Effects of microalgal polyunsaturated fatty acid oil on body weight and lipid accumulation in the liver of C57BL/6 mice fed a high fat diet.

Go Ryeo-Eun,Seo Jeong-Woo,Lee Hae-Miru,Lee Geum-A,Hong Won-Kyung,Choi Kyung-Chul,Kim Cho-Won,Hwang Kyung-A,Park Geon-Tae,Jeon So-Ye

doi:10.7555/jbr.30.2016k0004

Abstract

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.

Highlights

Obesity is caused by a prolonged energy imbalance; namely, high energy intake exceeding energy expenditure
Commercial fish oil labeled with omega-3 oil was found to have more saturated fatty acids than polyunsaturated fatty acids (PUFAs) and more omega-3 oils than omega-6 oils, with a n-6 oils to n-3 oils ratio (n-6:n-3) of 0.08 (Table 2)
Comparison of the amount of PUFAs revealed that microalgal oil contained more PUFAs than the commercial omega-3 fish oil and that this commercial fish oil contained much more saturated fatty acids than PUFAs, contrary to expectations from its label as omega-3 oil

Summary

Introduction

Obesity is caused by a prolonged energy imbalance; namely, high energy intake exceeding energy expenditure. It leads to circulatory and metabolic disorders such as arteriosclerosis, hypertension, coronary heart disease, and type 2 diabetes. Effects of microalgal polyunsaturated fatty acid on fatty liver devoted to the discovery of anti-obesity drugs, dietary therapy is considered to be more important and is still the first choice in the treatment of disorders resulting from obesity[1]. Anti-obesity healthy foods derived from natural substances are generally preferred for safe long-term treatment over drugs which may have side effects. Foods rich in dietary fiber are well-known to have anti-obesity effects that occur by facilitating a reduction in body fat and body weight loss[2,3,4]. Recent studies have shown that dietary polyphenols, including green tea catechins and epigallocatechin gallates, resveratrol, and curcumin have preventative effects on obesity and obesity-related chronic diseases[5,6,7]

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