Ingestion of mannose ameliorates thioacetamide-induced intrahepatic oxidative stress, inflammation and fibrosis in rats

Identification of a novel biomarker for sarcopenia diagnosis using serum metabolomic analysis: a pilot study

PURPOSE

This pilot study compared serum metabolites in participants with and without sarcopenia.

METHODS

Metabolomic techniques were applied to identify serum metabolites and novel biomarkers specific to patients with sarcopenia. In accordance with AWGS2019 criteria, sarcopenia was defined as low muscle mass plus either low muscle strength/low physical function, and severe sarcopenia was defined as low muscle mass, low muscle strength, and low physical function all together.

RESULTS

The sarcopenia group had higher hypoxanthine, galactose, and mannose levels but lower triethanolamine and homogentisic acid levels than the non-sarcopenia group. The severe sarcopenia group had lower levels of alpha-tocopherol than the mild and moderate sarcopenia groups.

CONCLUSION

This study is the first to identify hypoxanthine as a potential biomarker for sarcopenia in humans and provides new insights into the pathophysiology of sarcopenia. Furthermore, the identified metabolites may be useful for the early detection of sarcopenia.

Hepatoprotective Effects of Biochanin A on Thioacetamide-Induced Liver Cirrhosis in Experimental Rats

The protective effect of biochanin A (BCA) on the histopathology, immunohistochemistry, and biochemistry of thioacetamide (TAA)-induced liver cirrhosis in vivo was investigated. There was a significant reduction in liver weight and hepatocyte propagation, with much lower cell injury in rat groups treated with BCA (25 mg/kg and 50 mg/kg) following a TAA induction. These groups had significantly lower levels of proliferating cell nuclear antigen (PCNA) and α-smooth muscle actin (α-SMA). The liver homogenates showed increased antioxidant enzyme activity of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), as well as decreased malondialdehyde (MDA) levels. The serum biomarkers associated with liver function, namely alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and gamma glutamyl transaminase (GGT), returned to normal levels, comparable to those observed in both the normal control group and the reference control group. Taken together, the normal microanatomy of hepatocytes, the inhibition of PCNA and α-SMA, improved antioxidant enzymes (SOD, CAT, and GPx), and condensed MDA with repairs of liver biomarkers validated BCA's hepatoprotective effect.

Biased Quantification of Rat Liver Fibrosis-Meta-Analysis with Practical Recommendations and Clinical Implications

For liver fibrosis assessment, the liver biopsy is usually stained with Masson's trichrome (MT) or picrosirius red (PSR) to quantify liver connective tissue (LCT) for fibrosis scoring. However, several concerns of such semiquantitative assessments have been raised, and when searching for data on the amount of LCT in healthy rats, the results vastly differ. Regarding the ongoing reproducibility crisis in science, it is necessary to inspect the results and methods, and to design an unbiased and reproducible method of LCT assessment. We searched the Medline database using search terms related to liver fibrosis, LCT and collagen, rat strains, and staining methods. Our search identified 74 eligible rat groups in 57 studies. We found up to 170-fold differences in the amount of LCT among healthy Wistar and Sprague-Dawley rats, with significant differences even within individual studies. Biased sampling and quantification probably caused the observed differences. In addition, we also found incorrect handling of liver fibrosis scoring. Assessment of LCT using stereological sampling methods (such as systematic uniform sampling) would provide us with unbiased data. Such data could eventually be used not only for the objective assessment of liver fibrosis but also for validation of noninvasive methods of the assessment of early stages of liver fibrosis.

Molecular mechanisms in thioacetamide-induced acute and chronic liver injury models

Thioacetamide (TAA) undergoes bioactivation in the liver by the CYP450 2E1 enzyme, resulting in the formation of TAA-S-oxide and TAA-S-dioxide. TAA-S-dioxide induces oxidative stress via lipid peroxidation of the hepatocellular membrane. A single TAA dose (50-300 mg/kg) administration initiates hepatocellular necrosis around the pericentral region after its covalent binding to macromolecules in the liver. Intermittent TAA administration (150-300 mg/kg, weekly thrice, for 11-16 weeks) activates transforming growth factor (TGF)-β/smad3 downstream signaling in injured hepatocytes, causing hepatic stellate cells (HSCs) to acquire myofibroblast like phenotype. The activated HSCs synthesize a variety of extracellular matrix, leading to liver fibrosis, cirrhosis, and portal hypertension. The TAA induced liver injury varies depending on the animal model, dosage, frequency, and routes of administration. However, TAA induces hepatotoxicity in a reproducible manner, and it is an ideal model to evaluate the antioxidant, cytoprotective, and antifibrotic compounds in experimental animals.

Biochanin A in murine Schistosoma mansoni infection: effects on inflammation, oxidative stress and fibrosis

Biochanin A (BCA) is a multifunctional natural compound that possesses anti-infective, anti-inflammatory, anti-oxidative and hepatoprotective effects. The aim of the study was to assess the therapeutic efficacy of BCA on Schistosoma mansoni-infected mice. Fifty mice were divided into six different groups as non-infected, non-infected BCA-treated, infected untreated, early infected BCA-treated (seven days post-infection (dpi)), late infected BCA-treated 60 dpi and infected praziquantel (PZQ)-treated groups. Parasitological, histopathological examination and immunohistochemical staining of transforming growth factor (TGF)-β, inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX-2) were investigated in liver sections. Cytochrome P450 (CYP450) gene expression of S. mansoni was evaluated by quantitative real-time polymerase chain reaction (RT-qPCR). A single dose of BCA significantly reduced worm burden in early (82.14%) and late infection (77.74%), mean tissue egg load in early (7.27 ± 0.495) and late BCA administration (7.63 ± 0.435) and decreased granuloma size. CYP450 mRNA expression was significantly reduced in early BCA treatment as compared to late treatment which emphasizes that early administration of BCA had more pronounced effects on worms than late administration. Both early and late BCA administration led to significant reduction in inflammatory cytokines as TGF and iNOS. Although the reduction of TGF and iNOS in BCA-treated mice was superior to PZQ, no statistically significant differences were noted. However, a significant downregulation of COX2 was noted in hepatocytes as compared to both infected control and PZQ-treated mice. BCA has schistosomicidal, anti-inflammatory, antioxidant and anti-fibrotic effects and could be regarded as a potential drug in schistosomiasis treatment.

Mannose inhibits Plasmodium parasite growth and cerebral malaria development via regulation of host immune responses

D-mannose can be transported into a variety of cells via glucose transporter (GLUT), and supraphysiological levels of D-mannose impairs tumor growth and modulates immune cell function through mechanisms such as interference with glycolysis and induction of oxidative stress. Blood-stage Plasmodium mainly depends on glycolysis for energy supply and pathological immune response plays a vital role in cerebral malaria. However, it is not clear whether mannose affects malaria blood-stage infection. Here, we fed D-mannose to Plasmodium berghei-infected mice and found weight loss and reduced parasitemia without apparent side effects. Compromised parasitemia in C57BL/6 mice was accompanied by an increase in splenic macrophages compared to an untreated group. When mannose was applied to a rodent experimental cerebral malaria (ECM) model, the incidence of ECM decreased. Expression of activation marker CD69 on T cells in peripheral blood and the brain were reduced, and cerebral migration of activated T cells was prevented by decreased expression of CXCR3. These findings suggest that mannose inhibits Plasmodium infection by regulating multiple host immune responses and could serve as a potential strategy for facilitating malaria treatment.

Sesamol protects against liver fibrosis induced in rats by modulating lysophosphatidic acid receptor expression and TGF-β/Smad3 signaling pathway

The present study aimed to investigate the hepatoprotective effect of sesamol (SML), a nutritional phenolic compound obtained from sesame seeds, in liver fibrosis induced by thioacetamide (TAA) in rats and to explore the underlying mechanisms. Thirty-two male Sprague–Dawley rats were equally divided into four groups: control, TAA, TAA + SML 50 mg/kg, and TAA + SML 100 mg/kg groups. Liver functions and hepatic contents of glutathione (GSH) and malondialdehyde (MDA) were measured colorimetrically. Gene expressions of lysophosphatidic acid receptor (LPAR)-1 and -3, connective tissue growth factor (CTGF), transforming growth factor (TGF)-β1, small mothers against decapentaplegic (Smad)-3 and -7, α-smooth muscle actin (α-SMA), and cytokeratin 19 (CK19) were analyzed by qRT-PCR. Moreover, phosphorylated Smad3 (pSmad3) was quantified by ELISA. Additionally, TGF-β1, α-SMA, CK19, and vascular endothelial growth factor (VEGF) protein concentrations were semi-quantitatively analyzed by immunostaining of liver sections. SML treatment markedly improved liver index and liver functions. Moreover, SML protected against liver fibrosis in a dose-dependent manner as indicated by down-regulation of LPAR1, LPAR3, CTGF, TGF-β1/Smad3, and α-SMA expressions and a decrease in pSmad3 level, as well as an up-regulation of Smad7 expression. In addition, SML suppressed ductular reaction hinted by the decrease in CK19 expression. These results reveal the anti-fibrotic effect of SML against liver fibrosis that might be attributed to down-regulation of LPAR1/3 expressions, inhibition of TGF-β1/Smad3 pathway, and ductular reaction.