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Impact of Fish Oil and Flaxseed Oil on HIF-2α, COX-2 and IFN-γ Protein Expression: A Case Study in Rats With Kidney
Zeki Erol1, Jerina Rugji2, Ayşe Aydoğan3
1Department of Food Hygiene and Technology, Faculty of Veterinary Medicine, Dokuz Eylül University, Kiraz, İzmir, Turkey.
Objectives:
This study set out to investigate kidney damage by examining the levels of key proteins-HIF-2α, COX-2 and IFN-γ in rats with disrupted circadian rhythms. It also explored how fish oil and flaxseed oil might influence the intensity of inflammation and its effects on kidney health.
Methods:
Circadian rhythm disorder model groups consisted of eight rats each. Except for the control group, other groups (circadian rhythm, flaxseed oil and fish oil groups) were exposed to an adjustable light/dark cycle for 19 days, while the control group was kept on a standard light/dark cycle. In addition to standard food and water ad libitum nutrition for 19 days in four groups, 1000 mg/kg/day flaxseed oil was given to the flaxseed oil group and 400 mg/kg/day fish oil was given to the fish oil group by gavage for 19 days. Histological lesions in tissues were evaluated by Haematoxylin-Eosin staining and using a sequential grading system. For immunohistochemical analysis, IFN-γ, COX-2 and HIF-2 antibodies were used to evaluate the degree of immunohistochemical reactivity of the cells.
Results:
Nutrition unequivocally plays a critical role in regulating circadian rhythms, as factors such as meal timing, nutrient composition and gut health directly influence the body's internal clock and overall rhythm stability. Omega-3 fatty acids are known to influence immune, inflammatory and neurological pathways-all of which are controlled by the circadian clock. When circadian rhythms are disrupted, key signalling proteins such as HIF-2α, COX-2 and IFN-γ become dysregulated, leading to potential kidney damage. Remarkably, treatments with fish oil and flaxseed oil have been shown to reduce inflammation markers, effectively mitigating kidney damage and offering significant anti-inflammatory benefits. These results emphasize the aptitude of incorporating fish oil and flaxseed oil into the diet as a powerful strategy to combat kidney damage and slow the pathological effects caused by circadian rhythm disruption.
Conclusion:
Circadian rhythm disturbances are associated with various health problems, including kidney damage characterized by microhaemorrhage and inflammatory cell infiltration. In this study, fish oil and flaxseed oil demonstrated protective, anti-inflammatory effects by reducing levels of HIF-2α, COX-2 and IFN-γ and improving kidney pathology. These effects were evaluated within the scope of an animal model, and the findings provide valuable preliminary data for future human studies.
Insights
Disrupted circadian rhythms can harm kidneys by altering key proteins. Fish oil and flaxseed oil show promise in reducing inflammation and protecting kidney health in rats.
Area of Science:
- Biochemistry
- Physiology
- Nutrition Science
Background:
- Circadian rhythm disruption is linked to kidney damage, involving proteins like HIF-2α, COX-2, and IFN-γ.
- Nutrition, particularly omega-3 fatty acids, influences circadian stability and inflammatory pathways.
- Dysregulation of key signaling proteins contributes to kidney pathology under disrupted rhythms.
Purpose of the Study:
- To investigate kidney damage in rats with disrupted circadian rhythms.
- To examine the impact of fish oil and flaxseed oil on inflammation and kidney health.
- To analyze the levels of HIF-2α, COX-2, and IFN-γ in response to circadian disruption and oil supplementation.
Main Methods:
- Rats were subjected to disrupted light/dark cycles to model circadian rhythm disorder.
- Flaxseed oil (1000 mg/kg/day) and fish oil (400 mg/kg/day) were administered via gavage for 19 days.
- Kidney tissue was assessed using Hematoxylin-Eosin staining and immunohistochemistry for IFN-γ, COX-2, and HIF-2α.
Main Results:
- Disrupted circadian rhythms led to kidney damage, evidenced by histological lesions.
- Fish oil and flaxseed oil treatments reduced inflammation markers and mitigated kidney damage.
- Levels of HIF-2α, COX-2, and IFN-γ were reduced by fish oil and flaxseed oil supplementation.
Conclusions:
- Circadian rhythm disturbances contribute to kidney damage through inflammatory pathways.
- Fish oil and flaxseed oil possess protective and anti-inflammatory effects on the kidneys.
- Findings suggest dietary omega-3 fatty acids may be beneficial in managing kidney damage associated with circadian disruption.
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