Potential efficacious materials investigation of Yi-Yi Mixture based on Metabolome-oriented network pharmacology strategy.

Yi-Yi Mixture, an efficient Chinese medicine preparation composed of four herbal medicines, has been used in clinical practice in China for the treatment of acute pancreatitis over twenty years. However, its functional materials against acute pancreatitis remains unclear, which is a huge obstacle for quality control. In this study, a metabolome-oriented network pharmacology strategy was proposed to clarify its potential substances and further screen out quality markers. Firstly, an Ultra-High performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry method was utilized to profile the chemical constituents in Yi-Yi Mixture. Secondly, metabolic exposure of chemical constituents as well as their global metabolites produced in biological systems were profiled and defined as metabolome of Yi-Yi Mixture. Then, the metabolome targets were predicted based on network analysis. As a result, a total of 66 chemical components were characterized, including 6 stilbenes, 21 anthraquinones, 7 phenols, 13 neolignans, 3 naphthalenes and 16 other types. Moreover, metabolic profiles of YYM (32 prototypes and 37 metabolites) were analyzed in rat bio-samples. Among them, resveratrol, emodin, chrysophanol, rhein and their derivatives were detected in multiple tissues/organs, revealing their potential as key pharmacodynamic substances. These were further confirmed by metabolome-oriented network analysis and molecular docking techniques. This is the first comprehensive investigation on chemical and metabolic profiles of Yi-Yi Mixture, and the results provided scientific foundation for further research on quality control and clinical-safe medication administration.

TLR4 upregulates CBS expression through NF-κB activation in a rat model of irritable bowel syndrome with chronic visceral hypersensitivity.

AIM: To investigate the roles of toll-like receptor 4 (TLR4) and nuclear factor (NF)-κB on cystathionine ß synthetase (CBS) expression and visceral hypersensitivity in rats. METHODS: This study used 1-7-wk-old male Sprague-Dawley rats. Western blot analysis was employed to measure the expression of TLR4, NF-κB and the endogenous hydrogen sulfide-producing enzyme CBS in colon dorsal root ganglia (DRG) from control and "irritable bowel syndrome" rats induced by neonatal colonic inflammation (NCI). Colon-specific DRG neurons were labeled with Dil and acutely dissociated to measure excitability with patch-clamp techniques. Immunofluorescence was employed to determine the co-expression of TLR4, NF-κB and CBS in DiI-labeled DRG neurons. RESULTS: NCI significantly upregulated the expression of TLR4 in colon-related DRGs (0.34 ± 0.12 vs 0.72 ± 0.02 for the control and NCI groups, respectively, P < 0.05). Intrathecal administration of the TLR4-selective inhibitor CLI-095 significantly enhanced the colorectal distention threshold of NCI rats. CLI-095 treatment also markedly reversed the hyperexcitability of colon-specific DRG neurons and reduced the expression of CBS (1.7 ± 0.1 vs 1.1 ± 0.04, P < 0.05) and of the NF-κB subunit p65 (0.8 ± 0.1 vs 0.5 ± 0.1, P < 0.05). Furthermore, the NF-κB-selective inhibitor pyrrolidine dithiocarbamate (PDTC) significantly reduced the upregulation of CBS (1.0 ± 0.1 vs 0.6 ± 0.1, P < 0.05) and attenuated visceral hypersensitivity in the NCI rats. In vitro, incubation of cultured DRG neurons with the TLR4 agonist lipopolysaccharide significantly enhanced the expression of p65 (control vs 8 h: 0.9 ± 0.1 vs 1.3 ± 0.1; control vs 12 h: 0.9 ± 0.1 vs 1.3 ± 0.1, P < 0.05; control vs 24 h: 0.9 ± 0.1 vs 1.6 ± 0.1, P < 0.01) and CBS (control vs 12 h: 1.0 ± 0.1 vs 2.2 ± 0.4; control vs 24 h: 1.0 ± 0.1 vs 2.6 ± 0.1, P < 0.05), whereas the inhibition of p65 via pre-incubation with PDTC significantly reversed the upregulation of CBS expression (1.2 ± 0.1 vs 0.6 ± 0.0, P < 0.01). CONCLUSION: Our results suggest that the activation of TLR4 by NCI upregulates CBS expression, which is mediated by the NF-κB signaling pathway, thus contributing to visceral hypersensitivity.