Inflammatory markers response to citrulline supplementation in patients with non-alcoholic fatty liver disease: a randomized, double blind, placebo-controlled, clinical trial

Citrulline and ADI-PEG20 reduce inflammation in a juvenile porcine model of acute endotoxemia

Background

Arginine is a conditionally essential amino acid that is depleted in critically ill or surgical patients. In pediatric and adult patients, sepsis results in an arginine-deficient state, and the depletion of plasma arginine is associated with greater mortality. However, direct supplementation of arginine can result in the excessive production of nitric oxide (NO), which can contribute to the hypotension and macrovascular hypo-reactivity observed in septic shock. Pegylated arginine deiminase (ADI-PEG20, pegargiminase) reduces plasma arginine and generates citrulline that can be transported intracellularly to generate local arginine and NO, without resulting in hypotension, while maintaining microvascular patency. The objective of this study was to assess the efficacy of ADI-PEG20 with and without supplemental intravenous citrulline in mitigating hypovolemic shock, maintaining tissue levels of arginine, and reducing systemic inflammation in an endotoxemic pediatric pig model.

Methods

Twenty 3-week-old crossbred piglets were implanted with jugular and carotid catheters as well as telemetry devices in the femoral artery to measure blood pressure, body temperature, heart rate, and respiration rate. The piglets were assigned to one of three treatments before undergoing a 5 h lipopolysaccharide (LPS) infusion protocol. Twenty-four hours before LPS infusion, control pigs (LPS; n=6) received saline, ADI-PEG20 pigs (n=7) received an injection of ADI-PEG20, and seven pigs (ADI-PEG20 + CIT pigs [n=7]) received ADI-PEG20 and 250 mg/kg citrulline intravenously. Pigs were monitored throughout LPS infusion and tissue was harvested at the end of the protocol.

Results

Plasma arginine levels decreased and remained low in ADI-PEG20 + CIT and ADI-PEG20 pigs compared with LPS pigs but tissue arginine levels in the liver and kidney were similar across all treatments. Mean arterial pressure in all groups decreased from 90 mmHg to 60 mmHg within 1 h of LPS infusion but there were no significant differences between treatment groups. ADI-PEG20 and ADI-PEG20 + CIT pigs had less CD45+ infiltrate in the liver and lung and lower levels of pro-inflammatory cytokines in the plasma.

Conclusion

ADI-PEG20 and citrulline supplementation failed to ameliorate the hypotension associated with acute endotoxic sepsis in pigs but reduced systemic and local inflammation in the lung and liver.

Association between serum trace element, mineral, and amino acid levels with non-alcoholic fatty liver disease (NAFLD) in adult women

The objective of the present study is assessment of serum trace element and amino acid levels in non-alcoholic fatty liver disease (NAFLD) patients with subsequent evaluation of its independent associations with markers of liver injury and metabolic risk.

MATERIALS AND METHODS

140 women aged 20-90 years old with diagnosed NAFLD and 140 healthy women with a respective age range were enrolled in the current study. Analysis of serum and hair levels of trace elements and minerals was performed with inductively-coupled plasma mass-spectrometry (ICP-MS). Serum amino acid concentrations were evaluated by high-pressure liquid chromatography (HPLC) with UV-detection. In addition, routine biochemical parameters including liver damage markers, alanine aminotransferase (ALT) and gamma-glutamyltransferase (GGT), were assessed spectrophotometrically.

RESULTS

The findings demonstrated that patients with NAFLD were characterized by higher ALT, GGT, lactate dehydrogenase (LDH) and cholinesterase (CE) activity, as well as increased levels of total cholesterol, low-density lipoprotein cholesterol, triglycerides, and uric acid. NAFLD patients were characterized by reduced serum and hair Co, Se, and Zn levels, as well as hair Cu content and serum Mn concentrations in comparison to controls. Circulating Ala, Cit, Glu, Gly, Ile, Leu, Phe, and Tyr levels in NAFLD patients exceeded those in the control group. Multiple linear regression demonstrated that serum and hair trace element levels were significantly associated with circulating amino acid levels after adjustment for age, BMI, and metabolic parameters including liver damage markers.

CONCLUSION

It is proposed that altered trace element handling may contribute to NAFLD pathogenesis through modulation of amino acid metabolism.

Dose-response effect of L-citrulline on skeletal muscle damage after acute eccentric exercise: an in vivo study in mice

Background

Eccentric exercise may trigger mechanical stress, resulting in muscle damage that may decrease athletic performance. L-citrulline potentially prevents skeletal muscle damage after acute eccentric exercise. This study aimed to assess the dose-response effect of L-citrulline as a preventive therapy for skeletal muscle damage in mice after acute eccentric exercise.

Methods

This is a controlled laboratory in vivo study with a post-test-only design. Male mice (BALB/c, n = 25) were randomized into the following groups: a normal control (C1) (n = 5); a negative control (C2) with downhill running and placebo intervention (n = 5); treatment groups: T1 (n = 5), T2 (n = 5), and T3 (n = 5), were subjected to downhill running and 250, 500, and 1,000 mg/kg of L-citrulline, respectively, for seven days. Blood plasma was used to determine the levels of TNNI2 and gastrocnemius muscle tissue NOX2, IL-6, and caspase 3 using ELISA. NF-κB and HSP-70 expressions were determined by immunohistochemistry.

Results

Skeletal muscle damage (plasma TNNI2 levels) in mice after eccentric exercise was lower after 250 and 500 mg/kg of L-citrulline. Further, changes in oxidative stress markers, NOX2, were reduced after a 1,000 mg/kg dose. However, a lower level of change has been observed in levels of cellular response markers (NF-κB, HSP-70, IL-6, and caspase 3) after administration of L-citrulline doses of 250, 500, and 1,000 mg/kg.

Conclusion

L-citrulline may prevent skeletal muscle damage in mice after acute eccentric exercise through antioxidant effects as well as inflammatory and apoptotic pathways. In relation to dose-related effects, it was found that L-citrulline doses of 250, 500, and 1,000 mg/kg significantly influenced the expression of NF-κB and HSP-70, as well as the levels of IL-6 and caspase 3. Meanwhile, only doses of 250 and 500 mg/kg had an impact on TNNI2 levels, and the 1,000 mg/kg dose affected NOX2 levels.

Exploring the Impact of Nutrition on Non-Alcoholic Fatty Liver Disease Management: Unveiling the Roles of Various Foods, Food Components, and Compounds

There is a need to introduce standardized treatment options for non-alcoholic fatty liver disease (NAFLD) due to its global prevalence and the complications of this disease. Many studies have revealed that food-derived substances may be beneficial in dealing with this disease. Therefore, this review aims to evaluate the recently published studies on the food-derived treatment options for NAFLD. A comprehensive search of the PubMed database using keywords such as "NAFLD", "nutrition", "food", "derived", "therapy", and "guidelines" yielded 219 relevant papers for our analysis, published from 2004 to 2023. The results show the significant benefits of food-derived treatment in NAFLD therapy, including improvements in liver histology, hepatic fat amounts, anthropometric measures, lipid profile, and other metabolic measures. The availability of the substances discussed makes them a significant adjuvant in the treatment of this disease. The usefulness of Viusid as additional therapy to diet and physical activity should be emphasized due to improvements in liver histology; however, many other substances lead to a decrease in liver fat amounts including, e.g., berberine or omega-3 fatty acids. In addition, the synbiotic Protexin seems to be useful in terms of NAFLD treatment, especially because it is effective in both obese and lean subjects. Based on the latest research results, we suggest revising the therapeutic recommendations for patients suffering from NAFLD.

The effects of L-citrulline adjunctive treatment of Toxoplasma gondii RH strain infection in a mouse model

Toxoplasma gondii is a zoonotic intracellular protozoan parasite and its therapeutic limitations are one of its major problems. L-citrulline is an organic compound that has beneficial effects on many diseases. The purpose of this study was to assess the impact of L-citrulline, alone or in combination with sulfamethoxazole-trimethoprim (SMZ-TMP) on acute toxoplasmosis caused by Toxoplasma gondii RH virulent strain. In our study, 60 Swiss albino mice were divided into two main groups; the control group and the infected treated group, which was subdivided into group IIa: infected treated with L-citrulline, group IIb: infected treated with SMZ-TMP, and group IIc: infected treated with L-citrulline combined with SMZ-TMP. The effects of treatment were assessed by parasitological study, electron microscopic study of tachyzoites, and histopathological study of the liver. Moreover, ELISA measurement of the serum level of Interferon-gamma, Interleukin 10, Nitric oxide, and apoptotic markers was used. It was noticed that L-citrulline combined with SMZ-TMP significantly increased the survival time of infected mice with a significant decrease in the number of tachyzoites compared to the other groups. Moreover, it increased the levels of measured cytokines and serum anti-apoptotic proteins Bcl-2 and improved the extent of liver cell damage associated with a decrease in inflammatory infiltration. In conclusion, L-citrulline supplementation was found to be effective against acute toxoplasmosis, especially when combined with SMZ-TMP as it has multifactorial mechanisms; nitric oxide production, anti-inflammatory, anti-apoptotic, and immune stimulator.

The Effects of Probiotics on Small Intestinal Microbiota Composition, Inflammatory Cytokines and Intestinal Permeability in Patients with Non-Alcoholic Fatty Liver Disease

The prevalence of non-alcoholic fatty liver disease (NAFLD) has soared globally. As our understanding of the disease grows, the role of the gut-liver axis (GLA) in NAFLD pathophysiology becomes more apparent. Hence, we focused mainly on the small intestinal area to explore the role of GLA. We looked at how multi-strain probiotics (MCP^® BCMC^® strains) containing six different Lactobacillus and Bifidobacterium species affected the small intestinal gut microbiota, inflammatory cytokines, and permeability in NAFLD patients. After six months of supplementation, biochemical blood analysis did not show any discernible alterations in either group. Five predominant phyla known as Actinobacteria, Proteobacteria, Firmicutes, Bacteroidota and Fusobacteria were found in NAFLD patients. The probiotics group demonstrated a significant cluster formation of microbiota composition through beta-diversity analysis (p < 0.05). This group significantly reduced three unclassifiable species: unclassified_Proteobacteria, unclassified_Streptococcus, and unclassified_Stenotrophomonas. In contrast, the placebo group showed a significant increase in Prevotella_melaninogenica and Rothia_mucilaginosa, which were classified as pathogens. Real-time quantitative PCR analysis of small intestinal mucosal inflammatory cytokines revealed a significant decrease in IFN-γ (-7.9 ± 0.44, p < 0.0001) and TNF-α (-0.96 ± 0.25, p < 0.0033) in the probiotics group but an increase in IL-6 (12.79 ± 2.24, p < 0.0001). In terms of small intestinal permeability analysis, the probiotics group, unfortunately, did not show any positive changes through ELISA analysis. Both probiotics and placebo groups exhibited a significant increase in the level of circulating zonulin (probiotics: 107.6 ng/mL ± 124.7, p = 0.005 vs. placebo: 106.9 ng/mL ± 101.3, p = 0.0002) and a significant decrease in circulating zonula occluden-1 (ZO-1) (probiotics: -34.51 ng/mL ± 18.38, p < 0.0001 vs. placebo: -33.34 ng/mL ± 16.62, p = 0.0001). The consumption of Lactobacillus and Bifidobacterium suggested the presence of a well-balanced gut microbiota composition. Probiotic supplementation improves dysbiosis in NAFLD patients. This eventually stabilised the expression of inflammatory cytokines and mucosal immune function. To summarise, more research on probiotic supplementation as a supplement to a healthy diet and lifestyle is required to address NAFLD and its underlying causes.

Current Evidence of Watermelon (Citrullus lanatus) Ingestion on Vascular Health: A Food Science and Technology Perspective

The amino acid L-arginine is crucial for nitric oxide (NO) synthesis, an important molecule regulating vascular tone. Considering that vascular dysfunction precedes cardiovascular disease, supplementation with precursors of NO synthesis (e.g., L-arginine) is warranted. However, supplementation of L-citrulline is recommended instead of L-arginine since most L-arginine is catabolized during its course to the endothelium. Given that L-citrulline, found mainly in watermelon, can be converted to L-arginine, watermelon supplementation seems to be effective in increasing plasma L-arginine and improving vascular function. Nonetheless, there are divergent findings when investigating the effect of watermelon supplementation on vascular function, which may be explained by the L-citrulline dose in watermelon products. In some instances, offering a sufficient amount of L-citrulline can be impaired by the greater volume (>700 mL) of watermelon needed to reach a proper dose of L-citrulline. Thus, food technology can be applied to reduce the watermelon volume and make supplementation more convenient. Therefore, this narrative review aims to discuss the current evidence showing the effects of watermelon ingestion on vascular health parameters, exploring the critical relevance of food technology for acceptable L-citrulline content in these products. Watermelon-derived L-citrulline appears as a supplementation that can improve vascular function, including arterial stiffness and blood pressure. Applying food technologies to concentrate bioactive compounds in a reduced volume is warranted so that its ingestion can be more convenient, improving the adherence of those who want to ingest watermelon products daily.

Circulating metabolite profile in young adulthood identifies long-term diabetes susceptibility: the Coronary Artery Risk Development in Young Adults (CARDIA) study

AIMS/HYPOTHESIS

The aim of this work was to define metabolic correlates and pathways of diabetes pathogenesis in young adults during a subclinical latent phase of diabetes development.

METHODS

We studied 2083 young adults of Black and White ethnicity in the prospective observational cohort Coronary Artery Risk Development in Young Adults (CARDIA) study (mean ± SD age 32.1 ± 3.6 years; 43.9% women; 42.7% Black; mean ± SD BMI 25.6 ± 4.9 kg/m2) and 1797 Framingham Heart Study (FHS) participants (mean ± SD age 54.7 ± 9.7 years; 52.1% women; mean ± SD BMI 27.4 ± 4.8 kg/m2), examining the association of comprehensive metabolite profiles with endophenotypes of diabetes susceptibility (adipose and muscle tissue phenotypes and systemic inflammation). Statistical learning techniques and Cox regression were used to identify metabolite signatures of incident diabetes over a median of nearly two decades of follow-up across both cohorts.

RESULTS

We identified known and novel metabolites associated with endophenotypes that delineate the complex pathophysiological architecture of diabetes, spanning mechanisms of muscle insulin resistance, inflammatory lipid signalling and beta cell metabolism (e.g. bioactive lipids, amino acids and microbe- and diet-derived metabolites). Integrating endophenotypes of diabetes susceptibility with the metabolome generated two multi-parametric metabolite scores, one of which (a proinflammatory adiposity score) was associated with incident diabetes across the life course in participants from both the CARDIA study (young adults; HR in a fully adjusted model 2.10 [95% CI 1.72, 2.55], p<0.0001) and FHS (middle-aged and older adults; HR 1.33 [95% CI 1.14, 1.56], p=0.0004). A metabolite score based on the outcome of diabetes was strongly related to diabetes in CARDIA study participants (fully adjusted HR 3.41 [95% CI 2.85, 4.07], p<0.0001) but not in the older FHS population (HR 1.15 [95% CI 0.99, 1.33], p=0.07).

CONCLUSIONS/INTERPRETATION

Selected metabolic abnormalities in young adulthood identify individuals with heightened diabetes risk independent of race, sex and traditional diabetes risk factors. These signatures replicate across the life course.

Identification of Small Molecules of the Infective Stage of Human Hookworm Using LCMS-Based Metabolomics and Lipidomics Protocols

Hookworm infections affect millions of people worldwide and are responsible for impaired mental and physical growth in children, and anemias. There is no vaccine, and increasing anthelmintic drug resistance in nematodes of domestic animals, and reduced drug cure rates in nematode infections of humans is alarming. Despite this looming health problem, there is a significant knowledge gap in terms of nonproteinaceous "excretory/secretory products" (ESPs) and how they orchestrate a parasitic existence. In the current study, we have conducted the first metabolomic and lipidomic analysis of the infective third-stage filariform larvae (L3) of the predominant human hookworm Necator americanus using liquid chromatography-mass spectrometry. Altogether, we have identified a total of 645 small molecules that were mainly produced through amino acid and glycerophospholipid metabolism. Putatively, 495 metabolites were unique to the somatic tissue extract, and 34 metabolites were present only in the ESP component. More than 21 novel mass features with nitrogen and sulfur functional groups were detected in the ESP component for the first time from helminths. While this study could not establish the biological functions of the metabolites identified, literature searches revealed that these metabolites possess various biological properties, including anti-inflammatory activities. These metabolites are likely used by the parasite upon exposure to a host to facilitate skin penetration, passage through different tissues, and immune regulation in the small bowel. Overall, the results presented herein offer significant insight into the metabolome of N. americanus L3 and have the potential to instigate future work to establish biomarkers of infection. This area urgently needs attention, given the lack of sensitive point-of-care diagnostic tools.

Intermittent hypoxia aggravates non-alcoholic fatty liver disease via RIPK3-dependent necroptosis-modulated Nrf2/NFκB signaling pathway

AIMS

Hepatocyte necroptosis is a critical event in the progression of non-alcoholic fatty liver disease (NAFLD). Obstructive sleep apnea hypopnea syndrome (OSAHS) and chronic intermittent hypoxia (CIH) may be linked with the pathogenesis and the severity of NAFLD. However, the potential role of necroptosis in OSAHS-associated NAFLD has not been evaluated. The present study investigated whether IH could affect NAFLD progression through promoting receptor-interacting protein kinase-3 (RIPK3)-dependent necroptosis, oxidative stress, and inflammatory response, and further elucidated the underlying molecular mechanisms.

MAIN METHODS

LO2 cells were treated with palmitic acid (PA) and subjected to IH, and necroptosis, oxidative stress, and inflammation were assessed. The high-fat choline-deficient (HFCD)-fed mouse model was also used to assess the effects of CIH in experimental NAFLD in vivo.

KEY FINDINGS

In this study, we found that RIPK3-mediated necroptosis was activated both in the PA plus IH-treated LO2 cells and liver of HFCD/CIH mice, and which could trigger oxidative stress and inflammatory response by decreasing Nrf2 and increasing p-P65. RIPK3 downregulation significantly reduced hepatocyte necroptosis, and ameliorated oxidative stress and inflammation through modulating Nrf2/NFκB pathway in vitro and vivo. Similarly, pretreatment with TBHQ, an activator of Nrf2, effectively blocked the generation of oxidative productions and inflammatory cytokines. In addition, RIPK3 inhibitor GSK-872 or TBHQ administration obviously alleviated hepatic injury, including histology, transaminase activities, and triglyceride contents in vivo.

SIGNIFICANCE

IH aggravates NAFLD via RIPK3-dependent necroptosis-modulated Nrf2/NFκB signaling pathway, and which should be considered as a potential therapeutic strategy for the treatment of NAFLD with OSASH.

Citrulline, Biomarker of Enterocyte Functional Mass and Dietary Supplement. Metabolism, Transport, and Current Evidence for Clinical Use

L-Citrulline is a non-essential but still important amino acid that is released from enterocytes. Because plasma levels are reduced in case of impaired intestinal function, it has become a biomarker to monitor intestinal integrity. Moreover, oxidative stress induces protein citrullination, and antibodies against anti-citrullinated proteins are useful to monitor rheumatoid diseases. Citrullinated histones, however, may even predict a worse outcome in cancer patients. Supplementation of citrulline is better tolerated compared to arginine and might be useful to slightly improve muscle strength or protein balance. The following article shall provide an overview of L-citrulline properties and functions, as well as the current evidence for its use as a biomarker or as a therapeutic supplement.

Serum metabolomics of Bama miniature pigs bitten by Bungarus multicinctus

Bungarus multicinctus is one of the top ten venomous snakes in China, and its bite causes acute and severe diseases, but its pathophysiology remains poorly elucidated. Thus, an animal model of Bungarus multicinctus bite was established by intramuscular injection of 30μg/kg of Bungarus multicinctus venom, and then the serum metabolites were subsequently screened, identified and validated by ultra-performance liquid chromatography-quadrupole-time of flight-mass spectrometry (UPLC-Q-TOF-MS) methods to explore the potential biomakers and possible metabolic pathways. Untargeted metabolomics analysis showed that 36 and 38 endogenous metabolites levels changed in ESI+ and ESI-, respectively, KEGG pathway analysis showed that 5 metabolic pathways, including mineral absorption, central carbon metabolism in cancer, protein digestion and absorption, aminoacyl-tRNA biosynthesis and ABC transporters might be closely related to Bungarus multicinctus bite. Targeted metabolomics analysis showed that there were significant differences in serum D-proline, L-leucine and L-glutamine after Bungarus multicinctus bite (P < 0.05). In addition, receiver operating characteristic (ROC) analysis showed that the diagnostic efficiency of L-Glutamine was superior to other potential biomarkers and the AUC value was 0.944. Moreover, we found evidence for differences in the pathophysiology of glutamine between Bungarus multicinctus bite group and normal group, specifically with the content of glutamine synthetase (GS) and glutaminase (GLS). Taken together, the current study has successfully established an animal model of Bungarus multicinctus bite, and further identified the links between the metabolic perturbations and the pathophysiology and the potential diagnostic biomakers of Bungarus multicinctus bite, which provided valuable insights for studying the mechanism of Bungarus multicinctus bite.

The impact of L-citrulline supplementation on glucose homeostasis, lipid profile, and some inflammatory factors in overweight and obese patients with type 2 diabetes: A double-blind randomized placebo-controlled trial

This study investigated the impact of L-citrulline on glucose homeostasis, lipid profile, and inflammatory factors in overweight and obese patients with type 2 diabetes (T2D). In total, 54 participants with T2D were assigned to L-citrulline (3 g/day L-citrulline) or placebo groups and tested for 8 weeks. Serum levels of insulin, fasting glucose, hemoglobin A1c (HbA1c), lipid profile, tumor necrosis factor-α (TNF-α), high-sensitivity C-reactive protein (hs-CRP), and L-citrulline were measured pre- and post-intervention. Totally, 45 patients were enrolled in the research. L-citrulline supplementation decreased serum levels of insulin (p = .025), glucose (p = .032), HbA1c (p = .001), HOMA-IR (p = .037), TNF-α (p = .036), and hs-CRP (p = .027) significantly. At the end of the study, despite the significant decrease in serum levels of triglyceride (p = .027) and the increase in high-density lipoprotein cholesterol levels (p < .001) in the L-citrulline group, no significant differences were found for these parameters between the groups. Moreover, no significant inter- and intra-group changes were observed for dietary intakes, anthropometric indices, total and low-density lipoprotein cholesterol levels (p > .05). In conclusion, L-citrulline supplementation might improve glucose homeostasis, some lipid factors and inflammatory markers in overweight and obese patients with T2D.

Metabolomes and Lipidomes of the Infective Stages of the Gastrointestinal nematodes, Nippostrongylus brasiliensis and Trichuris muris

Soil-transmitted helminths, including hookworms and whipworms, infect billions of people worldwide. Their capacity to penetrate and migrate through their hosts’ tissues is influenced by the suite of molecules produced by the infective developmental stages. To facilitate a better understanding of the immunobiology and pathogenicity of human hookworms and whipworms, we investigated the metabolomes of the infective stage of Nippostrongylus brasiliensis third-stage larvae (L3) which penetrate the skin and Trichuris muris eggs which are orally ingested, using untargeted liquid chromatography-mass spectrometry (LC-MS). We identified 55 polar metabolites through Metabolomics Standard Initiative level-1 (MSI-I) identification from N. brasiliensis and T. muris infective stages, out of which seven were unique to excretory/secretory products (ESPs) of N. brasiliensis L3. Amino acids were a principal constituent (33 amino acids). Additionally, we identified 350 putative lipids, out of which 28 (all known lipids) were unique to N. brasiliensis L3 somatic extract and four to T. muris embryonated egg somatic extract. Glycerophospholipids and glycerolipids were the major lipid groups. The catalogue of metabolites identified in this study shed light on the biology, and possible therapeutic and diagnostic targets for the treatment of these critical infectious pathogens. Moreover, with the growing body of literature on the therapeutic utility of helminth ESPs for treating inflammatory diseases, a role for metabolites is likely but has received little attention thus far.

Chicoric Acid Ameliorates Nonalcoholic Fatty Liver Disease via the AMPK/Nrf2/NFκB Signaling Pathway and Restores Gut Microbiota in High-Fat-Diet-Fed Mice

This study examines the effects of chicoric acid (CA) on nonalcoholic fatty liver disease (NAFLD) in high-fat-diet- (HFD-) fed C57BL/6 mice. CA treatment decreased body weight and white adipose weight, mitigated hyperglycemia and dyslipidemia, and reduced hepatic steatosis in HFD-fed mice. Moreover, CA treatment reversed HFD-induced oxidative stress and inflammation both systemically and locally in the liver, evidenced by the decreased serum malondialdehyde (MDA) abundance, increased serum superoxide dismutase (SOD) activity, lowered in situ reactive oxygen species (ROS) in the liver, decreased serum and hepatic inflammatory cytokine levels, and reduced hepatic inflammatory cell infiltration in HFD-fed mice. In addition, CA significantly reduced lipid accumulation and oxidative stress in palmitic acid- (PA-) treated HepG2 cells. In particular, we identified AMPK as an activator of Nrf2 and an inactivator of NFκB. CA upregulated AMPK phosphorylation, the nuclear protein level of Nrf2, and downregulated NFκB protein level both in HFD mice and PA-treated HepG2 cells. Notably, AMPK inhibitor compound C blocked the regulation of Nrf2 and NFκB, as well as ROS overproduction mediated by CA in PA-treated HepG2 cells, while AMPK activator AICAR mimicked the effects of CA. Similarly, Nrf2 inhibitor ML385 partly blocked the regulation of antioxidative genes and ROS overproduction by CA in PA-treated HepG2 cells. Interestingly, high-throughput pyrosequencing of 16S rRNA suggested that CA could increase Firmicutes-to-Bacteroidetes ratio and modify gut microbial composition towards a healthier microbial profile. In summary, CA plays a preventative role in the amelioration of oxidative stress and inflammation via the AMPK/Nrf2/NFκB signaling pathway and shapes gut microbiota in HFD-induced NAFLD.

Effect of ginger (Zingiber officinale) on inflammatory markers: A systematic review and meta-analysis of randomized controlled trials

The aim of this systematic review and meta-analysis was to investigate the efficacy of ginger supplementation on circulating levels of C-reactive protein (CRP), high sensitivity C-reactive protein (hs-CRP), tumor necrosis factor-alpha (TNF-α), soluble intercellular adhesion molecule (sICAM), and interleukin-6 (IL-6) concentrations in randomized controlled trials (RCTs). The search included PubMed-Medline, EMBASE, Scopus, Web of Science and Cochrane Library databases to identify randomized clinical trials on the effect of ginger supplementation on circulation levels of CRP, hs-CRP, IL-6, sICAM, and TNF-α published up until February 1st, 2020. We did not restrict articles based on language of publication. Standard mean differences and 95% confidence intervals were calculated for net changes in inflammatory mediators using a random-effects model. Sixteen RCTs comprising 1010 participants were found to be eligible for this meta-analysis. There was a significant reduction of circulating CRP (SMD: -5.11, 95% CI: -7.91, -2.30, I2 = 98.1%), hs-CRP (SMD: -0.88, 95% CI: -1.63, -0.12, I2 = 90.8%) and TNF-α levels (SMD: -0.85, 95% CI: -1.48, -0.21, I2 = 89.4%) following ginger supplementation. However, meta-analysis results did not show any significant impact of ginger supplementation on IL-6 (SMD: -0.45, 95% CI: -1.29, 0.38, I2 = 89.2%), and sICAM levels (SMD: -0.05, 95% CI: -0.36, 0.26, I2 = 00.0%). This systematic review and meta-analysis of RCTs demonstrates a significant impact of ginger in lowering circulating CRP, hs-CRP and TNF-α levels. Large-scale RCTs are still needed to draw concrete conclusions about the effect of ginger on other inflammatory mediators.

Oxidant-induced modifications in the mucosal transcriptome and circulating metabolome of Atlantic salmon

Here we report the molecular networks associated with the mucosal and systemic responses to peracetic acid (PAA), a candidate oxidative chemotherapeutic in Atlantic salmon (Salmo salar). Smolts were exposed to different therapeutic doses (0, 0.6 and 2.4 mg/L) of PAA for 5 min, followed by a re-exposure to the same concentrations for 30 min 2 weeks later. PAA-exposed groups have higher external welfare score alterations, especially 2 weeks after the re-exposure. Cases of fin damage and scale loss were prevalent in the PAA-exposed groups. Transcriptomic profiling of mucosal tissues revealed that the skin had 12.5 % more differentially regulated genes (DEGs) than the gills following PAA exposure. The largest cluster of DEGs, both in the skin and gills, were involved in tissue extracellular matrix and metabolism. There were 22 DEGs common to both mucosal tissues, which were represented primarily by genes involved in the biophysical integrity of the mucosal barrier, including cadherin, collagen I α 2 chain, mucin-2 and spondin 1a. The absence of significant clustering in the plasma metabolomes amongst the three treatment groups indicates that PAA treatment did not induce any global metabolomic disturbances. Nonetheless, five metabolites with known functions during oxidative stress were remarkably affected by PAA treatments such as citrulline, histidine, tryptophan, methionine and trans-4-hydroxyproline. Collectively, these results indicate that salmon were able to mount mucosal and systemic adaptive responses to therapeutic doses of PAA and that the molecules identified are potential markers for assessing the health and welfare consequences of oxidant exposure.

The effects of omega-3 fatty acid supplementation on inflammatory factors in HIV-infected patients: A systematic review and meta-analysis of randomized clinical trials

High concentrations of C-reactive protein (CRP) and inflammatory markers are common in human immunodeficiency virus (HIV)-infected patients and are associated with non-HIV related comorbidity and mortality. Data on the benefits of omega-3 fatty acid (omega-3 FA) supplementation for improving inflammation status in HIV-infected patients are controversial. Thus, we conducted a systematic review and meta-analysis on the beneficial effects of omega-3 FAs on controlling inflammation in HIV-infected patients. We conducted a comprehensive search of the major biomedical databases, including PubMed, EMBASE, Scopus, Web of Science and Cochrane library, for all potentially relevant studies published without restriction from the beginning of time to June 2020. Overall, nine RCTs were included comprising a total of 427 participants. A random-effects model was used to calculate 95% confidence intervals (CI) and the effect was measured as standardized mean difference (SMD). Supplementation of omega-3 FAs showed a significant reduction of CRP (SMD: -0.27, 95% CI: -0.48 to -0.07, P = 0.007). There was no significant difference in levels of TNF-α (SMD: 0.03, 95% CI: -0.79 to 0.85, P = 0.94, I² = 87%) and IL-6 (SMD: -0.13, 95% CI: -0.59 to 0.32, P = 0.57, I² = 73%, Fig. 3). The results indicate that the supplementation of omega-3 FAs in HIV-infected patients significantly decreases serum CRP levels when compared to the control group, however has no significant effect on IL-6 and TNF-α levels.

Coenzyme Q10 supplementation and oxidative stress parameters: a systematic review and meta-analysis of clinical trials

PURPOSE

Oxidative stress (OS) is associated with several chronic complications and diseases. The use of coenzyme Q10 (CoQ10) as an adjuvant treatment with routine clinical therapy against metabolic diseases has shown to be beneficial. However, the impact of CoQ10 as a preventive agent against OS has not been systematically investigated.

METHODS

A systematic literature search was performed using the PubMed, SCOPUS, EMBASE, and Cochrane Library databases to identify randomized clinical trials evaluating the efficacy of CoQ10 supplementation on OS parameters. Standard mean differences and 95% confidence intervals were calculated for net changes in OS parameters using a random-effects model.

RESULTS

Seventeen randomized clinical trials met the eligibility criteria to be included in the meta-analysis. Overall, CoQ10 supplementation was associated with a statistically significant decrease in malondialdehyde (MDA) (SMD - 0.94; 95% CI - 1.46, - 0.41; I² = 87.7%) and a significant increase in total antioxidant capacity (TAC) (SMD 0.67; 95% CI 0.28, 1.07; I² = 74.9%) and superoxide dismutase (SOD) activity (SMD 0.40; 95% CI 1.12, 0.67; I² = 9.6%). The meta-analysis found no statistically significant impact of CoQ10 supplementation on nitric oxide (NO) (SMD - 1.40; 95% CI - 0.12, 1.93; I² = 92.6%), glutathione (GSH) levels (SMD 0.41; 95% CI - 0.09, 0.91; I² = 70.0%), catalase (CAT) activity (SMD 0.36; 95% CI - 0.46, 1.18; I² = 90.0%), or glutathione peroxidase (GPx) activities (SMD - 1.40; 95% CI: - 0.12, 1.93; I² = 92.6%).

CONCLUSION

CoQ10 supplementation, in the tested range of doses, was shown to reduce MDA concentrations, and increase TAC and antioxidant defense system enzymes. However, there were no significant effects of CoQ10 on NO, GSH concentrations, or CAT activity.

Citrulline cooperatively exerts an anti-inflammatory effect on synovial cells with glucosamine and N-acetylglucosamine

The aim of the present study was to evaluate the anti-inflammatory effects of citrulline (Cit), glucosamine (GlcN) and N-acetylglucosamine (GlcNAc) on synovial cells, which are primarily involved in inflammatory joint diseases. The combined effect of Cit, GlcN and GlcNAc on synovial cell inflammation was assessed by measuring IL-1β-induced IL-6 production. GlcN and GlcNAc (0.5 mM each) alone did not suppress IL-6 production, whereas Cit (0.5 mM) did significantly suppress IL-6 production. Furthermore, the combined effect of Cit, GlcNAc and GlcN was examined; Cit + GlcN and Cit + GlcNAc significantly suppressed not only IL-6 production, but also phosphorylation of ERK1/2. Similarly, combination of GlcN + GlcNAc significantly suppressed IL-6 production and phosphorylation of ERK1/2. These observations suggest that among Cit, GlcNAc and GlcN, the combination of Cit with GlcN or GlcNAc exerts a synergistic anti-inflammatory effect on synovial cells, thereby possibly exhibiting chondroprotective effects and alleviating inflammatory joint diseases.