Amaranth and its oil inhibit cholesterol biosynthesis in 6-week-old female chickens.

All amaranth varieties contain tocotrienols and squalene compounds which are known to affect cholesterol biosynthesis. Therefore, in the present study, the influence of dietary supplementation of whole seed, popped, and milled amaranth and amaranth oil on cholesterogenesis was studied in 6-wk-old female chickens. Serum total cholesterol and LDL-cholesterol were lowered 10-30% and 7-70% (P < 0.01), respectively, in birds fed amaranth-containing diets. HDL-cholesterol was not affected by amaranth supplementation. Activities of liver cholesterol 7alpha-hydroxylase (the enzyme responsible for cholesterol breakdown into bile acids) were 10-18% higher (P < 0.01) than those of controls for birds fed most forms of amaranth and its oil, whereas activities of liver 3-hydroxy-3-methylglutaryl coenzyme A reductase (the rate-limiting enzyme for cholesterol biosynthesis) were lowered by about only 9% (P < 0.01) by popped, milled amaranth and its oil. This lack of marked inhibition of this enzyme suggests the presence of some other potent cholesterol inhibitor(s) apart from tocotrienols and squalene in amaranth.