Ascorbic acid potentiates photodynamic inactivation mediated by octyl gallate and blue light for rapid eradication of planktonic bacteria and biofilms

This study reported for the first time that Ascorbic acid (AA) could appreciably boost the efficiency of Octyl gallate (OG)-mediated photodynamic inactivation (PDI) on Escherichia coli and Staphylococcus aureus in planktonic and biofilm states. The combination of OG (0.075 mM) and AA (200 mM) with 420 nm blue light (212 mW/cm2) led to a >6 Log killing within only 5 min for E. coli and S. aureus and rapid eradication of biofilms. The mechanism of action appears to be the generation of highly toxic hydroxyl radicals (•OH) via photochemical pathways. OG was exposed to BL irradiation to generate various reactive oxygen radicals (ROS) and the addition of AA could transform singlet oxygen (1O2) into hydrogen peroxide (H2O2), which could further react with AA to generate enormous •OH. These ROS jeopardized bacteria and biofilms by nonspecifically attacking various biomacromolecules. Overall, this PDI strategy provides a powerful microbiological decontamination modality to guarantee safe food products.

Layer-by-layer growth of Cu3(HHTP)2 films on Cu(OH)2 nanowire arrays for high performance ascorbic acid sensing

Growing three-dimensional (3D) metal organic frameworks (MOFs) via heterogeneous epitaxial growth on metal hydroxide arrays are effective for constructing electrochemical sensor. However, the growth of MOFs is difficult to control, resulting in thick and irregular morphologies and even damage the metal hydroxide template. In this work, Cu3(HHTP)2 (HHTP = 2, 3, 6, 7, 10, 11-hexahydroxytriphenylene) films with controllable thickness and morphology were successfully prepared on Cu(OH)2 nanowire arrays (NWAs) through layer-by-layer (LBL) growth method. We have discovered that the LBL cycle and the reaction solvent composition are crucial for growing homogenous MOF thin films. The Cu3(HHTP)2 based ascorbic acid (AA) sensor, fabricated in ethanol within 10 LBL cycles, generated an ultrahigh sensitivity of 821.64 μA mM-1 cm-2 in the range of 6-981.41 μM, a low detection limit of 60 nM as well as the great selectivity, stability and reproducibility. Moreover, the relative deviation for AA detection in two fruit juices were 3.22 % and 3.71 %, and the test result for human sweat fall within the normal AA concentration range, verifying the feasibility of as-prepared sensor for practical application.

Ultrasonic-assisted extraction and UHPLC determination of ascorbic acid, polyphenols, and half-maximum effective concentration in Citrus medica and Ziziphus spina-christi fruits using multivariate experimental design

This study aimed to determine the concentrations of ascorbic acid and polyphenols in fruits and peels of Citrus medica and Ziziphus spina-christi grown in Ethiopia. Conditions of ultrasound-assisted extraction (UAE) and ultra-high-performance liquid chromatography coupled with a diode array detector (HPLC-DAD) were optimized, using a multivariate experimental design. The optimum conditions of UAE were 15 min extraction time at 35 ℃, with 75 % aqueous methanol as solvent, and a fruit powder-to-solvent ratio (m/v) of 1:15. Among the different drying conditions investigated, freeze-drying was found to be appropriate for analyzing ascorbic acid, polyphenols, and antioxidant potential. The overall ranges, across the fruits and peels, of ascorbic acid, total polyphenols, and antioxidant potentials (EC50) obtained were 8.7 ± 1.4-91.2 ± 2.6 mg/100 g, 253.0 ± 6.3-764.1 ± 25.8 mg GAE/100 g and 2.4 ± 0.1-26.1 ± 2.9 mg/mL, respectively. This indicates that the fruits and peels of the studied plants are advantageous as sources of ascorbic acid and polyphenols.

Ascorbic acid predominantly kills cancer stem cell-like cells in the hepatocellular carcinoma cell line Li-7 and is more effective at low cell density and in small spheroids

The development of therapies that target cancer stem cells (CSCs) is an important challenge in cancer research. The antioxidant system is enhanced in CSCs, which may lead to resistance to existing therapies. Ascorbic acid (AA) has the potential to act as both an antioxidant and a pro-oxidant agent, but its effects on CSCs are a subject of current research. Here, we investigated the effect of AA focusing specifically on CSCs with the hepatocellular carcinoma cell line Li-7. The Li-7 cell line is heterogenous consisting of CD166- and CD166+ cells; CD166- cells include CSC-like cells (CD13+CD166- cells) and CD13-CD166- cells that can revert to CD13+CD166- cells. The addition of AA to the culture medium caused cell death in both cell populations in CD166- cells in a concentration dependent manner. In contrast, AA administration had a limited effect on CD166+ non-CSC cells. The level of reactive oxygen species after AA treatment was elevated only in CD166- cells. The effect of AA only occurred at low cell densities in 2D and 3D cultures. In a mouse tumor model injected with Li-7 cells, intraperitoneal administration of AA failed to prevent tumor formation but appeared to delay tumor growth. Our findings shed light on why AA administration has not become a mainstream treatment for cancer treatment; however, they also show the possibility that AA can be used in therapies to suppress CSCs.

Low-interference and sensitive electrochemical detection of glucose and lactate using boron-doped diamond electrode and electron mediator menadione

To minimize background interference in electrochemical enzymatic biosensors employing electron mediators, it is essential for the electrochemical oxidation of electroactive interfering species (ISs), such as ascorbic acid (AA), to proceed slowly, and for the redox reactions between electron mediators and ISs to occur at a low rate. In this study, we introduce a novel combination of a working electrode and an electron mediator that effectively mitigates interference effects. Compared to commonly used electrodes such as Au, glassy carbon, and indium tin oxide (ITO), boron-doped diamond (BDD) electrodes demonstrate significantly lower anodic current (i.e., lower background levels) in the presence of AA. Additionally, menadione (MD) exhibits notably slower reactivity with AA compared to other electron mediators such as Ru(NH3)63+, 4-amino-1-naphthol, and 1,4-naphthoquinone, primarily due to the lower formal potential of MD compared to AA. This synergistic combination of BDD electrode and MD is effectively applied in three biosensors: (i) glucose detection using electrochemical-enzymatic (EN) redox cycling, (ii) glucose detection using electrochemical-enzymatic-enzymatic (ENN) redox cycling, and (iii) lactate detection using ENN redox cycling. Our developed approach significantly outperforms the combination of ITO electrode and MD in minimizing IS interference. Glucose in artificial serum can be detected with detection limits of ~ 20 μM and ~ 3 μM in EN and ENN redox cycling, respectively. Furthermore, lactate in human serum can be detected with a detection limit of ~ 30 μM. This study demonstrates sensitive glucose and lactate detection with minimal interference, eliminating the need for (bio)chemical agents to remove interfering species.

Combining fluorescent quantum dots with transition metal oxide shell as core-shell nanocomposite for turn-on sensing of ascorbic acid

Ascorbic acid (AA) is an essential vitamin in humans, and numerous AA detection studies have been conducted. Most quantum dots (QDs)-based approaches depend on redox reactions involving AA, and they require the introduction of an intermediate (e.g., metal ions, OPD, TMB) or the assembly of fluorescent substances with nanosheets (such as MnO2) that can be degraded by AA. These methods are complex, unstable, and are susceptible to interferences. To address these problems, a core-shell fluorescence probe was developed for turn-on sensing of AA. The transition metal oxide shell FeOOH was generated around the surface of CuInZnS QDs to quench the fluorescence. In the presence of AA, the FeOOH shell was decomposed into Fe2+ and the fluorescence of QDs was recovered. Using a physical shell, the obtained nanocomposite realized direct AA detection, avoiding the effects of interfering substances caused by QDs exposure. Moreover, our probe showed great potential in point-of-care tests and was readily adapted for use as a smartphone-assisted paper sensor.

Exploring the biofunctionalities of lactic fermented cactus pear (Opuntia elatior Mill.) fruit beverage: an exotic superfood

Cactus pear fruit is known with many health benefits in ethnomedicine of countries like Mexico, Portugal, Chine, India etc. The study was aimed to develop biofunctional lactic fermented cactus pear fruit beverage to add values to the medicinal fruit. The processing parameters such as quantity of freeze dried cactus pear fruit powder, sucrose and incubation time were optimised using response surface methodology. The optimized product was then subjected to proximate compositional, physicochemical, biofunctional and microbial analysis. The lactic fermented cactus pear fruit beverage was prepared by mixing 12% [w/v] freeze dried cactus pear fruit powder and 3% sucrose in water, then pasteurised and inoculated with 3% Lactobacillus fermentum MTCC 25515 and Lactobacillus rhamnosus M9, then incubated at 37 °C for 6 h. The moisture content of the beverage was 87.77% and major constituent was carbohydrate (9.58% per wet matter basis). The 100 mL beverage contains 89.84 mg GAE phenolic compounds, 5.86 mg QE flavonoids, 71.82 mg betacyanin, 28.08 mg betaxanthin, 10.59 mg ascorbic acid. The beverage also exhibited 58% ABTS antioxidant activity. The beverage was shelf stable for 20 days at 7 ± 1 °C. Such a biofunctional beverage loaded with antioxidant potential can be consumed as refreshing drink.

Graphical abstract

Pulsed electric field technology in vegetable and fruit juice processing: A review

The worldwide market for vegetable and fruit juices stands as a thriving sector with projected revenues reaching to $81.4 billion by 2024 and an anticipated annual growth rate of 5.27% until 2028. Juices offer a convenient means of consuming bioactive compounds and essential nutrients crucial for human health. However, conventional thermal treatments employed in the juice and beverage industry to inactivate spoilage and pathogenic microorganisms, as well as endogenous enzymes, can lead to the degradation of bioactive compounds and vitamins. In response, non-thermal technologies have emerged as promising alternatives to traditional heat processing, with pulsed electric field (PEF) technology standing out as an innovative and sustainable choice. In this context, this comprehensive review investigated the impact of PEF on the microbiological, physicochemical, functional, nutritional, and sensory qualities of vegetable and fruit juices. PEF induces electroporation phenomena in cell membranes, resulting in reversible or irreversible changes. Consequently, a detailed examination of the effects of PEF process variables on juice properties is essential. Monitoring factors such as electric field strength, frequency, pulse width, total treatment time, and specific energy is important to ensure the production of a safe and chemically/kinetically stable product. PEF technology proves effective in microbial and enzymatic inactivation within vegetable and fruit juices, mitigating factors contributing to deterioration while maintaining the physicochemical characteristics of these products. Furthermore, PEF treatment does not compromise the content of substances with functional, nutritional, and sensory properties, such as phenolic compounds and vitamins. When compared to alternative processing methods, such as mild thermal treatments and other non-thermal technologies, PEF treatment consistently demonstrates comparable outcomes in terms of physicochemical attributes, functional properties, nutritional quality, and overall safety.

The effects of antioxidant supplementation on short-term mortality in sepsis patients

Background

The occurrence and development of sepsis are related to the excessive production of oxygen free radicals and the weakened natural clearance mechanism. Further dependable evidence is required to clarify the effectiveness of antioxidant therapy, especially its impact on short-term mortality.

Objectives

The purpose of this systematic review and meta-analysis was to evaluate the effect of common antioxidant therapy on short-term mortality in patients with sepsis.

Methods

According to PRISMA guidelines, a systematic literature search on antioxidants in adults sepsis patients was performed on PubMed/Medline, Embase, and the Cochrane Library from the establishment of the database to November 2023. Antioxidant supplements can be a single-drug or multi-drug combination: HAT (hydrocortisone, ascorbic acid, and thiamine), ascorbic acid, thiamine, N-acetylcysteine and selenium. The primary outcome was the effect of antioxidant treatment on short-term mortality, which included 28-day mortality, in-hospital mortality, intensive care unit mortality, and 30-day mortality. Subgroup analyses of short-term mortality were used to reduce statistical heterogeneity and publication bias.

Results

Sixty studies of 130,986 sepsis patients fulfilled the predefined criteria and were quantified and meta-analyzed. Antioxidant therapy reduces the risk of short-term death in sepsis patients by multivariate meta-analysis of current data, including a reduction of in-hospital mortality (OR = 0.81, 95% CI 0.67 to 0.99; P = 0.040) and 28-day mortality (OR = 0.81, 95% CI 0.69 to 0.95]; P = 0.008). Particularly in subgroup analyses, ascorbic acid treatment can reduce in-hospital mortality (OR = 0.66, 95% CI 0.90 to 0.98; P = 0.006) and 28-day mortality (OR = 0.43, 95% CI 0.24 to 0.75; P = 0.003). However, the meta-analysis of RCTs found that antioxidant therapy drugs, especially ascorbic acid, did substantially reduce short-term mortality(OR = 0.78, 95% CI 0.62 to 0.98; P = 0.030; OR = 0.57, 95% CI 0.36 to 0.91; P = 0.020).

Conclusions

According to current data of RCTs, antioxidant therapy, especially ascorbic acid, has a trend of improving short-term mortality in patients with sepsis, but the evidence remains to be further demonstrated.

Ascorbic acid biosynthesis in Pacific abalone Haliotis discus hannai Ino and L-gulonolactone oxidase gene loss as an independent event

Up to now, it has been believed that invertebrates are unable to synthesize ascorbic acid (AA) in vivo. However, in the present study, the full-length CDs (Coding sequence) of L-gulonolactone oxidase (GLO) from Pacific abalone (Haliotis discus hannai Ino) were obtained through molecular cloning. The Pacific abalone GLO contained a FAD-binding domain in the N-termination, and ALO domain and conserved HWAK motif in the C-termination. The GLO gene possesses 12 exons and 11 introns. The Pacific abalone GLO was expressed in various tissues, including the kidney, digestive gland, gill, intestine, muscle and mantle. The GLO activity assay revealed that GLO activity was only detected in the kidney of Pacific abalone. After a 100-day feeding trial, dietary AA levels did not significantly affect the survival, weight gain, daily increment in shell length, and feed conversion ratio of Pacific abalone. The expression of GLO in the kidney was downregulated by dietary AA. These results implied that the ability to synthesize AA in abalone had not been lost. From the evolutionary perspective, the loss of GLO occurred independently as an independent event by matching with the genomes of various species. The positive selection analysis revealed that the GLO gene underwent purifying selective pressure during its evolution. In conclusion, the present study provided direct evidence to prove that the GLO activity and the ability to synthesize AA exist in abalone. The AA synthesis ability in vertebrates might have originated from invertebrates dating back 930.31 million years.

Strategic design, theoretical insights, synthesis, and unveiling antioxidant potential in a novel ascorbic acid analog

CONTEXT

In this study, we investigated the antioxidant potential of a novel ascorbic acid analog, DsD, assessing its interactions with the methylperoxyl (CH3OO·) radical in aqueous and lipid environments. Our focus was on understanding the acid-base equilibrium and how pH affects DsD's primary reaction mechanisms. Our findings indicate a marked preference for hydrogen atom transfer in lipid media, contrasting with sequential proton loss electron transfer (SPLET) in aqueous solutions. Remarkably, DsD's radical scavenging activity significantly outperforms ascorbic acid, being 4.05 and 9469.70 times more potent in polar and lipid contexts, respectively. This suggests DsD's superior efficacy as an antioxidant, potentially offering enhanced protection in biological systems. Additionally, we have demonstrated DsD's synthetic feasibility through a straightforward condensation reaction between ascorbic acid and 1,2-diaminoethane, followed by comprehensive physicochemical and spectroscopic characterization.

METHODS

All computational analyses in this study were conducted using the Gaussian 09 software suite, employing the M05-2X functional and the 6-31 + G(d) basis set. Enthalpy calculations were executed under standard conditions (298.15 K and 1 atm), incorporating appropriate thermodynamic corrections. Rate constants were evaluated using transition state theory (TST), and the overall assessment of radical scavenging activity was guided by the Quantum Mechanics-based Test for Overall Radical Scavenging Activity (QMORSA) protocol.

Exogenous application of ascorbic acid improves physiological and productive traits of Nigella sativa

For thousands of years, plants have been utilized for medicinal purposes. For its naturally existing antibacterial properties, Nigella sativa is one of the most researched herbs. A study was conducted during rabi 2020-21 at The University of Haripur in order to evaluate the potential of ascorbic acid as plant growth enhancer. Two concentrations of ascorbic acid i-e 350 μm and 400 μm were sprayed along with control and water only spray on Nigella sativa crop. The study was arranged in RCBD two factor factorial arrangement. Factor A: ascorbic acid concentrations along with control and water spray, factor B: Growth stages (Stage1 = 40 days after sowing, Stage 2 = 80 DAS, Stage 3 = 120 DAS, Stage 4 = 40 + 80 DAS, Stage 5 = 40 + 120 DAS, Stage 6 = 80 + 120 DAS, Stage 7 = 40 + 80 + 120 DAS). Crop was sown in first week of November. Results reviled that chlorophyll b content, fixed oil content, 1000 seed weight, grain yield, Photosynthetic rate (μ mole m-2s-1), Transpiration rate (mmole m-2s-1), photosynthetic water use efficiency, Internal CO2 concentration (Ci) of leaf tissue and Stomatal conductance (mmole m-2s-1) were significantly affected by ascorbic acid concentrations and stage of application. Crop growth rate increased by 19.88% and 17.29%, chlorophyll b by 12.3% and 11.2%, fixed oil by 11.7% and 9%, grain yield by 10.29% and 9.8%, harvest index by 4% and 5.7% photosynthetic rate by 33%, 20% and stomatal conductance by 24.24% and 24.25 with application of ascorbic acid @ 350 μm, over control and water spray respectively. On the basis of these results it is concluded that application of ascorbic acid at the rate of 350 μm, followed by ascorbic acid at the rate of 400 μm significantly improves black cumin (Nigella sativa) yield and production. Hence it is recommended to apply ascorbic acid at the rate of 350 μm at 40 + 80+120 days after sowing of Nigella sativa crop for obtaining maximum results.

Variations of oxidative potential of PM2.5 in a medium-sized residential city in South Korea measured using three different chemical assays

Although it is evident that PM2.5 has serious adverse health effects, there is no consensus on what the biologically effective dose is. In this study, the intrinsic oxidative potential (OPm) and the extrinsic oxidative potential (OPv) of PM2.5 were measured using three chemical assays including dithiothreitol (DTT), ascorbic acid (AA), and reduced glutathione (GSH), along with chemical compositions of PM2.5 in South Korea. Among the three chemical assays, only OPmAA showed a statistically significant correlation with PM2.5 while OPmGSH and OPmDTT were not correlated with PM2.5 mass concentration. When the samples were categorized by PM2.5 mass concentrations, the variations in the proportion of Ni, As, Mn, Cd, Pb, and Se to PM2.5 mass closely coincided with changes in OPm across all three assays, suggesting a potential association between these elements and PM2.5 OP. Multiple linear regression analysis identified the significant PM components affecting the variability in extrinsic OPv. OPvAA was determined to be significantly influenced by EC, K+, and Ba while OC and Al were common significant factors for OPvGSH and OPvDTT. It was also found that primary OC was an important variable for OPvDTT while secondary OC significantly affected the variability of OPvGSH.

Exogenous ascorbic acid as a potent regulator of antioxidants, osmo-protectants, and lipid peroxidation in pea under salt stress

Pea (Pisum sativum L.), a globally cultivated leguminous crop valued for its nutritional and economic significance, faces a critical challenge of soil salinity, which significantly hampers crop growth and production worldwide. A pot experiment was carried out in the Botanical Garden, The Islamia University of Bahawalpur to alleviate the negative impacts of sodium chloride (NaCl) on pea through foliar application of ascorbic acid (AsA). Two pea varieties Meteor (V1) and Sarsabz (V2) were tested against salinity, i.e. 0 mM NaCl (Control) and 100 mM NaCl. Three levels of ascorbic acid 0 (Control), 5 and 10 mM were applied through foliar spray. The experimental design was completely randomized (CRD) with three replicates. Salt stress resulted in the suppression of growth, photosynthetic activity, and yield attributes in pea plants. However, the application of AsA treatments effectively alleviated these inhibitory effects. Under stress conditions, the application of AsA treatment led to a substantial increase in chlorophyll a (41.1%), chl. b (56.1%), total chl. contents (44.6%) and carotenoids (58.4%). Under salt stress, there was an increase in Na+ accumulation, lipid peroxidation, and the generation of reactive oxygen species (ROS). However, the application of AsA increased the contents of proline (26.9%), endogenous AsA (23.1%), total soluble sugars (17.1%), total phenolics (29.7%), and enzymatic antioxidants i.e. SOD (22.3%), POD (34.1%) and CAT (39%) in both varieties under stress. Salinity reduced the yield attributes while foliarly applied AsA increased the pod length (38.7%), number of pods per plant (40%) and 100 seed weight (45.2%). To sum up, the application of AsA alleviated salt-induced damage in pea plants by enhancing photosynthetic pigments, both enzymatic and non-enzymatic activities, maintaining ion homeostasis, and reducing excessive ROS accumulation through the limitation of lipid peroxidation. Overall, V2 (Sarsabz) performed better as compared to the V1 (Meteor).

Differential effects of theasinensins and epigallocatechin-3-O-gallate on phospholipid bilayer structure and liposomal aggregation

(-)-Epigallocatechin-3-O-gallate (EGCg), the major catechin responsible for the health-enhancing and disease-preventive effects of green tea, is susceptible to auto-oxidation at physiological pH levels. However, whether the oxidized EGCg resulting from its oral consumption possesses any bioactive functions remains unclear. This study presents a differential analysis of intact and oxidized EGCg regarding their interactions with phosphatidylcholine liposomes, serving as a simple biomembrane model. In the presence of ascorbic acid, pre-oxidized EGCg induced liposomal aggregation in a dose-dependent manner, whereas intact EGCg did not. Toxicity evaluation using calcein-loaded liposomes revealed that liposomal aggregation is associated with minimal membrane damage. Through fractionation of the oxidized EGCg sample, the fraction containing theasinensins showed high liposomal aggregation activity. Overall, these results suggest that oxidatively condensed EGCg dimers may stimulate various cells by altering the plasma membrane in a manner different from that of EGCg monomers.

Effects of H2S-donor ascorbic acid derivative and ischemia/reperfusion-induced injury in isolated rat hearts

Hydrogen sulfide (H2S), a gasotransmitter, plays a crucial role in vasorelaxation, anti-inflammatory processes and mitigating myocardial ischemia/reperfusion-induced injury by regulating various signaling processes. We designed a water soluble H2S-releasing ascorbic acid derivative, BM-164, to combine the beneficial cardiovascular and anti-inflammatory effects of H2S with the excellent water solubility and antioxidant properties of ascorbic acid. DPPH antioxidant assay revealed that the antioxidant activity of BM-164 in the presence of a myocardial tissue homogenate (extract) increased continuously over the 120 min test interval due to the continuous release of H2S from BM-164. The cytotoxicity of BM-164 was tested by MTT assay on H9c2 cells, which resulted in no cytotoxic effect at concentrations of 10 to 30 μM. The possible beneficial effects of BM-164 (30 µM) was examined in isolated 'Langendorff' rat hearts. The incidence of ventricular fibrillation (VF) was significantly reduced from its control value of 79 % to 31 % in the BM-164 treated group, and the infarct size was also diminished from the control value of 28 % to 14 % in the BM-164 treated group. However, coronary flow (CF) and heart rate (HR) values in the BM-164 treated group did not show significantly different levels in comparison with the drug-free control, although a non-significant recovery in both CF and HR was observed at each time point. We attempted to reveal the mechanism of action of BM-164, focusing on the processes of autophagy and apoptosis. The expression of key autophagic and apoptotic markers in isolated rat hearts were detected by Western blot analysis. All the examined autophagy-related proteins showed increased expression levels in the BM-164 treated group in comparison to the drug-free control and/or ascorbic acid treated groups, while the changes in the expression of apoptotic markers were not obvious. In conclusion, the designed water soluble H2S releasing ascorbic acid derivative, BM-164, showed better cardiac protection against ischemia/reperfusion-induced injury compared to the untreated and ascorbic acid treated hearts, respectively.

Evaluation of AgNCs@PEI and their integrated hydrogel for colorimetric and fluorometric detection of ascorbic acid

A dual-mode colorimetric and fluorometric sensor based on water soluble silver nanoclusters (AgNCs@PEI) is developed for quantitative and visual detection of ascorbic acid (Asc A). The detection method relies on the Asc A induced aggregation of AgNCs@PEI, which resulted in fluorecsence quenching of the sensor. The clusters exhibited a unique combination of static and collisional quenching with a wide range of dynamic detection (1-105 µM) Linear relationship was observed in the concentration range 102-103 µM using fluorescence and 0.2 × 102-5 × 103 μM using absorbance spectroscopy with respective detection limits of 10.65 μM and 2.49 μM. The corresponding colorimetric and fluorometric changes can be easily monitored by the naked eye with a visual detection limit of 103 μM. AgNCs@PEI were further integrated within a hydrogel for developing a solid-state visual detection platform. Notably, the sensing response of the clusters towards Asc A remained unaltered even after hydrogel integration. Additionally, digital image analysis was adopted, which improved the sensitivity of instrument-free fluorescence detection of Asc A. Analysis by the developed sensor showed excellent recovery percentages of Asc A in spiked urine samples, which further underscores the practical applicability of the sensor.

Effect of high-dose vitamin C on renal ischemia-reperfusion injury

Acute kidney injury frequently occurs after cardiac surgery, and is primarily attributed to renal ischemia-reperfusion (I/R) injury and inflammation from surgery and cardiopulmonary bypass. Vitamin C, an antioxidant that is often depleted in critically ill patients, could potentially mitigate I/R-induced oxidative stress at high doses. We investigated the effectiveness of high-dose vitamin C in preventing I/R-induced renal injury. The ideal time and optimal dosage for administration were determined in a two-phase experiment on Sprague-Dawley rats. The rats were assigned to four groups: sham, IRC (I/R + saline), and pre- and post-vitC (vitamin C before and after I/R, respectively), with vitamin C administered at 200 mg/kg. Additional groups were examined for dose modification based on the optimal timing determined: V100, V200, and V300 (100, 200, and 300 mg/kg, respectively). Renal I/R was achieved through 45 min of ischemia followed by 24 h of reperfusion. Vitamin C administration during reperfusion significantly reduced renal dysfunction and tubular damage, more than pre-ischemic administration. Doses of 100 and 200 mg/kg during reperfusion reduced oxidative stress markers, including myeloperoxidase and inflammatory responses by decreasing high mobility group box 1 release and nucleotide-binding and oligomerization domain-like receptor 3 inflammasome. Overall beneficial effect was most prominent with 200 mg/kg. The 300 mg/kg dose, however, showed no additional benefits over the IRC group regarding serum blood urea nitrogen and creatinine levels and histological evaluation. During reperfusion, high-dose vitamin C administration (200 mg/kg) significantly decreased renal I/R injury by effectively attenuating the major triggers of oxidative stress and inflammation.

Contact lens sensor for ocular inflammation monitoring

Contact lens sensors have been emerging as point-of-care devices in recent healthcare developments for ocular physiological condition monitoring and diagnosis. Fluorescence sensing technologies have been widely applied in contact lens sensors due to their accuracy, high sensitivity, and specificity. As ascorbic acid (AA) level in tears is closely related to ocular inflammation, a fluorescent contact lens sensor incorporating a BSA-Au nanocluster (NC) probe is developed for in situ tear AA detection. The NCs are firstly synthesized to obtain a fluorescent probe, which exhibits high reusability through the quench/recover (KMnO4/AA) process. The probe is then encapsulated with 15 wt% of poly(vinyl alcohol) (PVA) and 1.5 wt% of citric acid (CA) film, and implemented on a closed microfluidic contact lens sensing region. The laser-ablated microfluidic channel in contact lens sensors allows for tear fluid to flow through the sensing region, enabling an in-situ detection of AA. Meanwhile, a smartphone application accompanied by a customized 3D printed readout box is developed for image caption and algorism to quantitative analysis of AA levels. The contact lens sensor is tested within the readout box and the emission signal is collected through the smartphone camera at room temperature with an achieved LOD of 0.178 mmol L-1 (0.0-1.2 mmol L-1). The operational and storage lifetime is also evaluated to characterize the sensor properties and resulted in 20 h and 10 days, respectively. The reusable AA contact lens sensor is promising to lead to an alternative accessible diagnostic method for ocular inflammation in point-of-care settings.

Implication of Rac1 GTPase in molecular and cellular mitochondrial functions

Rac1 is a member of the Rho GTPase family which plays major roles in cell mobility, polarity and migration, as a fundamental regulator of actin cytoskeleton. Signal transduction by Rac1 occurs through interaction with multiple effector proteins, and its activity is regulated by guanine nucleotide exchange factors (GEFs) and GTPase-activating proteins (GAPs). The small protein is mainly anchored to the inner side of the plasma membrane but it can be found in endocellular compartments, notably endosomes and cell nuclei. The protein localizes also into mitochondria where it contributes to the regulation of mitochondrial dynamics, including both mitobiogenesis and mitophagy, in addition to signaling processes via different protein partners, such as the proapoptotic protein Bcl-2 and chaperone sigma-1 receptor (σ-1R). The mitochondrial form of Rac1 (mtRac1) has been understudied thus far, but it is as essential as the nuclear or plasma membrane forms, via its implication in regulation of oxidative stress and DNA damages. Rac1 is subject to diverse post-translational modifications, notably to a geranylgeranylation which contributes importantly to its mitochondrial import and its anchorage to mitochondrial membranes. In addition, Rac1 contributes to the mitochondrial translocation of other proteins, such as p53. The mitochondrial localization and functions of Rac1 are discussed here, notably in the context of human diseases such as cancers. Inhibitors of Rac1 have been identified (NSC-23766, EHT-1864) and some are being developed for the treatment of cancer (MBQ-167) or central nervous system diseases (JK-50561). Their effects on mtRac1 warrant further investigations. An overview of mtRac1 is provided here.

Profiling the antioxidant biomarkers in marine fish larvae: a comparative assessment of different storage conditions to select the optimal strategy

Research on antioxidant biomarkers can generate profound insights into the defense mechanisms of fish larvae against different stressors and can reveal manipulation strategies for improved growth and survival. However, the number of samples to process and unavailability of required infrastructure in larval-rearing facilities limit the immediate processing, requiring the preservation of specimens. Silver pompano (Trachinotus blochii), a potential marine aquaculture species, shows a low larval survival rate due to poorly developed antioxidant mechanism. In this context, 39 storage conditions, including three storage temperatures and different buffers, were scrutinized to select the most suitable preservation strategy for five important antioxidant biomarkers of fish larvae, viz. catalase activity, superoxide dismutase (SOD) activity, measurement of lipid peroxidation, reduced glutathione (GSH), and ascorbic acid contents. The paper proposes the optimum larval storage conditions for these five evaluated antioxidant biomarkers to generate similar results in preserved and non-preserved larval samples. Larval samples preserved in PBS at lower temperatures (- 20 °C and - 80 °C) are recommended for evaluating catalase activity and ascorbic acid content. Catalase activity can also be evaluated by preserving the larval samples at - 20 °C or - 80 °C without buffers. Larval samples held in PBS or without any buffers at - 20 °C and at - 80 °C were found to be suitable for SOD and GSH evaluation, respectively. Preservation in 50% glacial acetic acid at - 80 °C or - 20 °C was preferred for the lipid peroxidation assays. Apart from methodological perspectives, the paper provides insights into the dynamics of larval antioxidant profiles of T. blochii, for the first time.

A fluorescence "turn-on" sensor for ascorbic acid in fruit juice and beverage based on ascorbate oxidase-like activity of citric acid-derived carbon dots

Citric acid-derived carbon dots (CA-CDs) without any modifications were found to have the ascorbate oxidase (AAO)-like activity. The CA-CDs have high affinity for ascorbic acid (AA), which is similar to natural AAO. The robustness of CA-CDs is greater than that of AAO. Based on the AAO mimetic activity of CA-CDs, a sensitive turn-on mode and natural enzyme-free fluorescence detection method has been developed for AA in some fruit juice and beverage samples with satisfied recoveries. This study provides CDs-based AAO mimetic nanozymes to replace the expensive natural enzymes or heavy metal-based nanozymes, which will show great potential in biological and food assays.

Direct seeding compromised the vitamin C content of baby vegetables and the glucosinolate content of mature vegetables in Asian leafy brassicas

This study hypothesised that direct seeding may compromise the nutritional quality of crops, as they may not release the nutrients that are triggered by the stress of transplantation. To that end, the effect of direct seeding on the nutrient content of bok choy (Brassica rapa subsp. chinensis), choy sum (Brassica rapa subsp. chinensis var. parachinensis) and mao bai (Brassica oleracea var. capitata) was investigated at the baby- and commercially-mature stages. Direct seeding had distinct effects on each stage. Directly seeded baby vegetables had 39 to 51 % less ascorbic acid and 21 to 30 % less vitamin K than transplanted baby vegetables (p < 0.05). For mature crops, direct seeding decreased the total glucosinolate content by 12 to 40 % (p < 0.05). Thus, while direct seeding may profit vegetable producers, its impact on nutrient quality merits careful consideration.

Exploring transient global transcriptional changes induced by ascorbic acid revealed via atKAS-seq profiling

Transcription initiates the formation of single-stranded DNA (ssDNA) regions within the genome, delineating transcription bubbles, a highly dynamic genomic process. Kethoxal-assisted single-stranded DNA sequencing (KAS-seq) utilizing N3-kethoxal has emerged as a potent tool for mapping specific guanine positions in ssDNA on a genome-wide scale. However, the original KAS-seq method required the costly Accel-NGS Methyl-seq DNA library kit. This study introduces an optimized iteration of the KAS-seq technique, referred to as adapter-tagged KAS-seq (atKAS-seq), incorporating an adapter tagging strategy. This modification involves integrating sequencing adapters via complementary strand synthesis using random N9 tagging. Additionally, by harnessing the potential of ascorbic acid (ASC), recognized for inducing global epigenetic changes, we employed the atKAS-seq methodology to elucidate critical pathways influenced by short-term, high-dose ASC treatment. Our findings underscore that atKAS-seq enables rapid and precise analyses of transcription dynamics and enhancer activities concurrently. This method offers a streamlined, cost-efficient, and low-input approach, affirming its utility in probing intricate genomic regulatory mechanisms.

Effect of tropospheric ozone and its protectants on gas exchange parameters, antioxidant enzymes and quality of Garlic (Allium sativum. L)

An experimental study was conducted to assess the detrimental effect of ground-level ozone (O3) on garlic physiology and to find out appropriate control measures against ground-level O3, at TNAU-Horticultural Research farm, Udhagamandalam. Elevated ground ozone levels significantly decreased garlic leaf chlorophyll, photosynthetic rate, stomatal conductance, total soluble solids and pungency. The garlic chlorophyll content was highest in ambient ozone level and lowest in elevated ozone@200 ppb, highest stomatal conductance was recorded in ambient ozone with foliar spray of 3%Panchagavya, and the lowest was observed in elevated ozone@200 ppb. Since the elevated O3 had reduced in garlic photosynthetic rate significantly the lowest was observed in elevated O3@200 ppb and the highest photosynthetic rate was observed in ambient Ozone with foliar spray 3% of panchagavya after a week. The antioxidant enzymes of garlic were increased with increased concentration of tropospheric ozone. The highest catalase (60.97 µg of H2O2/g of leaf) and peroxidase (9.13 ΔA/min/g of leaf) concentration was observed at 200 ppb elevated ozone level. Garlic pungency content was highest in ambient ozone with foliar spray of 0.1% ascorbic acid and the lowest was observed under elevated O3@200 ppb. Highest total soluble solids were observed in ambient ozone with foliar spray of 3%Panchagavya and the lowest observed in elevated ozone@200 ppb. Thus, tropospheric ozone has a detrimental impact on the physiology of crops, which reduced crop growth and yield. Under elevated O3 levels, ascorbic acid performed well followed by panchagavya and neem oil. The antioxidant such as catalase and peroxidase had positive correlation among themselves and had negative correlation with chlorophyll content, stomatal conductance, photosynthetic rate, pungency and TSS. The photosynthetic rate has high positive correlation with chlorophyll content, pungency and TSS. Correlation analysis confirmed the negative effects of tropospheric ozone and garlic gas exchange parameters and clove quality. The ozone protectants will reduce stomatal opening by which the entry of O3 in to the cell will be restricted and other hand they also will alleviate ROS and allied stresses.

Vitamin C deficiency can lead to pulmonary hypertension: a systematic review of case reports

BACKGROUND

In the early literature, unintentional vitamin C deficiency in humans was associated with heart failure. Experimental vitamin C deficiency in guinea pigs caused enlargement of the heart. The purpose of this study was to collect and analyze case reports on vitamin C and pulmonary hypertension.

METHODS

We searched Pubmed and Scopus for case studies in which vitamin C deficiency was considered to be the cause of pulmonary hypertension. We selected reports in which pulmonary hypertension was diagnosed by echocardiography or catheterization, for any age, sex, or dosage of vitamin C. We extracted quantitative data for our analysis. We used the mean pulmonary artery pressure (mPAP) as the outcome of primary interest.

RESULTS

We identified 32 case reports, 21 of which were published in the last 5 years. Dyspnea was reported in 69%, edema in 53% and fatigue in 28% of the patients. Vitamin C plasma levels, measured in 27 cases, were undetectable in 24 and very low in 3 cases. Diet was poor in 30 cases and 17 cases had neuropsychiatric disorders. Right ventricular enlargement was reported in 24 cases. During periods of vitamin C deficiency, the median mPAP was 48 mmHg (range 29-77 mmHg; N = 28). After the start of vitamin C administration, the median mPAP was 20 mmHg (range 12-33 mmHg; N = 18). For the latter 18 cases, mPAP was 2.4-fold (median) higher during vitamin C deficiency. Pulmonary vascular resistance (PVR) during vitamin C deficiency was reported for 9 cases, ranging from 4.1 to 41 Wood units. PVR was 9-fold (median; N = 5) higher during vitamin C deficiency than during vitamin C administration. In 8 cases, there was direct evidence that the cases were pulmonary artery hypertension (PAH). Probably the majority of the remaining cases were also PAH.

CONCLUSIONS

The cases analyzed in our study indicate that pulmonary hypertension can be one explanation for the reported heart failure of scurvy patients in the early literature. It would seem sensible to measure plasma vitamin C levels of patients with PH and examine the effects of vitamin C administration.

Indoxacarb poisoning causing methemoglobinemia treated with parenteral vitamin C: a case report

INTRODUCTION

This case study reports on a suicide attempt involving indoxacarb and vitamin C. Indoxacarb is a neurotoxic insecticide used in agriculture and as a flea controller in pets. Cotton, vegetables, and fruits are treated with indoxacarb, an insecticide that can be applied both indoors and outdoors. It causes skin allergies, methemoglobinemia, and hemolytic anemia. It is also attributed to allergic reactions through ingestion, inhalation, physical contact, and translaminar action. This case report highlights use of vitamin C in methemoglobinemia caused by indoxacarb poisoning. Indoxacarb poisoning has the potential to be extremely serious and even lethal. In this instance, the patient initially had no symptoms after ingesting a substance containing indoxacarb in an attempt at suicide. However, further tests revealed methemoglobinemia and low oxygen levels.

CASE PRESENTATION

A 28-year-old south-east Asian female patient ingested an insecticide containing 5.25% novaluron, 4.5% indoxacarb, and 25% thiamethoxam, and reported that she noticed muddy brown urine but presented with no active signs or symptoms of poisoning. Upon examination, the patient was fully conscious, alert, and hemodynamically stable, but had an oxygen saturation of 84%. Gastric lavage was performed, and blood investigations revealed a muddy-brown-colored blood sample and methemoglobin levels of 12%. The patient was treated with high-dose vitamin C and showed significant improvement, with a drop in methemoglobin levels to 1.2% and an increase in oxygen saturation to 97%.

DISCUSSION

Indoxacarb poisoning can cause severe methemoglobinemia. Vitamin C may be a useful treatment option for methemoglobinemia caused by indoxacarb, particularly in cases in which traditional treatment with methylene blue is contraindicated or not tolerated. Hence high doses of ascorbic acid, that is, vitamin C, were administered to the patient, which lowered their methemoglobin levels and improved oxygen levels without much safety concerns.

CONCLUSION

This example emphasizes the significance of early indoxacarb poisoning detection and treatment as well as the possible advantages of utilizing ascorbic acid in the management of methemoglobinemia, and highlights the use of vitamin C in the treatment of methemoglobinemia caused by indoxacarb poisoning. Therefore, it is important for healthcare professionals to be aware of the potential for indoxacarb to cause methemoglobinemia and to consider vitamin C as a treatment option.

Hierarchical N-doped porous carbon scaffold Cu/Co-oxide with enhanced electrochemical sensing properties for the detection of glucose in beverages and ascorbic acid in vitamin C tablets

This research focuses on the development of a highly efficient electrocatalyst, CuxO/NPC@Co3O4/NPC-10-7, for detecting glucose and ascorbic acid. In a 0.1 M NaOH solution, the modified electrode exhibits a sensitivity of 3314.29 μA mM-1 cm-2 for glucose detection. The linear range for ascorbic acid sensing is 0.5 μM - 23.332 mM, with a detection limit as low as 0.24 μM. In a 0.1 M PBS solution, the linear range for ascorbic acid detection extends to 43.328 mM, which represents the best performance reported to date by chronoamperometry. Moreover, the electrode demonstrates high accuracy, with a recovery rate of 96.80 % - 103.60 % for glucose detection and a recovery rate of 95.25 % - 104.83 % for ascorbic acid detection. These results suggest that the CuxO/NPC@Co3O4/NPC-10-7 modified electrode shows significant potential for practical applications in food detection.

Riboflavin (vitamin B2) sensitized photooxidation of ascorbic acid (vitamin C): A kinetic study

Ascorbic acid (AH2) photoxidation sensitized by riboflavin (RF) has been studied between pH 2.0 and 12.0 in ambient air and anaerobic environment using UV and visible irradiation sources. The kinetics of AH2 degradation in aqueous medium along with RF is found to be first-order for its photodegradation. AH2 photolysis rate constants in aerobic and anaerobic conditions with RF (1.0-5.0 × 10-5 M) are 0.14-3.89 × 10-2 and 0.026-0.740 × 10-2 min-1, respectively. The rate constants (k2) of second-order kinetics for AH2 and RF photochemical interaction in aerobic and anaerobic conditions are in the range of 0.24-3.70 to 0.05-0.70 × 10-3 M-1 min-1, respectively, which manifests that increasing the RF concentration also increases the rate of photodegradation (photooxidation) of AH2. The k2 versus pH graph is bell-shaped which indicates that increasing the pH increases photolytic degradation rate of AH2 with RF. Increasing the pH results in the increased ionization of AH2 (ascorbyl anion, AH-) and redox potential which leads to the higher rates of photodegradation of AH2. Two-component spectrophotometric (243 and 266 nm, AH2 and RF, respectively) and high-performance liquid chromatography (HPLC) methods have been used to determine the concentration of AH2 and RF in pure and degraded solutions. The results obtained from these two methods are compared using a student t-test which showed no noteworthy difference between them.

Electrochemical determination of ascorbic acid using palladium supported on N-doped graphene quantum dot modified electrode

To precise screening concentration of ascorbic acid (AA), a novel electrochemical sensor was prepared using palladium nanoparticles decorated on nitrogen-doped graphene quantum dot modified glassy carbon electrode (PdNPs@N-GQD/GCE). For this purpose, nitrogen doped GQD nanoparticles (N-GQD) were synthesized from a citric acid condensation reaction in the presence of ethylenediamine and subsequently modified by palladium nanoparticles (PdNPs). The electrochemical behavior of AA was investigated, in which the oxidation peak appeared at 0 V related to the AA oxidation. Considering the synergistic effect of Pd nanoparticles as an active electrocatalyst, and N-GQD as an electron transfer accelerator and electrocatalytic activity improving agent, PdNPs@N-GQD hybrid materials showed excellent activity in the direct oxidation of AA. In the optimal conditions, the voltammetric response was linear in the range from 30 to 700 nM and the detection limit was calculated to be 23 nM. The validity and the efficiency of the proposed sensor were successfully tested and confirmed by measuring AA in real samples of chewing tablets, and fruit juice.

Vitamin C deficiency alters the transcriptome of the rat brain in a glucocorticoid-dependent manner, leading to microglial activation and reduced neurogenesis

Vitamin C (VitC) is maintained at high concentrations in the brain and is an essential micronutrient for brain function. VitC deficiency leads to neuropsychiatric scurvy, which is characterized by depression and cognitive impairment. However, the molecular mechanism by which mild VitC deficiency impairs brain function is currently unknown. In the present study, we conducted RNA sequencing analysis and found that a short-term VitC deficiency altered the brain transcriptome in ODS rats, which cannot synthesize VitC. Bioinformatic analysis indicated that VitC deficiency affected the expression of genes controlled by the glucocorticoid receptor in the brain. We confirmed an increased secretion of glucocorticoids from the adrenal gland during VitC deficiency. We found that non-neuronal cells, including microglia, which are resident immune cells in the brain, changed their transcriptional patterns in response to VitC deficiency. Immunohistochemical analysis revealed that the quiescent ramified microglia transform into the activated amoeboid microglia during three weeks of VitC deficiency. The morphological activation of microglia was accompanied by increased expression of proinflammatory cytokines such as interleukin-6 in the hippocampus. Furthermore, VitC deficiency decreased the number of newly born neurons in the dentate gyrus of the hippocampus, suggesting that VitC was required for adult neurogenesis that plays a crucial role in learning and memory. Our findings may provide insights into the molecular mechanisms underlying the maintenance of normal brain function by adequate levels of VitC.

A sensing platform for ascorbic acid based on the spatial confinement of covalent organic frameworks

Essential to many activities in our bodies, ascorbic acid is a small molecule essential to human health and physiological processes. In this study, a covalent organic framework called TpNda-COF was synthesized, which is composed of Tp (triformylephloroglucinol) and Nda (1, 5-napthalenediamine). This framework acts as a mimic enzyme and displays excellent oxidase-like activity when stimulated with purple light (at = 405 nm). It catalyzes the oxidation of 3,3',5,5'-tetramethylbenzydine (TMB) by generating O2- free radicals in the presence of oxygen. The resulting oxTMB shows a characteristic absorption peak at 652 nm. The biomimetic catalysis efficiency is significantly improved due to spatial restriction. By introducing ascorbic acid (AA) in the system, the blue oxTMB is reduced to colorless TMB. The decrease in absorption peak intensity can be quantitatively measured using a UV-Vis spectrophotometer, enabling the detection of AA. The sensing platform demonstrates excellent selectivity and sensitivity. It has a wide linear detection range from 5 μM to 50 μM, with a low detection limit of 1.44 μM. Advantages such as the easy control of light, high stability and efficient oxidation are provided by the TpNda-COF mimic oxidase. This innovative method presents a promising and cost-effective approach for rapid detection of ascorbic acid, with potential applications across various fields.

Intrauterine arsenic exposure induces glucose metabolism disorders in adult offspring by targeting TET2-mediated DNA hydroxymethylation reprogramming of HNF4α in developing livers, an effect alleviated by ascorbic acid

Exposure to arsenic during gestation has lasting health-related effects on the developing fetus, including an increase in the risk of metabolic disease later in life. Epigenetics is a potential mechanism involved in this process. Ten-eleven translocation 2 (TET2) has been widely considered as a transferase of 5-hydroxymethylcytosine (5hmC). Here, mice were exposed, via drinking water, to arsenic or arsenic combined with ascorbic acid (AA) during gestation. For adult offspring, intrauterine arsenic exposure exhibited disorders of glucose metabolism, which are associated with DNA hydroxymethylation reprogramming of hepatic nuclear factor 4 alpha (HNF4α). Further molecular structure analysis, by SEC-UV-DAD, SEC-ICP-MS, verified that arsenic binds to the cysteine domain of TET2. Mechanistically, arsenic reduces the stability of TET2 by binding to it, resulting in the decrease of 5hmC levels in Hnf4α and subsequently inhibiting its expression. This leads to the disorders of expression of its downstream key glucose metabolism genes. Supplementation with AA blocked the reduction of TET2 and normalized the 5hmC levels of Hnf4α, thus alleviating the glucose metabolism disorders. Our study provides targets and methods for the prevention of offspring glucose metabolism abnormalities caused by intrauterine arsenic exposure.

Bacillus safensis filtrate-based ZnO nanoparticles control black heart rot disease of apricot fruits by maintaining its soluble sugars and carotenoids

Black heart rot is a serious disease of apricot and it has been reported to be caused by Alternaria solani, around the world. The present research was designed to control this disastrous disease using zinc oxide nanoparticles (b-ZnO NPs). These NPs were synthesized in the filtrate of a useful bacterium (Bacillus safensis) and applied to control black heart rot of apricot. After synthesis, the reduction of b-ZnO NPs was confirmed by UV-visible spectroscopy, at 330 nm. Fourier transform infrared (FTIR) spectra ensured the presence of multiple functional groups (alcohols, phenols, carboxylic acids, nitro compounds and amines) on the surface of b-ZnO NPs. X-Ray diffraction (XRD) analysis elucidated their average size (18 nm) while scanning electron microscopy (SEM) micrograph described the spherical shape of b-ZnO NPs. The synthesized b-ZnO NPs were applied in four different concentrations (0.25 mg/ml, 0.50 mg/ml, 0.75 mg/ml, 1.0 mg/ml) under both in vitro and in vivo conditions. These NPs were very efficient in inhibiting mycelial growth (85.1%) of A. solani at 0.75 mg/ml concentration of NPs, in vitro. Same concentration also performed best, in vivo, and significantly reduced disease incidence (by 67%) on self-inoculated apricot fruit. Apart from this, application of b-ZnO NPs helped apricot fruit to maintain its quality under fungal-stress conditions. The decay of apricot fruit was reduced and they maintained greater firmness and higher weight. Moreover, b-ZnO NPs treated fruits controlled black heart rot disease by maintaining higher contents of ascorbic acid, soluble sugars and carotenoids. These b-ZnO NPs were produced in powder form for their easy carriage to the farmers' fields.

Application of smart chemometric models for spectra resolution and determination of challenging multi-action quaternary mixture: statistical comparison with greenness assessment

A multivariate spectrophotometric method is a potential approach that enables discrimination of spectra of components in complex matrices (e.g., pharmaceutical formulation) serving as a substitution method for chromatography. Four green smart multivariate spectrophotometric models were proposed and validated, including principal component regression (PCR), partial least-squares (PLS), multivariate curve resolution-alternating least squares (MCR-ALS), and artificial neural networks (ANN). The developed chemometric models were compared to resolve highly overlapping spectra of Paracetamol (PARA), Chlorpheniramine maleate (CPM), Caffeine (CAF), and Ascorbic acid (ASC). The four multivariate calibration models were assessed via recoveries percent, and root mean square error of prediction. Hence, the proposed models were efficiently applied with no need for any preliminary separation step. The models were utilized to analyze the studied components in their combined pharmaceutical formulation (Grippostad® C capsules). Analytical GREEnness Metric Approach (AGREE) and eco-scale tools were applied to assess the greenness of the established models and found to be 0.77 and 85, respectively. Moreover, the proposed models have been compared to official ones showing no considerable variations in accuracy and precision. Therefore, these models can be highly advantageous for conducting standard pharmaceutical analysis of the substances researched within product testing laboratories.

Vitamin Supplement Use in Patients With CKD: Worth the Pill Burden?

All vitamins play essential roles in various aspects of body function and systems. Patients with chronic kidney disease (CKD), including those receiving dialysis, may be at increased risk of developing vitamin deficiencies due to anorexia, poor dietary intake, protein energy wasting, restricted diet, dialysis loss, or inadequate sun exposure for vitamin D. However, clinical manifestations of most vitamin deficiencies are usually subtle or undetected in this population. Testing for circulating levels is not undertaken for most vitamins except folate, B12, and 25-hydroxyvitamin D because assays may not be available or may be costly to perform and do not always correlate with body stores. The last systematic review through 2016 was performed for the Kidney Disease Outcome Quality Initiative (KDOQI) 2020 Nutrition Guideline update, so this article summarizes the more recent evidence. We review the use of vitamins supplementation in the CKD population. To date there have been no randomized trials to support the benefits of any vitamin supplementation for kidney, cardiovascular, or patient-centered outcomes. The decision to supplement water-soluble vitamins should be individualized, taking account the patient's dietary intake, nutritional status, risk of vitamins deficiency/insufficiency, CKD stage, comorbid status, and dialysis loss. Nutritional vitamin D deficiency should be corrected, but the supplementation dose and formulation need to be personalized, taking into consideration the degree of 25-hydroxyvitamin D deficiency, parathyroid hormone levels, CKD stage, and local formulation. Routine supplementation of vitamins A and E is not supported due to potential toxicity. Although more trial data are required to elucidate the roles of vitamin supplementation, all patients with CKD should undergo periodic assessment of dietary intake and aim to receive various vitamins through natural food sources and a healthy eating pattern that includes vitamin-dense foods.

Does vitamin C supplementation in milk improve growth and health of diarrheic calves?

The objective of this study was to investigate how supplementing vitamin C (VC) in milk affects growth, starter intake, blood metabolites, and the health of young calves classified into healthy or diarrheic groups. Calves were classified as diarrheic if they experienced diarrhea for at least 3 days from birth to day 7, otherwise, they were classified as healthy (i.e., days with diarrhea < 3). From day 8 of age, a total of 48 Holstein calves were divided into four groups based on a 2 × 2 factorial arrangement, with calf health status (healthy or diarrheic) and VC supplementation (VC+ or VC-) to pasteurized milk (0 or 2 g/d; 50% purity) being the main experimental factors. Calves were fed equal amounts of milk until weaning (d 60). Calves continued to be monitored until they reached 74 days of age. Calves in the VC+ group were heavier at weaning (74.3 vs. 72.2 kg; P = 0.04) compared to those calves that did not receive VC. Blood total antioxidant capacity (d 53 and 67) and superoxide dismutase activity (d 53) were greater (P < 0.01) in VC+ vs. VC- calves. Calf health status and VC supplementation interacted (P = 0.03) for blood β-hydroxybutyrate on d 53, with the lowest concentration observed in diarrheic/VC- calves. Calves in the diarrheic group had a lower total antioxidant capacity (P = 0.01) but a greater neutrophil-to-lymphocyte ratio on d 53 and 67 (P < 0.01) than calves in the healthy group. Before weaning (d 53), neutrophil-to-lymphocyte ratio was greater, but hemoglobin was lower (P = 0.02) in calves classified into the diarrheic group that did not receive supplemental VC. The number of days medicated for diarrhea treatment was lower in VC+ calves than those in VC- group (1.73 vs. 2.47 days; P = 0.05). Overall, VC supplementation in pasteurized milk improved calf growth and health. Calves that experienced elevated episodes of diarrhea within the first week of life benefited more from supplemental VC than those classified into the healthy group.

Mechanism of interaction between ascorbic acid and soil iron-containing minerals for peroxydisulfate activation and organophosphorus flame retardant degradation

Soil constituents may play an important role in peroxydisulfate (PDS)-based oxidation of organic contaminants in soil. Iron-containing minerals (Fe-minerals) have been found to promote PDS activation for organics degradation. Our study found that ascorbic acid (H2A) could enhance PDS activation by soil Fe-minerals for triphenyl phosphate (TPHP) degradation. Determination and characterization analyses of Fe fractions showed that H2A could induce the reductive dissolution of solid Fe-minerals and the increasing of oxygen vacancies/hydroxyl groups content on Fe-minerals surface. The increasing of divalent Fe (Fe(II)) accelerated PDS activation to generate reactive oxygen species (ROS). Electron paramagnetic resonance (EPR) and quenching studies showed that sulfate radicals (SO4•-) and hydroxyl radicals (HO•) contributed significantly to TPHP degradation. The composition and content of Fe-minerals and soil organic matter (SOM) markedly influenced ROS transformations. Surface-bond and structural Fe played the main role in the production of Fe(II) in reaction system. The high-concentration SOM could result in ROS consumption and degradation inhibition. Density functional theory (DFT) studies revealed that H2A is preferentially adsorbed at α-Fe2O3(012) surface through Fe-O-C bridges rather than hydrogen bonds. After absorption, H atoms on H2A may further be migrated to adjacent O atoms on the α-Fe2O3(012) surface. With the transformation of H atoms to the α-Fe2O3(012) surface, the Fe-O-C bridge is broken and one electron is transferred from the O to Fe atom, inducing the reduction of trivalent Fe (Fe(III)) atom. MS/MS2 analysis, HPLC analysis, and toxicity assessment demonstrated that TPHP was transformed to less toxic 4-hydroxyphenyl diphenyl phosphate (OH-TPHP), diphenyl hydrogen phosphate (DPHP), and phenyl phosphate (PHP) through phenol-cleavage and hydroxylation processes, and even be mineralized in reaction system.

Dual-spot ratiometric microfluidic paper-based analytical device for accuracy and precision improvement

Instrumental and environmental fluctuations are common sources of error in smartphone-based optical detection, significantly affecting the accuracy of analytical measurements. In this regard, spotting the sample and reference simultaneously and in close proximity compensates for the fluctuations. This "dual-spot" design is similar to the double-beam technique used in spectrophotometry, which reduces fluctuations in the results. The underlying hypothesis is that any instrumental and/or environmental factors influencing the color intensity in the detection zones will similarly impact the color intensity in the control zone under the same conditions. To test our design, a ratiometric microfluidic paper-based analytical device (μPAD), functionalized with a mixture of green-emissive carbon dots (CDs) and red-emissive ethidium bromide, was developed for the selective detection of ascorbic acid (AA). The green emission of the CDs is quenched by both AA and Fe3+; NaF was thus loaded onto the 3D connector as a masking agent to remove the interference effect of the Fe3+ ions. The color variations were monitored under a UV lamp, using a smartphone to capture the images, and the RGB intensities were processed using the Color Grab application. The proposed double-spot method greatly enhanced the analytical precision and accuracy of the device. A linear working range from 0 to 125 μM was obtained, and the limit of detection was 2.71 μM. The μPAD was successfully used for the detection of AA in human serum, with recoveries from 87.27 to 98.52 %.

Superoxide dismutase-like cerium dioxide hollow sphere-based highly specific photoelectrochemical biosensing for ascorbic acid

Conventional N-type semiconductor-based photoelectrochemical (PEC) sensors are difficult to achieve high selectivity for ascorbic acid (AA) detection in real samples because co-existing reducing agents act as hole sacrificial agents like AA to promote the increase of photocurrent. Cerium dioxide (CeO2) is a superoxide dismutase-like nanozyme with the reversible Ce3+/Ce4+ redox pair as well as one of alternative N-type semiconductors. To address the problem of PEC detection selectivity of AA, bifunctional CeO2 is a good choice. Herein, a novel and rational PEC biosensor for AA is constructed based on CeO2 hollow spheres as both AA superoxide dismutase-like nanozyme and the photoelectric beacon, which enable the PEC approach with high selectivity. In this protocol, AA can selectively induce a decrease in the CeO2-based photoanode current, which is significantly different from the conventional N-type semiconductor-based PEC sensor, this unique working mechanism is also proposed. The results show that the CeO2-based photocurrent response decreases linearly with AA concentrations in the ranges of 1 μM-600 μM and 600 μM-3000 μM, with a limit of detection of 0.33 μM. Moreover, the fabricated PEC biosensor has advantages of cost-effectiveness, replicability, and stability. Additionally, the sensor is competent for AA determination in practical settings and has achieved satisfactory results.

Ascorbate and its transporter SVCT2: The dynamic duo's integrated roles in CNS neurobiology and pathophysiology

Ascorbate is a small antioxidant molecule essential for the proper development and function of the brain. Ascorbate is transported into the brain and between brain cells via the Sodium vitamin C co-transporter 2 (SVCT2). This review provides an in-depth analysis of ascorbate's physiology, including how ascorbate is absorbed from food into the CNS, emphasizing cellular mechanisms of ascorbate recycling and release in different CNS compartments. Additionally, the review delves into the various functions of ascorbate in the CNS, including its impact on epigenetic modulation, synaptic plasticity, and neurotransmission. It also emphasizes ascorbate's role on neuromodulation and its involvement in neurodevelopmental processes and disorders. Furthermore, it analyzes the relationship between the duo ascorbate/SVCT2 in neuroinflammation, particularly its effects on microglial activation, cytokine release, and oxidative stress responses, highlighting its association with neurodegenerative diseases, such as Alzheimer's disease (AD). Overall, this review emphasizes the crucial role of the dynamic duo ascorbate/SVCT2 in CNS physiology and pathology and the need for further research to fully comprehend its significance in a neurobiological context and its potential therapeutic applications.

A bioinspired and sustainable route for the preparation of Ag-crosslinked alginate fibers decorated with silver nanoparticles

Functional materials obtained through green and sustainable routes are attracting particular attention due to the need to reduce the environmental impact of the chemical industry. In this work we propose a bioinspired approach for the preparation of alginate fibers containing silver nanoparticles (AgNPs), to be used for antimicrobial purposes. We demonstrate that filiform polymeric structures with length of a few meters can be easily obtained by extruding an alginate solution in an aqueous Ag+-containing bath (i.e. wet spinning) and that treating the fibers with freshly-squeezed lemon juice leads to the formation of AgNPs homogeneously distributed within the polymeric network. Using mixtures of ascorbic and citric acid to mimic lemon juice composition we highlight the influence of the aforementioned molecules on the nanoparticles formation process as well as on the properties of the fibers. Varying the amount of citric and ascorbic acid used for the treatment allows to finely tune the thermal, morphological and water absorption properties of the fibers. This evidence, along with the possibility to easily monitor the preparation through FT-IR spectroscopy, endows the fibers with a high application potential in several fields such as wound healing, water/air purification and agriculture.

Intra-articular injection of ascorbic acid enhances microfracture-mediated cartilage repair

Previous studies have confirmed that ascorbic acid (AA) can promote cartilage repair and improve cartilage differentiation in bone marrow mesenchymal stem cells. However, the use of microfracture (MFX) combined with AA to repair cartilage damage has not been studied. This study established a rabbit animal model and treated cartilage injury with different concentrations of AA combined with MFX. Macroscopic observations, histological analysis, immunohistochemical analysis and reverse transcription quantitative polymerase chain reaction analysis of TGF-β, AKT/Nrf2, and VEGF mRNA expression were performed. The results showed that intra-articular injection of AA had a positive effect on cartilage repair mediated by microfractures. Moreover, 10 mg/ml AA was the most effective at promoting cartilage repair mediated by microfractures. Intra-articular injection of AA promoted the synthesis of type II collagen and the formation of glycosaminoglycans by downregulating the mRNA expression of TGF-β and VEGF. In summary, this study confirmed that AA could promote cartilage repair after MFX surgery.

A fluorescent dual-emitting platform for fluorescent "turn-on" ratiometric detection of ascorbic acid in beverages utilizing luminol-embedded iron-based metal-organic frameworks

A fluorescent dual-emitting platform for fluorescent "turn-on" ratiometric detection of ascorbic acid in beverages was developed utilizing luminol-embedded iron-based metal-organic frameworks (luminol@Fe-DOBDC MOFs). Luminol@Fe-DOBDC MOFs with fluorescent emissions at 430 nm and 540 nm under excitation wavelength of 365 nm were applied to detect ascorbic acid on the basis of ascorbic acid triggering the reduction of Fe3+ into Fe2+. In the presence of ascorbic acid, fluorescent intensity at 540 nm was increased significantly while fluorescent intensity at 430 nm was changed slightly. Two emission peaks separated by 110 nm can eliminate environmental interferences by built-in self-calibration of ratiometric signal, enhancing the sensitivity and accuracy. The increasing ratiometric fluorescent intensity (I540 nm/I430 nm) has linear relationship with the concentration of ascorbic acid from 0.2 to 30 μM with limit of detection of 70 nM. It is an efficient, sensitive and accurate platform to detect ascorbic acid in commercial beverages using transition-metal-based MOFs.

Multi-component determination based on high quantum yield "on-off-on" carbon quantum dots sensor

The nitrogen(N)-sulfur(S)-sodium(Na(I)) co-doped carbon quantum dots (CQDs) were synthesized via a one-step hydrothermal method, which exhibited a remarkably high fluorescence quantum yield (24.58%) and exceptional optical properties. The fluorescence "on-off-on" sensor was constructed. The fluorescence of CQDs was rapidly quenched with Fe(III) and the fluorescence recovered by ascorbic acid (Asc) partially and arginine (Arg)/histidine (His) completely. The CQDs fluorescence sensor demonstrated rapid response, exceptional sensitivity, excellent stability, remarkable selectivity, and robust anti-interference performance, which was feasible to simultaneously determine the concentrations of multiple analytes in the sample with satisfactory recovery rates. The "on-off-on" fluorescence mechanism of CQDs was investigated, revealing the significant potential of carbon nano-functionalized materials in the field of drug detection through fluorescence sensing.

Co-encapsulation and release of apigenin and ascorbic acid in polyelectrolyte multilayer capsules for targeted polycystic ovary syndrome

Polycystic ovary syndrome (PCOS), a prevalent endocrine disorder in women of reproductive age, is linked to hormonal imbalances and oxidative stress. Our study investigates the regenerative potential of apigenin (AP, hydrophobic) and ascorbic acid (AC, hydrophilic) encapsulated within poly (allylamine hydrochloride) and dextran sulfate (PAH/DS) hollow microcapsules for PCOS. These microcapsules, constructed using a layer-by-layer (LbL) assembly, are found to be 4 ± 0.5 μm in size. Our research successfully demonstrates the co-encapsulation of AP and AC in a single PAH/DS system with high encapsulation efficiency followed by successful release at physiological conditions by CLSM investigations. In vitro tests with testosterone-treated CHO cells reveal that the dual-drug-loaded PAH/DS capsules effectively reduce intracellular ROS levels and apoptosis and offering protection. In an in-vivo zebrafish model, these capsules demonstrate active biodistribution to targeted ovaries and reduce testosterone levels through radical scavenging. Histopathological examinations show that the injected dual-drug-loaded PAH/DS microcapsules assist in the development of ovarian follicles in testosterone-treated zebrafish. Hence, this dual-drug-loaded system, capable of co-encapsulating two natural compounds, effectively interacts with ovarian cells, reducing cellular damage and normalizing PCOS conditions.

Ascorbic acid prevents stress-induced hypercoagulability in overweight and obese individuals

Ascorbic acid (AA) may contribute to restoring hemostatic balance after mental stress (MS) in overweight/obese adults. We aimed to determine the effects of AA administration on hemostatic responses to MS in overweight/obese men. Fourteen overweight/obesity men (27 ± 7 years; BMI: 29.7 ± 2.6 kg m-2) performed the Stroop color-word stress task for 5 min after non-simultaneous infusion of placebo (PL, 0.9% NaCl) and AA (3 g). Blood was collected at baseline, during MS, and 60 min after MS to measure: activated partial thromboplastin time, prothrombin time, and fibrinogen concentration, by coagulometer; platelet-derived microvesicles (PMV, mv/μL), by flow cytometry; nitrite (μM), by chemiluminescence. In PL session, MS led to decreases in PTs (stress, p = 0.03; 60 min, p < 0.001), PT-INR (stress, p < 0.001; 60 min, p < 0.01), aPTTs (60 min, p = 0.03), aPTT ratio (60 min, p = 0.04) and fibrinogen (60 min, p = 0.04), while increased PT activity (60 min, p = 0.01) when compared to baseline. Furthermore, AA increased PTs (60 min, p < 0.001), PT-INR (60 min, p = 0.03) and decreased PT activity (60 min, p < 0.001) and fibrinogen (stress, p = 0.04) when compared to PL. Nitrite was increased in response to stress during AA session (p < 0.001 vs PL). There was no difference in PMV. Ascorbic acid prevented the impaired hemostatic profile and improved nitrite response to stress in the overweight and obese adults.

Alleviation of radiation combined skin injury in rat model by topical application of ascorbate formulation

PURPOSE

This research endeavor was undertaken to elucidate the impact of an innovative ascorbate formulation on the regeneration process of full-thickness excision wounds in a rat model exposed to whole-body gamma irradiation, replicating conditions akin to combat or radiation emergency scenarios.

MATERIALS AND METHODS

We established a comprehensive rat model by optimizing whole body γ-radiation doses (5-9 Gy) and full-thickness excision wound sizes (1-3 cm2) to mimic radiation combined injury (RCI). The developed RCI model was used to explore the healing potential of ascorbate formulation. The study includes various treatment groups (i.e., sham control, radiation alone, wound alone, radiation + wound, and radiation + wound + formulation). The ascorbate formulation was applied twice daily, with a 12-hour gap between each application, starting 1 hour after the initiation of the wound. The healing potential of the formulation in the RCI context was evaluated over 14 days through hematological, molecular, and histological parameters.

RESULTS

The combination of a 5 Gy radiation dose and a 1 cm2 wound was identified as the optimal setting to develop the RCI model for subsequent studies. The formulation was used topically immediately following RCI, and then twice daily until complete healing. Treatment with the ascorbate formulation yielded noteworthy outcomes and led to a substantial reduction (p < .05) in the wound area, accelerated epithelialization periods, and an increased wound contraction rate. The formulation's localized healing response improved organ weights, normalized blood parameters, and enhanced hematopoietic and immune systems. A gene expression study revealed the treatment up-regulated TGF-β and FGF, and down-regulated PDGF-α, TNF-α, IL-1β, IL-6, MIP-1α, and MCP-1 (p < .05). Histopathological assessments supported the formulation's effectiveness in restoring cellular architecture and promoting tissue regeneration.

CONCLUSION

Topical application of the ascorbate formulation in RCI resulted in a significant improvement in delayed wound healing, leading to accelerated wound closure by mitigating the expression of inflammatory responses.

Randomized trial to assess the potential role of ascorbic acid and statin for post-contrast acute kidney injury prevention

PURPOSE

To evaluate the effect of using statins and ascorbic acid for the prevention of post-contrast acute kidney injury (PC-AKI) in patients undergoing urologic diagnostic elective contrast-enhanced computed tomography (CECT).

METHODS

This registered trial (NCT03391830) was for statin naïve patients underwent elective CECT. Patients were randomized allocated to two groups: the first group received atorvastatin 80-mg the day before the study and atorvastatin 40-mg two hours before the CECT and for continue on atorvastatin 40-mg two days after CECT; plus ascorbic acid 500 mg with atorvastatin. The other group received two tablets of placebo once/daily before the procedure and for another 3 days. The primary outcome was to assess the incidence PC-AKI.

RESULTS

The baseline parameters were comparable between both groups. The final median (interquartile range "IQR") serum creatinine were 0.80 (0.60, 1.00) and 0.80 (0.60, 1.00), respectively, with insignificant p-value (p = 0.8). The median (IQR) final estimated GFR were 95.2 (72.8, 108.1) and 88.6 (71.9, 111.0) mL/min in placebo and statin plus ascorbic acid groups, respectively (p = 0.48). The eGFR difference median (IQR) were - 6.46 (- 11.72, - 4.18) and - 6.57 (- 13.38, - 3.82) ml/min in placebo and statin plus ascorbic acid groups, respectively (p = 0.58). PC-AKI occurred in 11 patients (9.8%) in placebo group and in 3 patients (3%) in statin plus ascorbic acid group (p = 0.04).

CONCLUSIONS

Statin and ascorbic acid did not statistically improve neither serum creatinine nor eGFR values in patient underwent CECT. However, it can decrease the incidence of the clinically insignificant PC-AKI.

A Dual-Mode Detection Sensor Based on Nitrogen-Doped Carbon Dots for Visual Detection of Fe(III) and Ascorbic Acid via a Smartphone

Accurately and promptly detecting Fe3+ and ascorbic acid (AA) is a crucial objective. In this study, nitrogen-doped carbon dots (N-CDs) were synthesized using a one-step hydrothermal synthesis method with 6,9-diamino-2-ethoxyacridine lactate as the precursor. The introduction of Fe3+ and AA resulted in both fluorescence (FL) quenching and enhancement of the synthesized N-CDs. The fluorescent response of the N-CDs probe to Fe3+ was observed in the concentration range of 5-20 µM and 25-50 µM, with a limit of detection (LOD) of 290 nM. Remarkably, the fluorescence of the N-CDs was recovered upon the addition of AA to the N-CDs-Fe3+ system. Using the "off-on" fluorescent N-CDs probe, a linear range of 40-90 µM was achieved with an LOD of 0.69 µM. Additionally, the feasibility of employing a smartphone equipped with an RGB Color Picker was demonstrated for the analysis of Fe3+ and AA concentrations, providing a novel visual detection method. Furthermore, the application of N-CDs in solution demonstrated considerable potential for visually detecting Fe3+ and AA. The proposed dual-mode detection sensor was found to be simple, efficient, and stable, enabling the successful determination of Fe3+ and AA in practical samples with satisfactory results.