Beneficial Effects of Isoflavones in the Kidney of Obese Rats Are Mediated by PPAR-Gamma Expression.

Edson De Andrade Pessoa,Márcia Bastos Convento,Ala Moana Leme,Maria De Fátima Vattimo,Andréia Silva De Oliveira,Adriana Carbonel,Fernanda Teixeira Borges,Cassiane Dezoti,Bianca Castino,Sheila Marques Fernandes,Nestor Schor,Alef Aragão

doi:10.3390/nu12061624

Edson De Andrade Pessoa, Márcia Bastos Convento + Show 10 more

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https://doi.org/10.3390/nu12061624

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Abstract

Several studies have demonstrated an important association between altered lipid metabolism and the development of kidney injury because of a high-fat diet. Fructose is also closely associated with renal injury. We opted for a combination of fructose and saturated fats in a diet (DH) that is a model known to induce renal damage in order to evaluate whether soy isoflavones could have promising use in the treatment of renal alterations. After two months of ingestion, there was an expansion of visceral fat, which was associated with long-term metabolic disorders, such as sustained hyperglycemia, insulin resistance, polyuria, dyslipidemia, and hypertension. Additionally, we found a decrease in renal blood flow and an increase in renal vascular resistance. Biochemical markers of chronic kidney disease were detected; there was an infiltration of inflammatory cells with an elevated expression of proinflammatory cytokines (tumor necrosis factor-α, interleukin (IL)-6, and IL-1β), the activation of the renin–angiotensin system, and oxidative/nitrosative stress. Notably, in rats exposed to the DH diet for 120 days, the concomitant treatment with isoflavones after 60 days was able to revert metabolic parameters, renal alterations, and oxidative/nitrosative stress. The beneficial effects of isoflavones in the kidney of the obese rats were found to be mediated by expression of peroxisome proliferator-activated receptor gamma (PPAR-γ).

Highlights

The Occidental diet (OD) and lifestyle have led to the pandemic of obesity [1,2,3,4]
The DH group was fed a high-fat/high-fructose diet for 120 days to induce obesity, whereas the DH and ISO group was fed high-fat/high-fructose diet for 120 days; after 60 days, this group was concomitantly treated with isoflavones until the end of the experimental protocol
We observed a significant increase in urinary protein excretion (Figure 3F) in the rats fed the DH diet at all experimental periods, whereas the DH and ISO group showed an increase only before the treatment with isoflavones (60 days) in comparison to the control group (CTL) group at the same experimental period

Summary

Introduction

The Occidental diet (OD) and lifestyle have led to the pandemic of obesity [1,2,3,4]. Some of the damaging renal consequences of obesity may be mediated by downstream comorbid conditions such as hypertension or diabetes mellitus (DM). Nutrients 2020, 12, 1624 that could directly impact the kidneys and that are induced by the endocrine activity of the adipose tissue [8]. These include the development of inflammation, insulin resistance, oxidative stress, abnormal lipid metabolism, and the activation of the renin–angiotensin system (RAS) [9]. Corn fructose is highly consumed in the OD (instead of glucose in desserts, condiments, and carbonated beverages) as a sweetening substitute [10,11]

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