Protective Effects of Vitamin C, Alone or in Combination with Vitamin A, on Endotoxin-Induced Oxidative Renal Tissue Damage in Rats

Pet Wellness and Vitamin A: A Narrative Overview

The health of companion animals, particularly dogs and cats, is significantly influenced by nutrition, with vitamins playing a crucial role. Vitamin A, in particular, is indispensable, with diverse roles ranging from vision to immune modulation and reproduction. Despite its importance, the metabolism and dietary requirements of vitamin A in companion animals remain complex and not fully understood. This review provides a comprehensive overview of the historical perspective, the digestion, the metabolism, the physiological roles, the deficiency, the excess, and the interactions with other micronutrients of vitamin A in companion animals. Additionally, it highlights future research directions and gaps in our understanding. Insights into the metabolism of vitamin A in companion animals, personalized nutrition strategies based on genetic variability, longitudinal studies tracking the status of vitamin A, and investigations into its immunomodulatory effects are crucial for optimizing pet health and wellness. Furthermore, understanding the stability and bioavailability of vitamin A in pet food formulations is essential for ensuring the provision of adequate micronutrients. Overall, this review underscores the importance of vitamin A in companion animal nutrition and the need for further research to enhance our understanding and to optimize dietary recommendations for pet health and well-being.

Evidence for the Metabolic Activation of Deferasirox In Vitro and In Vivo

Deferasirox (DFS) is used for the treatment of iron accumulation caused by the need for long-term blood transfusions, such as thalassemia or other rare anemia. Liver injury due to exposure to DFS has been documented, and the toxic mechanisms of DFS are unknown. The present study aimed to investigate the reactive metabolites of DFS in vitro and in vivo to help us understand the mechanisms of DFS hepatotoxicity. Two hydroxylated metabolites (5-OH and 5'-OH) were identified during incubation of DFS-supplemented rat liver microsomes. Such microsomal incubations fortified with glutathione (GSH) or N-acetylcysteine (NAC) as capture agents offered two GSH conjugates and two NAC conjugates. These GSH conjugates and NAC conjugates were also detected in bile and urine of rats given DFS. CYP1A2 and CYP3A4 were found to dominate the metabolic activation of DFS. Administration of DFS induced decreased cell survival in cultured primary hepatocytes. Pretreatment with ketoconazole and 1-aminobenzotrizole made hepatocytes less susceptible to the cytotoxicity of DFS.

Antioxidant Activity of Vitamin C against LPS-Induced Septic Cardiomyopathy by Down-Regulation of Oxidative Stress and Inflammation

In severe cases of sepsis, endotoxin-induced cardiomyopathy can cause major damage to the heart. This study was designed to see if Vitamin C (Vit C) could prevent lipopolysaccharide-induced heart damage. Eighteen Sprague Dawley male rats (n = 6) were divided into three groups. Rats received 0.5 mL saline by oral gavage in addition to a standard diet (Control group), rats received one dose of endotoxin on day 15 (lipopolysaccharide) (LPS) (6 mg/kg), which produced endotoxemia (Endotoxin group), and rats that received 500 mg/Kg BW of Vit C by oral gavage for 15 days before LPS administration (Endotoxin plus Vit C group). In all groups, blood and tissue samples were collected on day 15, six hours after LPS administration, for histopathological and biochemical analysis. The LPS injection lowered superoxide dismutase (SOD) levels and increased malondialdehyde in tissues compared with a control group. Furthermore, the endotoxin group showed elevated inflammatory biomarkers, tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). Both light and electron microscopy showed that the endotoxic-treated group’s cardiomyocytes, intercalated disks, mitochondria, and endothelial cells were damaged. In endotoxemic rats, Vit C pretreatment significantly reduced MDA levels and restored SOD activity, minimized biomarkers of inflammation, and mitigated cardiomyocyte damage. In conclusion: Vit C protects against endotoxin-induced cardiomyopathy by inhibiting oxidative stress cytokines.

Plasma Antioxidant Potential at Admission is Associated with Length of ICU Stay in Child with Sepsis: A Pilot Study

OBJECTIVE

To assess the relationship between biomarkers of oxidative stress (OS) and the length of stay in intensive care units (LSICU) in septic children.

METHODS

Clinical parameters and biomarkers of OS were measured in 16 children admitted for sepsis in an intensive care unit. The associations between biomarkers of OS and the LSICU were assessed by linear correlation. Multiple linear regression models were constructed to adjust other variables.

RESULTS

The mean of LSICU was 7.13 ± 4.17 days. LSICU was associated with the catalase activity (rho =0.56, p-value =0.024) and the ferric reducing ability of plasma (FRAP, r = 0.73, p-value =0.001). However, only FRAP at ICU admission was independently associated with LSICU, which rose 0.21 days for each 10 µmol/l of increase in the FRAP level.

CONCLUSION

We conclude for first time that FRAP level at ICU admission is independently associated with LSICU in pediatric patients.

Mahdy E, R. Youness E, Shafee N, S.S. Mowafy M, M. Mabrouk M. Effect of Co Enzyme Q10 Alone or in Combination with Vitamin C on Lipopolysaccharide-Induced Brain Injury in Rats

Our was to determine the impact of CoenzymeQ10 (Co Q10) and vitamin C alone or in combination on oxidative stress in brain tissue of rats during endotoxemia induced by single intraperitoneal dose of Lipopolysaccharide (LPS), 500µg/kg. Both CoQ10&vitamin C were given orally to rats with doses (200&100 mg/kg) respectively for 7successive days prior induction of endotoxemia .LPS injected, with Co Q10 with doses (100 &200 mg/kg) &vit. C (50&100 mg/kg).In addition CoQ10 and vitamin C together in doses (100&50 mg/kg) & (200&100 mg/kg) respectively were added to LPS-treated rats. Then euthanized 4 hours later. Histopathological assessment of brain tissue was done. Results: LPS injection induced oxidative stress in brain tissue, resulting in marked increase in malondiadehyde (MDA), nitrite (NO) and Amyloid beta (Aβ), while decreasing reduced glutathione (GSH), paraoxonase-1 (PON1) and brain derived neurotrophic factor (BDNF).CoQ10 and vit.C administration with doses(200&100 mg/ kg) before endotoxemia result in reduction of brain MDA, NO and Aβ, while increasing levels of GSH, PON1 and BDNF compared to controls. The addition of both Co Q10 &vit.C to LPS- treated rats lead to decrease of brain NO, MDA and Aβ, also increase of GSH, PON1 and BDNF. This effect was more obviouswith high doses, this due to the ameliorating effect of both CoQ10 and vit.C on oxidative stress of brain tissue during endotoxemia.This consisted with the histopathological results. Conclusion: this work focuses on the possible role of CoQ10 &vit.C as antioxidants in protecting brain tissue.

Pretreatment of curcumin attenuates coagulopathy and renal injury in LPS-induced endotoxemia

Disseminated intravascular coagulation (DIC) is a lethal situation in severe infections, characterized by the systemic formation of microthrombi complicated with bleeding tendency and organ dysfunction. Current clinical trials are not promising. In this study, we investigated the protective effect of curcumin in a lipopolysaccharide (LPS)-induced DIC model in rats. Experimental DIC was induced by sustained infusion of LPS (10 mg/kg body weight) for 4 h through the tail vein. Curcumin (60 mg/kg body weight) was given intraperitoneally 3 h before LPS infusion. Results showed that, in vivo, curcumin reduced the mortality rate of LPS-infused rats by decreasing the circulating TNF-α levels and the consumption of peripheral platelets and plasma fibrinogen. Furthermore, in vivo curcumin also has the effect of preventing the formation of fibrin deposition in the glomeruli of kidney. These results reveal the therapeutic potential of curcumin in infection-related coagulopathy of DIC.

Mercuric chloride induced hepatotoxic and hematologic changes in rats

This study focuses on investigating the possible protective effect of sodium selenite (Na2SeO3) and/or vitamin E against mercuric chloride (HgCl2)-induced hepatotoxicity in rat. Male rats were given HgCl2 (1 mg/kg body weight (bw)) and HgCl2 plus Na2SeO3 (0.25 mg/kg bw) and/or vitamin E (100 mg/kg bw) daily via gavage for 4 weeks. HgCl2-treated groups had significantly higher white blood cell and thrombocyte counts than the control group. Serum activities of alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, γ-glutamyl-transferase, and lactate dehydrogenase significantly increased and serum levels of total protein, albumin, triglyceride, total cholesterol, and low-density lipoprotein cholesterol significantly decreased in the HgCl2-treated groups compared with control group. Malondialdehyde level significantly increased and superoxide dismutase, catalase, and glutathione peroxidase activities decreased in liver tissue of HgCl2-treated rats. Also, HgCl2 exposure resulted in histopathological changes. Supplementation of Na2SeO3 and/or vitamin E provided partial protection in hematological and biochemical parameters that were altered by HgCl2. As a result, Na2SeO3 and/or vitamin E significantly reduced HgCl2-induced hepatotoxicity, but not protected completely.

N-acetylcysteine reduces the renal oxidative stress and apoptosis induced by hemorrhagic shock

BACKGROUND

Renal ischemia/reperfusion injury induced by hemorrhagic shock (HS) and subsequent fluid resuscitation is a common cause of acute renal failure. The objective of this study was to evaluate the effect of combining N-acetylcysteine (NAC) with fluid resuscitation on renal injury in rats that underwent HS.

MATERIALS AND METHODS

Two groups of male Wistar rats were induced to controlled HS at 35 mm Hg mean arterial pressure for 60 min. After this period, the HS and fluid resuscitation (HS/R) group was resuscitated with lactate containing 50% of the blood that was withdrawn. The HS/R + NAC group was resuscitated with Ringer's lactate combined with 150 mg/kg of NAC and blood. The sham group animals were catheterized but were not subjected to shock. All animals were kept under anesthesia and euthanized after 120 min of fluid resuscitation or observation.

RESULTS

Animals treated with NAC presented attenuation of histologic lesions, reduced oxidative stress, and apoptosis markers when compared with animals from the HS/R group. The serum creatinine was similar in all the groups.

CONCLUSIONS

NAC is a promising drug for combining with fluid resuscitation to attenuate the kidney injury associated with HS.

Could pyelonephritic scarring be prevented by anti-inflammatory treatment? An experimental model of acute pyelonephritis

Objectives. This study aimed to demonstrate if the addition of anti-inflammatory treatment to antibiotic therapy shows any superiority to the treatment with antibiotic only. Methods. Forty-nine Wistar rats were divided into 7 groups. Pyelonephritis was performed by E. coli injection to upper pole of kidneys except control group. Group 2 was not treated. Ceftriaxone, ketoprofen, “ceftriaxone + ketoprofen,” methylprednisolone, and “ceftriaxone + methylprednisolone” were given in the groups. The technetium-99m-dimercaptosuccinic acid scintigraphies were performed in 3rd day to detect pyelonephritis and 10th week to detect renal scarring. All kidneys were also histopathologically evaluated. Results. When 3rd day and 10th week scintigraphies were compared, initial 2.00 ± 0.30 point pyelonephritis score resulted in 0.71 ± 0.36 renal scar score in “ceftriaxone + ketoprofen” group (P = 0.039). Initial 2.00 ± 0.43 point pyelonephritis score resulted in 0.86 ± 0.26 renal scar score in “ceftriaxone + methylprednisolone” group (P = 0.041). Renal scar score was declined in “ceftriaxone + ketoprofen” group and “ceftriaxone + methylprednisolone” group compared with no-treatment group on 10th week of the study (P = 0.026, P = 0.044). On histopathological evaluation, it was seen that renal scar prevalence and expansion declined significantly in “ceftriaxone + ketoprofen and ceftriaxone + methylprednisolone” (P = 0.011, P = 0.023). Conclusion. It was evidenced that ceftriaxone treatment in combination with ketoprofen or methylprednisolone declined scar formation in scintigraphic and histopathologic examinations of the kidneys.

The benefits of hypothermic machine perfusion are enhanced with Vasosol and α-tocopherol in rodent donation after cardiac death livers

The use of hypothermic machine perfusion (HMP) has recently been used to show an improvement in both standard and extended criteria donor liver grafts but creating a more dynamic preservation environment that can be supplemented with a variety of additives to aid in cold temperature metabolism and vasodilatation. Increasing the benefits of HMP, we explore the use of α-tocopherol in reducing inflammatory markers and apoptotic pathways to reduce the incidence of preservation injury. We explored the use of a donation after cardiac death (DCD) rodent model to test the additive benefits of α-tocopherol in HMP. The addition of α-tocopherol reduced the level of alanine aminotransferase (ALT) over the course of reperfusion as well, reduced the levels of inflammatory cytokines within a 90 minute reperfusion biopsy. Further benefit was seen with α-tocopherol through the reduction of the level of caspase 3/7 in the circulation, shown to be a result of the reduction of the levels of Cytochrome C mRNA. Liver perfusion with Vasosol® and HMP could benefit further from the addition of α-tocopherol to existing formulations of Vasosol®.

Effects of a Rubus coreanus Miquel supplement on plasma antioxidant capacity in healthy Korean men

Korean raspberry, Rubus coreanus Miquel (RCM), contains high concentrations of phenolic compounds, which prevent oxidative stress. To determine the effect of RCM on antioxidant capacity in humans, we assessed in vivo lipid oxidation and antioxidant enzyme activities from plasma in 15 healthy men. The subjects ingested 30 g of freeze-dried RCM daily for 4 weeks. Blood was taken at baseline and at the end of the study to determine blood lipid profiles, fasting plasma glucose, liver function, lipid peroxidation, and antioxidant enzyme activities. RCM supplementation had no effect on blood lipid or fasting plasma glucose concentrations but decreased alkaline phosphatase activity. RCM supplementation increased glutathione peroxidase activities (P < 0.05) but had no effect on lipid peroxidation. These results suggest that short-term RCM supplementation may offer health benefits by enhancing antioxidant capacity in a healthy population.

Vitamin E attenuates liver injury induced by exposure to lead, mercury, cadmium and copper in albino mice

Water pollution is the contamination of water resources by harmful wastes or toxins. Both community and private sources of drinking water are susceptible to a myriad of chemical contaminants. Heavy metals pollution of surface water can create health risks. The present study was aimed to investigate the effect of vitamin E supplementation on male mice exposed to a mixture of some heavy metals (lead, mercury, cadmium and copper) in their drinking water for seven weeks. Significant increases of blood alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), gamma glutamyl transferase (GGT) were detected in heavy metals-treated mice. Histopathologically, the liver sections from heavy metals-treated mice showed severe changes including disarrangement of hepatic strands, rupture in hepatocytes, advanced hepatocellular necrosis, dilation and congestion of blood vessels with hemorrhage, dense lymphocytic infiltration round the central vein and dark stained hepatocytic nuclei indicating cell pycnosis. Administration of vitamin E at a dose of 50 IU/kg body weight, five times weekly improved the observed biochemical and histopathological changes induced by these heavy metals intoxication. Hence, the results of this study suggest that vitamin E protects against these heavy metals-induced liver injury and the attenuating effect of vitamin E may be due to its antioxidant activity.

Evaluation of Effectiveness of Vitamins C and E on Prevention of Renal Scar due to Pyelonephritis in Rat

Aim was evaluation of the effects of cosupplementation of, vitamins E and C, in preventing renal scarring in acute pyelonephritis. Animals and Treatments. Sixty rats were used, bacteria was injected through kidney. The rats were arranged randomly in 3 groups of 20 rats each. Rats in groups 1 and 2 were given once-daily intraperitoneal injections of gentamicin for ten consecutive days, beginning on the third day after inoculation. In group 2, vitamins E and C cotreatment and in group 3, vitamins E and C cotreatment without gentamicin injection were started. Three rats in each group were killed 24 hours after the inoculation (for infection and inflammation document) and forty-eight hours after the antibiotic injection (for efficacy of treatment). After eight weeks, the rest of rats were killed, and kidneys evaluated for percent of scaring. Result. There was also significant difference of degree of scar formation (1.4 and 3.4% versus 8.6%, P = .001). The group which received gentamicin only had moderate to severe scaring, but the two groups which received vitamin C and vitamin E showed no or mild renal scaring. Conclusion. The study showed that administration of antioxidants can protect scaring due to pyelonephritis with or without antibiotic administration.

Oxidative stress as a novel target in pediatric sepsis management

Sepsis with secondary multisystem organ dysfunction syndrome is the leading cause of death in the pediatric intensive care unit. Increased reactive oxygen species may influence circulating and endothelial cells, contributing to inflammatory tissue injury and explaining the tissue hypoxia paradigm based on microvascular dysfunction. An impaired mitochondrial cellular oxygen utilization, rather than inadequate oxygen delivery, was claimed to play a more important role in the development of multisystem organ dysfunction syndrome. Anyway, it seems plausible that reactive oxygen species can mediate the pathophysiologic processes occurring in sepsis. However, the consensus guidelines for the management of patients with these conditions do not include the enhancement of antioxidant potential. Therefore, further investigation is needed to support interventions aimed to attenuate the severity of the systemic compromise by abrogating the mechanism of oxidative damage. Antioxidant supplementation currently in use lacks a mechanistic support. Specific pharmacologic targets, such as mitochondria or Nicotinamide Adenine Dinucleotide Phosphate-Oxidase (NADPH) oxidase system, need to be explored. Furthermore, the early recognition of oxidative damage in these seriously ill patients and the usefulness of oxidative stress biomarkers to define a cut point for more successful therapeutic antioxidant interventions to be instituted would offer a new strategy to improve the outcome of critically ill children.

Protective effect of resveratrol on acute endotoxemia-induced nephrotoxicity in rat through nitric oxide independent mechanism

Lipopolysaccharide (LPS) is a glycolipid component of the cell wall of gram negative bacteria inducing deleterious effects on the kidney. Endotoxemia-induced nephrotoxicity is characterized by disturbed intracellular redox balance and reactive oxygen species (ROS) accumulation leading to DNA, proteins and membrane lipid damages. Resveratrol (trans-3,5,4'-trihydroxystilbene) is a polyphenol displaying antioxidant and anti-inflammatory properties. This study investigated its effects on LPS-induced nephrotoxicity in rats. Resveratrol counteracted all LPS-induced changes in renal haemodynamic parameters. In the kidney resveratrol abrogated LPS-induced lipoperoxidation and antioxidant enzyme activities depletion as superoxide dismutase (SOD) and catalase (CAT) but not peroxidase (POD) activity. LPS increased plasma and urine nitric oxide (NO) level and resveratrol reversed them. More importantly, LPS-induced iron mobilization from plasma to kidney, which was also abolished by resveratrol treatment. All these results suggest that resveratrol exerted strong antioxidant properties against LPS-induced nephrotoxicity and that its mode of action seemed to involve iron shuttling proteins.

Protective effect of resveratrol in endotoxemia-induced acute phase response in rats

Lipopolysaccharide (LPS), a glycolipid component of the cell wall of gram-negative bacteria can elicit a systemic inflammatory process leading to septic shock and death. Acute phase response is characterized by fever, leucocytosis, thrombocytopenia, altered metabolic responses and redox balance by inducing excessive reactive oxygen species (ROS) generation. Resveratrol (trans-3,5,4' trihydroxystilbene) is a natural polyphenol exhibiting antioxidant and anti-inflammatory properties. We investigated the protective effect of resveratrol on endotoxemia-induced acute phase response in rats. When acutely administered by i.p. route, resveratrol (40 mg/kg b.w.) counteracted the effect of a single injection of LPS (4 mg/kg b.w.) which induced fever, a decrease in white blood cells (WBC) and platelets (PLT) counts. When i.p. administered during 7 days at 20 mg/kg per day (subacute treatment), resveratrol abrogated LPS-induced erythrocytes lipoperoxidation and catalase (CAT) activity depression to control levels. In the plasma compartment, LPS increased malondialdehyde (MDA) via nitric monoxide (NO) elevation and decreased iron level. All these deleterious LPS effects were reversed by a subacute resveratrol pre-treatment via a NO independent way. Resveratrol exhibited potent protective effect on LPS-induced acute phase response in rats.

Persistent Oxidative Stress after Myocardial Infarction Treated by Percutaneous Coronary Intervention

Acute myocardial infarction causing cardiac ischemia is responsible for the majority of cardiac related deaths. Medical interventions that ensure rapid reperfusion, such as percutaneous coronary intervention, are aimed to allow myocardial re-oxygenation. However, this generates reactive oxygen species, resembling ischemia-reperfusion type of injury based on oxidative stress. In the present study we monitored dynamic changes of total serum peroxides, total antioxidant capacity and soluble intercellular adhesion molecule-1 as well as the titer of antibodies against oxidized low-density lipoproteins in the blood during the convalescence period of 32 patients with acute myocardial infarction treated by percutaneous coronary intervention. Samples were taken at admittance and at two hours, four hours, three days and seven days following percutaneous coronary intervention. Total antioxidant capacity dropped to 82% (p < 0.05). The titer of antibodies against oxidized low-density lipoproteins transiently decreased within the first three days, and increased afterwards. The values of serum peroxides and soluble intercellular adhesion molecule-1 increased continuously in respect to the initial levels reaching the maximum at the time of release from hospital. These findings indicate a persistent oxidative stress that might be associated with intravascular inflammation in patients during convalescence and release from hospital.

Endotoxin increases ascorbate recycling and concentration in mouse liver

Sublethal exposure to Escherichia coli endotoxin [lipopolysaccharide (LPS)] attenuates the lethal effects of subsequent insults associated with oxidative stress, such as higher LPS dose, septic peritonitis, and ischemia. Because administration of the antioxidant ascorbate protects against these same insults and injection of dehydroascorbic acid (DHAA) protects against ischemia, the hypothesis that sublethal LPS increases endogenous ascorbate concentration and recycling (i.e., synthesis from DHAA) was tested. Injection of LPS [5 x 10(6) endotoxin units/kg body weight, i.p.] in mice caused a temporary inhibition of food intake, which was significant by 20 h and recovered within 3 d. LPS increased ascorbate concentration in adrenal gland, heart, kidney, and liver. LPS had similar effects in wild-type and Slc23a2+/- mice despite the latter's deficiency in the ascorbate transporter SVCT2. In liver, the ascorbate response to LPS was not accompanied by change in glutathione concentration. LPS decreased gulonolactone oxidase activity, which is rate-limiting for de novo synthesis of ascorbate from glucose, but increased the rate of DHAA reduction to ascorbate. In conclusion, sublethal endotoxin increases ascorbate recycling in liver and ascorbate concentration in liver, adrenal gland, heart, and kidney. The enhanced rate of ascorbate production from DHAA may protect these organs against the reactive oxygen species produced by subsequent, potentially lethal challenges.