Metabolomic Study to Determine the Mechanism Underlying the Effects of Sagittaria sagittifolia Polysaccharide on Isoniazid- and Rifampicin-Induced Hepatotoxicity in Mice.

In this study, a non-targeted metabolic profiling method based on ultra-performance liquid chromatography-high resolution mass spectrometry (UPLC-HRMS) was used to characterize the plasma metabolic profile associated with the protective effects of the Sagittaria sagittifolia polysaccharide (SSP) on isoniazid (INH)-and rifampicin (RFP)-induced hepatotoxicity in mice. Fourteen potential biomarkers were identified from the plasma of SSP-treated mice. The protective effects of SSP on hepatotoxicity caused by the combination of INH and RFP (INH/RFP) were further elucidated by investigating the related metabolic pathways. INH/RFP was found to disrupt fatty acid metabolism, the tricarboxylic acid cycle, amino acid metabolism, taurine metabolism, and the ornithine cycle. The results of the metabolomics study showed that SSP provided protective effects against INH/RFP-induced liver injury by partially regulating perturbed metabolic pathways.

Sagittaria sagittifolia polysaccharide protects against six-heavy-metal-induced hepatic injury associated with the activation of Nrf2 pathway to regulate oxidative stress and apoptosis.

The hepatic protective role of Sagittaria sagittifolia polysaccharide (SSP) and its possible mechanism were discussed in mice and L02 hepatocytes injured by heavy metals mixture of Cd + Cr (VI) + Pb + Mn + Zn + Cu. After 30-day intervention, blood and liver samples were collected for the relevant assessments. Methyl thiazolyl tetrazolium (MTT) assay showed 24 h was the best protecting point and the SSP protection at 1 mg/mL was strongest in L02 hepatocytes. SSP can alleviated hepatic injury, as evidenced by significantly decreased the activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and the malondialdehyde (MDA) content, also increased the superoxide dismutase (SOD) activity and glutathione (GSH), total sulphydryl (T-SH) contents. SSP effectively reduced pathological damage of mice and accumulation of heavy metals in liver, as well as decreased the level of reactive oxygen species (ROS) in L02 hepatocytes. After SSP treatment, the protein expressions or gene transcription of nuclear factor erythroid 2-related factor 2 (Nrf2), NAD(P)H dehydrogenase, quinone 1 (NQO1) and heme oxygenase1 (HO-1) decreased in L02. The protein expression of Nrf2 and NQO1 were increased while HO-1 was decreased in liver. Besides, SSP can attenuates apoptosis through reducing the protein expression of Bcl-2-associated X protein (Bax) and caspase-3, and increasing B-cell lymphoma gene 2 (Bcl-2) and B-cell lymphoma-extra large (Bcl-xl). SSP protects against six-heavy-metal-induced hepatic injury in mice and L02 hepatocytes. Supported by Nrf2 gene silencing, the mechanisms may correlate with activating Nrf2 pathway to mitigate oxidative stress and apoptosis.

Sagittaria sagittifolia polysaccharide interferes with arachidonic acid metabolism in non-alcoholic fatty liver disease mice via Nrf2/HO-1 signaling pathway.

BACKGROUNDS: Non-alcoholic fatty liver disease (NAFLD) is currently one of the most common chronic liver diseases especially in developed countries. Modern research shows an obvious protective effect of Sagittaria sagittifolia L. (Alismataceae) on glucose and lipid metabolism disorders. Previous studies had reported that Sagittaria sagittifolia polysaccharide (SSP) has potent protective effects on drug-induced liver injury. Based on this, we speculated that Sagittaria sagittifolia polysaccharide also has protective effects on NAFLD and performed experiments to explore this more. METHODS: Outstanding protective effects of SSP against NAFLD in mice was observed with Hematoxylin and Eosin (H&E) and uranium acetate-citrate stain in our prophase research. By performing bioinformatics analysis on plasma metabolic data which is obtained from ultra-performance liquid chromatography-high resolution mass spectrometry (UPLC-HRMS), we found the regulatory mechanisms and key nodes behind the beneficial effect with IPA (Ingenuity Pathway Analysis) software. Immunohistochemical staining and Western blot were performed for further validation on expression variations of key proteins. RESULTS: Regulatory pathways were enriched with 33 significant differential metabolites that responded to SSP treatment in plasma, and specifically, the ones related to arachidonic acid metabolism showed high participation. Moreover, the expression patterns of upstream regulators, Nrf2 and HO-1, were found to be significantly regulated upon SSP treatment. CONCLUSIONS: In conclusion, our findings illustrated a novel perspective that SSP exerts preventive protection against high-fat diet-induced NAFLD by interfering with arachidonic acid metabolism via Nrf2/HO-1 signaling pathway in liver oxidative stress, providing an attractive point for the breakthrough of related natural medicine development.