Nathaniel Uwagboe Asiriuwa^{1, 2}, George Eriyamremu¹, Precious Osaretin Osemwenkhae¹

Abstract

Purpose: To investigate the effect of fresh and stored palm oil of varied free fatty acids (FFA) levels on lipid metabolism and cardiovascular health in Wistar rats. Methods: Thirty-six (36) rats, randomly divided into six groups of six rats each, were used in this study. Group I comprised rats fed normal diet (control group) while Group II served as control and was given fresh palm oil containing 0.4 % FFA. Groups III – VI were administered palm oil (480 mg/kg body weight) of varied FFA levels (4.8, 8.4, 21.9, and 42.7 %), respectively. Body weight, lipid profile, cardiovascular disease risk indices, expression of peroxisome proliferator activator receptor gamma (PPAR-γ) and LDL-receptor genes as well as heart histology of the rats were determined. Results: There was a significant increase in body weight of normal and study groups, with the fresh palm oil group gaining more weight (p < 0.05). However, groups exposed to moderate FFA levels (4.8 and 8.4 %) exhibited reduced weight changes. Administration of palm oil led to a non-significant reduction in serum total cholesterol concentration (p > 0.05). Also, a significant reduction in the triglyceride concentrations of study groups was observed compared to normal control rats (p < 0.05). Furthermore, palm oil improved the lipid profile by reducing serum concentrations of LDL-cholesterol and increasing the synthesis of HDL-cholesterol of the animals. In addition, cardiovascular disease risk factors decreased significantly in study groups compared to normal rats while an upregulation of PPAR-γ and LDL-receptor genes was observed in the palm oil groups (p < 0.05). Furthermore, normal heart histology was observed in all the animals. Conclusion: This study suggests that fresh and stored palm oil improves lipid profile and cardiovascular disease risk factors and is therefore beneficial for cardiovascular health.