Phytochemical Analysis and in vivo Toxicity Study of Extracted Walnut oil in Sprague Dawley Rats

Background: Medicinal plants have been the focus of scientific research for many decades worldwide, especially those used in traditional medicine. Objective: To perform the phytochemical analysis of extracted walnut oil (EWO) and its subchronic toxicity profile in Sprague Dawley rats. Methods: In this experimental study, the collected Kurdish walnut was authenticated by an authorized taxonomist and the core was obtained. Then, the walnut oil was extracted using the cold press method and sent for phytochemical analysis using GC-MS. Accordingly, the male Sprague Dawley rats were treated with varying doses of the EWO for four consecutive weeks, and animals were checked daily for abnormality and toxicity behaviours while they were weighed each week. At the end of the study, animals were sacrificed under deep anaesthesia, blood samples and organs were collected, and various hematological and biochemical tests were performed together with histopathological analysis. Results: GC-MS analysis showed that EWO contained 49 compounds, some critical in biomedical fields. The body weight of all treated animals was increased significantly. No significant changes were seen for hematological tests except platelets, which decreased in all treated groups (p = 0.015) compared to the control group. At the same time, AST and chloride levels were decreased (p = 0.002 and p = 0.012, respectively), while total protein and calcium were increased (p = 0.004 and p = 0.033, respectively). Simultaneously, histopathological analysis showed no severe lesions in the brain, moderate lesions in the liver and mild, moderate and severe lesions in the kidneys. Conclusions: EWO is rich in various compounds that contain active medicinal components. The EWO can be used at low doses as it does not affect most hematological and biochemical tests and has no significant toxicity in the vital organs of experimental rats.