Evaluation of the effects of Iranian propolis on the severity of post operational-induced peritoneal adhesion in rats

Peritoneal adhesion is a major complication of surgery that can lead to serious problems such as bowel obstruction, pain, infertility and even mortality. Propolis is a honey bee product with anti-inflammatory and anti-oxidant activities that could potentially protect against adhesive surgical complications.

Forty 8-weeks-old rats (275 ± 25 g) were divided into five groups: normal group without any surgical procedure, and experimental groups treated with normal saline, 50 mg/kg, 100 mg/kg and 200 mg/kg of propolis. Peritoneal adhesions were examined macroscopically and also, the levels of inflammatory factors (IL-6, IL-1β and TNF-α), growth factors (TGF-β1 and VEGF) were evaluated in the study groups using ELISA. Biochemical indices of oxidative status including Nitric Oxide (NO), Malondialdehyde (MDA) and Glutathione (GSH) were also measured.

Peritoneal adhesion scores, IL-1β, IL-6, TNF-α, TGF-β1, VEGF, NO, GSH and MDA levels were significantly different between the study groups (p < 0.001). Propolis treatment reduced peritoneal adhesion (p < 0.001), TNF-α (p < 0.001), IL-1β (p < 0.001), IL-6 (p < 0.001), TGF-β1 (p < 0.001), VEGF (p < 0.001), NO (p < 0.001) and MDA (p < 0.001), while GSH levels were increased (p < 0.001) compared with the vehicle group. Our results showed that higher dose of propolis was associated with significantly greater reductions in peritoneal adhesion (p < 0.001), TNF-α (p < 0.001), IL-1β (p < 0.001), IL-6 (p < 0.001), VEGF (p < 0.001), NO (p < 0.001) and MDA (p < 0.001), a greater increase in GSH levels (p < 0.001) compared with the lower dose.

Propolis treatment can dose-dependently reduce peritoneal adhesion through its anti-inflammatory, anti-angiogenic and antioxidant properties. Therefore, propolis might serve as a protective agent against post-surgical adhesive complications.