Effectiveness of different antioxidants in suppressing the evolution of thermally induced peroxidation products in hemp seed oil.

Several scientific studies have warned that the ingestion of dietary lipid oxidation products (LOPs) may initiate or exacerbate the development of several chronic non-communicable diseases in humans. Indeed, the constantly increasing consumption of culinary oils by larger global populations indicates the need for scientific techniques to suppress the evolution of LOPs in thermo-oxidised oils. This study employed a 600.13 MHz frequency NMR spectrometer in evaluating the effect of 10, 50, and 100 ppm concentrations of chemical compounds reported to have antioxidant properties in continuously-stirred and thermally stressed polyunsaturated fatty acid (PUFA)-rich hemp seed oil at a frying temperature of 180℃ for 180 min. Research data acquired showed that the antioxidants α- and γ-tocopherol, γ-oryzanol, ß-carotene, eugenol, resveratrol, ascorbyl palmitate, gentisic acid, and L-ascorbic acid all played a vital role in suppressing the evolution of secondary aldehydic lipid oxidation products in hemp seed oil. However, the most ineffective LOP-suppressing agent was L-lysine, an observation which may be accountable by its poor oil solubility. Nonetheless, trends deduced for compounds acting as antioxidants were mainly unique for each class of agent tested. Conversely, the antioxidant capacity of resveratrol was consistently higher, and this effect was found to be independent of its added amounts. This report provides a direct approach in developing scientific methods for the suppression of LOPs in thermo-oxidatively susceptible PUFA-rich cooking oils.

Antioxidant supplementation for sickle cell disease.

BACKGROUND: Sickle cell disease (SCD) refers to a group of genetic disorders characterized by the presence of an abnormal haemoglobin molecule called haemoglobin S (HbS). When subjected to oxidative stress from low oxygen concentrations, HbS molecules form rigid polymers, giving the red cell the typical sickle shape. Antioxidants have been shown to reduce oxidative stress and improve outcomes in other diseases associated with oxidative stress. Therefore, it is important to review and synthesize the available evidence on the effect of antioxidants on the clinical outcomes of people with SCD. OBJECTIVES: To assess the effectiveness and safety of antioxidant supplementation for improving health outcomes in people with SCD. SEARCH METHODS: We used standard, extensive Cochrane search methods. The latest search date was 15 August 2023. SELECTION CRITERIA: We included randomized and quasi-randomized controlled trials comparing antioxidant supplementation to placebo, other antioxidants, or different doses of antioxidants, in people with SCD. DATA COLLECTION AND ANALYSIS: Two authors independently extracted data, assessed the risk of bias and certainty of the evidence, and reported according to Cochrane methodological procedures. MAIN RESULTS: The review included 1609 participants in 26 studies, with 17 comparisons. We rated 13 studies as having a high risk of bias overall, and 13 studies as having an unclear risk of bias overall due to study limitations. We used GRADE to rate the certainty of evidence. Only eight studies reported on our important outcomes at six months. Vitamin C (1400 mg) plus vitamin E (800 mg) versus placebo Based on evidence from one study in 83 participants, vitamin C (1400 mg) plus vitamin E (800 mg) may not be better than placebo at reducing the frequency of crisis (risk ratio (RR) 1.18, 95% confidence interval (CI) 0.64 to 2.18), the severity of pain (RR 1.33, 95% CI 0.40 to 4.37), or adverse effects (AE), of which the most common were headache, nausea, fatigue, diarrhoea, and epigastric pain (RR 0.56, 95% CI 0.31 to 1.00). Vitamin C plus vitamin E may increase the risk of SCD-related complications (acute chest syndrome: RR 2.66, 95% CI 0.77 to 9.13; 1 study, 83 participants), and increase haemoglobin level (median (interquartile range) 90 (81 to 96) g/L versus 93.5 (84 to 105) g/L) (1 study, 83 participants) compared to placebo. However, the evidence for all the above effects is very uncertain. The study did not report on quality of life (QoL) of participants and their caregivers, nor on frequency of hospitalization. Zinc versus placebo Zinc may not be better than placebo at reducing the frequency of crisis at six months (rate ratio 0.62, 95% CI 0.17 to 2.29; 1 study, 36 participants; low-certainty evidence). We are uncertain whether zinc is better than placebo at improving sickle cell-related complications (complete healing of leg ulcers at six months: RR 2.00, 95% CI 0.60 to 6.72; 1 study, 34 participants; very low-certainty evidence). Zinc may be better than placebo at increasing haemoglobin level (g/dL) (MD 1.26, 95% CI 0.44 to 1.26; 1 study, 36 participants; low-certainty evidence). The study did not report on severity of pain, QoL, AE, and frequency of hospitalization. N-acetylcysteine versus placebo N-acetylcysteine (NAC) 1200 mg may not be better than placebo at reducing the frequency of crisis in SCD, reported as pain days (rate ratio 0.99 days, 95% CI 0.53 to 1.84; 1 study, 96 participants; low-certainty evidence). Low-certainty evidence from one study (96 participants) suggests NAC (1200 mg) may not be better than placebo at reducing the severity of pain (MD 0.17, 95% CI -0.53 to 0.87). Compared to placebo, NAC (1200 mg) may not be better at improving physical QoL (MD -1.80, 95% CI -5.01 to 1.41) and mental QoL (MD 2.00, 95% CI -1.45 to 5.45; very low-certainty evidence), reducing the risk of adverse effects (gastrointestinal complaints, pruritus, or rash) (RR 0.92, 95% CI 0.75 to 1.14; low-certainty evidence), reducing the frequency of hospitalizations (rate ratio 0.98, 95% CI 0.41 to 2.38; low-certainty evidence), and sickle cell-related complications (RR 5.00, 95% CI 0.25 to 101.48; very low-certainty evidence), or increasing haemoglobin level (MD -0.18 g/dL, 95% CI -0.40 to 0.04; low-certainty evidence). L-arginine versus placebo L-arginine may not be better than placebo at reducing the frequency of crisis (monthly pain) (RR 0.71, 95% CI 0.26 to 1.95; 1 study, 50 participants; low-certainty evidence). However, L-arginine may be better than placebo at reducing the severity of pain (MD -1.41, 95% CI -1.65 to -1.18; 2 studies, 125 participants; low-certainty evidence). One participant allocated to L-arginine developed hives during infusion of L-arginine, another experienced acute clinical deterioration, and a participant in the placebo group had clinically relevant increases in liver function enzymes. The evidence is very uncertain whether L-arginine is better at reducing the mean number of days in hospital compared to placebo (MD -0.85 days, 95% CI -1.87 to 0.17; 2 studies, 125 participants; very low-certainty evidence). Also, L-arginine may not be better than placebo at increasing haemoglobin level (MD 0.4 g/dL, 95% CI -0.50 to 1.3; 2 studies, 106 participants; low-certainty evidence). No study in this comparison reported on QoL and sickle cell-related complications. Omega-3 versus placebo Very low-certainty evidence shows no evidence of a difference in the risk of adverse effects of omega-3 compared to placebo (RR 1.05, 95% CI 0.74 to 1.48; 1 study, 67 participants). Very low-certainty evidence suggests that omega-3 may not be better than placebo at increasing haemoglobin level (MD 0.36 g/L, 95% CI -0.21 to 0.93; 1 study, 67 participants). The study did not report on frequency of crisis, severity of pain, QoL, frequency of hospitalization, and sickle cell-related complications. AUTHORS' CONCLUSIONS: There was inconsistent evidence on all outcomes to draw conclusions on the beneficial and harmful effects of antioxidants. However, L-arginine may be better than placebo at reducing the severity of pain at six months, and zinc may be better than placebo at increasing haemoglobin level. We are uncertain whether other antioxidants are beneficial for SCD. Larger studies conducted on each comparison would reduce the current uncertainties.

Vitamin C and E antioxidant supplementation may significantly reduce pain symptoms in endometriosis: A systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: The primary challenge encountered by individuals diagnosed with endometriosis is the experience of pain. Emerging research indicates that oxidative stress is implicated in the initiation of pain associated with endometriosis. Vitamins C and E are known for their antioxidative properties. The primary objective of this study is to assess the efficacy of antioxidant supplementation, consisting of these vitamins, in the management of pain associated with endometriosis. METHODS: A comprehensive search was conducted on the ClinicalTrials.gov, Scopus, Europe PMC, and Medline databases up until August 23rd, 2023, utilizing a combination of relevant keywords. This review incorporates literature that examines the relationship between antioxidant supplementation and pain in endometriosis. We employed fixed-effect models to analyze the risk ratio (RR) and present the outcomes together with their corresponding 95% confidence intervals (CI). RESULTS: A total of five RCTs were incorporated. The results of our meta-analysis indicated that antioxidant supplementation with vitamin C and E combination was associated with higher proportion of endometriosis patients reporting reduced chronic pelvic pain (RR 7.30; 95%CI: 3.27-16.31, p<0.00001, I2 = 0%), alleviations of dysmenorrhea (RR 1.96; 95%CI: 1.25-3.07, p = 0.003, I2 = 39%), and dyspareunia (RR 5.08; 95%CI: 2.10-12.26, p = 0.0003, I2 = 0%) than patients only receiving placebo. CONCLUSIONS: This study suggests the potential ability of vitamin C and E in alleviating pain symptoms experienced by individuals with endometriosis.

Managing children with frequent respiratory infections and associated wheezing: a preliminary randomized study with a new multicomponent nasal spray.

BACKGROUND: Preschoolers frequently have respiratory infections (RIs), which may cause wheezing in some subjects. Type 2 polarization may favor increased susceptibility to RIs and associated wheezing. Non-pharmacological remedies are garnering increasing interest as possible add-on therapies. The present preliminary study investigated the efficacy and safety of a new multi-component nasal spray in preschoolers with frequent RIs and associated wheezing. METHODS: Some preschoolers with these characteristics randomly took this product, containing lactoferrin, dipotassium glycyrrhizinate, carboxymethyl-beta-glucan, and vitamins C and D3 (Saflovir), two sprays per nostril twice daily for 3 months. Other children were randomly treated only with standard therapy. Outcomes included the number of RIs and wheezing episodes, use of medications, and severity of clinical manifestations. RESULTS: Preschoolers treated add-on with this multicomponent product experienced fewer RIs and used fewer beta-2 agonists than untreated children (P = 0.01 and 0.029, respectively). CONCLUSIONS: This preliminary study demonstrated that a multicomponent product, administered add-on as a nasal spray, could reduce the incidence of RIs and use of symptomatic drugs for relieving wheezing in children.

Scurvy masquerading as IgA vasculitis.

BACKGROUND: Vitamin C deficiency, or scurvy, is rare but poses risks for children with poor diets, limited resources, or malabsorption issues. It may also be common in children with restrictive or selective dietary habits in children with global developmental delay, autism spectrum disorder, and physical disabilities. Symptoms include fatigue, irritability, joint and muscle pain, joint swellings, edema, swollen gums, easy bruising, and delayed wound healing. Early recognition and prompt intervention are essential to prevent the progression of symptomatic vitamin C deficiency in children. CASE PRESENTATION: We present a case of a 13-year-old boy with developmental delay secondary to Lennox Gastaut syndrome referred for suspected recurrent, severe, and atypical IgA vasculitis. He presented with irritability, loss of appetite, petechial and ecchymotic lower limb lesions, unilateral gum swelling, severe arthritis, peripheral oedema, severe weight loss, anaemia, and raised inflammatory markers. Multiple investigations were performed before the diagnosis of scurvy was made. A surgical finding of friable gingival tissue with multiple loose teeth, a skin biopsy with follicular hyperkeratosis and extravasated perifollicular red blood cells, and a typical X-ray finding led to the diagnosis of scurvy. CONCLUSION: Scurvy should be given careful consideration as a differential diagnosis in patients presenting with musculoskeletal issues, mucocutaneous complaints, and constitutional symptoms such as malaise, asthenia, irritability, and loss of appetite. A focused and detailed dietary history looking for a lack of good sources of vitamin C can be an easy indicator of this differential. Imaging studies revealing the typical features can also help make the diagnosis. Pathology of the skin revealing pathognomonic features can add to the certainty of the diagnosis. In the absence of all else, the rapid response to treatment with an appropriate dose of vitamin C has a diagnostic and therapeutic role.

Risk indicators for the severity of erosive wear in deciduous dentition of Mexican schoolchildren aged 5 to 7 years.

The objective of this work was to estimate the prevalence and severity of erosive tooth wear (ETW), and to identify risk indicators of deciduous dentition of a group of schoolchildren from public schools in Tlalnepantla de Baz, State of Mexico. A cross-sectional study was carried out in 352 schoolchildren from 5 to 7 years old. The severity of the ETW was evaluated using the Basic Erosive Wear Examination (BEWE). Risk indicators were evaluated through a survey which included food and beverage consumption, consumption habits, vitamin C consumption, gastroesophageal reflux, heartburn, belching, xerostomia, vomiting and teeth grinding. Multinomial logistic regression models were fitted. The prevalence of ETW was 99.7% (n = 351). Regarding severity, 46.6% were at a null/mild level, 27.3% moderate, and 26.1% severe. Males were more likely to present severe ETW (odds ratio (OR) = 2.23, 95% confidence interval (CI), 1.27-3.93; p = 0.005). The risk indicators for the severity of ETW were the frequent consumption of citrus fruits (OR = 2.09, 95% CI, 1.12-3.89; p = 0.021), fruit juice (OR = 1.99, 95% CI, 1.06-3.75; p = 0.033), processed beverages (OR = 2.15, 95% CI, 1.23-3.78; p = 0.008) and hot sauce (OR = 1.82, 95% CI, 1.03-3.20; p = 0.036). The prevalence of ETW in the deciduous dentition was very high (99.7%) and ~1/3 for severe ETW. The dietary factors associated with severe ETW are part of the regular consumption of Mexican school-age children, which impact their oral health condition. It is important to establish intervention strategies from the infant stage, focused on both children and their caregivers.

Synchronizing positive effect of vitamin C and chromium on hyper lipidemia, hyperglycemia, liver enzymes and BMI of diabetes mellitus type 2 patients.

This study investigates the combined effect of vitamin C and chromium on BMI, lipid profile, LFTs and HbA1c of Diabetes Mellitus type 2 patients. This is randomized controlled trial study. For this study a total of 60 patients (n=28 female, n=32 male) Diabetes Mellitus type 2 patients were selected. They were divided into treatment group (vitamin C (500mg) Chromium (200µg) and control group (placebo) comprising thirty patients per group. Mean age in control group and treatment group is 33± 5.729 and 33±7.017 respectively. Statistical analysis showed significant results of lipid profile; total cholesterol (mg/dl) 198±66.1 P=0.008, High-Density Lipoprotein 38±7.5, P<0.001, Low Density Lipoprotein (LDL) (mg/dl) 105.1±22.4, P=0.002 and Triglycerides 191±64.3, P=0.02 are respectively. Levels of serum ALT (u/l) (34.7±9.1, P<0.001) and AST (u/l) (31.6 ±8.6, P<0.001) were significantly lower as compared to control group. HbA1c percentages were also normalized (5.45±0.2, P<.001) as compared to group 2. BMI values were also improved (P=0.01) after treatment. Combined supplementation of vitamin C and chromium reduce the plasma lipid percentage, blood glucose levels and also improve the ALT and AST functions.

Combined transcriptomics and proteomics unveil the impact of vitamin C in modulating specific protein abundance in the mouse liver.

BACKGROUND: Vitamin C (ascorbate) is a water-soluble antioxidant and an important cofactor for various biosynthetic and regulatory enzymes. Mice can synthesize vitamin C thanks to the key enzyme gulonolactone oxidase (Gulo) unlike humans. In the current investigation, we used Gulo-/- mice, which cannot synthesize their own ascorbate to determine the impact of this vitamin on both the transcriptomics and proteomics profiles in the whole liver. The study included Gulo-/- mouse groups treated with either sub-optimal or optimal ascorbate concentrations in drinking water. Liver tissues of females and males were collected at the age of four months and divided for transcriptomics and proteomics analysis. Immunoblotting, quantitative RT-PCR, and polysome profiling experiments were also conducted to complement our combined omics studies. RESULTS: Principal component analyses revealed distinctive differences in the mRNA and protein profiles as a function of sex between all the mouse cohorts. Despite such sexual dimorphism, Spearman analyses of transcriptomics data from females and males revealed correlations of hepatic ascorbate levels with transcripts encoding a wide array of biological processes involved in glucose and lipid metabolisms as well as in the acute-phase immune response. Moreover, integration of the proteomics data showed that ascorbate modulates the abundance of various enzymes involved in lipid, xenobiotic, organic acid, acetyl-CoA, and steroid metabolism mainly at the transcriptional level, especially in females. However, several proteins of the mitochondrial complex III significantly correlated with ascorbate concentrations in both males and females unlike their corresponding transcripts. Finally, poly(ribo)some profiling did not reveal significant enrichment difference for these mitochondrial complex III mRNAs between Gulo-/- mice treated with sub-optimal and optimal ascorbate levels. CONCLUSIONS: Thus, the abundance of several subunits of the mitochondrial complex III are regulated by ascorbate at the post-transcriptional levels. Our extensive omics analyses provide a novel resource of altered gene expression patterns at the transcriptional and post-transcriptional levels under ascorbate deficiency.

Vitamin C alleviates hyperglycemic stress in retinal pigment epithelial cells.

BACKGROUND: Retinal pigment epithelial cells (RPECs) are a type of retinal cells that structurally and physiologically support photoreceptors. However, hyperglycemia has been shown to play a critical role in the progression of diabetic retinopathy (DR), which is one of the leading causes of vision impairment. In the diabetic eye, the high glucose environment damages RPECs via the induction of oxidative stress, leading to the release of excess reactive oxygen species (ROS) and triggering apoptosis. In this study, we aim to investigate the antioxidant mechanism of Vitamin C in reducing hyperglycemia-induced stress and whether this mechanism can preserve the function of RPECs. METHODS AND RESULTS: ARPE-19 cells were treated with high glucose in the presence or absence of Vitamin C. Cell viability was measured by MTT assay. Cleaved poly ADP-ribose polymerase (PARP) was used to identify apoptosis in the cells. ROS were detected by the DCFH-DA reaction. The accumulation of sorbitol in the aldose reductase (AR) polyol pathway was determined using the sorbitol detection assay. Primary mouse RPECs were isolated from adult mice and identified by Rpe65 expression. The mitochondrial damage was measured by mitochondrial membrane depolarization. Our results showed that high glucose conditions reduce cell viability in RPECs while Vitamin C can restore cell viability, compared to the vehicle treatment. We also demonstrated that Vitamin C reduces hyperglycemia-induced ROS production and prevents cell apoptosis in RPECs in an AR-independent pathway. CONCLUSIONS: These results suggest that Vitamin C is not only a nutritional necessity but also an adjuvant that can be combined with AR inhibitors for alleviating hyperglycemic stress in RPECs.

Impact of exogenous melatonin foliar application on physiology and fruit quality of wine grapes (Vitis vinifera) under salt stress.

Soil salinisation is an important abiotic stress faced in grape cultivating, leading to weakened plant vigour and reduced fruit quality. Melatonin as a novel hormone has shown positive exogenous application value. Therefore, this study used wine grape (Vitis vinifera ) 'Pinot Noir' as a test material to investigate the changes of foliar spraying with different concentrations of melatonin on the physiology and fruit quality of wine grapes in a field under simulated salt stress (200mmolL-1 NaCl). The results showed that foliar spraying of melatonin significantly increased the intercellular CO2 concentration, maximum photochemical quantum yield of PSII, relative chlorophyll and ascorbic acid content of the leaves, as well as the single spike weight, 100-grain weight, transverse and longitudinal diameters, malic acid, α-amino nitrogen and ammonia content of fruits, and decreased the initial fluorescence value of leaves, ascorbate peroxidase activity, glutathione content, fruit transverse to longitudinal ratio and tartaric acid content of plants under salt stress. Results of the comprehensive evaluation of the affiliation function indicated that 100µmolL-1 melatonin treatment had the best effect on reducing salt stress in grapes. In summary, melatonin application could enhance the salt tolerance of grapes by improving the photosynthetic capacity of grape plants under salt stress and promoting fruit development and quality formation, and these results provide new insights into the involvement of melatonin in the improvement of salt tolerance in crop, as well as some theoretical basis for the development and industrialisation of stress-resistant cultivation techniques for wine grapes.

Gamma-aminobutyric acid (GABA) improves salinity stress tolerance in soybean seedlings by modulating their mineral nutrition, osmolyte contents, and ascorbate-glutathione cycle.

BACKGROUND: In plants, GABA plays a critical role in regulating salinity stress tolerance. However, the response of soybean seedlings (Glycine max L.) to exogenous gamma-aminobutyric acid (GABA) under saline stress conditions has not been fully elucidated. RESULTS: This study investigated the effects of exogenous GABA (2 mM) on plant biomass and the physiological mechanism through which soybean plants are affected by saline stress conditions (0, 40, and 80 mM of NaCl and Na2SO4 at a 1:1 molar ratio). We noticed that increased salinity stress negatively impacted the growth and metabolism of soybean seedlings, compared to control. The root-stem-leaf biomass (27- and 33%, 20- and 58%, and 25- and 59% under 40- and 80 mM stress, respectively]) and the concentration of chlorophyll a and chlorophyll b significantly decreased. Moreover, the carotenoid content increased significantly (by 35%) following treatment with 40 mM stress. The results exhibited significant increase in the concentration of hydrogen peroxide (H2O2), malondialdehyde (MDA), dehydroascorbic acid (DHA) oxidized glutathione (GSSG), Na+, and Cl- under 40- and 80 mM stress levels, respectively. However, the concentration of mineral nutrients, soluble proteins, and soluble sugars reduced significantly under both salinity stress levels. In contrast, the proline and glycine betaine concentrations increased compared with those in the control group. Moreover, the enzymatic activities of ascorbate peroxidase, monodehydroascorbate reductase, glutathione reductase, and glutathione peroxidase decreased significantly, while those of superoxide dismutase, catalase, peroxidase, and dehydroascorbate reductase increased following saline stress, indicating the overall sensitivity of the ascorbate-glutathione cycle (AsA-GSH). However, exogenous GABA decreased Na+, Cl-, H2O2, and MDA concentration but enhanced photosynthetic pigments, mineral nutrients (K+, K+/Na+ ratio, Zn2+, Fe2+, Mg2+, and Ca2+); osmolytes (proline, glycine betaine, soluble sugar, and soluble protein); enzymatic antioxidant activities; and AsA-GSH pools, thus reducing salinity-associated stress damage and resulting in improved growth and biomass. The positive impact of exogenously applied GABA on soybean plants could be attributed to its ability to improve their physiological stress response mechanisms and reduce harmful substances. CONCLUSION: Applying GABA to soybean plants could be an effective strategy for mitigating salinity stress. In the future, molecular studies may contribute to a better understanding of the mechanisms by which GABA regulates salt tolerance in soybeans.

Ascorbic acid metabolism and functions.

This Special Issue was assembled to mark the 25th anniversary of the proposal of the d -mannose/ l -galactose (Smirnoff-Wheeler) ascorbate biosynthesis pathway in plants ( Wheeler et al., 1998 ). The issue aims to assess the current state of knowledge and to identify outstanding questions about ascorbate metabolism and functions in plants.

Comparative Transcriptome Analysis Reveals the Protective Role of Melatonin during Salt Stress by Regulating the Photosynthesis and Ascorbic Acid Metabolism Pathways in Brassica campestris.

Salinity stress is a type of abiotic stress which negatively affects the signaling pathways and cellular compartments of plants. Melatonin (MT) has been found to be a bioactive compound that can mitigate these adverse effects, which makes it necessary to understand the function of MT and its role in salt stress. During this study, plants were treated exogenously with 100 µM of MT for 7 days and subjected to 200 mM of salt stress, and samples were collected after 1 and 7 days for different indicators and transcriptome analysis. The results showed that salt reduced chlorophyll contents and damaged the chloroplast structure, which was confirmed by the downregulation of key genes involved in the photosynthesis pathway after transcriptome analysis and qRT-PCR confirmation. Meanwhile, MT increased the chlorophyll contents, reduced the electrolyte leakage, and protected the chloroplast structure during salt stress by upregulating several photosynthesis pathway genes. MT also decreased the H2O2 level and increased the ascorbic acid contents and APX activity by upregulating genes involved in the ascorbic acid pathway during salt stress, as confirmed by the transcriptome and qRT-PCR analyses. Transcriptome profiling also showed that 321 and 441 DEGs were expressed after 1 and 7 days of treatment, respectively. The KEGG enrichment analysis showed that 76 DEGs were involved in the photosynthesis pathway, while 35 DEGs were involved in the ascorbic acid metabolism pathway, respectively. These results suggest that the exogenous application of MT in plants provides important insight into understanding MT-induced stress-responsive mechanisms and protecting Brassica campestris against salt stress by regulating the photosynthesis and ascorbic acid pathway genes.

Physicochemical Properties and Antioxidant Activity of CRISPR/Cas9-Edited Tomato SGR1 Knockout (KO) Line.

Tomatoes contain many secondary metabolites such as ß-carotene, lycopene, phenols, flavonoids, and vitamin C, which are responsible for antioxidant activity. SlSGR1 encodes a STAY-GREEN protein that plays a critical role in the regulation of chlorophyll degradation in tomato leaves and fruits. Therefore, the present study was conducted to evaluate the sgr1 null lines based on their physicochemical characteristics, the content of secondary metabolites, and the γ-Aminobutyric acid (GABA) content. The total soluble solids (TSS), titrated acidity (TA), and brix acid ratio (BAR) of the sgr1 null lines were higher than those of the wild type(WT). Additionally, the sgr1 null lines accumulated higher levels of flavor-inducing ascorbic acid and total carotenoids compared to WT. Also, the total phenolic content, total flavonoids, GABA content, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical content of the sgr1 null lines were higher than those of the WT. Therefore, these studies suggest that the knockout of the SGR1 gene by the CRISPR/Cas9 system can improve various functional compounds in tomato fruit, thereby satisfying the antioxidant properties required by consumers.

Combined Metabolite and Transcriptomic Profiling Unveil a Potential Gene Network Involved in the Triterpenoid Metabolism of Rose roxburghii.

Rose roxburghii, a horticulturally significant species within the Rosa genus of the Rosaceae family, is renowned for its abundance of secondary metabolites and ascorbate, earning it the title 'king of vitamin C'. Despite this recognition, the mechanisms underlying the biosynthesis and regulation of triterpenoid compounds in R. roxburghii remain largely unresolved. In this study, we conducted high-performance liquid chromatography profiling across various organs of R. roxburghii, including fruit, root, stem, and leaves, revealing distinct distributions of triterpenoid compounds among different plant parts. Notably, the fruit exhibited the highest total triterpenoid content, followed by root and stem, with leaf containing the lowest levels, with leaf containing the lowest levels. Transcriptomic analysis unveiled preferential expression of members from the cytochrome P450 (CYP) and glycosyltransferase (UGT) families, likely contributing to the higher accumulation of both ascorbate and triterpenoid compounds in the fruits of R. roxburghii compared to other tissues of R. roxburghii. Transcriptomic analysis unveiled a potential gene network implicated in the biosynthesis of both ascorbate and triterpenoid compounds in R. roxburghii. These findings not only deepen our understanding of the metabolic pathways in this species but also have implications for the design of functional foods enriched with ascorbate and triterpenoids in R. roxburghii.

Association of dietary vitamin C intake with depression in adults: A cross-sectional study of NHANES from 2005 to 2020.

BACKGROUND: The aim of this study was to evaluate the association between dietary vitamin C intake and depression in adults. METHODS: This cross-sectional study utilized data from the National Health and Nutrition Examination Survey (NHANES) during 2005 to 2020. Logistic regressions and restricted cubic spline (RCS) regression were used to assess the association between dietary vitamin C intake and depression. Additionally, we performed stratified and sensitivity analyses to evaluate the stability of the results. RESULTS: This study included 38,157 participants, with 3448 (9.04 %) of them experiencing depression. The vitamin C intake was negatively associated with depression after adjusting for all covariates (OR = 0.91, 95%CI: 0.88-0.94, P < 0.001). Similar inverse associations were observed when vitamin C intake was transformed into categorical variables. Individuals in higher quartiles of dietary vitamin C intake (Q2, Q3, and Q4) had lower odds ratios (ORs) compared to those in the lowest quartile (Q1), as indicated by adjusted ORs of 0.78 (95 % CI: 0.71-0.87, P < 0.001), 0.74 (95 % CI: 0.67-0.82, P < 0.001), and 0.73 (95 % CI: 0.65-0.81, P < 0.001), respectively. The RCS analysis found an L-shaped nonlinear relationship between dietary vitamin C intake and depression, after adjusting for all covariates (P for non-linearity<0.001). Consumption of vitamin C was inversely associated with depression (OR = 0.994, 95%CI: 0.993-0.996, P < 0.001) for intakes below 93.61 mg, but there was no association between dietary vitamin C intake and depression (P = 0.980) for intakes of 93.61 mg or higher. The inverse associations between vitamin C intake and depression remained robust in stratified and sensitivity analyses. LIMITATIONS: This study was a cross-sectional study, and therefore unable to establish a causal relationship between dietary vitamin C intake and depression. We are unable to fully eliminate the confounding effects resulted from other unmeasured or unknown factors. CONCLUSION: The study revealed a negative association between dietary vitamin C intake and depression, as well as an L-shaped nonlinear relationship between vitamin C intake and depression.

Improved biodistribution and enhanced immune response of subunit vaccine using a nanostructure formed by self-assembly of ascorbyl palmitate.

New adjuvant strategies are needed to improve protein-based subunit vaccine immunogenicity. We examined the potential to use nanostructure of 6-O-ascorbyl palmitate to formulate ovalbumin (OVA) protein and an oligodeoxynucleotide (CpG-ODN) (OCC). In mice immunized with a single dose, OCC elicited an OVA-specific immune response superior to OVA/CpG-ODN solution (OC). Rheological studies demonstrated OCC's self-assembling viscoelastic properties. Biodistribution studies indicated that OCC prolonged OVA and CpG-ODN retention at injection site and lymph nodes, reducing systemic spread. Flow-cytometry assays demonstrated that OCC promoted OVA and CpG-ODN co-uptake by Ly6ChiCD11bhiCD11c+ monocytes. OCC and OC induced early IFN-γ in lymph nodes, but OCC led to higher concentration. Conversely, mice immunized with OC showed higher serum IFN-γ concentration compared to those immunized with OCC. In mice immunized with OCC, NK1.1+ cells were the IFN-γ major producers, and IFN-γ was essential for OVA-specific IgG2c switching. These findings illustrate how this nanostructure improves vaccine's response.

The Involvement of Ascorbic Acid in Cancer Treatment.

Vitamin C (VC), also known as ascorbic acid, plays a crucial role as a water-soluble nutrient within the human body, contributing to a variety of metabolic processes. Research findings suggest that increased doses of VC demonstrate potential anti-tumor capabilities. This review delves into the mechanisms of VC absorption and its implications for cancer management. Building upon these foundational insights, we explore modern delivery systems for VC, evaluating its use in diverse cancer treatment methods. These include starvation therapy, chemodynamic therapy (CDT), photothermal/photodynamic therapy (PTT/PDT), electrothermal therapy, immunotherapy, cellular reprogramming, chemotherapy, radiotherapy, and various combination therapies.

Efficacy and safety of vitamin C supplementation in the treatment of community-acquired pneumonia: a systematic review and meta-analysis with trial sequential analysis.

Community-acquired pneumonia (CAP) poses a significant global health challenge, prompting exploration of innovative treatments. This systematic review and meta-analysis aimed to evaluate the efficacy and safety of vitamin C supplementation in adults undergoing treatment for CAP. A comprehensive search of the MEDLINE, Embase, CINAHL, the Cochrane Central Register of Controlled Trials, and Clinical Trials.gov databases from inception to 17 November 2023 identified six randomized-controlled-trials (RCTs) meeting inclusion criteria. The primary outcome analysis revealed a non-significant trend towards reduced overall mortality in the vitamin C group compared to controls (RR 0.51; 95% CI 0.24 to 1.09; p = 0.052; I2 = 0; p = 0.65). Sensitivity analysis, excluding corona-virus-disease 2019 (COVID-19) studies and considering the route of vitamin C administration, confirmed this trend. Secondary outcomes, including hospital length-of-stay (LOS), intensive-care-unit (ICU) LOS, and mechanical ventilation, exhibited mixed results. Notably, heterogeneity and publication bias were observed in hospital LOS analysis, necessitating cautious interpretation. Adverse effects were minimal, with isolated incidents of nausea, vomiting, hypotension, and tachycardia reported. This meta-analysis suggests potential benefits of vitamin C supplementation in CAP treatment. However, inconclusive findings and methodological limitations warrants cautious interpretation, emphasising the urgency for high-quality trials to elucidate the true impact of vitamin C supplementation in CAP management.

Structure, mechanism, and evolution of the last step in vitamin C biosynthesis.

Photosynthetic organisms, fungi, and animals comprise distinct pathways for vitamin C biosynthesis. Besides this diversity, the final biosynthetic step consistently involves an oxidation reaction carried out by the aldonolactone oxidoreductases. Here, we study the origin and evolution of the diversified activities and substrate preferences featured by these flavoenzymes using molecular phylogeny, kinetics, mutagenesis, and crystallographic experiments. We find clear evidence that they share a common ancestor. A flavin-interacting amino acid modulates the reactivity with the electron acceptors, including oxygen, and determines whether an enzyme functions as an oxidase or a dehydrogenase. We show that a few side chains in the catalytic cavity impart the reaction stereoselectivity. Ancestral sequence reconstruction outlines how these critical positions were affixed to specific amino acids along the evolution of the major eukaryotic clades. During Eukarya evolution, the aldonolactone oxidoreductases adapted to the varying metabolic demands while retaining their overarching vitamin C-generating function.