Investigation of the effectiveness of Hypericum perforatumand Nigella sativa oil on intraperitoneal adhesions in rats

INVESTIGATION OF THE EFFECTIVENESS OF HYPERICUM PERFORATUM AND NIGELLA SATIVA OIL ON INTRAPERITONEAL ADHESIONS IN RATS Tekin S. Aydın Adnan Menderes University, Institute of Health Sciences, Veterinary Surgery Program, PhD Thesis, Aydın, 2025. Objective: This study aimed to evaluate the potential anti-adhesive effects of St. John's Wort oil (Hypericum perforatum) and black seed oil (Nigella sativa) in a rat model of experimentally induced intraperitoneal adhesions. The investigation was based on the known anti- inflammatory, antioxidant, antibacterial, and immunomodulatory properties of these agents, and included assessments at macroscopic, histopathological, and immunohistochemical levels. Methods: Fifty male Sprague-Dawley rats were randomly assigned into five groups to establish an intraperitoneal adhesion model. The groups received either no treatment (control), physiological saline, olive oil, St. John's Wort oil, or black seed oil. On postoperative day 14, relaparotomy was performed. Adhesion severity was scored macroscopically using the Nair scoring system. Histopathological analyses were conducted to assess the degree of fibrosis and inflammation semi-quantitatively. Additionally, immunohistochemical evaluation was performed to determine the expression levels of TGF-β1 and iNOS cytokines. Statistical analyses were performed using the Kruskal-Wallis and chi-square tests, with a significance level set at p < 0.05. Results: Macroscopic analysis revealed that diffuse adhesion formation was significantly lower in the black seed oil and saline-treated groups (p = 0.006), whereas the olive oil group showed the highest degree of diffuse adhesions. Histopathological findings indicated that fibrosis and inflammatory infiltration were less pronounced in the St. John's Wort and black seed oil groups. Immunohistochemical results demonstrated intense TGF-β1 expression, particularly in areas of fibrous band formation, while iNOS expression remained low across all groups. Conclusion: Black seed oil and physiological saline were found to be effective in preventing the development of intraperitoneal adhesions. Olive oil was ineffective in this regard, while St. x John's Wort oil exhibited moderate protective effects. Increased TGF-β1 expression was directly correlated with fibrosis severity, suggesting a pivotal role in adhesion pathophysiology. These findings indicate that adhesion formation is influenced not only by inflammation but also by fibroblast activity, and emphasize the need for future immunomodulatory therapeutic strategies targeting cytokines such as TGF-β1.