Reduced in-vivo C-reactive protein aortic tissue expression following tocotrienol-enriched mixed fraction supplementation in cholesterol-induced atherosclerosis

Abstract

Atherosclerosis is the underlying pathology behind cardiovascular disease, the main cause of death in worldwide. Inflammation plays a pivotal role in its pathogenesis. Tocotrienol is a palm derived vitamin E component, known have potent anti-inflammatory properties. The effect of tocotrienol on formation and progression of atherosclerosis is unknown. Aim: to determine the anti-inflammatory and anti-atherosclerotic effects of tocotrienol-enriched mixed fraction (TEMF) supplementation in hypercholesterolaemia induced rabbits. Methods: 20 New Zealand white rabbits were randomised into two groups and fed with 1% high cholesterol diet (HCD) for (i) 2 weeks in group A and (ii) 8 weeks in group B, followed by randomization into two treatment groups: (i) TEMF (15mg/kg) or (ii) placebo for 8 weeks. During the 8 week treatment duration, all the groups were given normal diet. Analyses of atherosclerotic lesions were performed while expression of inflammatory was evaluated using immunohistochemistry. Results: There were no significant reduction in atherosclerotic lesions with TEMF treatment for both groups A and B. However, there were significantly lower positive tissue expression in TEMF compared to placebo for CRP (3.01 ± 0.86 vs. 25.51 ± 10.85%; p=0.05) and SMA (3.91 ± 1.33 vs. 16.19 ± 4.08%; p=0.04) in early atherosclerosis. In addition, no significant differences were observed between TEMF and placebo in both groups A and B for NFκB, IL-6, ICAM-1, E-selectin and MMP-12. Conclusion: Eight weeks treatment with TEMF has neutral effects on atherosclerotic lesions in both early and severe atherosclerosis. However, TEMF treatment reduces aortic intimal tissue expression of CRP especially in early atherosclerosis indicating its in vivo anti-inflammatory effects.