Objective: To investigate the therapeutic effect of Nephrolepis cordifolia leaf decoction (NLD) on anal ulcer model in mice and explore its mechanism. Method: The anal ulcer model was prepared by applying 0.5 mL of 20% acetic acid (HAc) into the anus of mice.The 50 Kunming mice were randomly divided into normal group

model group

low

middle and high dose NLD (0.45

0.9 and 1.8 g · kg-1) groups

10 mice in each group. All the mice were killed on the 10th day after NLD application. Their anal and rectal tissues were collected and the mRNA expression levels of nuclear transcription factor-κB (NF-κB)

tumor necrosis factor-α (TNF-α)

interleukin-1β (IL-1β) and cyclooxygenase-2 (COX-2) in the anal and rectal tissues of each group were detected by Real-time fluorescence quantitative reverse transcription polymerase chain reaction (Real-time PCR). Western blot was used to detect the protein expression levels of NF-κB

TNF-α

IL-1β and COX-2 in anal and rectal tissues of mice in each group. Morphological changes of anal and rectal tissues in mice were observed by hematoxylin-eosin (HE) staining. Result: NLD could restore the growth of mice body mass

reduce the rectoanal coefficient and down-regulate NF-κB

TNF-α

IL-1β and COX-2 mRNA expression in the anal and rectal tissues of mice (P<0.01)

inhibit the activity of NF-κB

TNF-α

IL-1β and COX-2 protein expression in the anal and rectal tissues of mice (P<0.01). NLD 0.9 and 1.8 g · kg-1 could inhibit the infiltration of inflammatory cells and submucosa vasodilation and improve the corresponding inflammatory response. Conclusion: NLD has protective effect on the inflammatory response of acetic acid-induced anal ulcer in mice

and the mechanism may be related to inhibiting NF-κB mRNA and protein expression and down-regulating the gene expression of downstream inflammatory factors TNF-α

IL-1β and COX-2.