Effect of tocotrienol-rich fraction (TRF) on lipid profile in hyperlipidemic experimental animal model: a systematic...

Hyperlipidemia, characterized by elevated lipid levels, is a major risk factor for cardiovascular diseases (CVD), including atherosclerosis. Tocotrienol-rich fraction (TRF), a potent form of vitamin E, has demonstrated promising lipid-lowering effects due to its antioxidant and anti-inflammatory properties. This systematic review and meta-analysis aimed to evaluate the effects of TRF on lipid profiles in hyperlipidemic experimental animal models and to comparatively assessed their suitability for preclinical research. A total of eight eligible studies published between 2002 and 2024 were included. TRF significantly reduced total cholesterol (effect size = - 4.675, p < 0.0001), LDL (- 4.847, p < 0.0001), and triglycerides (- 4.736, p < 0.0001), while significantly increasing HDL (4.001, p < 0.0001), particularly in rats and mice. Meanwhile, comparative analysis showed that New Zealand white rabbits, hamsters, and genetically modified mice exhibit lipid metabolism profiles closer to humans and respond to lower TRF doses over shorter durations. Conversely, rats, though less prone to diet-induced atherosclerosis, responded well to higher doses over longer periods. However, the predominance of rat studies, absence of standard drug comparators, and variability in dosing and duration limit translational interpretation. Future studies should utilize physiologically relevant models and adopt standardized experimental protocols to better assess TRF's therapeutic potential in CVD management.