Objective: To observe the therapeutic effect of Arnebiae Radix oil ointment (AROO) on a rat model of pressure ulcer (PU) and its possible mechanism

in order to provide the experimental evidence for clinical application. Method: Rats were randomly divided into seven groups

namely blank control group

sham group

model group

positive control group

middle-dose AROO group

high-dose AROO group and iodine group. The PU model was induced by applying magnets over irons that were implanted under the skin of rats except for blank control and sham group. AROO was applied the next day after modeling. Rats in blank control

sham group and model group were treated with normal saline

where as the other groups were given the corresponding medicines once a day. After three days of administration

the morphologic and color changes in skin were observed

and the histopathological changes in pressed skin tissues were observed under microscope. Nuclear transcription factor-κB p65(NF-κB p65) was detected by immunohistochemistry; WST-1 and microplate method were used to detect the superoxide dismutase (SOD) and malondialdehyde (MDA) in rat serum. And the levels of interleukin-lα (IL-lα) and tumor necrosis factorα-α (TNF-α) in rat serum were detected as well by enzyme linked immunosorbent assay (ELISA). Result: Compared with blank control and sham group

compressed skin parts of the rats in model group were red and swollen; and pathological observation showed that the cell lines were disordered

the cell gaps were widened

and the inflammatory cells were infiltrated. The levels of TNF-α

IL-1α and MDA in the serum and the expression of NF-κB p65 were significantly increased

while the level of SOD was reduced. After being treated with AROO for 3 days

the swelling in compressed tissues subsided

the pathological status was significantly improved

the inflammation was relieved

and the content of SOD in middle and high-dose groups was significantly higher than that of model group. However

the content of MDA was significantly lower than that of model group (P <0.05

P<0.01)

the levels of TNF-α and IL-1α in the serum of high-dose group were significantly lower than those in model group (P<0.05)

and the NF-κB p65 protein expression in high-dose group was significantly lower than model group (P<0.05). Conclusion: AROO has a therapeutic effect on rat PU model. Its mechanism is possibly related to the regulation of NF-κB p65 expression and the content of IL-1α

TNF-α

SOD and MDA in rat serum.