Standardised pomegranate peel extract lavage prevents postoperative peritoneal adhesion by regulating TGF-β and VEGF levels

Peritoneal adhesion represents a severe complication following surgery. Punica granatum (pomegranate) possesses several anti-oxidative and anti-inflammatory properties. Pomegranate peel extract (PPEx) can alleviate the production of various inflammatory factors and cytokines. Thus, we sought to evaluate the anti-adhesion effects of pomegranate in rats. Thirty male Wistar rats (6-week-old, 220 ± 20 g) were divided into five groups (n = 6): normal group without any surgical procedures, control group, and experimental groups receiving 2 ml of 1%, 2%, and 4% w/v PPEx, respectively. Peritoneal adhesions were examined macroscopically. Furthermore, we evaluated inflammatory cytokines levels [interleukin 6 (IL-6), and tumour necrosis factor-α (TNF-α)], growth factors [transforming growth factor- β1 (TGF-β1), and vascular endothelial growth factor (VEGF)], and oxidative stress parameters [nitric oxide metabolites (NO), and malondialdehyde (MDA), and glutathione (GSH)] using biochemical methods. Our results showed that the adhesion score and IL-6, TNF-α, TGF-β1, VEGF, NO, and MDA levels were increased in the control group. In contrast, the GSH level was diminished in the control group compared with the normal group (P < 0.001). PPEx (1 and 2% w/v) markedly reduced all measured parameters compared with the control group (P < 0.001–0.05). PPEx may reduce peritoneal adhesion by alleviating adhesion formation, IL-6, TNF-α, TGF-β1, VEGF, NO, and MDA, and stimulating anti-oxidative factors. Therefore, PPEx may be considered an appropriate candidate for the treatment of postoperative peritoneal adhesion.