Therapeutic effect of total flavonoids of Sargentodoxa cuneata on ulcerative colitis in mice by correcting gut dysbiosis

Sargentodoxa cuneata is a traditional Chinese herb commonly used for the treatment of ulcerative colitis (UC) in clinical practice. However, the effects of total flavonoids of Sargentodoxa cuneata (TFSc) remain unclear. In this study, we explored the effects and mechanisms of action of TFSc in mice with dextran sulfate sodium-induced UC. The TFSc components were identified using liquid chromatography-tandem mass spectrometry. Mice with UC were orally administered TFSc to evaluate its effects on colon and liver damage. Changes in gut microbiota were analyzed using 16S rRNA gene sequencing. Moreover, the levels of short-chain fatty acids (SCFAs) and few organic acids in the intestinal contents were measured. Furthermore, the correlation amongst gut flora, SCFAs, and organic acids was studied. A total of 304 compounds were identified. TFSc alleviated the symptoms of UC in mice, inhibited weight loss, reduced the disease activity index, and improved colon shortening along with cardiac and hepatic indices. Furthermore, TFSc mitigated pathological changes in the colon and liver, and reduced the TNF-alpha levels in colon tissues of mice with UC. TFSc also modulated intestinal flora disorders, increased the levels of four SCFAs (isocaproic acid, 3-hydroxyisovaleric acid, isobutyric acid, and ethylmethylacetic acid), and decreased the levels of two organic acids (malonic acid and succinic acid). The differential regulation of SCFAs and organic acids by TFSc was strongly associated with specific gut flora. TFSc showed potential for improving colon and liver injury in mice with UC by regulating the intestinal flora and associated metabolites (SCFAs and organic acids). These findings provide new evidence for developing TFSc as a drug for treating UC and UC-related liver injuries.