Background:Hypercholesterolemia is one of the most important risk factors for atherosclerosis and subsequent cardiovascular diseases.Objective:The present work was aimed to study the efficacy of curcuminoid fraction from Curcuma xanthorrhiza and its curcuminoid cider in reducing blood cholesterol level and four genes related to oxidative stress, including cluster of differentiation 44 (CD44), intercellular adhesion molecule 1 (ICAM-1), inducible nitric oxide synthase (iNOS), and lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) in high-cholesterol fed rats in vivo.Materials and Methods:Twenty-four male Sprague-Dawley rats were divided into six groups, namely normal group diet, high-cholesterol diet (HCD) 2%, HCD + 100 mg/kg b.w. curcuminoid fraction, HCD + 300 mg/kg b.w. curcuminoid fraction, HCD + cider 1% v/v, and HCD + curcuminoid cider 2% v/v for 4 weeks. Total cholesterol levels were measured at day 1, 14, and 28. Vascular tissues and organs from lung and liver were collected for RNA extraction, followed by quantitative analysis using real-time polymerase chain reaction (PCR).Results:Our results demonstrated that among all the treatment groups, curcuminoid cider at 2% v/v significantly lowered total cholesterol level compared to those of positive control. Real-time PCR data showed both curcuminoid fractions (100 and 300 mg/kg) and curcuminoid cider (1 and 2% v/v) inhibited the gene expression of CD44, ICAM-1, iNOS, and LOX-1, indicating their hypocholesterolemic effects via attenuating genes related to oxidative stress in rats in vivo.Conclusion:Oral administration of curcuminoid fraction and its cider product may exert potential inhibitory effects on oxidative stress related-genes for preventing hypercholesterolemia-induced atherosclerosis in vivo.SUMMARY Curcuminoid and its cider significantly inhibited the gene expression of CD44, ICAM-1, iNOS, and LOX-1 in rats in vivoCurcuminoid and its cider suppressed oxidative stress-related genes inducing formation of atherosclerosisCurcuminoid and its cider may offer cardioprotective effect for preventing hypercholesterolemia-induced atherosclerosis Abbreviations Used: ROS: Reactive oxygen species, NO: Nitric oxide, NOS: NO synthase, NADPH: Nicotinamide adenine dinucleotide phosphate, CD44: Cluster of differentiation 44, ICAM-1: Intercellular adhesion molecule 1, iNOS: inducible NOS, LOX-1: lectin-like oxidized LDL receptor-1, HMG-CoA: 3-hydroxy-3-methylglutaryl-coenzyme A, 5-HMF: 5-hydroxymethylfurfural, HCD: High-cholesterol diet