Possible involvement of tetrahydrobiopterin in the disturbance of redox homeostasis in sepsis - Induced brain dysfunction

Free Radicals, Mitochondrial Dysfunction and Sepsis-induced Organ Dysfunction: A Mechanistic Insight

Sepsis is a complex clinical condition and a leading cause of death worldwide. During Sepsis, there is a derailment in the host response to infection, which can progress to severe sepsis and multiple organ dysfunction or failure, which leads to death. Free radicals, including reactive oxygen species (ROS) generated predominantly in mitochondria, are one of the key players in impairing normal organ function in sepsis. ROS contributing to oxidative stress has been reported to be the main culprit in the injury of the lung, heart, liver, kidney, gastrointestinal, and other organs. Here in the present review, we describe the generation, and essential properties of various types of ROS, their effect on macromolecules, and their role in mitochondrial dysfunction. Furthermore, the mechanism involved in the ROS-mediated pathogenesis of sepsis-induced organ dysfunction has also been discussed.

Garden Cress (Lepidium sativum) Seeds Ameliorated Aluminum-Induced Alzheimer Disease in Rats Through Antioxidant, Anti-Inflammatory, and Antiapoptotic Effects

Background

Bioaccumulation of aluminum in the brain is associated with adverse neuroinflammatory and neurodegenerative changes, such as those seen in Alzheimer's disease (AD).

Objective

This study aimed to assess the impact of the administration of Lepidium sativum (LS) extract on behavioral, biochemical, and cerebral histopathological changes in rats with AlCl₃-induced AD and explore the mechanism behind this effect.

Materials and Methods

This study was conducted on 40 male albino rats divided into four groups (n=10): LS (control, 20 mg/kg body weight for 8 weeks), AD (AlCl_3, 10 mg/kg body weight), and an LS-treated AD group. Behavioral assessment included radial armed maze and active avoidance training tests. Proinflammatory cytokines, oxidant/antioxidant markers, Aβ, AchE, tau protein, TGFβ₁, homocysteine, folic acid, and vitamin B₁₂ were biochemically assessed in the serum. The cerebral cortex was histopathologically examined.

Results

AlCl₃ administration significantly impaired rats' memory, indicating AD-like behavioral changes, significantly increased (P<0.001) oxidative stress markers, enhanced proinflammatory cytokines, and significantly increased AChE (P<0.001) adding to cytotoxic effects and neuronal loss in the cerebral cortex. LS administration significantly improved the antioxidant parameters, reduced proinflammatory cytokines, and alleviated AD-associated histopathological changes.

Conclusion

LS ameliorated AlCl₃-induced changes through its antioxidant, anti-inflammatory, and antiapoptotic effects, suggesting that it has a neuroprotective effect.

Carnitine, apelin and resveratrol regulate mitochondrial quality control (QC) related proteins and ameliorate acute kidney injury: role of hydrogen peroxide

Mitochondrial impairment is recognised as a prominent feature in kidney diseases. Therefore, we investigated whether the effects of resveratrol, L-carnitine, and apelin in the acute kidney injury model were associated with modulation of mitochondrial quality control (QC) related proteins, intra-renal renin-angiotensin (RAS) activity, adenosine triphosphate (ATP) and Na⁺-K⁺ ATPase gene expression. Rats were randomly assigned to 7 groups: Distilled water injected control group, DMSO injected control group, distilled water injected lipopolysaccharide (LPS) group, DMSO injected LPS group, resveratrol injected LPS group, L-carnitine injected LPS group and apelin 13 injected LPS group. We observed that resveratrol, L-carnitine, and apelin treatments altered mitochondrial (QC) related protein levels (Pink1, Parkin, BNIP-3, Drp1, and PGC1α), decreased intra-renal RAS parameters, increased ATP level and upregulated Na⁺-K⁺ ATPase gene expression in renal tissue. Our results provide new insight into the role of mitochondrial quality control and how different antioxidants exert beneficial effects on acute kidney injury.

Accelerating Effect of Cucurbita pepo L. Fruit Extract on Excisional Wound Healing in Depressed Rats Is Mediated through Its Anti-Inflammatory and Antioxidant Effects

Background: Chronic stress can hinder wound healing as it suppresses both the cellular and innate immune responses. Objectives: The study aims to assess the effectiveness of the administration of topical and oral Cucurbita pepo L. (CP) ethanolic extract in prompting excisional wound healing in rats exposed to chronic stress, and to explain how it works. Materials and methods: Fifty albino rats assigned to five groups (n = 10) were utilized in this study. The chronic unpredictable mild stress (CUMS) model was used for 4 weeks to induce depressive-like behavior in rats, and a forced swim test and corticosterone were assessed to confirm its occurrence. During the experiment, an excisional wound was induced in the rats and followed. Oxidant/antioxidants status and pro-inflammatory cytokines levels were measured in the serum and wound area. Gene expression of pro-inflammatory cytokines was also assessed using RT-PCR. Wound closure histopathological changes and immunohistochemical expression of CD68, CD3, and CD4 at the wound area was assessed. Results: The administration of CP, both orally and topically, significantly reduced (p < 0.001) the depressive-like behavior and corticosterone and pro-inflammatory cytokines levels, while it significantly up-regulated the antioxidant activity compared to the untreated and topically CP-treated groups. Both topically CP-treated and combined CP-treated groups showed complete re-epithelialization, reduced inflammatory cells infiltration, collagen fibers deposition, and significantly increased CD3, CD4 positive T cells count, with a superior effect in the combined CP-treated groups. Conclusion: Cucurbita pepo L., administrated both topically and orally, can enhance the wound healing process in rats with depressive-like behavior mostly through the antioxidant, anti-inflammatory, and antidepressant activities observed in this study.

Iron dyshomeostasis and time-course changes in iron-uptake systems and ferritin level in relation to pro-inflammatory microglia polarization in sepsis-induced encephalopathy

Encephalopathy is a frequent and lethal consequence of sepsis. Recently, a growing body of evidence has provided important insights into the role of iron dyshomeostasis in the context of inflammation. The molecular mechanisms underlying iron dyshomeostasis and its relationship with macrophage phenotypes are largely unknown. Here, we aimed to characterize the changes in iron-transporter and storage proteins and the microglia phenotype that occur during the course of sepsis, as well as their relationship with sepsis-induced encephalopathy. We used a cecal ligation and puncture (CLP) murine model that closely resembles sepsis-induced encephalopathy. Rats were subjected to CLP or sham laparotomy, then were neurologically assessed at 6 h, 24 h, and 3 days after sepsis induction. The serum and brain were collected for subsequent biochemical, histological, and immunohistochemical assessment. Here, an iron excess was observed at time points that followed the pro-inflammatory macrophage polarization in CLP-induced encephalopathy. Our results revealed that the upregulation of non-transferrin-bound iron uptake (NTBI) and ferritin reduction appeared to be partially responsible for the excess free iron detected within the brain tissues. We further demonstrated that the microglia were shifted toward the pro-inflammatory phenotype, leading to persistent neuro-inflammation and neuronal damage after CLP. Taken together, these findings led us to conclude that sepsis increased the susceptibility of the brain to the iron burden via the upregulation of NTBI and the reduction of ferritin, which was concomitantly and correlatively associated with dominance of pro-inflammatory microglia and could explain the neurological dysfunction observed during sepsis.

Roles of neutrophil reactive oxygen species (ROS) generation in organ function impairment in sepsis

Sepsis is a condition of severe organ failure caused by the maladaptive response of the host to an infection. It is a severe complication affecting critically ill patients, which can progress to severe sepsis, septic shock, and ultimately death. As a vital part of the human innate immune system, neutrophils are essential in resisting pathogen invasion, infection, and immune surveillance. Neutrophil-produced reactive oxygen species (ROS) play a pivotal role in organ dysfunction related to sepsis. In recent years, ROS have received a lot of attention as a major cause of sepsis, which can progress to severe sepsis and septic shock. This paper reviews the existing knowledge on the production mechanism of neutrophil ROS in human organ function impairment because of sepsis.

Nanoparticles of Costus&nbsp;speciosus Ameliorate Diabetes-Induced Structural Changes in Rat Prostate through Mediating the Pro-Inflammatory Cytokines IL 6, IL1β and TNF-α

Diabetes mellitus is a common global health problem. Among the complications that are frequently associated with DM are the alternation of sexual function and fertility, especially in young men. This study aimed to assess the efficacy of nanoparticles of Costus speciosus (C. speciosus) in preserving the prostatic structure of diabetic rats and to explore the mechanism behind this effect. A model of DM was induced in male albino rats by a single intraperitoneally injection of streptozotocin (STZ, 60 mg/kg body weight). Five groups (n = 10 each) of rats were included in this study: the control, C. speciosus gold nanoparticles-treated (150 mg/kg body weight through gastric intubation for 30 days), untreated diabetic, metformin-treated diabetic (500 mg/kg/day gastric intubation for 30 days) and the C. speciosus-treated diabetic group. The blood glucose, insulin and testosterone levels as well as oxidants/antioxidants status were assessed in the serum. Gene expression of proinflammatory cytokines TNF-α, IL1β and IL-6 were assessed in the prostate homogenate. At the end of the experiment, the rats were sacrificed and the prostate was dissected out and prepared for histopathological and immunohistochemistry study using Ki67 and Bcl-2. C. Speciosus nanoparticles significantly decreased (p = 0.03) the blood glucose level while significantly increasing insulin (p = 0.01) and testosterone (p = 0.04) levels compared to the untreated diabetic rats. Oxidants/antioxidants status was markedly improved after administration of C. speciosus. Prostatic expression of the mRNA of pro-inflammatory cytokines IL-6, IL1β and TNF-α was down-regulated in metformin- and C. speciosus-treated rats. The histological structure of the ventral prostate was preserved in metformin- and C. speciosus-treated diabetic rats with a significantly thicker epithelial cell layer and significant increase immunoexpression in Bcl-2 and Ki67. In conclusion, the protective effect induced by C. speciosus nanoparticles on the prostate of diabetic rats might be directly mediated through the down-regulation of inflammatory cytokines and the up-regulation of antioxidant activity and indirectly mediated through the anti-hyperglycemic effect through enhancing insulin secretion.

Anagliptin prevents lipopolysaccharide (LPS)- induced inflammation and activation of macrophages

Sepsis is a multiple organ dysfunction syndrome (MODS) induced by infection, which significantly threatens public health. The overactivation of inflammatory reactions and oxidative stress participate in the pathogenesis of sepsis. Anagliptin, a novel anti-diabetic agent widely applied for the treatment of type II diabetes, has been recently claimed to possess anti-inflammatory properties. Here, the protective effects of anagliptin on lipopolysaccharide (LPS)- stimulated macrophages will be checked to explore the possible pharmacological property of anagliptin on sepsis. The state of oxidative stress was dramatically activated by LPS, accompanied by the upregulation of toll-like receptor 4 (TLR4) and high mobility group box-1 (HMGB-1), as well as the elevated expression of inducible nitric oxide synthase (iNOS) and production of nitric oxide (NO). After treatment with anagliptin, the state of oxidative stress in macrophages was alleviated, with the downregulation of TLR4, HMGB-1, iNOS, and the declined release of NO. The excessive secretion of inflammatory factors, activation of the NF-κB pathway, and promoted expression level of receptor-interacting protein 1 (RIP1) were observed in LPS- stimulated macrophages, all of which were greatly reversed by the introduction of anagliptin. Lastly, the protective properties of anagliptin on LPS- treated macrophages, including the inhibitory effects on inflammation and the NF-κB pathway, were dramatically abolished by the overexpression of RIP1 in macrophages. Collectively, anagliptin prevented LPS-induced inflammation and activation of P338D1 macrophages by repressing the expression level of RIP1.

An Ethanolic Extract of Cucurbita pepo L. Seeds Modifies Neuroendocrine Disruption in Chronic Stressed Rats and Adrenal Expression of Inflammatory Markers and HSP70

Background: Pumpkins (Cucurbita pepo L.) were described to have antioxidant, anti-inflammatory, anti-fatigue, and antidepressant-like effect. The adrenal gland is an important stress-responsive organ that maintains homeostasis during stress.

Objectives: This study aimed to assess the efficacy of the administration of Cucurbita pepo L. (CP) extract in relieving behavioral, biochemical, and structural changes in the adrenal gland induced by exposure to chronic unpredictable mild stress (CUMS) and to explore the mechanism behind this impact.

Materials and Methods: Forty male albino rats were divided into 4 groups (n = 10): control, CUMS, fluoxetine-treated, and CP-treated groups. Behavioral changes, corticosterone level, pro-inflammatory cytokines TNF-α and IL-6, and oxidant/antioxidant profile were assessed in the serum at the end of the experiment. Adrenal glands were processed for histopathological and immunohistochemical assessment. Gene expression of caspase-3 and Ki67 and heat shock protein 70 (HSP70) were assessed in adrenal glands using RT-PCR.

Results: The CP extract significantly reduced the corticosterone level (p < 0.001), immobility time (p < 0.001), and inflammatory and oxidative changes associated with CUMS-induced depression compared to the untreated group. The CP extract alleviated CUMS-induced adrenal histopathological changes and significantly reduced apoptosis (p < 0.001) and significantly upregulated antioxidant levels in the serum.

Conclusion:Cucurbita pepo L. effectively ameliorated the chronic stress-induced behavioral, biochemical, and adrenal structural changes mostly through its antioxidant and anti-inflammatory effects.

IκB kinase inhibition remodeled connexins, pannexin-1, and excitatory amino-acid transporters expressions to promote neuroprotection of galantamine and morphine

Inflammatory pathway and disruption in glutamate homeostasis join at the level of the glia, resulting in various neurological disorders. In vitro studies have provided evidence that membrane proteins connexions (Cxs) are involved in glutamate release, meanwhile, excitatory amino-acid transporters (EAATs) are crucial for glutamate reuptake (clearance). Moreover, pannexin-1 (Panx-1) activation is more detrimental to neurons. Their expression patterns during inflammation and the impacts of IκB kinase (IKK) inhibition, morphine, and galantamine on the inflammatory-associated glutamate imbalance remain elusive. To investigate this, rats were injected with saline or lipopolysaccharide. Thereafter, vehicles, morphine, galantamine, and BAY-117082 were administered in different groups of animals. Subsequently, electroencephalography, enzyme-linked immunosorbent assay, western blot, and histopathological examinations were carried out and various indicators of inflammation and glutamate level were determined. Parallel analysis of Cxs, Panx-1, and EAAts in the brain was performed. Our findings strengthen the concept that unregulated expressions of Cxs, Panx-1, and EAATs contribute to glutamate accumulation and neuronal cell loss. Nuclear factor-kB (NF-κB) pathway can significantly contribute to glutamate homeostasis via modulating Cxs, Panx-1, and EAATs expressions. BAY-117082, via inhibition of IkK, promoted the anti-inflammatory effects of morphine as well as galantamine. We concluded that NF-κB is an important component of reshaping the expressions of Cxs, panx-1, and EAATs and the development of glutamate-induced neuronal degeneration.

Brain-derived Neurotropic factor (BDNF) mediates the protective effect of Cucurbita pepo L. on salivary glands of rats exposed to chronic stress evident by structural, biochemical and molecular study

BACKGROUND

Acute and chronic stresses affect the salivary glands, representing the source of plasma BDNF during stressful conditions. Pumpkin is a medicinal plant with an evident antioxidant, anti-inflammatory and potential antidepressant effects.

OBJECTIVE

To assess the structural and biochemical effects induced by exposure to chronic unpredictable mild stress (CUMS) on salivary glands of albino rats, and to evaluate the role of pumpkin extract (Pump) in ameliorating this effect.

METHODOLOGY

Four groups (n=10 each) of male albino rats were included in this study: the control, CUMS, Fluoxetine-treated and Pump-treated. The corticosterone, the pro-inflammatory cytokines, tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6), and the oxidant/antioxidant profile were all assessed in the serum. The level of BDNF mRNA was measured in the salivary glands using qRT-PCR. Histopathological changes of the salivary glands were also assessed.

RESULTS

The depressive-like status was confirmed behaviorally and biochemically. Exposure to CUMS significantly up-regulated (p<0.001) the level of serum corticosterone. CUMS induced degenerative changes in the secretory and ductal elements of the salivary glands evident by increased apoptosis. Both Fluoxetine and Pumpkin significantly up-regulated (p<0.001) BDNF expression in the salivary glands and ameliorated the CUMS-induced histopathological and biochemical alterations in the salivary glands. Pumpkin significantly (p<0.001) increased the serum levels of antioxidant enzymes SOD, GPX and CAT, and reduced the serum levels of the pro-inflammatory cytokines TNF-α, IL-6.

CONCLUSION

Pumpkin ameliorates the depressive-like status induced in rats following exposure to chronic stress through exerting a promising anti-inflammatory, antioxidant and anti-depressant-like effects. The pumpkin, subsequently, improved stress-induced structural changes in the salivary glands that might be due to up-regulation of BDNF expression in the glands.

Musk (Moschus moschiferus) Attenuates Changes in Main Olfactory Bulb of Depressed Mice: Behavioral, Biochemical, and Histopathological Evidence

BACKGROUND

Musk (Moschus moschiferus) has been described to have a significant impact on the central nervous system, as well as anticonvulsion and antidepressant effects. This study was designed to evaluate the efficacy of musk in alleviating alterations induced in olfactory bulb of depressed mice exposed to chronic stress and identify the mechanism behind it.

METHODS

Fifty male albino mice were divided into five groups (n = 10 each): control, musk, chronic unpredictable mild stress (CUMS), fluoxetine-treated, and musk-treated groups were included in this study. Behavioral changes and serum levels of corticosterone and proinflammatory cytokines included tumor necrosis factor α, interleukin 6, and oxidant/antioxidant profile were assessed at the end of the experiment. Main olfactory bulb (MOB) has been processed for histopathological examination. Gene expression of caspase-3, glial fibrillary acidic protein, and Ki67 were assessed in the MOB using quantitative real-time polymerase chain reaction.

RESULTS

The study showed that musk inhalation significantly reduced (p < 0.001) corticosterone level, immobility time, inflammatory cytokines, and oxidative stress markers in CUMS-exposed mice compared to the untreated CUMS group. Musk lessened CUMS-associated neuronal alterations in the MOB and significantly reduced apoptosis and enhanced neural cell proliferation (p < 0.001) comparable to fluoxetine. Musk significantly enhanced the level of antioxidants in the serum and significantly reduced inflammatory cytokines. The anti-inflammatory and antioxidant activity of musk and its constituents seemed to be behind its neuroprotective effect observed in this study.

CONCLUSION

Musk effectively ameliorated the chronic stress-induced behavioral, biochemical, and neuronal structural changes in MOB mostly through its antioxidant and anti-inflammatory effect.

L. Cucurbita pepo Alleviates Chronic Unpredictable Mild Stress via Modulation of Apoptosis, Neurogenesis, and Gliosis in Rat Hippocampus

Pumpkin has received significant attention due to its nutritional compounds that have antioxidant, antifatigue, and anti-inflammatory effects. This study is aimed at assessing the antidepressant-like effect of L. Cucurbita pepo, sweet pumpkin, in an animal model of chronic unpredictable mild stress (CUMS) and investigating its effect on the histological structure of hippocampus compared to fluoxetine. Forty male albino rats assigned into the negative control, positive control (CUMS), and Flu-treated and pumpkin-treated groups (n = 10) were utilized in this study. Exposing rats to CUMS continued for 28 days, and treatments used were applied during the last 14 days of exposure. Behavioral, biochemical, and histopathological changes were assessed after 28 days. In this study, pumpkin significantly reduced the immobility time (p = 0.02), corticosterone (p < 0.001), TNF-α, IL-6 (p < 0.001), and malondialdehyde (p = 0.003), whereas it significantly increased the level of superoxide dismutase (SOD), catalase, and glutathione peroxidase (GPX) in the serum of rats exposed to CUMS. Pumpkin markedly relieved the degenerative and atrophic changes observed in the CA3 region and the dentate gyrus of the hippocampus. It significantly reduced caspase-3 and increased glial fibrillary acidic protein (GFAP) immunoexpression in the CA3 and DG. In conclusion, administration of pumpkin extract improved the behavioral, biochemical, and hippocampal pathological alternations induced in rats after exposure to CUMS in a comparable pattern to fluoxetine. This study highlighted the potential efficacy of pumpkin in alleviating depression disorder either alone or in conjugation with conventional antidepressant therapy.

Combined Oral and Topical Application of Pumpkin (Cucurbita pepo L.) Alleviates Contact Dermatitis Associated With Depression Through Downregulation Pro-Inflammatory Cytokines

Background: Depression and contact dermatitis (CD) are considered relatively common health problems that are linked with psychological stress. The antioxidant, anti-inflammatory, and antidepressant activities of pumpkin were previously reported. Objectives: This study aimed to evaluate the efficacy of the combined topical and oral application of pumpkin fruit (Cucurbita pepo L.) extract (PE) in relieving CD associated with chronic stress-induced depression and compare it to the topical pumpkin extract alone and to the standard treatment. Materials and Methods: Forty male albino rats were exposed to chronic unpredictable mild stress (CUMS) for 4 weeks for induction of depression and then exposed to (1-fluoro-2, 4-dinitrofluorobenzene, DNFB) for 2 weeks for induction of CD. Those rats were assigned into 4 groups (n = 10 each); untreated, betamethasone-treated, PE-treated and pumpkin extract cream, and oral-treated groups. Treatments were continued for 2 weeks. All groups were compared to the negative control group (n = 10). Depression was behaviorally and biochemically confirmed. Serum and mRNA levels of pro-inflammatory cytokines, such as TNF-α, IL-6, COX-2, and iNOS, were assessed. Oxidant/antioxidant profile was assessed in the serum and skin. Histopathological and immunohistochemical assessments of affected skin samples were performed. Results: Pumpkin extract, used in this study, included a large amount of oleic acid (about 56%). The combined topical and oral administration of PE significantly reduced inflammatory and oxidative changes induced by CD and depression compared to the CD standard treatment and to the topical PE alone. PE significantly alleviated CD signs and the histopathological score (p < 0.001) mostly through the downregulation of pro-inflammatory cytokines and the upregulation of antioxidants. Conclusion: Pumpkin extract, applied topically and orally, could be an alternative and/or complementary approach for treating contact dermatitis associated with depression. Further studies on volunteer patients of contact dermatitis are recommended.

Efficacy of Sweet Pumpkin in Relieving Contact Dermatitis in Chronically Stressed Rats

Background:

Contact dermatitis (CD) is considered among the common inflammatory skin diseases worldwide. Cucurbita moschata Duchesne has antioxidant, anti-inflammatory, and antidepressant activity beside many other beneficial effects.

Objectives:

This study aimed to assess the effect of pumpkin fruit extract in treating CD in mice exposed to chronic stress and to explore the mechanism through which pumpkin can relief these changes.

Materials and Methods:

Thirty male albino rats were divided into three groups (n = 10); the control and two experimental groups that were exposure to chronic unpredictable mild stress for 4 weeks then painting with 1-fluoro-2,4-dinitrofluorobenzene (DNFB) for 3 consecutive days/week for 2 weeks to induce CD. Biochemical assessment of corticosterone level and antioxidants activity was performed. Skin of affected areas was excised, processed for histopathological examination.

Results:

DNFB-induced CD presented with dryness, hardness, and scaling. There was a significant reduction (P < 0.001) in the levels of superoxide dismutase, glutathione peroxidase and catalase activity in the skin of rats had CD. Histopathologically, the shin showed hyperplastic-thickened epidermis, focal elongation of the rete ridges, inflammatory cells infiltration in the superficial dermis, and increased collagen fibers. Local administration of pumpkin extract significantly increased the antioxidants activity in the skin and alleviated the CD-associated changes.

Conclusions:

This study showed that the pumpkin fruit extract could have a potential in treating CD in stressed conditions mainly via its enhancement of skin antioxidant activity.

Molecular mechanisms by which iNOS uncoupling can induce cardiovascular dysfunction during sepsis: Role of posttranslational modifications (PTMs)

Human sepsis is the result of a multifaceted pathological process causing marked dysregulation of cardiovascular responses. A more sophisticated understanding of the pathogenesis of sepsis is certainly prerequisite. Evidence from studies provide further insight into the role of inducible nitric oxide synthase (iNOS) isoform. Results on inhibition of iNOS in sepsis models remain inconclusive. Concern has been devoted to improving our knowledge and understanding of the role of iNOS. The aim of this review is to define the role of iNOS in redox homeostasis disturbance, the detailed mechanisms linking iNOS and posttranslational modifications (PTMs) to cardiovascular dysfunctions, and their future implications in sepsis settings. Many questions related to the iNOS and PTMs still remain open, and much more work is needed on this.