Biochemical investigation of SIRT1, NF-κB, and certain oxidative stress markers in experimental dietary models

In this thesis study, the effects of different experimental dietary models—including the ketogenic diet (KD), high-fat diet (HFD), and vegan diet—on key gene expression factors (SIRT1 and NF-κB), specific oxidative stress markers (MDA, SOD, CAT, NO, TAS), and metabolic hormones (leptin, ghrelin, cortisol, and melatonin) were investigated. The findings demonstrated that the KD exerted beneficial effects by reducing oxidative stress and supporting anti-inflammatory processes, while the HFD was associated with increases in oxidative stress and inflammation markers. The vegan diet was observed to enhance the overall antioxidant defense mechanisms. In the KD group, a significant increase in CAT and TAS levels was detected, indicating an enhanced antioxidant capacity. In contrast, both the HFD and vegan diet groups showed a significant decrease in NO levels compared to the standard chow group. Moreover, no significant differences in MDA levels were found among the experimental diet groups (KD, HFD, and vegan diet) compared to the standard chow group, suggesting that lipid peroxidation did not accumulate during the 4-week feeding period. Regarding SOD activity, a decrease was observed in all diet groups relative to the control group. Melatonin levels were found to be higher in the vegan diet group compared to the KD group. Additionally, leptin and cortisol levels were elevated in the HFD group, whereas no significant changes in ghrelin levels were observed among the different diet models. Overall, the findings indicate that the type of diet can have significant effects on oxidative stress parameters and hormonal profiles.