Effect of amaranth oil on lipid metabolism of hamsters

Author(s)

Luíla Ivini Andrade de Castro

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Conjunto das Químicas (IQ e FCF) (CQ/DBDCQ)
• Defense date: 2011-05-09

Examining board members

Jose Alfredo Gomes Areas; Elizabeth Aparecida Ferraz da Silva Torres; Silvio José Valadão Vicente

• Advisor: Jose Alfredo Gomes Areas

Abstract

Introduction: Amaranth is a pseudo cereal of superior nutritional value, besides its property of reducing serum cholesterol. The lipid content of the grains is higher than common cereals, with high content of unsaturated fatty acids. Amaranth also presents significant amounts of squalene, a possible bioactive compound responsible for lowering cholesterol. Objective: To investigate the effect of amaranth oil and squalene on lipid metabolism in hamsters fed with saturated fat and cholesterol. Methodology: The amaranth oil was extracted by organic solvent (n-hexane) and its content of squalene was determined. The potential hypocholesterolemic effect of this oil was evaluated by a bioassay, which employed 40 weanling hamsters. The animals were divided into four groups of 10, differentiated by the diets: control [normal diet with 20% corn oil] (C), hypercholesterolemic [diet with 12% fat coconut, 8% corn oil, and 0.1% cholesterol] (H) amaranth oil [identical to (H) with amaranth oil replacing corn oil] (A) and squalene [identical to (H) + squalene in the proportion found in the amaranth oil] (E). They were all formulated according to the recommendations of NRC (1995) and AIN-93. After 28 days, the animals had blood collected by cardiac puncture, under anesthesia, being measured total cholesterol, triglycerides, HDL-C and plasma non-HDL cholesterol. After sacrifice, the livers of animals were collected for histological analysis and determination of cholesterol content. We also determined the levels of cholesterol and bile acids in the feces of animals. Results: There was no statistically significant difference in lipid profile and fecal excretion of cholesterol from animals in the hypercholesterolemic, amaranth oil and squalene groups. Fecal excretion of bile acids was higher in animals in groups of amaranth oil and squalene as compared with the control group and hypercholesterolemic group. The cholesterol content in liver of the animals from squalene group was higher compared to other groups, although this difference was not statistically significant except when compared to the control group. The highest grade of steatosis and parenchymal inflammation were found in the groups of amaranth oil and squalene. Conclusions: The amaranth oil and its component squalene had no effect hypocholesterolemic and promoted an increased excretion of bile acids in hamsters fed a diet containing high amounts of saturated fat and cholesterol. (AU)

• FAPESP's process: 08/07562-6 - Effect of amaranth oil (Amaranthus cruentus BRS-Alegria)on the lipid metabolism of hypercolesterolemic hamsters.
• Grantee: Luíla Ívini Andrade de Castro
• Support Opportunities: Scholarships in Brazil - Master