A High-Fructose Diet Formulated with Thermally Oxidized Monounsaturated Fat Aggravates Metabolic Dysregulation in Colon Epithelial Tissues of Rats

Abstract

Background

Various epidemiological and clinical studies have indicated a positive association of colon cancer with high sugar and thermally oxidized fats consumption. The present study evaluated the effects of fresh and thermally oxidized coconut (CO) and mustard oils (MO) along with a high-sugar diet in the rat colon mucosa.

Methods

The animals were fed with a modified diet containing high-fructose and different edible oils as fatty acids sources over a period of 30 weeks. Further, the development of insulin resistance and hyperglycemia were estimated biochemically. The changes in the redox status were estimated in terms of reduced glutathione (GSH), antioxidant enzymes and thiobarbituric acid reactive substances (TBARS). Changes in the expression of genes associated with inflammation and cell proliferation were evaluated by qPCR.

Results

The animals fed with high-fructose developed hyperglycemia and insulin resistance over 30 weeks. These animals had diminished GSH level, SOD activity and a concomitant increase in the TBARS level in the colon epithelial tissues. In addition, the expression of pro-inflammatory cytokines (IL-6 and TNF-α) was elevated while P53 and PPARγ were down-regulated. This heightened body metabolic dysregulation and associated oxidative damage and inflammation in the colon were exacerbated by thermally oxidized edible oils incorporated in the diet, with a more prominent effect was observed with TMO.

Conclusion

Feeding high-fructose diet with TMO increases the oxidative and inflammatory damages in the colon epithelium of Wistar rats. Therefore, the study cautions the prolonged consumption of thermally oxidized monounsaturated fat-rich edible oils, especially by individuals with type 2 diabetes.

Keywords:

• Coconut oil
• mustard oil
• thermal oxidation
• oxidative stress
• inflammation
• colon epithelial tissue

Disclosure statement

The authors have no conflict of interest in the present study.

Data availability statement

The data will be made available upon valid request.

Additional information

Funding

The study was supported by Council for Scientific and Industrial Research, India (File No. 09/869 (0012)/2012) EMR-I) in the form of Senior Research Fellowship (NET) to Dr. Arunaksharan Narayanankutty.