Beneficial effects of hydro-alcoholic extract of Zuccagnia punctata against atherosclerosis in normal weight obesity accompanied by hypercholesterolemia rabbit model

Abstract

Insulin resistance (IR) increases the synthesis of cholesterol so hypercholesterolemia is one regular feature of obesity. Rich in flavonoids Zuccagnia punctata extract (Zp-E) is a traditional herbal medicine found to be beneficial against hypercholesterolemia-induced oxidative damage. This study aimed to evaluate the effects of Zp-E in a diet-induced rabbit model of IR accompanied by hypercholesterolemia. The major components of the Zp-E were analyzed by using a reversed-phase HPLC method. Male hybrid rabbits (cross between New Zealand and Californian certificated breeds) were separated into six groups: 1: fed on regular chow (SD), 2: fed on SD supplemented with 18% fat and 0.3% cholesterol (HC-HFD), 3, 4, 5: fed on HC-HFD and orally administered 2.5 mg, 5 mg or 10 mg GAE/day of Zp-E, respectively, 6: fed on HC-HFD and orally administered 2.5 mg ezetimibe/kg/day. All diets were administered for 6 weeks. The major compounds of Zp-E identified were chalcones: 2′,4′-dihydroxy-3′-methoxychalcone and 2′,4′-dihydroxychalcone. Zp-E only at 2.5 mg GAE/day reduced total cholesterol and did not modify fasting glucose, visceral abdominal fat, or IR at any of the doses tested. Zp-E normalized TBARS levels, sudanophilic area, and intima/media ratio at all the doses tested while significantly improving acetylcholine relaxation only at 5 mg GAE/day. Despite Zp-E's failure to prevent IR under hypercholesterolemic conditions, the extract showed protective effects on blood vessels by preventing the formation of atherosclerotic plaque through its strong antioxidant properties.

Keywords

• zuccagnia punctata
• insulin resistance
• hypercholesterolemia
• flavonoids