The Preventive Effect of Systemic Honokiol and Systemic Pentoxifylline on Epidural Fibrosis

To investigate the preventive effects of systemic honokiol and pentoxifylline treatments on epidural fibrosis (EF) in the experimental laminectomy model.

Thirty-two rats were divided into four equal groups. Laminectomy was performed in all rats except for the control group. One group was kept as the negative control group. Moreover, 10 mg/kg pentoxifylline and 10 mg/kg honokiol were administered intraperitoneally for 5 days, respectively, to the other two groups. The rats were sacrificed after 4 weeks. The samples were examined biochemically in terms of oxidative stress and inflammation induced by tissue damage. Histopathological and immunohistochemical investigations were also performed to detect EF severity.

In honokiol and pentoxifylline groups compared with the negative control group, tumor necrosis factor-beta and interleukin-10 levels (indicating inflammation); myeloperoxidase, malondialdehyde, and hydroxyproline levels (indicating oxidative stress); and intercellular adhesion molecule levels (indicating fibrosis) were decreased. Histopathologically and immunohistochemically, EF was significantly reduced in the pentoxifylline and honokiol groups. Biochemical findings were consistent with the histopathological and immunohistochemical findings.

Both pentoxifylline and honokiol prevent EF formation. However, this effect is more pronounced in honokiol.