Objective:To investigate the hepatoprotective effect of N-acetylcysteine(NAC)on rats with liver injury induced by cisplatin and its effect on intestinal flora and the expression of interleukin-6(IL-6),tumor necrosis factor-α(TNF-α),and nuclear factor-kappa B(NF-κB).Methods:Male Sprague-Dawley rats were randomly divided into control group(CG),cisplatin group(CP),and NAC group.The rats in the NAC group were given NAC 15 mg/kg by gavage for 8 consecutive days.At half an hour after intragastric administration on the fifth day,all rats except those in the NC group were given intraperitoneal injection of 8 mg/kg cisplatin to induce acute liver injury.An automatic biochemical analyzer was used to measure the content of aspartate aminotransferase(AST),alanine aminotransferase(ALT),alkaline phosphatase(ALP),and total bilirubin(TBIL);liver index was calculated for the rats;Western blot was used to measure the relative expression levels of NF-κB,IL-6,and TNF-α in liver tissue;the 16S rDNA technique was used to measure and analyze the amplification information of the V3-V4 regions of each sample.Results:Compared with the NC group,the CP group had significant increases in the content of AST,ALT,ALP,and TBIL,while NAC reversed the abnormal liver function caused by cisplatin.Compared with the NC group,the CP group had a sig-nificant increase in liver index(P=0.000),while the NAC group had a significant reduction in liver index compared with the CP group(P=0.007).Compared with the NC group,the CP group had signifi-cant increases in the expression levels of IL-6,TNF-α,and NF-κB,while the NAC group showed reductions in the expression of these genes,with significant differences in the expression of IL-6 and TNF-α(P=0.006 and 0.000).Compared with the NC group,the CP group had a significant increase in the α-diversity index of intesti-nal flora,while compared with the CP group,the NAC group tended to have a reduction in the α-diversity index of intestinal flora.Com-pared with the CP group at the phylum level,the NAC group had an increase in the abundance of Actinobacteria and a reduction in the abundance of Firmicutes.Compared with the CP group at the genus level,the NAC group had a reduction in the abundance of Rumino-coccaceae and increases in the abundance of Bifidobacterium and Allobaculum.Conclusion:NAC can alleviate acute liver injury caused by cisplatin,possibly by downregulating the expression of IL-6,TNF-α,and NF-κB and regulating the abundance and diver-sity of intestinal flora.

Ulcerative colitis （UC） is a chronic recurrent inflammatory bowel disease which primarily affects the colonic mucosa. The UC patients mainly present diarrhea， abdominal pain， tenesmus， and mucous bloody stools， and even malnutrition and systemic symptoms in severe cases， with rising incidence， which has a significant impact on the health and quality of life of patients. The pathogenesis of UC is not clear， and the Western medical therapies include sulfasalazine， glucocorticoids， and immunosuppressants， which， however， have side effects and unsatisfactory effects. Chinese medicine with high safety， mild adverse reactions， and a multi-component， multi-target， and multi-pathway treatment manner has garnering increasing attention. Therefore， finding the Chinese medicine to treat UC has become a hot spot. Glycyrrhizae Radix et Rhizoma is one of the commonly used Chinese herbal medicines， with the effects of tonifying spleen and reinforcing qi， clearing heat and detoxifying， dispelling phlegm and relieving cough， relieving pain， and harmonizing medicines. Glycyrrhizae Radix et Rhizoma mainly contains glycyrrhizic acid， glycyrrhetinic acid， diammonium glycyrrhizinate and other active ingredients. Modern pharmacological studies have shown that Glycyrrhizae Radix et Rhizoma has anti-inflammatory， antioxidant， antimicrobial， and immunomodulatory activities. According to statistics， Glycyrrhizae Radix et Rhizoma is among the top three Chinese herbal medicines for the treatment of UC. The recent years have witnessed progress in the treatment of UC with Glycyrrhizae Radix et Rhizoma and the related prescriptions. The present study summarized the mechanisms underlying the anti-inflammatory， immunomodulatory， intestinal flora-regulating， cell apoptosis-inducing， and oxidative stress-reducing effects of the key chemical constituents （glycyrrhetinic acid， diammonium glycyrrhizinate， polysaccharide， glycyrrhetinic acid， and isoglycyrrhizin） and compound prescriptions of Glycyrrhizae Radix et Rhizoma. The findings provide a solid foundation for further development and clinical application of Glycyrrhizae Radix et Rhizoma.