Metabolomic discoveries for early diagnosis and traditional Chinese medicine efficacy in ischemic stroke

Ischemic stroke (IS), a devastating cerebrovascular accident, presents with high mortality and morbidity. Following IS onset, a cascade of pathological changes, including excitotoxicity, inflammatory damage, and blood-brain barrier disruption, significantly impacts prognosis. However, current clinical practices struggle with early diagnosis and identifying these alterations. Metabolomics, a powerful tool in systems biology, offers a promising avenue for uncovering early diagnostic biomarkers for IS. By analyzing dynamic metabolic profiles, metabolomics can not only aid in identifying early IS biomarkers but also evaluate Traditional Chinese Medicine (TCM) efficacy and explore its mechanisms of action in IS treatment. Animal studies demonstrate that TCM interventions modulate specific metabolite levels, potentially reflecting their therapeutic effects. Identifying relevant metabolites in cerebral ischemia patients holds immense potential for early diagnosis and improved outcomes. This review focuses on recent metabolomic discoveries of potential early diagnostic biomarkers for IS. We explore variations in metabolites observed across different ages, genders, disease severity, and stages. Additionally, the review examines how specific TCM extracts influence IS development through metabolic changes, potentially revealing their mechanisms of action. Finally, we emphasize the importance of integrating metabolomics with other omics approaches for a comprehensive understanding of IS pathophysiology and TCM efficacy, paving the way for precision medicine in IS management.

Blood and Brain Metabolites after Cerebral Ischemia

The study of an organism's response to cerebral ischemia at different levels is essential to understanding the mechanism of the injury and protection. A great interest is devoted to finding the links between quantitative metabolic changes and post-ischemic damage. This work aims to summarize the outcomes of the most studied metabolites in brain tissue-lactate, glutamine, GABA (4-aminobutyric acid), glutamate, and NAA (N-acetyl aspartate)-regarding their biological function in physiological conditions and their role after cerebral ischemia/reperfusion. We focused on ischemic damage and post-ischemic recovery in both experimental-including our results-as well as clinical studies. We discuss the role of blood glucose in view of the diverse impact of hyperglycemia, whether experimentally induced, caused by insulin resistance, or developed as a stress response to the cerebral ischemic event. Additionally, based on our and other studies, we analyze and critically discuss post-ischemic alterations in energy metabolites and the elevation of blood ketone bodies observed in the studies on rodents. To complete the schema, we discuss alterations in blood plasma circulating amino acids after cerebral ischemia. So far, no fundamental brain or blood metabolite(s) has been recognized as a relevant biological marker with the feasibility to determine the post-ischemic outcome or extent of ischemic damage. However, studies from our group on rats subjected to protective ischemic preconditioning showed that these animals did not develop post-ischemic hyperglycemia and manifested a decreased metabolic infringement and faster metabolomic recovery. The metabolomic approach is an additional tool for understanding damaging and/or restorative processes within the affected brain region reflected in the blood to uncover the response of the whole organism via interorgan metabolic communications to the stressful cerebral ischemic challenge.

Sex as a biological variable in determining the metabolic changes influencing acute ischemic stroke outcomes-Where is the data: A systematic review

Women continue to face a greater lifetime morbidity and mortality from stroke and have been shown to respond differently to stroke treatments compared to men. Since 2016, updated National Institutes of Health (NIH) policies require research studies to consider sex as a biological variable. However, the way in which this policy affects study design, analysis, and reporting is variable, with few studies performing and reporting a subgroup analysis based on biological sex. In acute ischemic stroke, the underlying biological explanation for sex-based differences in patient outcomes and response to treatments remains understudied. We performed a systematic review of preclinical and clinical research studies that explored sex differences in the metabolic response to acute ischemic stroke as it relates to neurological outcomes. Through a literature search in Ovid Medline, Embase, and Web of Science, 1,004 potential references were identified for screening. After abstract and full-text review, we identified only two studies which assessed metabolic response to acute ischemic stroke (within 72 h of last known well) and neurological outcome [Barthel Index, modified Rankin Scale (mRS) or an equivalent in preclinical models] and reported results based on biological sex. One article was a preclinical rat model and the other a clinical cohort study. In both studies, metabolites involved in amino acid metabolism, energy metabolism, fat metabolism, or oxidative stress were identified. We review these results and link to additional articles that use metabolomics to identify metabolites differentially expressed by sex or regulated based on stroke outcomes, but not both. The results of this systematic review should not only help identify targets in need of further investigation to improve the understanding of sex differences in the pathophysiology of acute ischemic stroke, but also highlight the critical need to expand the incorporation of sex as a biological variable in acute stroke research beyond simply including both sexes and reporting the proportion of males/females in each population studied.

Metabolomic Assessment of Acute Cholestatic Injuries Induced by Thioacetamide and by Bile Duct Ligation, and the Protective Effects of Huang-Lian-Jie-Du-Decoction

Huang-Lian-Jie-Du-Decoction, a traditional Chinese formula, has been reported to protect liver from various injuries. Two cholestasis models of rats induced by thioacetamide and by bile duct ligation were established and treated with Huang-Lian-Jie-Du-Decoction. Nuclear Magnetic Resonance-based urinary metabolic profiles were analyzed by orthogonal partial least squares discriminant analysis and univariate analysis to excavate differential metabolites associated with the injuries of the two models and the treatment effects of Huang-Lian-Jie-Du-Decoction. The two cholestatic models shared common metabolic features of excessive fatty acid oxidation, insufficient glutathione regeneration and disturbed gut flora, with specific characteristics of inhibited urea cycle and DNA damage in thioacetamide-intoxicated model, and perturbed Kreb's cycle and inhibited branched chain amino acid oxidation in bile duct ligation model. With good treatment effects, Huang-Lian-Jie-Du-Decoction could regain the balance of the disturbed metabolic status common in the two cholestasis injuries, e.g., unbalanced redox system and disturbed gut flora; and perturbed urea cycle in thioacetamide-intoxicated model and energy crisis (disturbed Kreb's cycle and oxidation of branched chain amino acid) in bile duct ligation model, respectively.

Pyrazinamide-induced hepatotoxicity and gender differences in rats as revealed by a 1H NMR based metabolomics approach

Pyrazinamide (PZA) is a well-known first line anti-tuberculosis drug used in combination with other drugs such as isoniazid and rifampicin. Unfortunately, PZA suffered from a high rate of hepatotoxicity and hyperuricemia, which has not been clearly elucidated, hindering its wide application for therapeutic purposes. The purpose of this investigation was to develop a model of rat sub-acute hepatotoxicity induced by PZA and to explore the affected metabolic pathways by a 1H NMR-based metabolomics approach complemented with histopathological analysis and clinical chemistry. Rats of both genders were administered with PZA by gavage at doses of 1.0 and 2.0 g kg-1 for 4 weeks. PZA decreased the weights of dosed rats and induced liver injury dose-dependently. The female rats were more sensitive to PZA induced damage. Orthogonal signal correction partial least-squares discriminant analysis (OSC-PLS-DA) of the NMR profiles of the rat liver and serum revealed that PZA produced a status of oxidative stress and disturbances in purine metabolism, energy metabolism and NAD+ metabolism in a gender-specific and dose-dependent manner. These findings could be helpful to clarify the mechanism of PZA-induced hepatotoxicity and hyperuricemia. This integrated metabolomics approach showcased its ability to characterize the global metabolic status of organisms, providing a powerful and feasible tool to probe drug induced toxicity or side effects.

1H NMR-based metabolomics study of liver damage induced by ginkgolic acid (15:1) in mice

Ginkgolic acid (15:1) is a major toxic component in extracts obtained from Ginkgo biloba (EGb) that has allergic and genotoxic effects. This study is the first to explore the hepatotoxicity of ginkgolic acid (15:1) using a NMR (nuclear magnetic resonance)-based metabolomics approach in combination with biochemistry assays. Mice were orally administered two doses of ginkgolic acid (15:1), and mouse livers and serum were then collected for NMR recordings and biochemical assays. The levels of activity of alanine aminotransferase (ALT) and glutamic aspartate transaminase (AST) observed in the ginkgolic acid (15:1)-treated mice suggested that it had induced severe liver damage. An orthogonal signal correction partial least-squares discriminant analysis (OSC-PLSDA) performed to determine the metabolomic profile of mouse liver tissues indicated that many metabolic disturbances, especially oxidative stress and purine metabolism, were induced by ginkgolic acid (15:1). A correlation network analysis combined with information related to structural similarities further confirmed that purine metabolism was disturbed by ginkgolic acid (15:1). This mechanism might represent the link between the antitumour activity and the liver injury-inducing effect of ginkgolic acid (15:1). A SUS (Shared and Unique Structure) plot suggested that a two-dose treatment of ginkgolic acid (15:1) had generally the same effect on metabolic variations but that its effects were dose-dependent, revealing some of the common features of ginkgolic acid (15:1) dosing. This integrated metabolomics approach helped us to characterise ginkgolic acid (15:1)-induced liver damage in mice.

Huang-Lian-Jie-Du decoction treated sepsis via regulating ERK and SRC/STAT3 pathways and ameliorating metabolic status

LPS disturbed the metabolomic profiles and activated the ERK and SRC/STAT3 signaling pathways of mice, and HLJDD exerted therapeutic effects on sepsis induced by LPS.