Investigation of the antioxidant effect of melatonin hormone in cats with hepatitis and cholangiohepatitis

The aim of this thesis is to investigate the effects of 7-day melatonin administration, in addition to the treatment for hepatitis and cholangiohepatitis diseases commonly observed in cats, on the treatment process and oxidative stress biomarkers in veterinary medicine. Liver diseases are common in cats and dogs. These diseases can cause various problems related to the quality of life of animals and can lead to the death of patients if they are not treated.Antioxidants can be produced naturally in the body or can be obtained exogenously from food. In the treatment of liver diseases, substances such as vitamin C (ascorbic acid), vitamin E (a-tocopherol), selenium, beta carotene, L-carnitine are used as antioxidants. One of them, melatonin, is the main secretory product of the pineal gland and is known to cooperate against oxidative stress in cells. Melatonin has important antioxidant and hepatoprotective effects in healthy individuals and oxidative stress caused by diseases. In studies conducted in humans, it was thought that melatonin could help in the treatment of liver diseases, especially by reducing oxidative stress, thanks to its antioxidant activity. For this purpose, it has been used in the treatment of liver diseases in humans in recent years. This study was planned because it was seen that there was no study on this area when the studies on cats and dogs with liver disease were examined. For this purpose, 4 different groups were formed. Normal liver therapy and melatonin therapy have been administered orally to 20 patients with hepatitis in the 1st group for 7 days, and normal liver therapy and melatonin therapy were administered orally for 7 days to 20 patients with cholangiohepatitis in the 2nd group. Normal liver therapy has been administered to 10 patients with hepatitis in the 3rd group for 7 days, and normal liver therapy was administered for 7 days to 10 patients in the 4th group with cholangiohepatitis. On the first day of their arrival and at the end of the 7th day, blood will be taken for complete blood count, biochemistry and oxidative stress biomarkers measurement. Statistically significant differences were found between the groups in terms of MON1 in the hemogram analysis (p<0.005). In the biochemical analysis, statistically significant differences were observed between the patient groups for ALB 2 (p<0.005), GGT1 (p<0.05), and T. BIL1 (p<0.05). Additionally, the SOD2 value was found to be higher in the fourth group compared to the second group, and in the first group compared to the second group (p<0.05). The antioxidant effects of melatonin tablets in cats with liver disease have not been pronounced due to factors such as the drug form, treatment duration, and dosage. To achieve more effective results, it is recommended to review these factors, such as using different forms of melatonin, extending the treatment duration, and adjusting the dosage according to the cats' needs. These adjustments could enhance the antioxidant effects of melatonin.