Dietary
polyunsaturated fatty acids (PUFAs), which are abundant in marine
fish oils, have recently received global attention for their prominent anti-obesogenic effects. Among PUFAs,
eicosapentaenoic acid (EPA; 20:5n-3) and
docosahexaenoic acid (DHA; 22:6n-3), which are n-3 long-chain PUFAs widely referred to as omega-3
oils, were reported to prevent the development of
obesity in rodents and humans. In the present study, we evaluated the anti-
obesity effects of microalgal oil on high-fat induced obese C57BL/6 mice, compared with commercial omega-3
fish oil and vegetable
corn oil. Microalgal oil is an inherent mixture of several PUFAs, including EPA, DHA and other
fatty acids produced from a marine microalgal strain of Thraustochytriidae sp. derived mutant. It was found to contain more PUFAs (>80%) and more omega-3
oils than commercial omega-3
fish oil (PUFAs >31%) and
corn oil (PUFAs 59%). All three types of
oils induced
weight loss in high-fat-induced obese mice, with the loss induced by microalgal oil being most significant at 9 weeks (10% reduction). However, the
oils tested did not improve blood
lipid levels, although microalgal oil showed an apparent inhibitory effect on
lipid accumulation in the liver. These findings may be attributed to the higher PUFA content, including omega-3
oils of microalgal oil than other
oils. Collectively, these findings suggest that microalgal oil, derived from Thraustochytriidae sp. derived mutant, is a prominent candidate for replacement of omega-3
fish oils based on its apparent anti-
obesity effect in vivo.