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Purpose: Rats fed a long-term sucrose-rich diet (SRD) developed adipose tissue dysfunction. In the adipose tissue of these SRD-fed rats, the present study analyzed the possible beneficial effects of dietary Salba (chia) seeds in improving or reversing the depletion of antioxidant defenses, changes in pro-inflammatory cytokines and ROS production., Methods: Wistar rats were fed a SRD for 3 months. After that, half of the animals continued with the SRD until month 6, while in the other half, corn oil was replaced by chia seeds for 3 months (SRD + chia). A reference group consumed a control diet all the time., Results: Compared with the SRD-fed rats, the animals fed a SRD + chia showed a reduction in epididymal fat pad weight; the activities of antioxidant enzymes CAT, SOD and GPx returned to control values, while GR significantly improved; mRNA GPx increased, and both mRNA SOD and the redox state of glutathione returned to control values; a significant increase in the expression of Nrf2 was recorded. These results were accompanied by a decrease in XO activity and ROS contents as well as plasma IL-6 and TNF-α levels. Chia seeds reversed the decrease in PPARγ protein mass level and increased the n-3/n-6 fatty acids ratio of membrane phospholipids. Besides, dyslipidemia and insulin sensitivity were normalized., Conclusion: This study provides new information concerning some mechanisms related to the beneficial effects of dietary chia seeds in reversing adipose tissue oxidative stress and improving the adipose tissue dysfunction induced by a SRD.

The dysfunctional adipose tissue of rats fed a sucrose-rich diet was investigated following the time course of the development of oxidative stress, changes in proinflammatory cytokines and adiponectin levels, and their relationship with insulin resistance. We analyzed the morphometric characteristics of epididymal adipocytes, de novo lipogenesis enzyme activities and cellular antioxidant defense, inflammatory mediators, adiponectin levels and insulin resistance in rats fed a sucrose-rich diet for 3, 15 or 30 weeks and compared to those fed a control diet. The results showed a depletion of antioxidant enzyme activities in the fat pads of rats fed a sucrose-rich diet, with an increase in xanthine oxidase activity and lipid peroxidation after 3, 15 and 30 weeks on the diet. Superoxide dismutase activity and the redox state of glutathione showed a significant decrease at weeks 15 and 30. This was accompanied by visceral adiposity and enhanced lipogenic enzyme activities. An increase in the plasma levels of proinflammatory markers (TNF-α and IL-6) was recorded only after 30 weeks on the diet. A reduction in plasma adiponectin levels accompanied the time course of deterioration of whole-body insulin sensitivity. The results suggest that lipid peroxidation, depletion of antioxidant defenses and changes in inflammatory cytokines induced by a sucrose-rich diet contribute to the dysregulation of adipose tissue and insulin resistance. Finally, these results show that the progressive deterioration of adipose tissue function, which begins in the absence of both visceral adiposity and overweight, is highly dependent on the length of time on the diet.

Abstract Background Eicosapentaenoic acid (EPA, C20:5n-3), docosahexaenoic acid (DHA, C22:6n-3) and arachidonic acid (AA, C20:4n-6) are long-chain polyunsaturated fatty acids (LCPUFAs) with relevant roles in the organism. EPA and DHA are synthesized from the precursor alpha-linolenic acid (ALA, C18:3n-3), whereas AA is produced from linoleic acid (LA, C18:2n-6) through the action of Δ5 and Δ6-desaturases. High-fat diet (HFD) decreases the activity of both desaturases and LCPUFA accretion in liver and other tissues. Hydroxytyrosol (HT), a natural antioxidant, has an important cytoprotective effects in different cells and tissues. Methods Male mice C57BL/6 J were fed a control diet (CD) (10% fat, 20% protein, 70% carbohydrates) or a HFD (60% fat, 20% protein, 20% carbohydrates) for 12 weeks. Animals were daily supplemented with saline (CD) or 5 mg HT (HFD), and blood and the studied tissues were analyzed after the HT intervention. Parameters studied included liver histology (optical microscopy), activity of hepatic desaturases 5 and 6 (gas-liquid chromatography of methyl esters derivatives) and antioxidant enzymes (catalase, superoxide dismutase, glutathione peroxidase, and glutathione reductase by spectrophotometry), oxidative stress indicators (glutathione, thiobarbituric acid reactants, and the antioxidant capacity of plasma), gene expression assays for sterol regulatory element-binding protein 1c (SREBP-1c) (qPCR and ELISA), and LCPUFA profiles in liver, erythrocyte, brain, heart, and testicle (gas-liquid chromatography). Results HFD led to insulin resistance and liver steatosis associated with SREBP-1c upregulation, with enhancement in plasma and liver oxidative stress status and diminution in the synthesis and storage of n-6 and n-3 LCPUFAs in the studied tissues, compared to animals given control diet. HT supplementation significantly reduced fat accumulation in liver and plasma as well as tissue metabolic alterations induced by HFD. Furthermore, a normalization of desaturase activities, oxidative stress-related parameters, and tissue n-3 LCPUFA content was observed in HT-treated rats over control animals. Conclusions HT supplementation prevents metabolic alterations in desaturase activities, oxidative stress status, and n-3 LCPUFA content in the liver and extrahepatic tissues of mice fed HFD.

Purpose: Rats fed a long-term sucrose-rich diet (SRD) developed adipose tissue dysfunction. In the adipose tissue of these SRD-fed rats, the present study analyzed the possible beneficial effects of dietary Salba (chia) seeds in improving or reversing the depletion of antioxidant defenses, changes in pro-inflammatory cytokines and ROS production.Methods: Wistar rats were fed a SRD for 3 months. After that, half of the animals continued with the SRD until month 6, while in the other half, corn oil was replaced by chia seeds for 3 months (SRD + chia). A reference group consumed a control diet all the time.Results: Compared with the SRD-fed rats, the animals fed a SRD + chia showed a reduction in epididymal fat pad weight; the activities of antioxidant enzymes CAT, SOD and GPx returned to control values, while GR significantly improved; mRNA GPx increased, and both mRNA SOD and the redox state of glutathione returned to control values; a significant increase in the expression of Nrf2 was recorded. These results were accompanied by a decrease in XO activity and ROS contents as well as plasma IL-6 and TNF-α levels. Chia seeds reversed the decrease in PPARγ protein mass level and increased the n-3/n-6 fatty acids ratio of membrane phospholipids. Besides, dyslipidemia and insulin sensitivity were normalized.Conclusion: This study provides new information concerning some mechanisms related to the beneficial effects of dietary chia seeds in reversing adipose tissue oxidative stress and improving the adipose tissue dysfunction induced by a SRD. [ABSTRACT FROM AUTHOR]