Investigation of the protective effects of gallic acid and lycopene against 4-nonylphenol toxicity in rat pancreas

INVESTIGATION OF THE PROTECTIVE EFFECTS OF GALLIC ACID AND LYCOPENE AGAINST 4-NONYLPHENOL TOXICITY IN RAT PANCREAS Menderes S. Aydın Adnan Menderes University, Institute of Health Sciences, Master's Program in Histology and Embryology (Veterinary), Master's Thesis, Aydın, 2025. Objective: This study aimed to histologically investigate whether gallic acid (GA) and lycopene (L) have a protective effect on the pancreas of rats exposed to 4-nonylphenol (4-NF). Materials and Methods: A total of 36 Sprague Dawley rats were used. The study was conducted in six groups: control, 4-NF, GA, lycopene, GA + 4-NF, and L + 4-NF (n=6 per group). The experiment lasted for 28 days. At the end of the experimental period, pancreatic tissues were collected, fixed routinely, and embedded in paraffin. Serial sections of 6 µm thickness were taken at 100 µm intervals and stained with Hematoxylin-Eosin (HE), Periodic Acid-Schiff (PAS), and Triple staining for general histological evaluation. Streptavidin-biotin-peroxidase staining method was applied to calculate the apoptotic cell density, islet number, islet diameter and area of the cells in the endocrine compartment of the pancreas. Data were statistically analyzed using the Kruskal-Wallis test. Results: In sections stained with Triple, PAS, and HE, the control, GA, and lycopene groups displayed similar and normal histomorphological features, while prominent cellular degeneration was observed in the 4-NF group. Reduced degeneration was noted in the GA + 4-NF and L + 4-NF groups. Immunohistochemical analysis revealed increased apoptosis, decreased islet number, and smaller islet sizes in the 4-NF group. These findings were confirmed statistically. Conclusion: This study concluded that 4-NF causes damage to pancreatic tissue, and both GA and lycopene exert protective effects by mitigating this damage. Keywords: 4-Nonylphenol, Gallic Acid, Lycopene, Pancreas, Rat.