Evaluation of prophylactic and therapeutic effects of sildenafil on acute radiation proctitis in rats

Abstract

Purpose: To investigate the prophylactic and therapeutical effects of sildenafil in a model of acute radiation proctitis (ARP). Methods: All experimental procedures of this study was examined by histopathological, immunohistochemical and transmission electron microscopic analysis. Results: Our histopathological evaluations indicated significant increases in lesion severity, cryptic apsis, cryptitis, cryptic distortion, reactive atypia and infiltration depth of the control (proctitis) group. While the prophylaxis group and the treatment group had significantly lower scores. High-dose group showed similar results as prophylaxis group. Histopathological findings of the prophylaxis group was more significant than the treatment group. Immunoreactivities of IL-1β, FGF-2, TNF-α and HIF-1α increased in the control group especially in the epithelial and cryptic regions. On the contrary, sildenafil application caused significant decreases of inflammatory markers in all treatment groups, specifically better results in the prophylaxis group. Conclusion: The sildenafil has anti-inflammatory effects on ARP, as well as protective effects against ARP and the protective effect of sildenafil surpasses its therapeutic effect histopathologically.

Changrui enema inhibits inflammation-induced angiogenesis in acute radiation proctitis by regulating NF-κB and VEGF

“…There are various treatments for radiation proctitis and these include medical therapies, hyperbaric oxygen and endoscopic therapies 20 . Many medical therapies have been proposed and developed, including anti-inflammatory agents (sulphasalazine, balsalazide and mesalazine), antioxidants (vitamin A, E and C) 21 , 22 , mucosal protectants (formalin, sildenafil and mesenchymal stem cell) 23 , 24 and so on. Apart from medical therapies, hyperbaric Oxygen appears to be an effective therapy for radiation proctitis according to some clinical trials 25 .…”

Sildenafil beyond erectile dysfunction and pulmonary arterial hypertension: Thinking about new indications

“…Sildenafil not only modulated skin injury and promoted its reconstruction, but also shortened the repairing time [171]. Prophylaxis and treatment with sildenafil modified radiation‐induced proctitis in the rats, lowered the histopathological score, and reduced the production of inflammatory cytokines [172].…”