Effect of Carica papaya Leaf Extract on Serum Lipids and Liver Metabolic Parameters of Rats Fed a High Cholesterol Diet

Abstract

Hyperlipidemia plays an important role in the development of atherosclerosis, the main cause of death in the world. In this study, the lipid-lowering effect of Carica papaya leaf in rats fed with a high cholesterol diet was evaluated. Daily doses of C. papaya extract 0, 31, 62 or 125 mg/kg body weight were orally administered in 300 μl polyethylene glycol to hypercholesterolemic rats; it was also administered 62 mg/kg body weight of the extract to rats with normal diet. After a 20-day treatment, the animals were sacrificed; blood and liver were analyzed. Hypercholesterolemic rats showed an increased serum and liver cholesterol, triacylglycerols, and atherogenic index. The C. papaya extract produced a significant decrease of serum and liver cholesterol concentrations in hypercholesterolemic rats, but did not modify serum or liver triacylglycerols; however, the extract reduced the atherogenic index in a dose-dependent manner. C. papaya treatment decreased LDL-C and increased HDL-C in serum significantly. When the oxygen consumption was evaluated in phosphorylating and resting states, the respiratory control in hypercholesterolemic rats mitochondria was lower than in normal diet rats. However, a higher respiratory control in hypercholesterolemic rats mitochondria was observed after C papaya treatment. The liver morphological data are in accordance with serum and liver biochemical values. Our data support that C. papaya has a significant hypocholesterolemic action and HDL-C raising effect on rats fed with a cholesterol-rich diet, however, the precise metabolites responsible of this effect remain unknown.