Vitamin C for the treatment of sepsis: The scientific rationale

High-dose Vitamin C injection ameliorates against sepsis-induced myocardial injury by anti-apoptosis, anti-inflammatory and pro-autophagy through regulating MAPK, NF-κB and PI3K/AKT/mTOR signaling pathways in rats

AIMS

This study aimed to evaluate the effects of VC on SIMI in rats.

METHODS

In this study, the survival rate of high dose VC for SIMI was evaluated within 7 days. Rats were randomly assigned to three groups: Sham group, CLP group, and high dose VC (500 mg/kg i.v.) group. The animals in each group were treated with drugs for 1 day, 3 days or 5 days, respectively. Echocardiography, myocardial enzymes and HE were used to detect cardiac function. IL-1β, IL-6, IL-10 and TNF-α) in serum were measured using ELISA kits. Western blot was used to detect proteins related to apoptosis, inflammation, autophagy, MAPK, NF-κB and PI3K/Akt/mTOR signaling pathways.

RESULTS

High dose VC improved the survival rate of SIMI within 7 days. Echocardiography, HE staining and myocardial enzymes showed that high-dose VC relieved SIMI in rats in a time-dependent manner. And compared with CLP group, high-dose VC decreased the expressions of pro-apoptotic proteins, while increased the expression of anti-apoptotic protein. And compared with CLP group, high dose VC decreased phosphorylation levels of Erk1/2, P38, JNK, NF-κB and IKK α/β in SIMI rats. High dose VC increased the expression of the protein Beclin-1 and LC3-II/LC3-I ratio, whereas decreased the expression of P62 in SIMI rats. Finally, high dose VC attenuated phosphorylation of PI3K, AKT and mTOR compared with the CLP group.

SIGNIFICANCE

Our results showed that high dose VC has a good protective effect on SIMI after continuous treatment, which may be mediated by inhibiting apoptosis and inflammatory, and promoting autophagy through regulating MAPK, NF-κB and PI3K/AKT/mTOR pathway.

Role of corticosteroids in the treatment of critically ill sepsis patients: a meta-analysis review

OBJECTIVE

It was to systematically evaluate the effect of corticosteroids on 28d all-cause mortality (ACM), in-hospital death rate, and ICU death rate in critically ill sepsis patients.

METHODS

PubMed, Embase, and Medline databases were used to screen the published literatures on the therapeutic effect of corticosteroids in the treatment of critically ill sepsis patients. After evaluating the quality of the included literatures, RevMan 5.3 software was used for meta-analysis. 4524 literatures regarding the application of corticosteroids to treat critically ill sepsis patients were preliminarily searched. After screening was carried out, 9 literatures were finally included. 2,850 patients were treated with corticosteroids and 2867 patients were treated with placebo.

RESULTS

The meta-analysis of the effect of corticosteroids versus placebo on 28dACM showed [OR = 0.87, 95% CI 0.78-0.98, Z = 2.22, P = 0.03], P < 0.05; the meta-analysis of the outcome of corticosteroids versus placebo on ICU death rate showed [OR = 0.77, 95% CI 0.63-0.94, Z = 2.60, P = 0.009], P < 0.05; and the meta-analysis of the effect of corticosteroids versus placebo on in-hospital death rate showed [OR = 0.80, 95% CI 0.66-0.96, Z = 2.34, P = 0.002], P < 0.05.

CONCLUSION

In summary, corticosteroids can reduce the death rate of critically ill sepsis patients to a certain extent and have good clinical application value.

Predicting hypovitaminosis C with LASSO algorithm in adult critically ill patients in surgical intensive care units: a bi-center prospective cohort study

Vitamin C played pleiotropic roles in critical illness and vitamin C insufficiency was predictive of the development of multiple organ failure. Currently, the prevalence of vitamin C insufficiency in Chinese critically ill patients is rarely determined and there are no established bedside tools to predict hypovitaminosis C. To develop a nomogram to identify patients with high risk of hypovitaminosis C, we performed a bi-center prospective cohort study at two ICUs of the first and sixth medical center in PLA General Hospital, Beijing, China from May 6th to July 31st, 2021 We identified 322 eligible patients. 62.4% patients were hypovitaminosis C. 7 features, including source of infection, the level of serum albumin, age, male gender, sepsis, vascular disease, and wasting of vitamin C by the kidney, were selected using LASSO algorithm and therefore included in the nomogram. In the testing set, our model showed moderate discrimination ability with areas under the curve of 0.75 [0.64-0.84]. Variable importance evaluated by SHAP value highlighted two novel important predictors, i.e., abdominal infection and the level of serum albumin. In conclusion, we first reported a high burden of vitamin C insufficiency in Chinese adult patient in the ICU. We also constructed a prediction model to timely identify patients with high risk of hypovitaminosis C, which allows the clinicians to choose appropriate candidates for Vitamin C repletion in clinical practice or clinical trials.

Investigating the individual and combined effects of coenzyme Q10 and vitamin C on CLP-induced cardiac injury in rats

Sepsis-induced cardiac injury represents a major clinical challenge, amplifying the urgency for effective therapeutic interventions. This study aimed to delve into the individual and combined prophylactic effects of Vitamin C (Vit C) and Coenzyme Q10 (CoQ10) against inflammatory heart injury in a cecal ligation and puncture (CLP) induced polymicrobial sepsis rat model. Thirty adult female Sprague-Dawley rats were randomly divided into five groups: Control, CLP, Vitamin C, CoQ10, and Vit C + CoQ10, each consisting of six rats. Treatments were administered orally via gavage for 10 days prior to the operation. Eighteen hours post-sepsis induction, the animals were euthanized, and specimens were collected for analysis. The study examined variations in oxidative (TOS, OSI, MDA, MPO) and antioxidative markers (TAS, SOD, CAT, GSH), histopathological changes, inflammatory cytokine concentrations (TNF-α, IL-1β), nitric oxide (NO) dynamics, and cardiac indicators such as CK-MB. Impressively, the combined regimen markedly diminished oxidative stress, and antioxidative parameters reflected notable enhancements. Elevated NO levels, a central player in sepsis-driven inflammatory cascades, were effectively tempered by our intervention. Histological examinations corroborated the biochemical data, revealing diminished cardiac tissue damage in treated subjects. Furthermore, a marked suppression in pro-inflammatory cytokines was discerned, solidifying the therapeutic potential of our intervention. Interestingly, in certain evaluations, CoQ10 exhibited superior benefits over Vit C. Collectively, these findings underscore the potential therapeutic promise of Vit C and CoQ10 combination against septic cardiac injuries in rats.

Investigation of the protective activity of baicalein on the lungs via regulation of various cellular responses in rats exposed to experimental sepsis

Backgrounds

In the present study, a cecal ligation and puncture (CLP)-induced experimental sepsis rat model was used to explore the effects of baicalein on inflammatory cytokine levels and oxidative stress as well as the possible regulatory role of nuclear factor-kappa B (NF-κB).

Methods

For that purpose, 42 Wistar albino rats were equally divided into control, sham, sepsis, B50 + S, B100 + S, S + B50, and S + B100 groups. The B50 + S and B100 + S groups received baicalein before the induction of sepsis, while the S + B50 and S + B100 groups received baicalein afterwards. Experimental sepsis in related groups is generated through ligation of cecum and a puncture in cecal wall. Serum samples were used for tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) analyses, and tissue Malondialdehyde (MDA), Superoxide dismutase (SOD), Glutathione (GSH), IL-6, and NF-κB levels were measured.

Results

Compared to the control group, there were significantly increases in the serum TNF-α, IL-6, tissue MDA, and NF-κB levels and decreases in the tissue SOD and GSH levels in the septic group (P < 0.05). Compared to the septic group, inflammation and oxidative stress were reduced in the baicalein-treated groups. Although all of the pre- and post-treatment protocols alleviated inflammation and oxidative stress to varying degrees, pre-treatment with 100 mg/kg was the most successful.

Conclusions

Findings of this study indicated that baicalein has the potential to reduce sepsis-related oxidative stress and inflammation in the lungs and that pathological outcomes could be regulated via NF-κB transcription factor activity.

High-dose ascorbic acid potentiates immune modulation through STAT1 phosphorylation inhibition and negative regulation of PD-L1 in experimental sepsis

Sepsis is a complex, multifactorial syndrome characterized by a dysregulated host response to infection, leading to severe organ dysfunction and high mortality rates among critically ill patients. Hypovitaminosis C and vitamin C deficiency are frequently observed in septic patients, prompting interest in the potential therapeutic role of ascorbic acid. Although intravenous administration of ascorbic acid has been investigated in multiple clinical trials for sepsis treatment, the specific immunomodulatory mechanisms underlying its effects remain elusive. This study aimed to investigate the protective effects of high-dose ascorbic acid on experimental sepsis. Results show that intravenous administration of high-dose ascorbic acid (250 mg/kg) attenuated sepsis-induced organ dysfunctions in a cecal ligation and puncture (CLP)-induced septic mouse model. Ascorbic acid improved splenic cell apoptosis and increased the number of CD3+ T cells in septic mice induced by CLP. Furthermore, ascorbic acid downregulated PD-L1 expression in livers, reduced PD-1 expression in spleens, and inhibited the phosphorylation of STAT1 at Y701 in multiple organs of CLP-induced septic mice. The in vitro experiments also revealed that 800 μM ascorbic acid suppressed STAT1 phosphorylation and inhibited lipopolysaccharide (LPS) and IFN-γ-induced PD-L1 expression in macrophages. These findings suggest that ascorbic acid prevents sepsis-associated organ dysfunction through the p-STAT1/PD-L1 signaling pathway. Our study provides new insights into the potential therapeutic use of ascorbic acid in sepsis.

Current Practice Review in the Management of Acute Respiratory Distress Syndrome

Acute respiratory distress syndrome (ARDS) presents as an acute inflammatory lung injury characterized by refractory hypoxemia and non-cardiac pulmonary edema. An estimated 10% of patients in the intensive care unit and 25% of those who are mechanically ventilated are diagnosed with ARDS. Increased awareness is warranted as mortality rates remain high and delays in diagnosing ARDS are common. The COVID-19 pandemic highlights the importance of understanding ARDS management. Treatment of ARDS can be challenging due to the complexity of the disease state and conflicting existing evidence. Therefore, it is imperative that pharmacists understand both pharmacologic and non-pharmacologic treatment strategies to optimize patient care. This narrative review provides a critical evaluation of current literature describing management practices for ARDS. A review of treatment modalities and supportive care strategies will be presented.

Nitrogen-doped porous carbon nanomaterials synthesized using a magadiite template as efficient peroxidase mimics for colorimetric detection of ascorbic acid as an antioxidant

Nanomaterials with intrinsic enzyme-like activity have gained substantial scientific attention as viable substitutes to natural biological enzymes owing to their cheap price and great stability. Numerous artificial enzyme mimics have been employed effectively in sectors such as sensing, environmental processing, and cancer treatment. In this study, novel nitrogen-doped porous carbon nanomaterials (CPs) were produced by modifying polypyrrole with magadiite using chemical oxidative polymerization and calcination methods. The obtained nitrogen-doped porous carbon nanomaterials exhibited improved peroxidase-like activity, which catalyzed the oxidation of 3,3,5,5-tetramethylbenzidine (TMB) in the presence of hydrogen peroxide (H2O2) to produce colorful compounds. Kinetic investigation revealed that the affinity for TMB of nitrogen-doped porous carbon peroxidase mimics was higher than that of genuine horseradish peroxidase (HRP). In addition, a sensitive assay with encouraging performance for the colorimetric detection of ascorbic acid (AA) was successfully fabricated employing nitrogen-doped porous carbon nanomaterials as peroxidase mimics. The results were satisfactory and demonstrated its potential application in antioxidant detection.

Antibiotic-Induced Dysbiosis of the Gut Microbiota Impairs Gene Expression in Gut-Liver Axis of Mice

Antibiotics can be a double-edged sword. The application of broad-spectrum antibiotics leads to the suppression of microorganisms in the human body without selective targeting, including numerous non-pathogenic microorganisms within the gut. As a result, dysbiosis of the gut microbiota can occur. The gut microbiota is a vast and intricate ecosystem that has been connected with various illnesses. Significantly, the gut and liver function in a closely coupled anatomical and physiological relationship referred to as the "gut-liver axis". Consequently, metabolites stemming from the gut microbiota migrate via the portal vein to the liver, thereby influencing gene expression and proper physiological activity within the liver. This study aimed to investigate the dysbiosis of gut microbiota ecology and the disruption of gene expression resulting from oral antibiotics and their subsequent recovery. In the experiment, mice were tube-fed neomycin (0.5 mg/mL) and ampicillin (1 mg/mL) for 21 days (ABX group) to conduct 16s rRNA sequencing. By simultaneously analyzing public datasets PRJDB6615, which utilized the same antibiotics, it was found that nearly 50% of the total microbiota abundance was attributed to the f__Lactobacillaceae family. Additionally, datasets GSE154465 and GSE159761, using the same antibiotics, were used to screen for differentially expressed genes pre-and post-antibiotic treatment. Quantitative real-time PCR was employed to evaluate gene expression levels before and after antibiotic treatment. It was discovered that oral antibiotics significantly disrupted gene expression in the gut and liver, likely due to the dysregulation of the gut microbiota ecology. Fecal microbiota transplantation (FMT) was found to be an effective method for restoring gut microbiota dysbiosis. To further enhance the restoration of gut microbiota and gene expression, an antioxidant, vitamin C, was added to the FMT process to counteract the oxidative effect of antibiotics on microorganisms. The results showed that FMTs with vitamin C were more effective in restoring gut microbiota and gene expression to the level of the fecal transplant donor.

High-Dose Vitamin C Alleviates Pancreatic Necrosis by Inhibiting Platelet Activation Through the CXCL12/CXCR4 Pathway in Severe Acute Pancreatitis

Background

Platelet activation in the early stage of pancreatitis is the key step developing into pancreatic necrosis. Studies suggested that vitamin C (Vit C) can inhibit platelet activity by targeting CXCL12/CXCR4 pathway. High-dose Vit C were showed to reduce pancreatic necrosis in severe acute pancreatitis (SAP) but the mechanism remains unclear. Here we speculate high-dose Vit C reduce pancreatic necrosis by inhibiting platelet activation through downregulating CXCL12/CXCR4 pathway.

Methods

The pancreatic microcirculation of rats was observed by intravital microscopy. The platelet activity of SAP rats treated with or without high-dose Vit C was analyzed by platelet function test. Besides, the activity of platelets preincubated with high-dose Vit C or vehicle from SAP patients was also evaluated. Then, the TFA (CXCR4 agonist) and rCXCL12 were used to neutralize the effect of high-dose Vit C in SAP rats treated with high-dose Vit C. Meanwhile, the levels of enzymes and inflammatory cytokines in rat plasma, and rats' pancreatic histopathology and mortality were assessed.

Results

Platelets from animals and patients with SAP are more sensitive to agonists and are more easily activated. Administration of high-dose Vit C significantly ameliorated excessive activation of platelets in SAP rats, ultimately increasing the microvessel density and inducing microthrombus and blood stasis; these results were consistent with clinical sample analysis. Moreover, high-dose Vit C significantly inhibited the release of amylase, lipase, TNF-α, and IL-6 in SAP rat plasma, reducing pancreatic damage and the mortality of SAP rats. However, using TFA and rCXCL12 significantly reversed the effect of high-dose Vit C on excessive activation of platelets, aggravating microcirculation impairment and pancreatic damage.

Conclusion

The present study suggests that high-dose Vit C can ameliorate pancreatic necrosis by improving microcirculation disorders of SAP. For the first time, the underlying mechanism is related with inhibiting platelet activation through the CXCL12/CXCR4 pathway.

A colorimetric smartphone-based sensor for on-site AA detection in tropical fruits using Fe-P/NC single-atom nanoenzyme

Ascorbic acid is one of the important vitamins to maintain human life activities and plays an irreplaceable role in regulating human redox metabolism. Fresh fruit can provide plenty of AA to maintain human metabolic balance. Thus, it is great significant to develop a rapid and convenient method for detection of AA to evaluate the freshness and nutritional quality of fruits. In this work, Fe single-atom nanoenzyme (Fe-SAN) based colorimetric sensor assisted with smartphone was designed for rapid and on-site AA detection in tropical fruits. Firstly, Fe-SAN with high oxidase-mimicking activity was synthesized by using green tea leaves as sources of carbon and nitrogen and NaH₂PO₂ as P source to obtain Fe-P/NC SAN, in which P was used to reconstruct the distribution of electronic to enhance the oxidase-mimicking activity of Fe-SAN. Besides, the as-synthesized Fe-P/NC SAN with remarkable oxidase-like activities could oxidize 3,3́,5,5́-tetramethylbenzidine (TMB) to blue colored oxidized TMB. AA could inhibit the oxidation of TMB, leading to blue fading. Based on the above principle, colorimetric sensor integrated with smartphone RGB mode was fabricated and exhibited a good linear detection range (0.5-100 μM) and low detection limit of 0.315 μM for AA detection under optimal conditions. More importantly, the developed sensor could rapidly and accurately detect AA in real sample, such as pineapple, wax apple and mango. Therefore, this research provides a new cost-effective method for the efficient and exact detection of AA in tropical fruit, which has a broad application prospect.

Effects of hydrocortisone combined with vitamin C and vitamin B1 versus hydrocortisone alone on microcirculation in septic shock patients: A pilot study

OBJECTIVE

To investigate the effects of hydrocortisone combined with vitamin C and vitamin B1 versus hydrocortisone on sublingual microcirculation in septic shock patients.

METHODS

This pilot study enrolled septic shock patients admitted to the ICU of a tertiary teaching hospital from February 2019 to January 2020. We randomly assigned the enrolled patients to the treatment group (hydrocortisone combined with vitamin C and vitamin B1 added to standard care) and the control group (hydrocortisone alone added to standard care) in a 1 : 1 ratio. The primary outcome was perfused small vascular density (sPVD) monitored by a sublingual microcirculation imaging system at 24 hours after treatment.

RESULTS

Twelve patients in the treatment group and ten in the control group completed the study. The baseline characteristics were comparable between the groups. No statistically significant difference was found in the sPVD between the groups at baseline. The sPVD in the treatment group was significantly higher than that in the control group at 4 hours after treatment (mean difference, 7.042; 95% CI, 2.227-11.857; P = 0.009) and 24 hours after treatment (mean difference, 7.075; 95% CI, 2.390-11.759; P = 0.008).

CONCLUSIONS

Compared with hydrocortisone, hydrocortisone combined with vitamin C and vitamin B1 significantly improves microcirculation in septic shock patients.

People with diabetes and hypovitaminosis C fail to conserve urinary vitamin C

Background

Hypovitaminosis C has negative health consequences. People with diabetes and hypovitaminosis C may fail to conserve vitamin C in the urine, thereby displaying evidence of inappropriate renal leak of vitamin C. This study describes the relationship between plasma and urinary vitamin C in diabetes, with a focus on the clinical characteristics of participants with renal leak.

Methods

Retrospective analysis of paired, non-fasting plasma and urine vitamin C, and also clinical characteristics, from participants with either type 1 or type 2 diabetes, recruited from a secondary care diabetes clinic. Plasma vitamin C thresholds for renal leak have been defined previously as 38.1 µmol/L for men and 43.2 µmol/L for women.

Results

Statistically significant differences in clinical characteristics were seen between those with; i) renal leak (N = 77) and; ii) hypovitaminosis C but no renal leak (N = 13) and; iii) normal plasma vitamin C levels (n = 34). Compared to participants with adequate plasma vitamin C levels, participants with renal leak tended to have type 2 (rather than type 1) diabetes, a lower eGFR and a higher HbA1c.

Conclusion

In the diabetes population studied, renal leak of vitamin C was common. In some participants, it may have contributed to hypovitaminosis C.

Vitamin C alleviates LPS-induced myocardial injury by inhibiting pyroptosis via the ROS-AKT/mTOR signalling pathway

BACKGROUND

The efficacy of vitamin C in sepsis remains controversial. Whether vitamin C can alleviate lipopolysaccharide (LPS)-induced myocardial injury by inhibiting pyroptosis has not been studied. This study aimed to evaluate the effects of vitamin C on LPS-induced myocardial injury in vitro.

METHODS

H9C2 cells were treated with indicated concentrations of LPS, and the cell viability was then assessed by CCK-8 assay. The levels of lactate dehydrogenase (LDH), CK-MB, IL-18 and IL-1β were examined by enzyme-linked immunosorbent assay (ELISA). The levels of intracellular reactive oxygen species (ROS) were measured using the fluorescent probe dichlorodihydrofluorescein diacetate (DCFH-DA). Western blot assays were conducted to determine the levels of the ROS-associated protein nicotinamide adenine dinucleotide phosphate oxidase 4 (Nox4) and pyroptosis-associated proteins, such as NOD-like receptor (NLR) family pyrin domain containing 3 (NLRP3), caspase-1 and gasdermin D (GSDMD). The AKT inhibitor MK-2206 was then applied to explore the signalling pathway. Finally, H9C2 cells were divided into the control group, LPS group, vitamin C + LPS group, and N-acetyl-L-cysteine (NAC) + LPS group. The intracellular ROS, levels of associated proteins, cell viability, and release of LDH, CK-MB, IL-18 and IL-1β were examined.

RESULTS

LPS decreased cell viability and induced ROS and pyroptosis in H9C2 cells in a dose-dependent manner. Moreover, LPS activated the AKT/mTOR pathway in H9C2 cells. The AKT inhibitor MK-2206 protected H9C2 cells from LPS-induced death by suppressing pyroptosis, without changing intracellular ROS level. Vitamin C significantly inhibited intracellular ROS and cell pyroptosis in LPS-treated H9C2 cells. Moreover, vitamin C suppressed the activation of the AKT/mTOR pathway.

CONCLUSIONS

Our data suggest that vitamin C alleviates LPS-induced myocardial injury by inhibiting pyroptosis via the ROS-AKT/mTOR signalling pathway and thus provide novel insights into the prevention of sepsis-induced myocardial dysfunction.

Current role of high dose vitamin C in sepsis management: A concise review

Sepsis and septic shock are common diagnoses for patients requiring intensive care unit admission and associated with high morbidity and mortality. In addition to aggressive fluid resuscitation and antibiotic therapy, several other drugs have been tried as adjuvant therapies to reduce the inflammatory response and improve outcomes. Vitamin C has been shown to have several biological actions, including anti-inflammatory and immunomodulatory effects, which may prove beneficial in sepsis management. Initial trials showed improved patient outcomes when high dose vitamin C was used in combination with thiamine and hydrocortisone. These results, along with relative safety of high-dose (supra-physiological) vitamin C, encouraged physicians across the globe to add vitamin C as an adjuvant therapy in the management of sepsis. However, subsequent large-scale randomised control trials could not replicate these results, leaving the world divided regarding the role of vitamin C in sepsis management. Here, we discuss the rationale, safety profile, and the current clinical evidence for the use of high-dose vitamin C in the management of sepsis and septic shock.

Early ascorbic acid administration prevents vascular endothelial cell damage in septic mice

Oxidation of BH₄, a cofactor of nitric oxide synthase (NOS), produces reactive oxygen species (ROS) through uncoupling of NOS and affects vascular endothelial dysfunction. Ascorbic acid (AsA) inhibits the oxidation of BH₄ and reduces ROS. However, the kinetic changes of BH₄ in sepsis and its effect on the kinetic changes in AsA administration therapy, as well as the appropriate timing of AsA administration for AsA therapy to be effective, are unclear. Mice with sepsis, induced by cecal ligation and puncture (CLP), were examined for the effect of AsA administration (200 mg/kg) on vascular endothelial cell dysfunction at two administration timings: early group (AsA administered immediately after CLP) and late group (AsA administered 12 h after CLP). Survival rates were compared between the early and late administration groups, and vascular endothelial cell damage, indicated by the dihydrobiopterin/tetrahydrobiopterin ratio, serum syndecan-1, and endothelial nitric oxide synthase, as well as liver damage, were examined. The early group showed significantly improved survival compared to the non-treatment group (p < 0.05), while the late group showed no improved survival compared to the non-treatment group. Compared to the non-treated group, the early AsA group showed less oxidation of BH₄ in sepsis. Syndecan1, a marker of vascular endothelial cell damage, was less elevated and organ damage was reduced in the early AsA-treated group. In septic mice, early AsA administration immediately after CLP may protect vascular endothelial cells by inhibiting BH₄ oxidation, thereby reducing organ dysfunction and improving survival.

Role of high dose vitamin C in management of hospitalised COVID-19 patients: A minireview

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has emerged as one of the most dreadful viruses the mankind has witnessed. It has caused world-wide havoc and wrecked human life. In our quest to find therapeutic options to counter this threat, several drugs have been tried, with varying success. Certain agents like corticosteroids, some anti-virals and immunosuppressive drugs have been found useful in improving clinical outcomes. Vitamin C, a water-soluble vitamin with good safety profile, has been tried to reduce progression and im-prove outcomes of patients with coronavirus disease 2019 (COVID-19). Because of its anti-oxidant and immunomodulatory properties, the role of vitamin C has expanded well beyond the management of scurvy and it is increasingly been employed in the treatment of critically ill patients with sepsis, septic shock, acute pancreatitis and even cancer. However, in spite of many case series, observational studies and even randomised control trials, the role of vitamin C remains ambiguous. In this review, we will be discussing the scientific rationale and the current clinical evidence for using high dose vitamin C in the management of COVID-19 patients.

Molecular mechanisms and therapeutic effects of different vitamins and minerals in COVID-19 patients

COVID-19 is a rapidly spreading disease, which has caught the world by surprise. Millions of people suffer from illness, and the mortality rates are dramatically high. Currently, there is no specific and immediate treatment for this disease. Remedies are limited to supportive regiments and few antiviral and anti-inflammatory drugs. The lack of a definite cure for COVID-19 is the reason behind its high mortality and global prevalence. COVID-19 can lead to a critical illness with severe respiratory distress and cytokine release. Increased oxidative stress and excessive production of inflammatory cytokines are vital components of severe COVID-19. Micronutrients, metalloids, and vitamins such as iron, manganese, selenium, Zinc, Copper, vitamin A, B family, and C are among the essential and trace elements that play a pivotal role in human nutrition and health. They participate in metabolic processes that lead to energy production. In addition, they support immune functions and act as antioxidants. Therefore, maintaining an optimal level of micronutrients intake, particularly those with antioxidant activities, is essential to fight against oxidative stress, modulate inflammation, and boost the immune system. Therefore, these factors could play a crucial role in COVID-19 prevention and treatment. In this review, we aimed to summarize antiviral properties of different vitamins and minerals. Moreover, we will investigate the correlation between them and their effects in COVID-19 patients.

Tubule-mitophagic secretion of SerpinG1 reprograms macrophages to instruct anti-septic acute kidney injury efficacy of high-dose ascorbate mediated by NRF2 transactivation

High-dose ascorbate confers tubular mitophagy responsible for septic acute kidney injury (AKI) amelioration, yet its biological roles in immune regulation remain poorly understood.

Methods: The role of tubular mitophagy in macrophage polarization upon high-dose ascorbate treatment was assessed by fluorescence-activated cell sorter analysis (FACS) in vitro and by immunofluorescence in AKI models of LPS-induced endotoxemia (LIE) from Pax8-cre; Atg7^flox/flox mice. The underlying mechanisms were revealed by RNA-sequencing, gene set enrichment analysis (GSEA), luciferase reporter, chromatin immunoprecipitation (ChIP) and adeno-associated viral vector serotype 9 (AAV9) delivery assays.

Results: High-dose ascorbate enables conversion of macrophages from a pro-inflammatory M1 subtype to an anti-inflammatory M2 subtype in murine AKI models of LIE, leading to decreased renal IL-1β and IL-18 production, reduced mortality and alleviated tubulotoxicity. Blockade of tubular mitophagy abrogates anti-inflammatory macrophages polarization under the high-dose ascorbate-exposed coculture systems. Similar abrogations are verified in LIE mice with tubular epithelium-specific ablation of Atg7, where the high-dose ascorbate-inducible renal protection and survival improvement are substantially weaker than their control littermates. Mechanistically, high-dose ascorbate stimulates tubular secretion of serpin family G member 1 (SerpinG1) through maintenance of mitophagy, for which nuclear factor-erythroid 2 related factor 2 (NRF2) transactivation is required. SerpinG1 perpetuates anti-inflammatory macrophages to prevent septic AKI, while kidney-specific disruption of SerpinG1 by adeno-associated viral vector serotype 9 (AAV9)-short hairpin RNA (shRNA) delivery thwarts the anti-inflammatory macrophages polarization and anti-septic AKI efficacy of high-dose ascorbate.

Conclusion: Our study identifies SerpinG1 as an intermediate of tubular mitophagy-orchestrated myeloid function during septic AKI and reveals a novel rationale for ascorbate-based therapy.

Bioinspired copper single-atom nanozyme as a superoxide dismutase-like antioxidant for sepsis treatment

Sepsis is a systemic inflammatory response syndrome with high morbidity and mortality mediated by infection-caused oxidative stress. Early antioxidant intervention by removing excessively produced reactive oxygen and nitrogen species (RONS) is beneficial to the prevention and treatment of sepsis. However, traditional antioxidants have failed to improve patient outcomes due to insufficient activity and sustainability. Herein, by mimicking the electronic and structural characteristics of natural Cu-only superoxide dismutase (SOD5), a single-atom nanozyme (SAzyme) featuring coordinately unsaturated and atomically dispersed Cu-N4 site was synthesized for effective sepsis treatment. The de novo-designed Cu-SAzyme exhibits a superior SOD-like activity to efficiently eliminate O2 •-, which is the source of multiple RONS, thus blocking the free radical chain reaction and subsequent inflammatory response in the early stage of sepsis. Moreover, the Cu-SAzyme effectively harnessed systemic inflammation and multi-organ injuries in sepsis animal models. These findings indicate that the developed Cu-SAzyme possesses great potential as therapeutic nanomedicines for the treatment of sepsis.

The Role and Efficacy of Vitamin C in Sepsis: A Systematic Review and Meta-Analysis

Clinical rationale for study: Despite advancements in critical care, the mortality rate of sepsis remains high, with an overall poor prognosis. There is a complex pathophysiology of a lethal cascade of cytokines and inflammatory proteins underlying sepsis. The use of vitamin C can theoretically suppress the inflammatory cascade but remains a questionable practice due to a lack of conclusive evidence. Aims of the study: To appraise the therapeutic role of vitamin C in sepsis. Materials and methods: A systematic review was conducted on PubMed, Embase, and the Central Cochrane Registry. The study included randomized clinical trials (RCTs) with vitamin C as an intervention arm in the septic patient population. For continuous variables, the difference in means (MD) and for discrete variables, the odds ratio (OR) was used. For effect sizes, a confidence interval of 95% was used. A p-value of less than 0.05 was used for statistical significance. The analysis was performed using a random-effects model irrespective of heterogeneity. Heterogeneity was evaluated using the I2 statistic. Results: 23 studies were included with the total sample size of 2712 patients. In patients treated with vitamin C, there was a statistically significant reduction in the mortality: OR = 0.778 (0.635 to 0.954), p = 0.016; the sequential organ failure assessment score (SOFA): MD = −0.749 (−1.115 to −0.383), p < 0.001; and the duration of vasopressor requirement: MD = −1.034 days (−1.622 to −0.445), p = 0.001. No significant difference was found in the hospital or ICU length of stay. Conclusions and clinical implications: Vitamin C treatment regimens were associated with reduced mortality, SOFA score, and vasopressor requirement compared to the control in sepsis. Given its low cost and minimal adverse effects, we strongly encourage further large, randomized trials to establish vitamin C as a standard of care in sepsis management.

Efficacy of High-Dose Vitamin C Infusion on Outcomes in Sepsis Requiring Mechanical Ventilation: A Double-Blind Randomized Controlled Trial

Background. Critically ill patients have an increased requirement for vitamin C in sepsis and these patients have low levels of vitamin C. The researchers validated the efficacy of high-dose vitamin C intravenous infusion (IVI) in patients with sepsis requiring mechanical ventilation. Methods. Forty patients were randomly assigned to 2 groups (20 each) in a 1 : 1 ratio in accordance with the vitamin C treatment regimen: Group I (GI): patients received 1.5 g/6 h vitamin C in 50 ml of dextrose 5% in water (D5W) IVI over 30 minutes for 4 consecutive days; Group II (GII): patients received 100 mg vitamin C/day as a first single dose in 50 ml of D5W IVI over 30 minutes and the other three subsequent doses were 50 ml of plain D5W IVI over 30 minutes for 4 consecutive days. Primary outcomes were the change in sequential organ failure assessment (SOFA) score at day 7, the incidence of ventilator-associated pneumonia (VAP), and the plasma vitamin C level. The glutathione peroxidase (GPX) activity, C-reactive protein (CRP) level, duration of vasopressor therapy, and 28-day mortality were secondary outcomes. Results. The change in SOFA score at day 7 showed a significant difference between GI and GII ( $p<0.001$ ). The incidence of early VAP was significantly lower in GI ( $p=0.044$ ). Vitamin C levels showed a significant rise in GI at day 1 and day 4 ( $p<0.001$ and $p<0.001$ , respectively). GPX activity of day 4 and day 7 was significantly higher in GI ( $p=0.005$ and $p=0.014$ , respectively). CRP levels of day 4 and day 7 were significantly higher in GII ( $p<0.001$ and $p<0.001$ , respectively). There was a significant difference in 28-day mortality ( $p=0.038$ ) and duration of vasopressor therapy ( $p=0.033$ ) in GI compared to GII. Conclusion. The early use of high-dose vitamin C intravenous infusion in patients with sepsis requiring mechanical ventilation in combination with the standard treatment for sepsis lowered the incidence of VAP, increased the antioxidant status, and improved the illness severity. Trial Registration. This trial is registered with ClinicalTrials.gov Identifier (NCT04029675).

Identifying potential biomarkers and therapeutic targets for dogs with sepsis using metabolomics and lipidomics analyses

Sepsis is a diagnostic and therapeutic challenge and is associated with morbidity and a high risk of death. Metabolomic and lipidomic profiling in sepsis can identify alterations in metabolism and might provide useful insights into the dysregulated host response to infection, but investigations in dogs are limited. We aimed to use untargeted metabolomics and lipidomics to characterize metabolic pathways in dogs with sepsis to identify therapeutic targets and potential diagnostic and prognostic biomarkers. In this prospective observational cohort study, we examined the plasma metabolomes and lipidomes of 20 healthy control dogs and compared them with those of 21 client-owned dogs with sepsis. Patient data including signalment, physical exam findings, clinicopathologic data and clinical outcome were recorded. Metabolites were identified using an untargeted mass spectrometry approach and pathway analysis identified multiple enriched metabolic pathways including pyruvaldehyde degradation; ketone body metabolism; the glucose-alanine cycle; vitamin-K metabolism; arginine and betaine metabolism; the biosynthesis of various amino acid classes including the aromatic amino acids; branched chain amino acids; and metabolism of glutamine/glutamate and the glycerophospholipid phosphatidylethanolamine. Metabolites were identified with high discriminant abilities between groups which could serve as potential biomarkers of sepsis including 13,14-Dihydro-15-keto Prostaglandin A₂; 12(13)-DiHOME (12,13-dihydroxy-9Z-octadecenoic acid); and 9-HpODE (9-Hydroxyoctadecadienoic acid). Metabolites with higher abundance in samples from nonsurvivors than survivors included 3-(2-hydroxyethyl) indole, indoxyl sulfate and xanthurenic acid. Untargeted lipidomic profiling revealed multiple sphingomyelin species (SM(d34:0)+H; SM(d36:0)+H; SM(d34:0)+HCOO; and SM(d34:1D3)+HCOO); lysophosphatidylcholine molecules (LPC(18:2)+H) and lipophosphoserine molecules (LPS(20:4)+H) that were discriminating for dogs with sepsis. These biomarkers could aid in the diagnosis of dogs with sepsis, provide prognostic information, or act as potential therapeutic targets.

The Variable Nature of Vitamin C—Does It Help When Dealing with Coronavirus?

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is still spreading worldwide. For this reason, new treatment methods are constantly being researched. Consequently, new and already-known preparations are being investigated to potentially reduce the severe course of coronavirus disease 2019 (COVID-19). SARS-CoV-2 infection induces the production of pro-inflammatory cytokines and acute serum biomarkers in the host organism. In addition to antiviral drugs, there are other substances being used in the treatment of COVID-19, e.g., those with antioxidant properties, such as vitamin C (VC). Exciting aspects of the use of VC in antiviral therapy are its antioxidant and pro-oxidative abilities. In this review, we summarized both the positive effects of using VC in treating infections caused by SARS-CoV-2 in the light of the available research. We have tried to answer the question as to whether the use of high doses of VC brings the expected benefits in the treatment of COVID-19 and whether such treatment is the correct therapeutic choice. Each case requires individual assessment to determine whether the positives outweigh the negatives, especially in the light of populational studies concerning the genetic differentiation of genes encoding the solute carriers responsible forVC adsorption. Few data are available on the influence of VC on the course of SARS-CoV-2 infection. Deducing from already-published data, high-dose intravenous vitamin C (HDIVC) does not significantly lower the mortality or length of hospitalization. However, some data prove, among other things, its impact on the serum levels of inflammatory markers. Finally, the non-positive effect of VC administration is mainly neutral, but the negative effect is that it can result in urinary stones or nephropathies.

A Review of Different Vaccines and Strategies to Combat COVID-19

In December 2019, an unknown viral infection emerged and quickly spread worldwide, resulting in a global pandemic. This novel virus caused severe pneumonia and acute respiratory distress syndrome caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). It has caused 6.25 millions of deaths worldwide and remains a major concern for health, society, and the economy. As vaccination is one of the most efficient ways to combat this pandemic, different vaccines were developed in a short period. This review article discusses how coronavirus affected the top nations of the world and the vaccines being used for the prevention. Amongst the vaccines, some vaccines have already been approved, and some have been involved in clinical studies. The article also provides insight into different COVID-19 vaccine platforms, their preparation, working, efficacy, and side effects.

Zinc augments the antiviral potential of HCQ/CQ and ivermectin to reduce the risks of more serious outcomes from COVID-19 infection

Treatments do not replace vaccinations or restrictions, but are practical, effective, and safe means to help to reduce the fatality associated with COVID-19 infection. While no treatment is available and effective for all the current and future variants of COVID-19, treatments reduce the risk of COVID-19 becoming endemic and reduce mortality and collateral damages. The use of Zinc (Zn) for COVID-19 infection is here reviewed. Zn supplementation may help in prevention as well as during the administration of therapies. Zn supplementation reduces the risks of serious outcomes from Covid19 infection. Evidence also suggests that Zn helps in treatments of COVID-19 infection if taken in conjunction with antiviral drugs. The literature supports the use of Zn, with improvements towards a lower risk ranging from 37% in late treatment, RR 0.63 CI [0.53-0.74], to 78% in sufficiency, RR 0.22 CI [0.05-0.96].

[Resuscitation strategy for patients with sepsis and septic shock]

Fluid and vasopressor resuscitation is, along with antimicrobial therapy and control of the focus of infection, a basic issue of the treatment of sepsis and septic shock. There is currently no accepted protocol that we can follow for the resuscitation of these patients and the Surviving Sepsis Campaign proposes controversial measures and without sufficient evidence support to establish firm recommendations. We propose a resuscitation strategy adapted to the situation of each patient: in the patient in whom community sepsis is suspected, we consider that the early administration of 30mL/kg of crystalloids is effective and safe; in the patient with nosocomial sepsis, we must carry out a more in-depth evaluation before initiating aggressive resuscitation. In patients who do not respond to initial resuscitation, it is necessary to increase monitoring level and, depending on the hemodynamic profile, administer more fluids, a second vasopressor or inotropes.

Is it time to reconsider the administration of thiamine alone or in combination with vitamin C in critically ill patients? A meta-analysis of clinical trial studies

Background

Although the effect of thiamine alone or in combination with vitamin C has been studied in multiple trials (RCT and interventional studies), their results are inconsistent. This meta-analysis aimed to assess impact of thiamine administration alone, thiamine in combination with vitamin C, and co-administration of low-dose hydrocortisone, vitamin C and thiamine (HVT) on clinical outcomes in critically ill patients.

Methods and materials

After electronic searches on PubMed, Scopus, Cochrane Library, and Web of Science databases, initially 3367 papers were found, and 20 interventional studies were included in our analysis. We assessed the risk-difference between treatment and control (standard treatment) groups by pooling available data on ICU length of stay, number of ventilator free days, mortality, and changes in Sequential Organ Failure Assessment (SOFA) scores.

Results

The results of present studies revealed no significant effect of thiamine in combination with vitamin C, and HVT on number of free days of ventilation. Thiamine alone supplementation was associated with high mortality percentage (WMD: 5.17%; 95% CI: 2.67, 7.67). Thiamine in combination with vitamin C had no significant impact on mortality rate. In contrast, HVT could decrease mortality rate (WMD: − 7.23%; 95% CI: − 10.31, − 4.16; I-square: 0.0%). There was no significant effect of thiamine alone, co-administration of thiamine and vitamin C, and HVT on ICU length of stay. The results of the meta-analysis showed that thiamine alone and HVT supplementation had no significant effect on SOFA score. Interestingly, co-supplementation of thiamine and vitamin C had a significant decreasing effect on SOFA score (WMD: − 0.73; 95% CI: − 1.29, − 0.17; I-square: 0.0%).

Conclusion

In contrast to HVT, thiamine supplementation alone was associated with increased mortality rate in ICU. However, co-supplementation of thiamine and vitamin C had a significant decreasing effect on SOFA score.

Thiamine, co-supplementation of thiamine and vitamin C and co-administration of hydrocortisone, vitamin C and thiamine (HVT) had no significant effect on free days of ventilation and ICU length of stay.

HVT could decrease and thiamine supplementation could increase mortality rate in ICU.

Co-supplementation of thiamine and vitamin C could decrease SOFA score.

Vitamin C-induced Hemolysis: Meta-summary and Review of Literature

Vitamin C is increasingly being used, and even high doses are considered safe. However, complications including hemolysis have been reported. We performed a systematic search from PubMed, Science Direct, and Google Scholar databases from January 1975 till July 31, 2021. Search terms used were "Vitamin C" OR "ascorbic acid" AND "haemolysis" OR "haemolytic anaemia." Data regarding patient's demographics, outcomes and dose, duration, and form of vitamin C were extracted. Fourteen case reports matched the selected criteria, with age ranging from 3 weeks to 75 years with 78.6% being males. About 71.4% were diagnosed to have glucose-6-phosphate dehydrogenase (G6PD) deficiency but previous hemolysis was reported in only two patients, and 57.1% were prescribed vitamin C for nutritional supplementation. The dose ranged from 1 to 200 g/day with 57.1% receiving intravenous formulations. Half of these patients developed other complications including acute kidney injury (AKI), disseminated intravascular coagulation, oxalosis, and methemoglobinemia. About 78.6% developed complications within 3 days of starting vitamin C and only one death was reported. Vitamin C is generally a safe drug but it should be prescribed with caution and only when benefits outweigh the risks. Physicians should be aware of potential complications like severe hemolysis and AKI, especially when using high doses and in G6PD deficiency.

HOW TO CITE THIS ARTICLE

Juneja D, Jain R, Nasa P. Vitamin C-induced Hemolysis: Meta-summary and Review of Literature. Indian J Crit Care Med 2022;26(2):224-227.

"MATH+" Multi-Modal Hospital Treatment Protocol for COVID-19 Infection: Clinical and Scientific Rationale

In December 2019, coronavirus disease 2019 (COVID-19), a severe respiratory illness caused by the new coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in Wuhan, China. The greatest impact that COVID-19 had was on intensive care units (ICUs), given that approximately 20% of hospitalized cases developed acute respiratory failure (ARF) requiring ICU admission. Based on the assumption that COVID-19 represented a viral pneumonia and no anti-coronaviral therapy existed, nearly all national and international health care societies recommended "supportive care only" avoiding other therapies outside of randomized controlled trials, with a specific prohibition against the use of corticosteroids in treatment. However, early studies of COVID-19-associated ARF reported inexplicably high mortality rates, with frequent prolonged durations of mechanical ventilation (MV), even from centers expert in such supportive care strategies. These reports led the authors to form a clinical expert panel called the Front-Line COVID-19 Critical Care Alliance (www.flccc.net). The panel collaboratively reviewed the emerging clinical, radiographic, and pathological reports of COVID-19 while initiating multiple discussions among a wide clinical network of front-line clinical ICU experts from initial outbreak areas in China, Italy, and New York. Based on the shared early impressions of "what was working and what wasn't working", the increasing medical journal publications and the rapidly accumulating personal clinical experiences with COVID-19 patients, a treatment protocol was created for the hospitalized patients based on the core therapies of methylprednisolone, ascorbic acid, thiamine, heparin and non-antiviral co-interventions (MATH+). This manuscript reviews the scientific and clinical rationale behind MATH+ based on published in-vitro, pre-clinical, and clinical data in support of each medicine, with a special emphasis of studies supporting their use in the treatment of patients with viral syndromes and COVID-19 specifically.

Insights Into Thiamine Supplementation in Patients With Septic Shock

Septic shock is associated with unacceptably high mortality rates, mainly in developing countries. New adjunctive therapies have been explored to reduce global mortality related to sepsis. Considering that metabolic changes, mitochondrial dysfunction and increased oxidative stress are specific disorders within the path of septic shock, several micronutrients that could act in cellular homeostasis have been studied in recent decades. Thiamine, also known as vitamin B1, plays critical roles in several biological processes, including the metabolism of glucose, synthesis of nucleic acids and reduction of oxidative stress. Thiamine deficiency could affect up to 70% of critically ill patients, and thiamine supplementation appears to increase lactate clearance and decrease the vasopressor dose. However, there is no evident improvement in the survival of septic patients. Other micronutrients such as vitamin C and D, selenium and zinc have been tested in the same context but have not been shown to improve the outcomes of these patients. Some problems related to the neutrality of these clinical trials are the study design, doses, route, timing, length of intervention and the choice of endpoints. Recently, the concept that multi-micronutrient administration may be better than single-micronutrient administration has gained strength. In general, clinical trials consider the administration of a single micronutrient as a drug. However, the antioxidant defense is a complex system of endogenous agents in which micronutrients act as cofactors, and the physiological interactions between micronutrients are little discussed. In this context, the association of thiamine, vitamin C and corticoids was tested as an adjunctive therapy in septic shock resulting in a significant decrease in mortality. However, after these initial results, no other study conducted with this combination could reproduce those benefits. In addition, the use of low-dose corticosteroids is recommended in patients with septic shock who do not respond to vasopressors, which can affect the action of thiamine. Therefore, given the excellent safety profile, good biologic rationale and promising clinical studies, this review aims to discuss the mechanisms behind and the evidence for single or combined thiamine supplementation improving the prognosis of patients with septic shock.

Pinocembrin ameliorates acute liver failure via activating the Sirt1/PPARα pathway in vitro and in vivo

Acute liver failure (ALF) is a life-threatening disease and affects multiple organ systems. Pro-inflammatory factors derived from macrophage plays a key role in septicemia. Pinocembrin is a natural favonoid compound, which can be extracted from honey, propolis and several other plants. Recent investigations demonstrate that Pinocembrin has a variety of pharmacological activities, including anti-inflammatory and antioxidant. To investigate the effects of Pinocembrin on ALF, we explored its possible molecular mechanisms through the experiments in vivo and in vitro. Pre-treatment with Pinocembrin attenuated LPS-induced hepatocyte dysfunction and reduced levels of pro-inflammatory factors and macrophages infiltration. Pinocembrin inhibited the hepatocyte apoptosis and pro-inflammatory reaction of peritoneal macrophages by reducing reactive oxygen species (ROS) via the Sirt1/PPARα signaling pathway. Our study suggests that Pinocembrin might represent a novel therapeutic drug and offers a new method for the treatment of ALF.

The Challenges and Effects of Ascorbic Acid Treatment of Acute Pancreatitis: A Systematic Review and Meta-Analysis of Preclinical and Clinical Studies

Background: Oxidative stress has been implicated in the pathogenesis of acute pancreatitis (AP), and ascorbic acid (AA), as an important endogenous antioxidant substance, has been shown to reduce AP severity in preclinical studies. However, the effects of AA supplementation in clinical settings remain controversial. Methods: PubMed, EMBASE, MEDLINE, and SCOPUS databases were searched, and both preclinical and clinical studies were included. For clinical trials, the primary outcome was incidence of organ failure, and for preclinical studies, the primary outcome was histopathological scores of pancreatic injuries. Results: Meta-analysis of clinical trials showed that compared with controls, AA administration did not reduce the incidence of organ failure or mortality during hospitalization but was associated with significantly reduced length of hospital stay. Meta-analysis of preclinical studies showed that AA supplementation reduced pancreatic injury, demonstrated as decreased histological scores and serum amylase, lipase levels. Conclusion: AA administration has no effect on survival or organ failure in patients with AP but may reduce the length of hospital stay. However, the evidence to date remains sparse, scattered, and of suboptimal quality, making it difficult to draw any firm conclusion on the clinical benefits of AA in AP.

Inflammatory Response Modulation by Vitamin C in an MPTP Mouse Model of Parkinson's Disease

Simple Summary

Vitamin C (Vit C), also called ascorbic acid, is a nutrient present in many foods, particularly citrus fruits and green vegetables. Inadequate dietary Vit C intake causes hypovitaminosis resulting in the risk of developing clinical scurvy, potentially fatal if untreated. Vit C represents one of the safest and most essential nutrients, with antioxidant and anti-inflammatory properties that protect living organisms against oxidative stress; due to this propriety, it is studied for applications in the prevention and management of different pathologies, including neurodegenerative disease. Persistent neuroinflammation is detrimental for the brain and may lead to pathogenesis and progression of neurodegenerative diseases like Parkinson’s disease (PD) and Alzheimer’s disease. The role of Vit C in the central nervous system is still debated.This study, utilizing a PD mouse model, has demonstrated that Vit C reduces neuroinflammation by the modulation of microglial responses and astrocyte activation, reducing dopaminergic neuronal cell loss involved in PD insurgence.Furthermore, mouse gait and spontaneous locomotor activity were partially ameliorated. In summary, we have demonstrated that the use of Vit C has neuroprotective effects in the brain, alleviating the inflammatory cascade and reducing the progression of PD.

Abstract

Vitamin C (Vit C) is anutrient present in many foods, particularly citrus fruits, green vegetables, tomatoes, and potatoes. Vit C is studied for its applications in the prevention and management of different pathologies, including neurodegenerative diseases. Neuroinflammation is a defense mechanism activated by a stimulus or an insult that is aimed at the preservation of the brain by promoting tissue repair and removing cellular debris; however, persistent inflammatory responses are detrimental and may lead to the pathogenesis and progression of neurodegenerative diseases like Parkinson’s disease (PD) and Alzheimer’s disease. PD is one of the most common chronic progressive neurodegenerative disorders, and oxidative stress is one of the most important factors involved in its pathogenesis and progression.Due to this, research on antioxidant and anti-inflammatory compounds is an important target for counteracting neurodegenerative diseases, including PD. In the central nervous system, the presence of Vit C in the brain is higher than in other body districts, but why and how this occurs is still unknown. In this research, Vit C, with its anti-inflammatory and anti-oxidative properties, is studied to better understand its contribution to brain protection; in particular, we have investigated the neuroprotective effects of Vit C in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced animal model of PD and its role in the modulation of neuroinflammation. First, we observed that Vit C significantly decreased the MPTP-induced loss of tyrosine hydroxylase (TH)-positive dopaminergic neuronal cells in the substantia nigra, as well as microglial cell activation and astrogliosis. Furthermore, gait and spontaneous locomotor activity, evaluated by an automated treadmill and the Open Field test, respectively, were partially ameliorated by Vit C treatment in MPTP-intoxicated animals. In relation to neuroinflammation, results show that Vit C reduced the protein and mRNA expression of inflammatory cytokines such as IL-6, TLR4, TNF-α, iNOS, and CD40, while anti-inflammatory proteins such as IL-10, CD163, TGF-β, and IL-4 increased. Interestingly, we show for the first time that Vit C reduces neuroinflammation by modulating microglial polarization and astrocyte activation. Moreover, Vit C was able to reduce NLRP3 activation, which is linked to the pathogenesis of many inflammatory diseases, including neuroinflammatory disorders. In conclusion, our study provides evidence that Vit C may represent a new promising dietary supplement for the prevention and alleviation of the inflammatory cascade of PD, thus contributing to neuroprotection.

Early administration of Vitamin C in patients with sepsis or septic shock in emergency departments: A multicenter, double blinded, randomized controlled trial: The C-EASIE trial protocol

Background

Sepsis is a potentially life-threatening condition characterized by a deregulated body’s response to infection causing injury to its own tissues and organs. Sepsis is the primary cause of death from infection. If not recognized and treated timely, it can evolve within minutes/hours to septic shock. Sepsis is associated with an acute deficiency of Vitamin C. Despite the proof-of-concept of the benefit of administering Vitamin C in patients with sepsis or septic shock, Vitamin C administration is not yet current practice.

Objective

To investigate the potential benefit of early administration of high doses of Vitamin C in addition to standard of care in patients with sepsis or septic shock.

Methods

This phase 3b multi-center trial is conducted in 8 hospitals throughout Belgium. In total 300 patients will be randomly assigned to one of two groups in a 1:1 allocation ratio. The intervention group will receive 1.5 g Vitamin C 4 times a day during 4 days, started within 6 hours after admission. The primary outcome is the average post-baseline patient SOFA score.

Conclusion

This trial will determine whether the early administration of Vitamin C in patients with sepsis or septic shock can lead to a more rapid solution of shock and less deterioration from sepsis to septic shock, hereby reducing morbidity and mortality as well as the length of hospital stay in this patient population.

Trial registration

The C-EASIE trial has been registered on the ClinicalTrials.gov website on 10 February 2021 with registration number NCT04747795.

Trial Sponsor

UZ Leuven (sponsor’s reference S63213)

Any Role of High-Dose Vitamin C for Septic Shock in 2021?

While the use of vitamin C as a therapeutic agent has been investigated since the 1950s, there has been substantial recent interest in the role of vitamin C supplementation in critical illness and particularly, sepsis and septic shock. Humans cannot synthesize vitamin C and rely on exogenous intake to maintain a plasma concentration of approximately 70 to 80 μmol/L. Vitamin C, in healthy humans, is involved with antioxidant function, wound healing, endothelial function, and catecholamine synthesis. Its function in the human body informs the theoretical basis for why vitamin C supplementation may be beneficial in sepsis/septic shock.Critically ill patients can be vitamin C deficient due to low dietary intake, increased metabolic demands, inefficient recycling of vitamin C metabolites, and loss due to renal replacement therapy. Intravenous supplementation is required to achieve supraphysiologic serum levels of vitamin C. While some clinical studies of intravenous vitamin C supplementation in sepsis have shown improvements in secondary outcome measures, none of the randomized clinical trials have shown differences between vitamin C supplementation and standard of care and/or placebo in the primary outcome measures of the trials. There are some ongoing studies of high-dose vitamin C administration in patients with sepsis and coronavirus disease 2019; the majority of evidence so far does not support the routine supplementation of vitamin C in patients with sepsis or septic shock.

Vitamin C for sepsis intervention: from redox biochemistry to clinical medicine

Vitamin C, also known as ascorbic acid or ascorbate, is a water-soluble vitamin synthesized in plants as well as in animals except humans and several other animal species. Humans obtain vitamin C from dietary sources and via vitamin supplementation. Vitamin C possesses important biological functions, including serving as a cofactor for many enzymes, acting as an antioxidant and anti-inflammatory compound, and participating in regulating stem cell biology and epigenetics. The multifunctional nature of vitamin C contributes to its essentialness in maintaining and safeguarding physiological homeostasis, especially regulation of immunity and inflammatory responses. In this context, vitamin C has been investigated for its efficacy in treating diverse inflammatory disorders, including sepsis, one of the major causes of death globally and for which currently there is no cure. Accordingly, this Mini-Review surveys recent major research findings on the effectiveness of vitamin C and the underling molecular mechanisms in sepsis intervention in both experimental animal models and randomized controlled trials. To set a stage for discussing the effects and mechanisms of vitamin C in sepsis intervention, this Mini-Review begins with an overview of vitamin C redox biochemistry and its multifunctional properties.

Circulating Complement C3-Alpha Chain Levels Predict Survival of Septic Shock Patients

BACKGROUND

Circulating complement C3 fragments released during septic shock might contribute to the development of complications such as profound hypotension and disseminated intravascular coagulation. The role of C3 in the course of septic shock varies in the literature, possibly because circulating C3 exists in different forms indistinguishable via traditional ELISA-based methods. We sought to test the relationship between C3 forms, measured by Western blotting with its associated protein size differentiation feature, and clinical outcomes.

METHODS

Secondary analysis of two prospective cohorts of patients with septic shock: a discovery cohort of 24 patents and a validation cohort of 181 patients. C3 levels were measured by Western blotting in both cohorts using blood obtained at enrollment. Differences between survivors and non-survivors were compared, and the independent prognostic values of C3 forms were assessed.

RESULTS

In both cohorts there were significantly lower levels of the C3-alpha chain in non-survivors than in survivors, and persisted after controlling for sequential organ failure assessment score. Area under the receiver operating characteristics to predict survival was 0.65 (95% confidence interval: 0.56-0.75). At a best cutoff value (Youden) of 970.6 μg/mL, the test demonstrated a sensitivity of 68.5% and specificity of 61.5%. At this cutoff point, Kaplan-Meier survival analysis showed that patients with lower levels of C3-alpha chain had significantly lower survival than those with higher levels (P < 0.001).

CONCLUSION

Circulating C3-alpha chain levels is a significant independent predictor of survival in septic shock patients.

Protective effects and mechanisms of high-dose vitamin C on sepsis-associated cognitive impairment in rats

Sepsis survivors present long-term cognitive deficits. The present study was to investigate the effect of early administration of high-dose vitamin C on cognitive function in septic rats and explore its possible cerebral protective mechanism. Rat sepsis models were established by cecal ligation and puncture (CLP). Ten days after surgery, the Morris water maze test was performed to evaluate the behavior and cognitive function. Histopathologic changes in the hippocampus were evaluated by nissl staining. The inflammatory cytokines, activities of antioxidant enzymes (superoxide dismutase or SOD) and oxidative products (malondialdehyde or MDA) in the serum and hippocampus were tested 24 h after surgery. The activity of matrix metalloproteinase-9 (MMP-9) and expressions of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1(HO-1) in the hippocampus were measured 24 h after surgery. Compared with the sham group in the Morris water maze test, the escape latency of sepsis rats was significantly (P = 0.001) prolonged in the navigation test, whereas the frequency to cross the platform and the time spent in the target quadrant were significantly (P = 0.003) reduced. High-dose vitamin C significantly decreased the escape latency (P = 0.01), but increased the time spent in the target quadrant (P = 0.04) and the frequency to cross the platform (P = 0.19). In the CLP+ saline group, the pyramidal neurons were reduced and distributed sparsely and disorderly, the levels of inflammatory cytokines of tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-10 in the serum and hippocampus were significantly increased (P = 0.000), the blood brain barrier (BBB) permeability in the hippocampus was significantly (P = 0.000) increased, the activities of SOD in the serum and hippocampus were significantly (P = 0.000 and P = 0.03, respectively) diminished while the levels of MDA in the serum and hippocampus were significantly (P = 0.007) increased. High-dose vitamin C mitigated hippocampus histopathologic changes, reduced systemic inflammation and neuroinflammation, attenuated BBB disruption, inhibited oxidative stress in brain tissue, and up-regulated the expression of nuclear and total Nrf2 and HO-1. High-dose vitamin C significantly (P < 0.05) decreased the levels of tumor necrosis factor- (TNF)-α, interleukin-6 (IL-6), MDA in the serum and hippocampus, and the activity of MMP-9 in the hippocampus, but significantly (P < 0.05) increased the levels of SOD, the anti-inflammatory cytokine (IL-10) in the serum and hippocampus, and nuclear and total Nrf2, and HO-1 in the hippocampus. In conclusion, high-dose vitamin C can improve cognition impairment in septic rats, and the possible protective mechanism may be related to inhibition of inflammatory factors, alleviation of oxidative stress, and activation of the Nrf2/HO-1 pathway.

Vitamin C for Sepsis and Septic Shock

BACKGROUND

Sepsis remains a leading cause of death in the critically ill. The combination of thiamine, vitamin C, and hydrocortisone has recently emerged as a potential adjunctive therapy and supportive care for patients with sepsis and septic shock.

AREAS OF UNCERTAINTY

Several randomized and observational controlled trials evaluated the role of vitamin C in sepsis and septic shock. However, there are variabilities in the findings of these studies that led to a substantial global debate on incorporating vitamin C therapy in clinical practice.

DATA SOURCES

A PubMed and Embase English language literature search through April 2021 was performed using the following terms: ascorbic acid, vitamin C, corticosteroid, hydrocortisone, thiamine, HAT, sepsis, and shock. Citations, including controlled trials, observational studies, review articles, guidelines, and consensus statements, were reviewed. The risk of bias for each clinical study was systematically evaluated. Relevant clinical data focusing on efficacy, safety, and special considerations regarding the use of vitamin C with and without thiamine and hydrocortisone in sepsis and septic shock were narratively summarized.

RESULTS

The most commonly used vitamin C dosing in sepsis and septic shock is 1.5 g every 6 hours with and without thiamine and hydrocortisone. Current literature is limited because of heterogeneity in vitamin C regimen used, initiation time, and duration of treatment. This limitation led to variability in outcomes evaluated. Vitamin C decreases proinflammatory mediators and slows the progression of endothelial injury in severe sepsis. There is an inconsistency between randomized controlled trials and observational controlled trials regarding mortality, resolution in organ failure, hospital and intensive care unit length of stay findings with the use of vitamin C in septic shock. Vitamin C seems to be safe in comparison with placebo.

CONCLUSIONS

Future studies with consistent end points, initiation time with an emphasis on early initiation, and standard vitamin C dosing regimen are needed to determine the overall benefit of vitamin C in sepsis.

Hydrocortisone, Ascorbic Acid, and Thiamine (HAT) Therapy Decreases Oxidative Stress, Improves Cardiovascular Function, and Improves Survival in Murine Sepsis

INTRODUCTION

A small clinical trial showed HAT therapy improved survival but no studies have been reported in animal models to examine potential mechanisms.

METHODS

Sepsis was induced in female mice using the cecal ligation and puncture (CLP) model. Physiologic parameters including heart rate (HR), pulse distension (PD), and respiratory rate (RR) were measured noninvasively at baseline, 6 and 24 h post CLP. These measurements stratified mice into predicted to live (Live-P) or die (Die-P). Mice were randomized to receive HAT therapy or vehicle. Oxidative stress was measured in peritoneal exudative cells 24 h after CLP.

RESULTS

HR, PD, and RR all declined within the first 6 h of sepsis and were significantly lower in the Die-P mice compared with Live-P. HR 6 h post-CLP best predicted mortality and continued to decline between 6 and 24 h post CLP. Oxidative stress in peritoneal cells harvested 24 h post CLP (determined by 8 isoprostaglandin F2α and protein carbonyl derivatives) was significantly higher in the Die-P mice. HAT therapy was initiated 7 h post-CLP after mortality prediction and stratification. HAT significantly reduced oxidative stress in the Die-P mice without altering these parameters in the Live-P mice. HAT treatment prevented the decline in HR, again only in the Die-P mice. Mice treated with HAT therapy had significantly better survival.

CONCLUSIONS

Physiologic parameters accurately predicted mortality. Die-P mice had significant oxidative stress compared with Live-P. HAT therapy significantly decreased oxidative stress, increased HR, and improved survival in the Die-P mice. These data suggest that HAT exerts a beneficial effect through reducing oxidative stress and improving cardiovascular function.

Sepsis-Induced Myocardial Dysfunction (SIMD): the Pathophysiological Mechanisms and Therapeutic Strategies Targeting Mitochondria

Sepsis is a lethal syndrome with multiple organ failure caused by an inappropriate host response to infection. Cardiac dysfunction is one of the important complications of sepsis, termed sepsis-induced myocardial dysfunction (SIMD), which is characterized by systolic and diastolic dysfunction of both sides of the heart. Mechanisms that contribute to SIMD include an excessive inflammatory response, altered circulatory, microvascular status, nitric oxide (NO) synthesis impairment, endothelial dysfunction, disorders of calcium regulation, cardiac autophagy anomaly, autonomic nervous system dysregulation, metabolic reprogramming, and mitochondrial dysfunction. The role of mitochondrial dysfunction, which is characterized by structural abnormalities, increased oxidative stress, abnormal opening of the mitochondrial permeability transition pore (mPTP), mitochondrial uncoupling, and disordered quality control systems, has been gaining increasing attention as a central player in the pathophysiology of SIMD. The disruption of homeostasis within the organism induced by mitochondrial dysfunction may also be an important aspect of SIMD development. In addition, an emerging therapy strategy targeting mitochondria, namely, metabolic resuscitation, seems promising. The current review briefly introduces the mechanism of SIMD, highlights how mitochondrial dysfunction contributes to SIMD, and discusses the role of metabolic resuscitation in the treatment of SIMD.

Effect of thiamine supplementation in critically ill patients: A systematic review and meta-analysis

INTRODUCTION

Several studies have previously shown the benefit of thiamine supplementation in critically ill patients. In order to fully appraise the available data, we performed a meta-analysis of 18 published studies.

METHODS

A thorough systematic search was conducted. The studies enrolling critically ill patients receiving thiamine supplementation was compared with the standard of care (SOC) group. Data was analyzed using RevMan 5.4. Clinical outcomes were pooled using Odds Ratio (OR) and mean differences.

RESULT

Eighteen studies (8 RCTs and 10 cohort studies) met the criteria for quantitative synthesis. In the analysis of RCTs, thiamine supplementation showed 42% lower odds of developing ICU delirium (OR 0.58, 95% CI, 0.34-0.98). A reduction in mortaliy was observed on performing fixed effect model analysis however, a level of statistical significance could not be reached on performing randon effect model analysis (OR, 0.78; 95% CI, 0.59 to 1.04). Further sub-group analysis of 13 studies in patients with sepsis, there was no difference in mortality between the two groups (OR, 0.83; 95% CI, 0.63 to 1.09).

CONCLUSION

Thiamine supplementation in critically ill patients showed a reduction in the incidence of ICU delirium among RCTs. However, there was no significant benefit in terms of overall mortality, and mortality in patients with sepsis. Further, large scale randomized prospective studies are warranted to investigate the role of thiamine supplementation in critically ill patients.

Therapeutic targets and signaling mechanisms of vitamin C activity against sepsis: a bioinformatics study

Sepsis is a life-threatening complication of pneumonia, including coronavirus disease-2019 (COVID-19)-induced pneumonia. Evidence of the benefits of vitamin C (VC) for the treatment of sepsis is accumulating. However, data revealing the targets and molecular mechanisms of VC action against sepsis are limited. In this report, a bioinformatics analysis of network pharmacology was conducted to demonstrate screening targets, biological functions, and the signaling pathways of VC action against sepsis. As shown in network assays, 63 primary causal targets for the VC action against sepsis were identified from the data, and four optimal core targets for the VC action against sepsis were identified. These core targets were epidermal growth factor receptor (EGFR), mitogen-activated protein kinase-1 (MAPK1), proto-oncogene c (JUN), and signal transducer and activator of transcription-3 (STAT3). In addition, all biological processes (including a top 20) and signaling pathways (including a top 20) potentially involved in the VC action against sepsis were identified. The hub genes potentially involved in the VC action against sepsis and interlaced networks from the Kyoto Encyclopedia of Genes and Genomes Mapper assays were highlighted. Considering all the bioinformatic findings, we conclude that VC antisepsis effects are mechanistically and pharmacologically implicated with suppression of immune dysfunction-related and inflammation-associated functional processes and other signaling pathways. These primary predictive biotargets may potentially be used to treat sepsis in future clinical practice.

Fat-Soluble Vitamins and the Current Global Pandemic of COVID-19: Evidence-Based Efficacy from Literature Review

The outbreak of pneumonia caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), later named COVID-19 by the World Health Organization (WHO), was initiated at Wuhan, Hubei, China, and there was a rapid spread of novel SARS-CoV-2 and the disease COVID-19 in late 2019. The entire world is now experiencing the challenge of COVID-19 infection. However, still very few evidence-based treatment options are available for the prevention and treatment of COVID-19 disease. The present review aims to summarize the publicly available information to give a comprehensive yet balanced scientific overview of all the fat-soluble vitamins concerning their role in SARS-CoV-2 virus infection. The roles of different fat-soluble vitamins and micronutrients in combating SARS-CoV-2 infection have been recently explored in several studies. There are various hypotheses to suggest their use to minimize the severity of COVID-19 infection. These vitamins are pivotal in the maintenance and modulation of innate and cell-mediated, and antibody-mediated immune responses. The data reported in recent literature demonstrate that deficiency in one or more of these vitamins compromises the patients’ immune response and makes them more vulnerable to viral infections and perhaps worse disease prognosis. Vitamins A, D, E, and K boost the body’s defense mechanism against COVID-19 infection and specifically prevent its complications such as cytokine storm and other inflammatory processes, leading to increased morbidity and mortality overemphasis. However, more detailed randomized double-blind clinical pieces of evidence are required to define the use of these supplements in preventing or reducing the severity of the COVID-19 infection.

Vitamin C measurement in critical illness: challenges, methodologies and quality improvements

Background There is renewed interest in high-dose vitamin C interventions in clinical medicine due to its antioxidant properties, safe use and cost-effectiveness. Yet, randomised control trials (RCTs) employing these interventions are failing to include robust analytical methodology and proper sample handling and processing techniques. Consequently, comparisons between studies becomes impossible as there is no metrological traceability and results may be prone to pre-analytical errors. Content Through published vitamin C stability studies, method comparison papers and data from vitamin C external quality assurance programs, an assessment was made on the functionality of current methods for critically ill patient samples. Summary Data was obtained from two external quality assurance programs, two papers assessing sample stability and interlaboratory agreement and a publication on vitamin C method comparisons. A shift from spectrophotometric and enzymatic methodologies to high performance liquid chromatography (HPLC) greatly improved the variability and interlaboratory agreement. Therefore, the current analytical performance of vitamin C HPLC methodologies are acceptable for the requirements of a high-dose vitamin C RCTs. Outlook Recommendations across the total testing process of vitamin C have been provided to improve the quality of the results. The harmonisation of sample handling and processing procedures will further improve the reliability of current analytical methodologies.