups: normal, whey protein-supplemented, hypothyroid, whey protein-supplemented hypothyroid, and levothyroxine-supplemented hypothyroid. All the PTU-treated groups showed degenerative alterations in thyroid histology. Whey protein supplementation causes a considerable decrease in MDA levels with an increase in the major antioxidant enzyme and ATPase activities, with p < 0.05. As a nutritional supplement, whey protein, at a 500 mg kg-1 dose, effectively boosts antioxidant activity without causing any toxicological concerns in long-term use.

Analysis of Antioxidants from Three Parts of Polygonum Chinense Based on Online Extraction High Performance Liquid Chromatography Antioxidant Analysis System.

In the current study, a rapid online extraction combined with high-performance liquid chromatography (HPLC) antioxidant analysis approach was developed to explore the antioxidant ingredients in three different parts of Polygonum Chinense. A total of 22 chromatographic peaks were found, among which 8 components were found for the first time. And among these 22 peaks, 19 of them were demonstrated as antioxidants. Furthermo, all three parts from Polygonum Chinense exhibited antioxidant activity (13.19, 3.89, and 19.85 mg CE/g extract, for the leaf, stem, and flower, respectively) and the antioxidant activity values of the leaf and flower were more than 3 times that of the stem. The leaf, flower, and stem of Polygonum Chinense had 17, 13, and 15 antioxidant components, respectively. Among them, neochlorogenic acid (2) and quercetin-3-O-malonylglucoside (18) were considered as the main antioxidants in the leaf of Polygonum Chinense. In terms of flower, geraniin (10) and quercetin-3-O-malonylglucoside (18) were proved as the major antioxidants. This is the first report on the antioxidant components from different parts of Polygonum Chinense. It provides foundational scientific data for the continued exploration of chemical and pharmacological study of Polygonum Chinense, beneficial for the future product development and quality evaluation improvement of Polygonum Chinense.

Level of uric acid and its, relationship with lipid peroxidation in sera of patients with acute coronary syndrome

Unstable angina pectoris often leads to acute myocardial infarction. Since uric acid is thought to be risk factor for cardiovascular disease and considered a major antioxidant in human blood .The level of uric acid and lipid peroxidation in the sera of patients with unstable angina and myocardial infarction were measured and compared to the healthy individuals. Twenty-nine patients with unstable angina and twenty-nine patients with myocardial infarction were studied and compared to twenty-five healthy individuals. Uric acid was measured by using Human Kit. Malondialdelyde (MDA) a lipid peroxidation marker, was measured by thiobarbituric acid method .Significant elevation of uric acid and MDA were observed in the sera of patients with unstable angina and myocardial infarction compared to the control group , while a non significant correlation between uric acid and lipid peroxidation were found in the present study in the sera of patients with unstable angina and myocardial infarction.

Combined environmental relevant exposure to perfluorooctanoic acid and zinc sulfate enhances apoptosis through binding with endogenous antioxidants in Daphnia magna

Perfluorooctanoic acid (PFOA) is a long-chain legacy congener of the per- and polyfluoroalkyl substances (PFAS) family, notorious as a "forever chemical" owing to its environmental persistence and toxic nature. Essential elements such as zinc (Zn) can cause toxic effects when they change their metal speciation and become bioavailable, such as zinc sulphate (ZnSO4). Combined toxicity assessment is a realistic approach and a challenging task to evaluate chemical interactions and associated risks. Therefore, the present study aims to elucidate the acute mixture toxicity (12–48 hours) of PFOA and ZnSO4 in Daphnia magna at environment-relevant concentrations (ERCs, low dose: PFOA 10 μg/L ZnSO4 20 μg/L; high dose: PFOA 20 μg/L ZnSO4 50 μg/L) in terms of developmental impact, apoptosis induction, and interaction with major endogenous antioxidants. Our results showed that deformity rates significantly increased (p < 0.05) with increasing exposure duration and exposure concentrations, compared to the control group. Further, lack of antenna, tale degeneration, and carapace alterations were the most commonly observed deformities following combined exposure to PFOA and ZnSO4, and these malformations were particularly pronounced after 48 h of exposure. Acridine orange (AO) staining was employed to examine apoptosis in D. magna, and apoptotic cells in terms of bright green fluorescence were detected in the abdominal claw carapace, heart, and post-abdominal area following exposure to a high dose of PFOA and ZnSO4. The molecular docking results revealed that both PFOA and ZnSO4 showed strong binding affinities with endogenous antioxidants CAT and GST, where PFOA was more strongly bound with CAT and GST with higher docking scores of -9.59 Kcal/mol and -7.49 Kcal/mol than those with ZnSO4 (-6.70 Kcal/mol and -6.55 Kcal/mol, respectively). In conclusion, the mixture exposure to PFOA and ZnSO4 at the environmental level induce developmental impacts and apoptosis through binding with major endogenous antioxidants in D. magna.

Human anti-apoptotic Bcl-2 and Bcl-xL proteins protect yeast cells from aging induced oxidative stress

Aging is a degenerative, biological, and time-dependent process that affects all organisms. Yeast aging is a physiological phenomenon characterized by the progressive transformation of yeast cells, resulting in modifications to their viability and vitality. Aging in yeast cells is comparable to that in higher organisms in some respects; however, due to their straightforward and well-characterized genetic makeup, these cells present unique advantages when it comes to researching the aging process. Here, we assessed the impact of human anti-apoptotic Bcl-2 and Bcl-xL proteins on aging using a yeast model. The findings clearly showed that these proteins exhibited remarkable anti-aging properties in yeast cells. Our data indicate that the presence of both proteins enhanced the reproductive survival of aging cells, likely by effecting the components functioning as both pro- and anti-oxidants, depending on the stage of yeast cell lifespan. Both proteins partially protected yeast cells from aging-related morphological deformations and cellular damage during the aging period. In particular, Bcl-xL expressing yeast cells reached the maximum activity levels for almost all of the major antioxidant enzymes and the total antioxidant status on the 8th day of lifespan and could provide effective protection at the latest stage of the investigated aging period. The chemometric data analysis of IR spectra confirmed the findings of the morphological and biochemical analyses. In this regard, specifically, understanding the mechanism of action on the cellular redox state of Bcl-xL in yeast may facilitate comprehension of its indirect antioxidant function in higher eukaryotes.

WTAP weakens oxaliplatin chemosensitivity of colorectal cancer by preventing PANoptosis

As the most abundant post-transcriptional modification in eukaryotes, N6-methyladenosine (m6A) plays a crucial role in cancer cell proliferation, invasion and chemoresistance. However, its specific effects on chemosensitivity to oxaliplatin-based regimens and the impact of these drugs on m6A methylation levels in colorectal cancer (CRC) remain largely unexplored. In this study, we demonstrated that the m6A methyltransferase Wilms tumor 1-associating protein (WTAP) weakens oxaliplatin chemosensitivity in HCT116 and DLD1 cells. Mechanistically, oxaliplatin treatment upregulated WTAP expression, preventing multiple forms of cell death simultaneously, a process known as PANoptosis, by decreasing intracellular oxidative stress through maintaining the expression of nuclear factor erythroid-2-related factor 2 (NRF2), a major antioxidant response element, in an m6A-dependent manner. In addition, high WTAP expression in CRC patients is associated with a poor prognosis and reduced benefit from standard chemotherapy by clinical data analysis of The Cancer Genome Atlas (TCGA) database and patient cohort study. These findings suggest that targeting WTAP-NRF2-PANoptosis axis could enhance the antitumor efficacy of oxaliplatin-based chemotherapy in CRC treatment.

Synergistic effects between microplastics and glyphosate on honey bee larvae

Microplastic (MPs) pollution has emerged as a global ecological concern, however, the impact of MPs exposure, particularly in conjunction with other pollutants such as glyphosate (GLY) on honey bee remains unknown. This study investigated the effects of exposure to different concentrations of MPs and their combination with GLY on honey bee larvae development, or during the larvae period, regulation of major detoxification, antioxidant and immune genes, and oxidative stress biomarkers. Results revealed that combined exposure to MPs and GLY decreased larvae survivorship and weight, while exposure to MPs alone showed no significant differences. Both MPs and GLY alone downregulated the defensin-1 gene, but only combined exposure with GLY downregulated the hymenoptaecin gene and increased catalase enzyme activity. The data suggest a synergistic effect of MPs and GLY, leading to immunosuppression and reduced larvae survival and weight. These findings highlight potential risks of two prevalent environmental pollutants on honey bee health.

Temperature change regulates pollen fertility of a PTGMS rice line PA64S by modulating the ROS homeostasis and PCD within the tapetum.

Photoperiod and temperature-sensitive male sterility rice is an important line for two-line hybrid rice, and the changes in the cultivation temperature strictly control its pollen fertility. However, the mechanism by which temperature variation regulates pollen fertility is still unclear. This study obtained stable fertile PA64S(F) and sterile PA64S(S) rice from PA64S by controlling temperature changes. PA64S(F) shows a normal anther development and fertile pollen under low temperature (21°C), and PA64S(S) shows delayed degradation of the tapetum cells, leading to abnormal pollen wall formation and ubisch development under normal temperature (28°C). The accumulation of reactive oxygen species (ROS) positively correlates with the programmed cell death (PCD) process of tapetum cells. The delayed accumulation of ROS in the PA64S(S) tapetum at early stages leads to a delayed initiation of the PCD process. Importantly, we localized ascorbic acid (ASA) accumulation in the tapetum cells and determined that ASA is a major antioxidant for ROS homeostasis. ROS-inhibited accumulation plants (PA64S-ASA) demonstrated pollen sterility, higher ASA and lower ROS accumulation in the tapetum, and the absence of PCD processes in the tapetum cell. Abnormal changes in the tapetum of PA64S(S) rice disrupted metabolic pathways such as lipid metabolism, cutin and wax synthesis, sugar accumulation, and phenylpropane, affecting pollen wall formation and substance accumulation, suggesting that the timely accumulation of ROS is critical for male fertility. This study highlights the central role of ROS homeostasis in fertility alteration and also provides an avenue to address the effect of environmental temperature changes on pollen fertility in rice.

Nutritional and Medicinal uses of Different Types of Berries and Rabbit

This abstract will provide an outline of the nutritional and therapeutic benefits of several berries. It will focus on the major vitamins, minerals, antioxidants, and phytochemicals found in berries, as well as how these compounds can benefit overall health and well-being. The study will also look into the possible therapeutic applications of berries in the prevention and treatment of several health disorders, including cardiovascular disease, diabetes, and cancer. It will discuss the differences in nutrient profiles and bioactive chemicals found in various berry species, as well as how these variances may influence their distinct health-promoting properties. Furthermore, the abstract will discuss any potential safety risks or contraindications related with berry eating, particularly for people who have certain medical problems or are taking specific drugs.

Identification and quantification of the antioxidants in Ginkgo biloba leaf.

The antioxidant activity of Ginkgo biloba leaf (GBL) extract is closely related to its efficacy against various diseases; however, the antioxidant activities of the specific constituents of GBL remain unclear. In this study, 194 GBL constituents were identified using ultra-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry, including 97 flavonoids, 37 terpenoids, 29 lignans, 19 carboxylic acids, 5 alkylphenolic acids, 5 alkylphenols, and 2 other compounds. The cleavage rules of the main constituents of GBL were dissected in detail. The 36 GBL constituents with high antioxidant activity were subsequently discovered using the oxygen radical absorbance capacity assay, including 30 flavonoids and six carboxylic acids. Finally, an HPLC analysis method was established to determine the content of the nine major antioxidants in the three batches of GBL. Among them, kaempferol 3-O-β-D-(6″-p-coumaroyl) glucopyranosyl-(1-2)-α-L-rhamnopyranoside, kaempferol-3-O-rutinoside, and rutin exhibited high antioxidant activity and were found in significant amounts in GBL, with concentrations greater than 0.7mg/g. These results provide an important reference for the development of pharmaceuticals and health products containing GBL.

In Vitro Antioxidant, Anti-Inflammatory Activity and Bioaccessibility of Ethanolic Extracts from Mexican Moringa oleifera Leaf.

This study aimed to assess the antioxidant and anti-inflammatory properties, and bioaccessibility of Moringa oleifera ethanolic extracts using pressurized liquid extraction with varying ethanol concentrations (0%, 30%, 50%, 70%, and 100%) in water-ethanol mixtures. Quercetin derivatives and neochlorogenic acid were identified as major compounds via high-performance liquid chromatography with diode array detection. The 70% ethanol extract displayed the highest antioxidant activity and phenolic content, highlighting a strong correlation between phenolics and antioxidant potential. Extracts prepared with 50% and 70% ethanol (30 μg/mL) significantly inhibited TNF-α, IL-1β, and IL-6 cytokine secretion, with the 70% ethanol extract demonstrating robust anti-inflammatory effects. During in vitro digestion (oral, gastric, and intestinal phases), minimal changes were noted in most phenolic compounds' post-oral phase, but reductions occurred after the gastric phase. Substantial decreases in major compounds and antioxidant activity were observed in post-gastric and intestinal phases. Overall, ethanolic extracts of Moringa oleifera, particularly those with 70% ethanol, exhibit promising antioxidant and anti-inflammatory properties, suggesting potential for developing therapeutic agents against oxidative stress and inflammation-related disorders. However, it is essential to protect these compounds to prevent their degradation during digestion.

Gpx4 Regulates Invariant NKT Cell Homeostasis and Function by Preventing Lipid Peroxidation and Ferroptosis.

Invariant NKT (iNKT) cells are a group of innate-like T cells that plays important roles in immune homeostasis and activation. We found that iNKT cells, compared with CD4+ T cells, have significantly higher levels of lipid peroxidation in both mice and humans. Proteomic analysis also demonstrated that iNKT cells express higher levels of phospholipid hydroperoxidase glutathione peroxidase 4 (Gpx4), a major antioxidant enzyme that reduces lipid peroxidation and prevents ferroptosis. T cell-specific deletion of Gpx4 reduces iNKT cell population, most prominently the IFN-γ-producing NKT1 subset. RNA-sequencing analysis revealed that IFN-γ signaling, cell cycle regulation, and mitochondrial function are perturbed by Gpx4 deletion in iNKT cells. Consistently, we detected impaired cytokine production, elevated cell proliferation and cell death, and accumulation of lipid peroxides and mitochondrial reactive oxygen species in Gpx4 knockout iNKT cells. Ferroptosis inhibitors, iron chelators, vitamin E, and vitamin K2 can prevent ferroptosis induced by Gpx4 deficiency in iNKT cells and ameliorate the impaired function of iNKT cells due to Gpx4 inhibition. Last, vitamin E rescues iNKT cell population in Gpx4 knockout mice. Altogether, our findings reveal the critical role of Gpx4 in regulating iNKT cell homeostasis and function, through controlling lipid peroxidation and ferroptosis.

The Influence of Betulin and Its Derivatives on Selected Colorectal Cancer Cell Lines' Viability and Their Antioxidant Systems.

Oxidative stress is considered one of the main reasons for the development of colorectal cancer (CRC). Depending on the stage of the disease, variable activity of the main antioxidant enzymes, i.e., superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), is observed. Due to limited treatment methods for CRC, new substances with potential antitumor activity targeting pathways related to oxidative stress are currently being sought, with substances of natural origin, including betulin, leading the way. The betulin molecule is chemically modified to obtain new derivatives with improved pharmacokinetic properties and higher biological activity. The aim of this study was to evaluate the effects of betulin and its new derivatives on viability and major antioxidant systems in colorectal cancer cell lines. The study showed that betulin and its derivative EB5 affect the antioxidant enzyme activity to varying degrees at both the protein and mRNA levels. The SW1116 cell line is more resistant to the tested compounds than RKO, which may be due to differences in the genetic and epigenetic profiles of these lines.

Antioxidative and Antiglycative Stress Activities of Selenoglutathione Diselenide.

The damage caused by oxidative and glycative stress to cells accumulates on a daily basis and accelerates aging. Glutathione (GSH), a major antioxidant molecule in living organisms, plays a crucial role in detoxifying the stress-causing substances inherent in cells, such as H2O2 and methylglyoxal (MG), an important intermediate of advanced glycation end-products (AGEs). In this study, we focused on the enhanced antioxidant capacity of the selenium analog of GSH, i.e., selenoglutathione (GSeH), compared to GSH, and examined its effects on the detoxification of stress-causing substances and improvement in cell viability. In cell-free systems, GSeH (1 mM) generated in situ from GSeSeG in the presence of NADPH and glutathione reductase (GR) rapidly reduced more than 80% of 0.1 mM H2O2, indicating the significant glutathione peroxidase (GPx)-like antioxidant activity of GSeSeG. Similarly, around 50% of 0.5 mM MG was degraded by 0.5 mM GSeH within 30 min through a non-enzymatic mechanism. It was also found that GSeSeG (0.05-0.5 mM) showed glutathione S-transferase (GST)-like activity against 1-chloro-2,4-dinitrobenzene (CDNB), a model substance of oxidative stress-causing toxic materials in cells. Meanwhile, HeLa cells that had been pre-treated with GSeSeG exhibited increased viability against 1.2 mM H2O2 (at [GSeSeG] = 0.5-50 μM) and 4 mM MG (at [GSeSeG] = 3 μM), and the latter effect was maintained for two days. Thus, GSeSeG is a potential antioxidant and antiglycative stress agent for cells.

Dietary curcumin supplementation attenuates hepatic damage and function abnormality in a chronic corticosterone-induced stress model in broilers

Chronic stress refers to the activation of the hypothalamic-pituitary-adrenal (HPA) axis and elevated blood contents of ACTH and corticosterone (CORT), exhibiting significant adverse effects on health outcomes. Currently, natural polyphenol compounds are increasingly being explored as potential therapeutic agents and have been considered as a treatment option for a variety of stress-induced diseases. Curcumin (CUR) is the main substance in Curcuma longa (Zingiberacea) rhizome that has strong health-beneficial properties. The study aimed to assess the potential protective effects of CUR on hepatic oxidative stress damage and abnormal lipid deposition in a chronic CORT-induced stress (CCIS) model in broilers. One hundred and twenty experimental broilers were randomly divided into 1) control group (CON), 2) CUR group (200 mg/kg feed), 3) CORT group (4 mg/kg BW CORT) and 4) CORT+CUR group (200 mg/kg feed plus 4 mg/kg BW CORT). The liver histology, glycolipid metabolism and oxidative stress were determined. In addition, qPCR was performed to identify shifts in genes expression. Compared with CON group, broilers under CCIS showed a decreased body weight, body weight gain and average daily gain, while dietary CUR significantly reversed these adverse effects. Furthermore, the plasma contents of TCH, TG, HDL-C, LDL-C, TP, GLB and AST were all significantly increased in CCIS broilers, while dietary CUR obviously alleviated the increase of TCH, HDL-C, LDL-C and AST, and relieved the hepatic lipid deposition disorder and liver injury. Moreover, CCIS significantly increased the contents of MDA in both liver and plasma, and decreased the content of plasma SOD, while CUR obviously reversed these changes, showing reduced oxidative stress damage. Finally, the mRNA expressions of FAS, ACC, SCD and the protein level of PPAR-γ were significantly increased, meanwhile the mRNA expression of lipolytic genes ACOX1, ATGL and CPT as well as two major intracellular antioxidant enzymes SOD1 and GPX1 were obviously decreased, while CUR effectively reversed these effects. These results showed that dietary CUR effectively alleviated CCIS-induced body weight loss, hepatic oxidative damage and lipid deposition disorder, suggesting the possible therapeutic effectiveness of CUR against hepatic damage and function abnormality caused by CCIS.

Bioactivity-Guided Isolation of Secondary Metabolites with Antioxidant and Antimicrobial Activities from Camellia fascicularis.

Camellia fascicularis has important ornamental, medicinal, and food values, which also have tremendous potential for exploiting bioactivities. We performed the bioactivity-guided (antioxidant and antimicrobial) screening of eight fractions obtained from the ethyl acetate phase of C. fascicularis. The antioxidant activity was measured by DPPH, ABTS, and FRAP, and the antibacterial activity was measured by the minimum inhibitory concentration (MIC) of Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus. The results of bioactivity-guided isolation indicated that the major antioxidant compounds in the ethanolic extracts of C. fascicularis may be present in fractions (Fr.) (A-G, obtained after silica gel column chromatography). Fr. (D-I, obtained after silica gel column chromatography) is a fraction of C. fascicularis with antimicrobial activity. The structures of compounds were determined by spectral analysis and nuclear magnetic resonance (NMR) combined with the available literature on secondary metabolites of C. fascicularis leaves. In this study, 17 compounds were identified, including four phenolics (1, 3-4, and 14), a phenylpropane (2), five terpenoids (5-7, 12, and 15), four flavonoids and flavonoid glycosides (8-10 and 16), and two lignins (13 and 17). Compounds 4-7, 13-15, and 17 were isolated from the genus Camellia for first time. The remaining compounds were also isolated from C. fascicularis for first time. The evaluation of antioxidant and antimicrobial activities revealed that compounds 1, 3, 9, 11, and 17 exhibited higher antioxidant activity than the positive control drug (ascorbic acid), and compounds 4, 8, 10, and 13 showed similar activity to ascorbic acid. The other compounds had weaker or no significant antioxidant activities. The MIC of antibacterial activity for compounds 4, 7, and 11-13 against P. aeruginosa was comparable to that of the positive control drug tetracycline at 125 µg/mL, and other secondary metabolites inhibited E. coli and S. aureus at 250-500 µg/mL. This is also the first report of antioxidant and antimicrobial activities of compounds 5-7, 13-15, and 17. The results of the study enriched the variety of secondary metabolites of C. fascicularis and laid the foundation for further research on the pharmacological efficacy and biological activity of this plant.

Pepper catalase: a broad analysis of its modulation during fruit ripening and by nitric oxide.

Catalase is a major antioxidant enzyme located in plant peroxisomes that catalyzes the decomposition of H2O2. Based on our previous transcriptomic (RNA-Seq) and proteomic (iTRAQ) data at different stages of pepper (Capsicum annuum L.) fruit ripening and after exposure to nitric oxide (NO) enriched atmosphere, a broad analysis has allowed us to characterize the functioning of this enzyme. Three genes were identified, and their expression was differentially modulated during ripening and by NO gas treatment. A dissimilar behavior was observed in the protein expression of the encoded protein catalases (CaCat1-CaCat3). Total catalase activity was down-regulated by 50% in ripe (red) fruits concerning immature green fruits. This was corroborated by non-denaturing polyacrylamide gel electrophoresis, where only a single catalase isozyme was identified. In vitro analyses of the recombinant CaCat3 protein exposed to peroxynitrite (ONOO-) confirmed, by immunoblot assay, that catalase underwent a nitration process. Mass spectrometric analysis identified that Tyr348 and Tyr360 were nitrated by ONOO-, occurring near the active center of catalase. The data indicate the complex regulation at gene and protein levels of catalase during the ripening of pepper fruits, with activity significantly down-regulated in ripe fruits. Nitration seems to play a key role in this down-regulation, favoring an increase in H2O2 content during ripening. This pattern can be reversed by the exogenous NO application. While plant catalases are generally reported to be tetrameric, the analysis of the protein structure supports that pepper catalase has a favored quaternary homodimer nature. Taken together, data show that pepper catalase is down-regulated during fruit ripening, becoming a target of tyrosine nitration, which provokes its inhibition.

Long-acting Erwinia chrysanthemi, Pegcrisantaspase, induces alternate amino acid biosynthetic pathways in a preclinical model of pancreatic ductal adenocarcinoma

BackgroundPancreatic ductal adenocarcinoma (PDAC) is an aggressive disease without meaningful therapeutic options beyond the first salvage therapy. Targeting PDAC metabolism through amino acid restriction has emerged as a promising new strategy, with asparaginases, enzymes that deplete plasma glutamine and asparagine, reaching clinical trials. In this study, we investigated the anti-PDAC activity of the asparaginase formulation Pegcrisantaspase (PegC) alone and in combination with standard-of-care chemotherapeutics.MethodsUsing mouse and human PDAC cell lines, we assessed the impact of PegC on cell proliferation, cell death, and cell cycle progression. We further characterized the in vitro effect of PegC on protein synthesis as well as the generation of reactive oxygen species and levels of glutathione, a major cellular antioxidant. Additional cell line studies examined the effect of the combination of PegC with standard-of-care chemotherapeutics. In vivo, the tolerability and efficacy of PegC, as well as the impact on plasma amino acid levels, was assessed using the C57BL/6-derived KPC syngeneic mouse model.ResultsHere we report that PegC demonstrated potent anti-proliferative activity in a panel of human and murine PDAC cell lines. This decrease in proliferation was accompanied by inhibited protein synthesis and decreased levels of glutathione. In vivo, PegC was tolerable and effectively reduced plasma levels of glutamine and asparagine, leading to a statistically significant inhibition of tumor growth in a syngeneic mouse model of PDAC. There was no observable in vitro or in vivo benefit to combining PegC with standard-of-care chemotherapeutics, including oxaliplatin, irinotecan, 5-fluorouracil, paclitaxel, and gemcitabine. Notably, PegC treatment increased tumor expression of asparagine and serine biosynthetic enzymes.ConclusionsTaken together, our results demonstrate the potential therapeutic use of PegC in PDAC and highlight the importance of identifying candidates for combination regimens that could improve cytotoxicity and/or reduce the induction of resistance pathways.

An in silico insight on inhibitory potential of short-chain PFHxA and PFHxS against endogenous antioxidant enzymes

Per- and polyfluoroalkyl substances (PFAS) are a large group of synthetic chemicals that are globally used in various commercial products like cloths, carpets, cookware, firefighting foams, cosmetics, electronic products, etc. Inappropriate disposal of these consumer products could lead to environmental contamination with PFAS. Nowadays short-chain PFAS are substituting the long chain PFAS due to their short half-life. However, multiple studies have suggested that short-chain PFAS such as Perfluorohexanoic acid (PFHxA) and Perfluorohexanesulfonic acid (PFHxS) modulate antioxidant enzyme activities, induce Reactive Oxygen Species production, and contribute to oxidative stress in organisms. Notably, experimental set-ups aiming to investigate the mode of action of these compounds on antioxidants are entirely lacking. Hence in the present study, a ligand-docking approach was adopted to investigate the potential intermolecular interactions between short-chain PFAS and major antioxidants such as Glutathione peroxidase-4, Glutathione reductase, Glutathione S-Transferase, Catalase, and Superoxide dismutase-1. Three-dimensional structures of proteins were processed and docked individually with PFHxA and PFHxS using the AutoDock vina.. Results indicated significant binding affinities between various antioxidant proteins and PFAS. Interestingly, non-covalent interactions such as H-bonds, van der Waals, CH bonds, halogen bonds, and alkyl/pi-alkyl were apparent at protein-ligand interface. Hence, these results suggest that both PFHxA and PFHxS may potentially interact with the endogenous antioxidants and this outcome can be detrimental to the redox homeostasis of living organisms.