Quercetin as natural strategy to avoid plasma lipid imbalance and intestinal mucosa oxidative stress caused by high fructose diet

Abstract

High Fructose Diet (HFD) is associated with development of metabolic syndrome, oxidative stress (OS) and inflammation. In recent decades, polyphenols have been postulated as strategic nutrients in antioxidant functional diets. Aim was to evaluate Quercetin (Q) ability to prevent OS in intestinal mucosa and to avoid glycemia and lipemia alterations generated by HFD.

Wistar rats were divided into different study groups: Control (C, no treatment); subjected to HFD for 60 days (HFD) and rats treated with HFD and Q (25, 50 or 75 mg/kg/pc, HFD+Q) last 15 days of treatment. After animal’s sacrifice, glucose, HbA1c, triglycerides (TG), total cholesterol and HDL-cholesterol in blood and glutathione (GSH) content and superoxide dismutase (SOD) and catalase (CAT) activity in intestinal mucosa homogenate were determined. Results were analyzed by ANOVA/Tukey (p<0.05).

All groups presented similar values of glycemia, HbA1c and total cholesterol. HFD rats had high TG levels and decreased HDL-cholesterol levels in relation to C (185±9.75 HFD* vs 90.75±7.26 C, *p<0.001 and 20±1.08 HFD* vs 26.25±1.65 C, *p<0.001), which was reflected in TG/HDL-col ratio increased, a cardiovascular risk and insulin resistance indicator (9.30±0, 57 HFD* vs 3.48±0.26 C, *p<0.001). Q evidences its protective effect by normalizing values of these parameters (TG/HDL-cholesterol: 7.29±0.42 HFD+Q25; 4.55±0.35 HFD+Q50; 5.60±0.30 HFD+Q75, *p<0.001 vs HFD). In relation to OS, we found that Q prevents SOD activity increment (31.22±3.5 HFD* vs 4.26±2.91 C; 9.85±4.03 HFD+Q25; 11.81±4.7 HFD+Q50, 17.59±3 HFD+Q75, *p<0.05) and CAT (45.85±5.26 HFD* vs 11.55±4.88 C, 17.34 ±3.98 HFD+Q25, 28.54±3.04 HFD+Q50, 17.67±3.89 HFD+Q75, *p<0.001). Added to this effect Q had ability to prevent GSH decrease in rat intestinal mucosa (3.93±0.14 HFD* vs 6.99±0.64 C, 7.22±0.55 HFD+ Q25 and 9.35±1.12 HFD+Q50, *p<0.05).

Our results indicate that Q has a protective effect against dyslipidemia and OS in intestinal mucosa generated by high fructose consumption, in this way, its constitutes a natural protective agent against alterations caused by current eating patterns.