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Reactive arthritis (ReA) is an aseptic synovitis condition that often develops 2-4 weeks after a distant (extra-articular) infection with Chlamydia, Salmonella, Shigella, Campylobacter, and Yersinia species. The metabolic changes in the synovial fluid (SF) may serve as indicative markers to both improve the diagnostic accuracy and understand the underlying inflammatory pathology of ReA. With this aim, the metabolic profiles of SF collected from ReA (n = 58) and non-ReA, i.e., rheumatoid arthritis (RA, n = 21) and osteoarthritis (OA, n = 20) patients, respectively, were measured using NMR spectroscopy and compared using orthogonal partial least-squares discriminant analysis (OPLS-DA). The discriminatory metabolic features were further evaluated for their diagnostic potential using the receiver operating characteristic (ROC) curve analysis. Compared to RA, two (alanine and carnitine), and compared to OA, six (NAG, glutamate, glycerol, isoleucine, alanine, and glucose) metabolic features were identified as diagnostic biomarkers. We further demonstrated the impact of ReA synovitis condition on the serum metabolic profiles through performing a correlation analysis. The Pearson rank coefficient (r) was estimated for 38 metabolites (profiled in both SF and serum samples obtained in pair from ReA patients) and was found significantly positive for 71% of the metabolites (r ranging from 0.17 to 0.87).

Hepatic encephalopathy (HE) is a debilitating neuropsychiatric complication associated with acute and chronic liver failure. It is characterized by diverse symptoms with variable severity that includes cognitive and motor deficits. The aim of the study is to assess metabolic alterations in the brain and liver using nuclear magnetic resonance (NMR) spectroscopy and subsequent multivariate analyses to characterize metabolic signatures associated with HE. HE was developed by bile duct ligation (BDL) that resulted in hepatic dysfunctions and cirrhosis as shown by liver function tests. Metabolic profiles from control and BDL rats indicated increased levels of lactate, branched-chain amino acids (BCAAs), glutamate, and choline in the liver, whereas levels of glucose, phenylalanine, and pyridoxine were decreased. In brain, the levels of lactate, acetate, succinate, citrate, and malate were increased, while glucose, creatine, isoleucine, leucine, and proline levels were decreased. Furthermore, neurotransmitters such as glutamate and GABA were increased, whereas choline and myo-inositol were decreased. The alterations in neurotransmitter levels resulted in cognitive and motor defects in BDL rats. A significant correlation was found among alterations in NAA/choline, choline/creatine, and NAA/creatine with behavioral deficits. Thus, the data suggests impairment in metabolic pathways such as the tricarboxylic acid (TCA) cycle, glycolysis, and ketogenesis in the liver and brain of animals with HE. The study highlights that metabolic signatures could be potential markers to monitor HE progression and to assess therapeutic interventions.

Spondyloarthritis (SpA) is an umbrella term for autoimmune rheumatic diseases that can affect the back, pelvis, neck and some larger joints, as well as internal organs, like the intestines and eyes. The most common of these diseases is ankylosing spondylitis (ASp) which predominantly affects the spine and sacroiliac joints causing characteristic inflammatory back pain (IBP) and severe spine stiffness. In addition, AsP may involve peripheral joints causing asymmetrical peripheral oligo-arthritis often associated with extra-articular symptoms such as acute anterior uveitis (iritis), psoriasis, enthesitis, dactylitis and chronic inflammatory bowel disease (IBD). These clinical features adversely affect the quality of life in ASp patients owing to restricted spinal/hip mobility, pain, fatigue, disease flares and depression. The clinical management of SpA is marred by delay in diagnosis, and paucity of biomarkers of disease activity. The present study aimed to explore the potential of serum metabolic profiling of patients with SpA to identify biomarker for the diagnosis and assessment of disease activity. The serum metabolic profiles of 81 patients with SpA were compared with that of 86 healthy controls (HC) using nuclear magnetic resonance (NMR) based metabolomics approach. Seventeen patients were followed-up after 3 months of standard treatment and paired sera were analyzed for effects of therapy. Comparisons were done using the multivariate partial least-squares discriminant analysis (PLS-DA) and the discriminatory metabolic entities were identified based on variable importance in projection (VIP) statistics and further evaluated for statistical significance (p-value

Peripheral nerves have the capacity for regeneration, but the rate of regeneration is so slow that many nerve injuries lead to incomplete recovery and permanent disability for patients. Macrophages play a critical role in the peripheral nerve response to injury, contributing to both Wallerian degeneration and nerve regeneration, and their function has recently been shown to be dependent on intracellular metabolism. To date, the impact of their intracellular metabolism on peripheral nerve regeneration has not been studied. We examined conditional transgenic mice with selective ablation in macrophages of solute carrier family 16, member 1 (Slc16a1), which encodes monocarboxylate transporter 1 (MCT1), and found that MCT1 contributed to macrophage metabolism, phenotype, and function, specifically in regard to phagocytosis and peripheral nerve regeneration. Adoptive cell transfer of wild-type macrophages ameliorated the impaired nerve regeneration in macrophage-selective MCT1-null mice. We also developed a mouse model that overexpressed MCT1 in macrophages and found that peripheral nerves in these mice regenerated more rapidly than in control mice. Our study provides further evidence that MCT1 has an important biological role in macrophages and that manipulations of macrophage metabolism can enhance recovery from peripheral nerve injuries, for which there are currently no approved medical therapies.

Background Diabetes is among the most prevalent diseases worldwide, of all the affected individuals a significant proportion of the population remains undiagnosed due to lack of specific symptoms early in this disorder and inadequate diagnostics. Diabetes and its associated sequela, i.e., comorbidity are associated with microvascular and macrovascular complications. As diabetes is characterized by an altered metabolism of key metabolites and regulatory pathways. Metabolic phenotyping can provide us with a better understanding of the unique set of regulatory perturbations that predispose to diabetes and its associated complication/comorbidities. Methodology The present study utilizes the analytical platform NMR spectroscopy coupled with Random Forest statistical analysis to identify the discriminatory metabolites in diabetes (DB = 38) vs. diabetes-related complication (DC = 35) along with the healthy control (HC = 50) subjects. A combined and pairwise analysis was performed to identify the discriminatory metabolites responsible for class separation. The perturbed metabolites were further rigorously validated using t-test, AUROC analysis to examine the statistical significance of the identified metabolites. Results The DB and DC patients were well discriminated from HC. However, 15 metabolites were found to be significantly perturbed in DC patients compared to DB, the identified panel of metabolites are TCA cycle (succinate, citrate), methylamine metabolism (trimethylamine, methylamine, betaine), -intermediates; energy metabolites (glucose, lactate, pyruvate); and amino acids (valine, arginine, glutamate, methionine, proline, and threonine). Conclusion The 1H NMR metabolomics may prove a promising technique to differentiate and predict diabetes and its complication on their onset or progression by determining the altered levels of the metabolites in serum.

The pathogenesis of the diabetic foot ulcer (DFU) is very complex. Among other known factors, such as poor innervation and vascularization, chronic infection and inflammation are critical factors that result in chronicity of these wounds. Novel and emerging concepts in chronic infection and inflammatory response are discussed in this chapter. Lack of adequate solutions for treatment of chronic wound infections such as antibiotic resistant and biofilm infections may result in serious consequences, including poor quality of life and amputations in patients with diabetes. Novel solutions that can counter these threats are urgently needed. A thorough understanding of the principles of immune dysfunction and insufficient resolution of inflammation will lead to innovative interventions that can drive a diabetic wound towards resolution of inflammation, which is conducive to healing.

Ethnopharmacological relevance Ficus racemosa (FR) has been used for thousands of years in Ayurvedic system of medicine in India and is closely associated with prevention, treatment and cure of various human ailments like obesity and diabetes. It is popularly known as gular. A vast and wide range of chemical compounds like polyphenols, friedelane-type triterpenes, norfriedelane type triterpene, eudesmane-type sesquiterpene including various glycosides had been isolated from this plant. However, no detail studies related to isolation of flavonoids has been reported previously with their antidiabetic, hypolipidemic and toxicological consequences. Aim of the study The present study was undertaken to evaluate antidiabetic, hypolipidemic and toxicological assessments of flavonoids isolated from Ficus racemosa (FR) stem bark. Materials and methods We isolated four flavonoids from stem bark of FR and structures were confirmed by Infrared spectroscopy (IR), Nuclear Magnetic Resonance (NMR) (both 1D and 2D), mass spectroscopy (MS). Later, these flavonoids were administered to streptozotocin (STZ) rats once in a day for a period of seven days at 100 mg/kg dose. We measured blood glucose level and body weight changes at different days (1st, 3rd, 5th and 7th days). Serum lipid profiles were also estimated to investigate the hypolipidemic potential of flavonoids in the similar experiment. Various oxidative stress parameters in pancreas and liver and hepatic biomarker enzymes in plasma were also determined to investigate the toxicity potential of isolated flavonoids. Finally, we performed docking studies to find out the mechanism of action. Results Our results collectively suggested that four flavonoids reduced blood glucose level and restored body weight, signifying antidiabetic action. There were reduction of other lipid profile parameters and increase of high density lipoprotein (HDL) during administration of flavonoids, also signifying hypolipidemic action. Various oxidative stress biomarkers and hepatic enzymes levels were also normalized with respect to diabetic control at the same time. Docking studies revealed that isolated flavonoids showed their antidiabetic potential via binding to PPARγ and GLUT1 receptors. Conclusion The isolated four flavonoids demonstrated good antidiabetic, hypolipidemic and antioxidant properties in STZ diabetic rats which supported the use of FR stem bark as useful supplementary drug for future antidiabetic therapy.

Background: Diabetes is among the most prevalent diseases worldwide, of all the affected individuals a significant proportion of the population remains undiagnosed because of a lack of specific symptoms early in this disorder and inadequate diagnostics. Diabetes and its associated sequela, i.e., comorbidity are associated with microvascular and macrovascular complications. As diabetes is characterized by an altered metabolism of key metabolites and regulatory pathways. Metabolic phenotyping can provide us with a better understanding of the unique set of regulatory perturbations that predispose to diabetes and its associated comorbidities. Methodology: The present study utilizes the analytical platform NMR spectroscopy coupled with Random Forest statistical analysis to identify the discriminatory metabolites of diabetes (DB) and diabetes-related comorbidity (DC) along with the healthy control (HC) subjects. A combined and pairwise analysis was performed, between the serum samples of HC (n=50), and DB (n=38), and DC (n=35) individuals to identify the discriminatory metabolites responsible for class separation. The perturbed metabolites were further rigorously validated using t-test, AUROC analysis to examine the statistical significance of the identified metabolites. Results: The DB and DC patients were well discriminated from HC. However, 15 metabolites were found to be significantly perturbed in DC patients compared to DB, the identified panel of metabolites are TCA cycle (succinate, citrate), methylamine metabolism (trimethylamine, methylamine, betaine), -intermediates; energy metabolites (glucose, lactate, pyruvate); and amino acids (valine, arginine, glutamate, methionine, proline and threonine). The metabolites were further used to identify the perturbed metabolic pathway and correlation of metabolites in DC patients. Conclusion: The 1H NMR metabolomics may prove a promising technique to differentiate and predict diabetes and its comorbidities on their onset or progression by determining the altered levels of the metabolites in serum.

Takayasu arteritis (TA) is a debilitating, systemic disease that involves the aorta and large arteries in a chronic inflammatory process that leads to vessel stenosis. Initially, the disease remains clinically silent (or remains undetected) until the patients present with vascular occlusion. Therefore, new methods for appropriate and timely diagnosis of TA cases are needed to start proper therapy on time and also to monitor the patient's response to the given treatment. In this context, NMR-based serum metabolomic profiling has been explored in this proof-of-principle study for the first time to determine characteristic metabolites that could be potentially helpful for diagnosis and prognosis of TA. Serum metabolic profiling of TA patients (n = 29) and healthy controls (n = 30) was performed using 1D (1)H NMR spectroscopy, and possible biomarker metabolites were identified. Using projection to least-squares discriminant analysis, we could distinguish TA patients from healthy controls. Compared to healthy controls, TA patients had (a) increased serum levels of choline metabolites, LDL cholesterol, N-acetyl glycoproteins (NAGs), and glucose and (b) decreased serum levels of lactate, lipids, HDL cholesterol, and glucogenic amino acids. The results of this study are preliminary and need to be confirmed in a prospective study.

Background There is an unmet need for biomarkers in Systemic Sclerosis (SSc). Despite its shortcomings, the modified Rodnan skin score (mRSS) has remained the standard disease assessment tool for SSc. Expression of certain genes, cartilage oligomeric matrix protein ( COMP ), thrombospondin-1 ( THS1 ), interferon-induced 44 ( IFI44 ) and sialoadhesin ( SIG1 ), and, more recently, Tenascin-C ( TNSC ), have been shown to correlate with skin fibrosis. However, assessment of the expression of these genes requires a skin biopsy. Hence, we used an open-ended approach to identify a serum-based biomarker of SSc. Objectives To identify small molecules in serum that correlate with mRSS and profibrotic genes that are upregulated in skin of SSc patients Methods We obtained serum and skin biopsies from 25 consenting adult patients with SSc and serum from 25 age- and sex-similar controls. mRNA levels of five genes: COMP , THS1 , IFI44 , SIG1 , and TNSC were estimated as fold-change relative to Glyceraldehyde 3-phosphate dehydrogenase ( GAPDH) , a housekeeping gene. H 1 NMR (Nuclear Magnetic Resonance) based metabolomics studies were performed on the sera using standard protocols. Principal component analysis (PCoA) and Partial Least Squares Discriminant Analysis (PLSDA) were used to delineate metabolites that were different between patients and healthy controls. Then spearman correlations (ρ) of these metabolites with mRSS and the fold-expression of the five pro-fibrotic genes were estimated. Results H 1 NMR based metabolomics identified 126 peaks that were different between patients and controls. Out of these, the levels of glycine had the best correlation with pro-fibrotic gene expression (ρ=0.5, p IFI44 ; ρ=0.44, p TNSC ). Choline inversely correlated with SIG1 (ρ=-0.41; p=0.05) while Glycerophosphocholine correlated with mRSS (ρ=0.50, p Conclusions H 1 NMR based metabolomics identified glycine, choline and their metabolites as potential biomarkers for skin fibrosis in SSc. These findings require validation in a larger cohort. References Farina G, Lafyatis D, Lemaire R, Lafyatis R. A four-gene biomarker predicts skin disease in patients with diffuse cutaneous systemic sclerosis. Arthritis Rheum. 2010 Feb;62(2):580–8. Bhattacharyya S, Wang W, Morales-Nebreda L, Feng G, Wu M, Zhou X, Lafyatis R, Lee J, Hinchcliff M, Feghali-Bostwick C, Lakota K, Budinger GR, Raparia K, Tamaki Z, Varga J.Tenascin-C drives persistence of organ fibrosis. Nat Commun. 2016 Jun 3;7:11703. Disclosure of Interest None declared

Pyrazinamide (PYZ)-an essential component of primary drug regimen used for the treatment and management of multidrug resistant or latent tuberculosis-is well known for its hepatoxicity. However, the mechanism of PYZ-induced hepatotoxicity is still unknown to researchers. Studies have shown that the drug is metabolized in the liver to pyrazinoic acid (PA) and 5-hydroxy pyrazinoic acid (5-OHPA) which individually may cause different degrees of hepatotoxicity. To evaluate this hypothesis, PYZ, PA, and 5-OHPA were administered to albino Wistar rats orally (respectively, at 250, 125, and 125 mg kg-1 for 28 days). Compared to normal rats, PYZ and its metabolic products decreased the weights of dosed rats and induced liver injury and a status of oxidative stress as assessed by combined histopathological and biochemical analysis. Compared to normal controls, the biochemical and morphological changes were more aberrant in PA- and 5-OHPA-dosed rats with respect to those dosed with PYZ. Finally, the serum metabolic profiles of rats dosed with PYZ, PA, and 5-OHPA were measured and compared with those of normal control rats. With respect to normal control rats, the rats dosed with PYZ and 5-OHPA showed most aberrant metabolic perturbations in their sera as compared to those dosed with PA. Altogether, the study suggests that PYZ-induced hepatotoxicity might be associated with its metabolized products, where 5-OHPA contributes to a higher degree in its overall toxicity than PA.

Aim: 6,7-dimethoxy-1,2,3,4-tetrahydro-isoquinoline-3-carboxylic acid (M1) was synthesized and evaluated for in-vivo antiproliferative action in diethylnitrosamine-induced hepatocarcinogenic rats. Materials & methods: The antiproliferative effect of M1 was assessed by various biochemical parameters, histopathology of liver and HPLC analysis. Proton nuclear magnetic resonance-based serum metabolic study was implemented on rat sera to explore the effects of M1 on hepatocellular carcinoma-induced metabolic alterations. Results: M1 showed protective action on liver and restored the arrangement of liver tissues in normal proportion. HPLC analysis displayed a good plasma drug concentration after its oral administration. Score plots of partial least squares discriminate analysis models exhibited that M1 therapy ameliorated hepatocellular carcinoma-induced metabolic alterations which signified its antiproliferative potential. Conclusion: M1 manifested notable antiproliferative profile, and warrants further investigation for future anticancer therapy., Lay abstract: Our previous study unveiled that an isoquinoline alkaloid (M1) isolated from Mucuna pruriens seeds had potent antiproliferative action on human hepatoma cells in vitro. In the present investigation we synthesized M1 and studied its in vivo antiproliferative effects in liver carcinogenic rats. To observe the effects of M1, various studies were conducted which include biochemical parameters of plasma and serum, histopathology of liver and HPLC analysis of plasma. In addition, 1H-NMR-based serum metabolic profiling was carried out to identify the effects of M1 on hepatocellular carcinoma-induced metabolic alterations. Our findings showed that compound M1 exemplifies remarkable efficacy against hepatocellular carcinoma.

Management of patient with Lupus Nephritis (LN) continues to remain a challenge for the treating physicians because of considerable morbidity and even mortality. The search of biomarkers in serum and urine is a focus of researchers to unravel new targets for therapy. In the present study, the utility of NMR-based serum metabolomics has been evaluated for the first time in discriminating LN patients from non-nephritis lupus patients (SLE) and further to get new insights into the underlying disease processes for better clinical management. Metabolic profiling of sera obtained from 22 SLE patients, 40 LN patients and 30 healthy controls (HC) were performed using high resolution 1D 1H-CPMG and diffusion edited NMR spectra to identify the potential molecular biomarkers. Using multivariate analysis, we could distinguish SLE and LN patients from HC and LN from SLE patients. Compared to SLE patients, the LN patients had increased serum levels of lipid metabolites (including LDL/VLDL lipoproteins), creatinine and decreased levels of acetate. Our results revealed that metabolic markers especially lipids and acetate derived from NMR spectroscopy has high sensitivity and specificity to distinguish LN among SLE patients and has the potential to be a useful adjunctive tool in diagnosis and clinical management of LN.