Quercetin Ameliorates Cardiovascular, Hepatic, and Metabolic Changes in Diet-Induced Metabolic Syndrome in Rats

Abstract

Metabolic syndrome is a risk factor for cardiovascular disease and nonalcoholic fatty liver disease (NAFLD). We investigated the responses to the flavonol, quercetin, in male Wistar rats (8-9 wk old) divided into 4 groups. Two groups were given either a corn starch-rich (C) or high-carbohydrate, high-fat (H) diet for 16 wk; the remaining 2 groups were given either a C or H diet for 8 wk followed by supplementation with 0.8 g/kg quercetin in the food for the following 8 wk (CQ and HQ, respectively). The H diet contained ~68% carbohydrates, mainly as fructose and sucrose, and ~24% fat from beef tallow; the C diet contained ~68% carbohydrates as polysaccharides and ~0.7% fat. Compared with the C rats, the H rats had greater body weight and abdominal obesity, dyslipidemia, higher systolic blood pressure, impaired glucose tolerance, cardiovascular remodeling, and NAFLD. The H rats had lower protein expressions of nuclear factor (erythroid-derived 2)-related factor-2 (Nrf2), heme oxygenase-1 (HO-1), and carnitine palmitoyltransferase 1 (CPT1) with greater expression of NF-κB in both the heart and the liver and less expression of caspase-3 in the liver than in C rats. HQ rats had higher expression of Nrf2, HO-1, and CPT1 and lower expression of NF-κB than H rats in both the heart and the liver. HQ rats had less abdominal fat and lower systolic blood pressure along with attenuation of changes in structure and function of the heart and the liver compared with H rats, although body weight and dyslipidemia did not differ between the H and HQ rats. Thus, quercetin treatment attenuated most of the symptoms of metabolic syndrome, including abdominal obesity, cardiovascular remodeling, and NAFLD, with the most likely mechanisms being decreases in oxidative stress and inflammation.

Quercetin reduces obesity-associated ATM infiltration and inflammation in mice: a mechanism including AMPKα1/SIRT1

“…Until now, the effect of quercetin on HFD-induced body weight gain has been debated, and several different groups have reported that dietary quercetin could not impact the body weight of HFD-fed animals ( 6,(16)(17)(18)(19). Similar to two other reports ( 20,21 ), we found here that the mice fed dietary quercetin had signifi cantly lower body weight gain than the mice fed only HFD during 8-12 weeks after diet interventions.…”

“…Quercetin, an important dietary fl avonoid, has been widely investigated because of its benefi cial effects on diabetes ( 7,22,24 ), hepatic fat accumulation ( 20 ), and metabolic syndromes ( 6,23 ). Adipose tissue infl ammation, especially ATM recruitment, has been regarded as an important central event in obesity-associated insulin resistance ( 3 ).…”

“…2E ) in EAT in HFDfed mice, suggesting that it improves glucose uptake in adipose tissues. Moreover, several recent studies have shown that dietary quercetin could improve insulin sensitivity in liver ( 6,20 ) and skeletal muscle ( 47 ), indicating that quercetin could improve systemic insulin resistance in HFD-fed mice.…”

Quercetin can reduce insulin resistance without decreasing adipose tissue and skeletal muscle fat accumulation

“…With regard to experiments performed in rats, no changes in adipose tissue weight were observed in animals fed a highfat diet supplemented with 0.03 % (25 mg diet/kg of body weight/day) for 4 weeks (Wein et al 2010). By contrast, quercetin attenuated abdominal obesity (-37 %) in animals fed on a high-fat diet supplemented with 0.08 % quercetin for 8 weeks (Panchal et al 2012). As indicated in the previous paragraph, reported data from studies carried out in mice have been obtained by using a wide range of quercetin doses (0.025-0.8 % in the diet).…”

The innovative “Bio-Oil Spread” prevents metabolic disorders and mediates preconditioning-like cardioprotection in rats

“…The rat length was evaluated by measuring the noseeanus distance [17]. Body mass index (BMI) was calculated as reported by Panchal SK et al [18] After the sacrifice, the abdominal fat tissue was removed and separately weighed. Plasma analysis Blood samples were collected both weekly and before the sacrifice, through the tail vein; the amount of blood was <1% of the body weight (e.g., 1 mL from a 250-g adult rat).…”