Research on the mechanisms of ethanol extract of Scutellaria baicalensis Georgi in improving CFA-induced inflammatory pain rats based on 1H NMR metabolomics / 药学学报

ABSTRACT

The purpose of this study was to investigate the effects of ethanol extract of Scutellaria baicalensis Georgi (SGE) on endogenous metabolites in toes of rats with inflammatory pain induced by complete Freund's adjuvant (CFA) based on 1H NMR metabolomics, which would provide foundation for revealing the effects and mechanisms of SGE in improving inflammatory pain. This animal experiment was approved by the Committee on the Ethics of Animal Experiments of Shanxi University (SXULL2022062). The rats model of inflammatory pain was induced by subcutaneous injection of CFA (0.1 mL), and the effect of low, medium and high doses of SGE (1.5, 3, 6 g·kg-1) on inflammatory pain were explored. The effects of SGE on relieving inflammatory pain was evaluated by mechanical nociceptive thresholds (MNTs) test. Western blot was used to detect the effects of SGE on protein expression of cyclooxygenase-2 (COX-2), nuclear factor kappa-B (NF-κB) and phospho-NF-κB (p-NF-κB). 1H NMR metabolomics was used to analyze the regulatory effects of SGE on endogenous metabolites in the toes of rats with inflammatory pain. The results showed that SGE (6 g·kg-1) could significantly relieve CFA-induced inflammatory pain, and also notably inhibit the protein expression of COX-2, NF-κB and p-NF-κB. SGE could markedly reverse the changes of 8 differential metabolites, such as glycine, glutamine, succinate, phosphorylcholine, etc. The metabolites were involved in eight metabolic pathways, such as glycine, serine and threonine metabolism, alanine, aspartate and glutamate metabolism, glyoxylate and dicarboxylate metabolism, glutathione metabolism, glycerophospholipid metabolism. These results suggest that SGE may relieve inflammatory pain by regulating NF-κB signaling pathway and metabolic abnormality.